Without the least vestige of land

And the crew were much pleased when they found it to be

A map they could all understand.

Lewis Carroll

Farewell!                 Photo: JCB

TRAINING:

In part 1, I expressed concerns over the training and in particular the need for any ECDIS user to be fully competent in the particular type of ECDIS placed on board his ship. Whilst such type specific expertise through training is being achieved the top end of the shipping industry, such as cruise liners and large tankers, the evidence is emerging of an alarming lack of comprehension by many officers of, not just their own system but of ECDIS and its functions in general. These are not just personal concerns but reflect those of many Industry observers.

Why is training such an issue?

Currently if you place any navigating officer on a bridge with a set of paper charts, even if they have been supplied by a country whose charting he has never seen before, he will recognise the key features and be able to plan a safe passage for any vessel to which he has been allocated.

This hasn’t happened by accident but is a direct result of the evolution of the paper chart over centuries which has been accompanied by similarly evolving chartwork skills passed on to successive generations of navigators. In contrast to such evolution, within the next eight years, the safety of the worlds’ shipping and coastlines will be dependent upon navigators fully comprehending not just the principles behind vector charting but the particular ECDIS operating system on their ship. As mentioned in part 1, despite an IMO model course being approved by the STCW committee in 1999, this course is not yet mandatory but ship owners / operators are required to train their officers to use ECDIS under their ISM policies. The top ship owners are sending their officers on training courses, based on the IMO model, run by their ECDIS suppliers and since these normally run for five days these officers will have a comprehensive understanding, not just of the principles of ECDIS, but also of their specific equipment. This is the ideal but only covers a minority group and because so many ship owners / operators now use crewing agencies the vast majority aren’t receiving such comprehensive training. The result is that, in order to tick the appropriate ISM box,these officers are being sent on very basic three day courses which can only ever be generic and with, no exam to pass, make no assessment as to an officer’s comprehension of the ECDIS concept or competence in its use.

Detail from a paper chart

An ECDIS “standard” display of the same area. Note the missing anchorage and restricted zone text & detail! The safety contour here has been set at 10m.

Poor training is a fundamental problem because navigating by use of ECDIS requires a completely new approach to chartwork and the adoption of totally new skills. When navigation by use of electronic charts was first muted there was considerable discussion as to how such a system should operate and although mariners preferred the familiarity of a scan of a paper chart into an electronic version of the same it was considered that, if accompanied by a comprehensive re-training programme, a three dimensional “intelligent” charting system could not just enhance safety but also provide a platform for integrating other information technologies into one central navigational console for the navigator. Thus the vector chart was born. So, here we are in 2010 with the technology in place but without the requisite training. The widespread concerns over this situation are valid because in order to navigate effectively using ECDIS a navigator must forget the two dimensional paper chart and navigate using the three dimensions in which the ship actually operates. Unfortunately, in order to avoid overloading the tiny screen, the vector chart hides much essential navigational information away on different “layers” and the navigator is therefore faced with three major problems. Firstly, he needs to know how to tailor his ECDIS to his ship and the intended passage. Secondly he needs to know what information is available within the ECDIS relevant to the intended passage and thirdly, where to find that information, recognise its relevance and effectively apply it. Quite a tall order for an officer who has joined a ship with an ECDIS that he’s never seen before after a 30 hour trip in a mini bus from Poland who’s only had a 45 minute hand over because the officer he’s relieving is going home in the same minibus. Yes, it has happened!!

Setting up the ECDIS

During the installation of an ECDIS, the supplier should have entered fixed vessel data such as the length and beam and also aligned the ship’s position on the ECDIS with the aerial position on the ship. The manoeuvring characteristics of the ship should also have been entered during installation and once set, this information cannot normally be altered by the operator. As the range is zoomed in, the ship position identifier on the chart will change from a spot surrounded by two concentric rings to a scale plan of the vessel so it is essential that this vessel data is correctly entered.

Generally, unless a vessel is spending a long period in port, it is recommended that the EDCIS is left switched on whilst in port because, like any computer a start up from cold can take a considerable time.

Preliminary set up:

Before commencing a passage the navigator must check the ECDIS for the proposed passage, firstly to ensure that the vessel has licenses for all the ENC charts ( called cells) and secondly to ensure that these are up to date with the latest corrections that are supplied, either by CD ROM or via an Internet connection. So, assuming that all the passage licenses are in order and up to date, the first thing that the navigator needs to do is to enter the ship’s draft and air draft and establish the safety contour based on draft and the required Under keel Clearance (UKC). For example, with a vessel of 6m draft the depth contour could be chosen as 8m. However, since most ENC data is supplied with preset contours, typically at 5m intervals the display will default to the next deepest contour which in this case would be 10m. All areas of less than 10m will show as blue and areas deeper than 10 will be displayed as white (see above picture). So as long as the ship remains in the white area, she is, in theory, safe! There are more complex facilities that can be set up if required but that is outside the scope of this article. In addition to the safety contour, this same depth of 8m can be set as the safety depth. In this case, if the navigator sets the ECDIS to display depths then all depths of less than  8m will show in bold type and those deeper than 8 will be a pale grey. This means that a depth of 9m, although within the 10m blue safety contour it will displayed in pale grey text whereas a depth of 7m will be displayed in bold black. The whole safety of the passage is dependent on this information being correct so, if a navigator fails to set this correctly, the scene is set for a disaster! It could be all to easy for a new watchkeeper joining a vessel that arrived in a loading port with a draft of 4m with the safety contour and depth set at 5m to forget to change the draft and depths to the loaded draft, especially if he was unfamiliar with the ECDIS type in use. Such a failure was responsible for the grounding of the CFL Performer in 2008 where the MAIB report states the following: ECDIS was the primary means of navigation, but none of the vessel’s bridge watchkeeping officers had been trained in its use. Consequently, many of the system’s features which could have prevented this accident were not utilised. However, assuming that our officer has fully trained on his ECDIS the next task is to set up a safety domain. IMO specifications require ECDIS to trigger alarms in the following circumstances:

If, within a specified time set by the mariner. the ship will cross the safety contour

If, within a specified time set by the mariner, the ship will cross the boundary of a prohibited area or of a geographical area for which special conditions exist

When the specified cross track limit for deviation from the planned route is exceeded

If continuing on its present course and over a specified time or distance set by the mariner, the ship will pass closer than a user-specified distance from a danger (eg obstruction wreck or rock) that is shallower than the mariner’s contour or an aid-to navigation.

In order for these requirements to be met  the navigator has to input the parameters for both depth and beam clearances and once set, upon checking any passage, ifany hazards are present along the proposed route then alarms will be generated from the relevant chart at the largest available scale whatever scale is being displayed on the screen.

ECDIS manufacturers often meet the requirements by allowing users to specify a safety domain for the vessel, effectively contained by the following parameters:

• In depth, by the safety contour and safety depth
• In forward extent, by the look-ahead time or look-ahead range
• In lateral closeness by a specified distance.

The following diagram which is reproduced courtesy of Dr. Andy Norris clarifies the concept.

Note that the safety domain requires the navigator to input the vessel / voyage specific parameters and so this must be done at this stage. Best practice would seem to dictate that these parameters should be established by the Master.

Setting all of these voyage safety features will require type specific knowledge of the ECDIS, underlining again the importance of specialist training!

The Passage Plan

Once the vessel’s dynamic parameters have been set the passage plan can be created and it is here that the difference between traditional chartwork and ECDIS working become apparent. Used correctly ECDIS planning provides for a safer  passage but if a navigator is lazy,  pressed for time or fatigued etc, then some important information may be overlooked.

Passage planning on an ECDIS requires exactly the same procedures as for a paper chart and the navigator must follow the same “best practice” guidelines as per the Bridge Procedures Guide  but with ECDIS, the process is complicated by the fact that the navigator needs to know what information is already incorporated into the ECDIS and what isn’t and this is where a weakness of ECDIS is exposed. For example if some changes to buoyage have taken place on the intended passage, a navigator using a paper chart will be aware of this because the amended buoyage will be pasted on the chart over the old system and is therefore immediately visible. With ECDIS, as reported in part 1, problems have arisen with synchronising electronic Notices to Mariners  (NtM) updates for ECDIS with the paper equivalent. So on an ECDIS it may not immediately be apparent as to whether or not the changes been included. Because of this anomaly between the printed and electronic versions of NtM’s, mariners are currently being advised to check all routes with the paper NtM’s. Not a good start for ECDIS!!

In addition to checking the NtM’s the navigator still needs to refer to the traditional printed passage planning documents such as tide & current tables, Lists of Lights, sailing directions, NAVTEXT etc. relevant to the proposed passage. To make life easier there are  an increasing number of companies offering electronic versions of these references and the UKHO have recently launched an “e-Navigator” service which provides all the necessary berth to berth ENC chart cells and other services and documentation relevant to the intended passage in a single download. As ECDIS take-up rates accelerate it is certain that all the major suppliers will offer full data packages which will remove the current tedious and error prone task of cross referencing electronic and printed information. However, this additional data can only be provided as an overlay onto the ENC and must be capable of being removed from the screen by means of a single operator action.

Once the navigator has all the relevant documentation to hand, the plan can commence and the first thing to check (that familiarisation again!) is whether waypoints for that passage already exist in the ECDIS database. If so it can be uploaded for re-use and by running an initial check the ECDIS will verify if the plan is safe for the dynamic parameters previously set. As well as alerting the navigator to any parts of the plan that are outside the  safety domain parameters, the ECDIS will also alert the navigator to charted features of relevance on the passage such as traffic separation zones, restricted areas, anchorages etc. How alerts are presented to the navigator are dependent on the manufacturer with the best automatically jumping to the problem area and others providing a simple drop down list.

If there is no existing passage in the ECDIS database then the navigator will have to create one. Waypoint databases are commercially available and some ECDIS manufacturers supply them with the ECDIS but whilst these are useful, it must be remembered that other vessels are likely to be using the same waypoints so a prudent navigator may wish to amend them, especially in areas of high traffic volumes such as the Dover Strait. CNIS at Dover have been frequently amazed to witness many vessels converging onto the same waypoint when plenty of sea room exists in the sea lane and this was identified as a factor by the MAIB investigation into the collision between the Dutch Aquamarine and the Ash, which tragically resulted in one fatality, in 2001.

If no pre-loaded waypoint list exists for the passage then the navigator will have to start from scratch, which isn’t the easiest procedure on an ECDIS. The main problem that traditional mariners find with this is the small screen size which makes it difficult to obtain the outline overview obtained from a small scale paper chart. However, in practice the advantage of the ECDIS is that by putting in the departure and arrival points any obstructions will be identified and the navigator can then move waypoints and re-check the outline route. For longer ocean passages the ECDIS really shines since it can instantaneously offer a great circle or Rhumb line route or a combination of both thus saving much tedious plotting.

Once a viable outline passage has been established it is then essential to check the whole route in detail using the zooming and scrolling facilities. Although this sounds tedious, it is actually easier and less error prone than drawing course lines on a series of passage charts of differing scales. However, it is essential that this process is done with extreme care because, as previously mentioned, many chart features such as submarine cables are hidden on the different layers of the ENC and essential detailed information such as notes pertaining to precautionary areas needs to be accessed and analysed for relevance by means of clicking on the ! symbol to obtain the “pick report” relating to the feature. Yet again, the effectiveness of this plan analysis is dependent upon the navigator being fully familiar with the particular ECDIS manufacturer’s operating system!

This pick report is one of the most essential tasks during planning because there are some confusing new symbols and display anomalies when compared to the paper chart as shown on the following pictures.

What’s this? A hazard of some sort! Dangerous wreck, Rock, underwater rock awash? It could just be depth unknown but the meaning will only de revealed by interrogating it and checking the object information file. Traditional symbols have been replaced by a new symbology by default but if the navigator prefers the  familiar object display it can be set via the menus. The following pictures show the difference.

Simplified symbols.

Traditional symbology.

These are just two examples of many ECDIS features that need to be fully understood to ensure a safe passage. Whilst all the planning is going on the navigator must never forget that he is working on a computer and he should save the plan at regular intervals to avoid totally losing all the detail in the case of a “crash”. Yes, that happens!

Best practice guidelines recommend that planning is undertaken ion the back up ECDIS unit so once the plan has been completed and fully verified it needs to be exported to the primary unit. This is increasingly done via a data link cable between the two systems. Some commentators have expressed concern that the main and back up units are linked together by such a cable maintaining that the two units should be totally independent to avoid any possibility of a virus or Trojan infecting both systems. However, such an arrangement would require the navigator to create two exactly identical plans for each unit which isn’t practically feasible. and transferring data by means of a memory stick or CD ROM would pose the same potential risk of viral infection but I am unaware of any ECDIS units having suffered from such computer viruses. However, many ECDIS run using the Windows platform and can be connected to the Internet, so that factor, coupled with the presence of unsecured CD, DVD and USB drives leads some to valid concerns that it may only be a matter of time before a virus attack happens. One essential factor that mustn’t be overlooked when transferring the voyage plan is that as a result of the primary and back up ECDIS being independent, the vessel specific safety depth and domain parameters must be set on each set independently and a prudent navigator will undertake the final route verification checks on both systems prior to the passage commencing.

Getting Underway

Once the plan has been saved and exported to the main ECDIS unit at the conning position the passage can commence and it is here that the advantages for a well trained bridge team are evident but for less well trained officers, unfamiliar with their ECDIS system, the differences between ECDIS and the traditional paper chart can result in some important features being overlooked. The performance standards require ECDIS units to have three display modes: Base, Standard and full

Base Display: This displays the absolute minimum information considered necessary for navigation such as the coastline, fixed structures and the safety contour. It is not recommended for navigation but some find it useful for de-cluttering the screen when checking ahead on a small scale.

Standard Display: This is the display for normal navigation and it is a requirement that it can be presented at any time by a single operator action. In addition to the information of the base display this mode contains the drying lines, buoys and other navigation marks, prohibited and restricted areas, separation and traffic routing and precautionary  area ( but not the notes!) Despite being the recommended display, this display doesn’t provide the same information as a paper chart with information such as buoy names and characteristics, anchorages, submarine cables etc

Full Display: This contains all the information contained within the ENC but due to the amount of data this mode tends to overload the typical small screens with text overwriting and concealing other objects except on the largest scales and so again isn’t recommended for navigation. Note that even on this full display mode much of the paper chart detail such as precautionary notes can only be accessed by interrogating objects on the chart to display a pick report of the required information.

In practice additional information is added onto the standard display via the ECDIS menu system to the preference of the watchkeeper but how this additional information is accessed and displayed is not standard and is left to the whim of the manufacturers. However, once set, many systems now permit different users to save their preferred display layout.

The fact that important detail isn’t instantly visible represents the key difference between paper charts and ECDIS. Even with comprehensive type specific training this factor represents the most dangerous aspect of navigating by means of ECDIS because whereas historically the navigator has become used to all the necessary information being visible on the paper chart, the vector chart requires the navigator to be inquisitive and interrogate objects and hunt for additional display features in menus and sub menus.

A full display. Note the depths less than 7m highlighted but also note that this display doesn’t show the text detail so information that is readily available can only be accessed by interrogating an object! with such a cluttered display on a small screen it is easy to overlook important navigational information.

On passage

Assuming the standard display is chosen the ECDIS will automatically choose the largest scale chart available and the default display mode is North Up with own ship in the centre and true motion so the ship moves to near the edge of the screen after which it will automatically reset as with true motion radar. Most navigators find this pretty useless so the menu system offers the same variety of tracking options as the radar.  Most users prefer the centre offset relative motion display but some advanced users on the cruise liners are increasingly using offset Head Up displays on both radar and ECDIS meaning that the displays correspond to the visual picture. The heading marker is a fixed line extending to the edge of the screen and again, in the same way as radar, the vector can be set to either GPS tracking or water tracking. GPS tracking is indicated by a double arrow head on the vector and water tracking by a single arrowhead. The route is usually displayed as a solid orange line. The brightness of the screen is adjustable and there are generally three screen display options of day, dusk and night. Additional care must be taken when in the night mode because some features, such as precautionary zones can be very indistinct.

If the ECDIS is part of an integrated system then information from other systems such as radar and AIS can be overlaid on the ECDIS display and this facility can be very useful. In particular the radar image can provide a valuable verification of the accuracy of the GPS input in coastal water in that the radar land image should align with the chart display. However it is recommended that such radar overlay isn’t left on permanently because not only could it mask important data but it also uses additional computing power which may overload the processors.

On normal passages the ECDIS provides an instant visual position check and alarms sound when a waypoint approaches or if the vessel wanders off track outside the pre-set safety domain or approaches a shoal or other charted hazard. One function that an ECDIS cannot currently perform is to integrate live tide data to produce real time depths so whilst the safety contour and depth settings are fine for normal deep water navigation, when the vessel needs to transit a tidal dependent area, such as arises in my own port, then the auto checking of the passage will flag up as being outside the parameters. Third party software can provide tidal data as an overlay and may also include a passage planning tool to calculate tidal windows etc but  such programs cannot interact with the ENC to produce live depth data. Consequently in tidal restricted areas the safety domain alarms will need to be disabled.

It is very easy for a watchkeeper to have unreasonable trust in the ECDIS position, reassuringly displayed on the chart but the verification of position by other means is as essential with ECDIS as with traditional paper chart navigation because if the GPS is in error then the whole ECDIS is rendered inaccurate and for this reason traditional navigation verification techniques must be used and tools to facilitate this are required to be readily available on the primary screen. If the aforementioned radar overlay isn’t available then VRM & EBL functions enable radar ranges and bearings to be transferred and electronic bearing markers permit traditional chartwork to be undertaken using visual bearings.

If a GPS error is identified then the input must be disabled and the ECDIS used as a traditional chart using traditional position fixing techniques but I understand that this is not a user friendly process on many ECDIS units!

Conclusion

ECDIS is a highly complex electronic tool and still in its infancy so it is inevitable that anomalies in the charting will be identified and the training of navigators will lag behind the implementation dates. In part 3 I will be examining some of the problems and accidents that have arisen already along with the vulnerabilities.

The need for ECDIS to be used with extreme caution was highlighted in February when an ENC error was identified resulting in the following emergency NAVTEX alert to be issued

Mariners are advised that ECDIS may not display some isolated shoal depths when operating in “base or standard display” mode. Route planning and monitoring alarms for these shoal depths may not always be activated. To ensure safe navigation and to confirm that a planned route is clear of such dangers, mariners should visually inspect the planned route and any deviations from it using ECDIS configured to display “all data”. The automated voyage planning check function should not be solely relied upon. The International Hydrographic Organisation (IHO) is leading technical action to resolve this matter. Further information will be made available through Notices to Mariners.

Such notices are alarming but in a few years time, as new navigators come through colleges having done all their chartwork exams on ECDIS, the teething problems should have been ironed out and this next generation of officers will be fully familiar with the operational aspects of ECDIS and navigational safety should be enhanced. Already, on cruise liners and other well managed ships ECDIS is being used as intended and the benefits are evident because in addition to the three dimensional safety domain features, when zoomed right in, a good quality ECDIS can be used as a berthing aid.

Visual assessment for swinging in a restricted area is difficult

The ECDIS provides valuable instant and predictive information.   Photos: Nigel Allen

A typical ECDIS console

At the end of 2008, the IMO Maritime Safety Committee approved the mandatory carriage of ECDIS for SOLAS vessels. The requirements are for ECDIS to be phased in for different classes of vessels between 2012 and 2018. One year on from the decision we are already seeing many vessels being fitted with electronic charts so pilots need to be aware of what is now becoming the primary on board navigation system. At first glance the electronic chart seems wonderful, your own ship is displayed on a computer screen sitting nicely in its exact position on the chart. But, is it real or is it an illusion?

Navigation by means of a fully approved ECDIS is totally different from traditional navigation using paper charts and requires detailed knowledge of the functions in order to ensure safe navigation yet, whereas traditional chartwork formed a major element of a deck officer’s navigation exams, electronic charts are being placed on board ships and officers are frequently expected to teach themselves how to use them in their own time by use of a thick and confusing manual. The situation is further complicated by the fact that different manufacturers provide different operating systems and features and so a watchkeeper could be fully competent in using one system but may then be transferred to another vessel with a totally different charting system. Currently, there appears to be considerable confusion over whether or not the electronic chart being displayed is an “official” ECDIS running an approved ENC ( Electronic Navigational Chart), an unapproved ECS (Electronic Charting System) or a RCDS (Raster Chart Display System). Unapproved systems must not be used for navigation but since they are usually located on the bridge front and even fitted into integrated bridge consoles they are commonly used as the primary navigation resource! I have frequently seen unauthorised electronic charts with a warning notice “Not to be used for navigation” fitted into the bridge console with the passage route displayed. There will be a set of paper charts on the chart table fully corrected up to date so the ship isn’t breaking any rules but it is obvious that many watchkeepers will just cast a glance at the electronic chart and be reassured that the ship is on-track. Even worse, some incidents have revealed that watchkeepers have trusted the position provided by such unauthorised systems despite conflicting visual and radar information. Such misguided trust is a human failing not limited to ship’s watchkeepers since vehicle drivers using electronic navigation systems will happily take articulated lorries down farm tracks or the wrong way down one-way streets!

Unfortunately, without comprehensive training in the ECDIS concept, such misguided trust on board ship is usually disastrous and tragically will almost inevitably result in fatalities.

Raster and Vector Electronic Charts

As the official ECDIS is phased in, one of the major problems is that for the last 15 years manufacturers have been producing electronic chart systems to a variety of differing standards and there are currently two totally different formats: Raster & Vector.

A raster chart is basically a scan of a paper chart

A Raster Navigation Chart (RNC) is basically a digitally scanned paper chart and the electronic chart database will be identical to a paper chart folio and the user license provides the relevant folios and corrections for a particular area with new editions being issued in an identical manner to those for paper charts. Raster charts are never approved for navigation. However, just to add a bit more confusion into the issue, the IMO permits raster charts to be used on an official ECDIS which can operate an approved Raster Chart Display System (RCDS).  The ECDIS can therefore be used to display a raster chart in areas where ENC data is not available or the full ENC license hasn’t been purchased. However, when in RCDS mode a warning should appear on the ECDIS screen and paper charts for the area must be carried and corrected up to date. This potentially dangerous “dual fuel” (as it is known) option will probably rapidly disappear rapidly as hydrographic offices complete the world database of approved ENC data since if a ship gets orders to proceed to an area not covered by its existing ENC license then, rather than keep paper chart folios and also pay for raster chart folios for the ECDIS, the ship will just have to email the chart supplier for the key to the additional areas and the access codes will be sent and the owners charged accordingly. Last year an interesting spat arose between the UKHO and an innovative chart supplier over the issue of access codes that I will cover later.

There are two main advantages with the raster chart. Firstly, they are cheap and so they have been a popular choice with ship owners. Indeed some Masters, whose owners are reluctant to invest in anything unnecessary, carry their own raster charts on a laptop with a cheap, low grade, GPS aerial plugged in. Such charts are usually from a somewhat dubious source. I have seen such laptops running charts that are at least ten years out of date. The Captain of course always states, “No no Mr. Pilot, not used for navigation. Paper charts all correct in chart room”!

The other advantage of a raster charts is that since it is a scanned version of a traditional paper chart the chart display is totally familiar to the navigator. However, this scanned format also represents the greatest drawback of the raster chart in that by being displayed on a small screen data which may be clear on a large paper chart may be lost and whilst switching to the larger scale chart for the area may clarify detail, the important overview of the passage ahead is lost whilst the alternative of “zooming in” on the smaller scale chart generally produces distortion. Another problem frequently arises in areas where two charts overlap where the software may become confused and the navigator then has to locate and manually input the correct chart from the database.

A typical small vessel bridge showing an unapproved ECS at the conning position

Vector charts are far more complex  being totally seamless and built from several different “layers” which cause additional features such as depth data to appear as the operator zooms in and therefore provides a less congested display on the smaller scales. However, in their wisdom the authorities have set the minimum screen display size at a tiny 27cm x 27cm which is about 1/4 the size of a paper chart so zooming in considerably reduces the view ahead for the passage and there is therefore a recommended optimum layer range set for navigation. The main danger of this layering function is that chart corrections and notices to mariners information is only required to be displayed on this optimum layer for navigation as decided by the ECDIS specifications. This results in another major disadvantage in that passage planning becomes more complex since a navigator will use a small scale display to plan a port to port passage but must then check the whole route at the largest scale in order to ensure that no hazards or obstructions are overlooked. I have now piloted many ships operating without paper charts and this factor is a common complaint amongst the watchkeepers using them.  Indeed many of these vessels still use paper planning charts for this reason, which reveals another problem in that some of the newly constructed vessels designed to operate without paper charts aren’t fitted with a chart table!!

However, once a safe passage route has been identified the advantages of the vector chart become evident because the chart display can then be configured specifically to the vessel’s parameters. Depth contours and “no-go” areas can be tailored to the ship’s particulars and hazards highlighted with alarms that can be activated if the vessel strays from the intended track or when approaching a hazard. The provision of  AIS overlay permits anti collision parameters to be set and radar and other data can be input and overlaid on the screen. Such features represent the great advantage of the vector chart and offer considerable potential to enhance safety but, in untrained hands, is can also be its greatest weakness. Because of its three dimensional functionality using layers of “objects” the techniques for navigating on a vector chart are totally different to the traditional paper chart methodology and so the comprehensive training in their use is paramount for the transition from a two dimensional paper chart.

This vector chart is an “AECDIS 2000″ but it isn’t an “approved” ECDIS and therefore must not be used for navigation so why is there a passage track on it?

Are all vector charts ENC’s?

Simple answer: NO! Whilst official ENC data is only supplied in vector format the vast majority of existing vector charts have been created by manufacturers using their own methodology for transferring data from existing paper charts into vector format. If this data hasn’t been provided by an approved hydrographic office using the authorised S-57 format then such vector charts are only classified as ECS and therefore cannot be used in place of paper charts.

Is an ECDIS an ENC?

A common misconception is that an ECDIS is an actual chart. In fact it is basically a display system meeting the strict specifications required to display the ENC data supplied by the approved HO’s. The following is the official definition for ECDIS:

IMO Resolution MSC 232 (82) defines an Electronic Chart Display and Information System (ECDIS) as: “a navigation information system which with adequate back-up arrangements can be accepted as complying with the up-to-date chart required by regulations V/19 and V/27 of the 1974 SOLAS Convention, as amended, by displaying selected information from a System Electronic Navigational Chart (SENC) with positional information from navigation sensors to assist the mariner in route planning and route monitoring, and if required display additional navigation-related information”.

An ECDIS also has to meet specific performance standards which are laid down in IMO Resolution A/817. This resolution describes the minimum performance standards for ECDIS, with reference to hardware, software, ENC and updates, user interface, integration with positioning sensors such as radar and other devices, etc.

The technical standards are set by the International Electrotechnical Commission (IEC) and it is the responsibility of the Classification Societies to assess whether a particular  ECDIS installation is compliant. Systems that comply with all requirements get a “Type Approval” certificate from the Classification Society and only such Type Approved installations can legitimately be called ECDIS.

An important point to note here is that an ECDIS can only be used in place of paper charts if the information being displayed is sourced from an ENC converted by a SENC. Confusing? Yes, because although manufacturers may fit type approved ECDIS, the ship owner, having fitted an ECDIS unit in anticipation of future carriage requirements, may not purchase licenses for ENC’s until legally required to do so and the chart may therefore only be a basic Electronic Chart System (ECS). So, until all vessels are finally fitted with “approved” systems over the next 8 years mariners in general and pilots in particular will be faced with a mix of approved and non approved electronic charts.

There is also a requirement for a back up system in case of ECDIS failure. The specifictions state

The purpose of an ECDIS back-up system is to ensure that safe navigation is not compromised in the event of ECDIS failure. This should include a timely transfer to the back-up system during critical navigation situations. The back- up system shall allow the vessel to be navigated safely until the termination of the voyage.

What’s the difference between ENC & SENC?

MSC 232 provides the following definitions:

ENC: means the database, standardised as to content, structure and format, for charting and updates issued for use with ECDIS by or on the authority of a Government, authorised Hydrographic Office or other relevant government institution, and which conforms to an IHO standard known as S-57/3. The ENC contains all the chart information necessary for safe navigation. On the ship, S-57/3 data is loaded into the ECDIS in a dedicated storage area, called the ENC database.

SENC:

Since the S-57/3 format is not suitable for data processing, the ECDIS has to

convert the ENC into a different format referred to as SENC. The resulting data is then loaded into a separate SENC database from where it is accessed by the chart display and navigational

functions of ECDIS and this database may also contain information added by the mariner or from other sources.

The ECDIS manufacturer may choose whatever format and database structure for the SENC, provided that the ENC data is not downgraded in accuracy and/or contents during the conversion process.

The ECDIS structure is best explained in the following diagram which I obtained from an excellent website on ECDIS at the following link:

www.fuerstenberg-dhg.de/index.php?&L=1

There are some concerns that the SENC is a potential weak link in the integrity of the ECDIS installation since the final chart display presented to the watchkeeper is in the hands of the ECDIS manufacturers rather than the Hydrographic Offices. There is also the fact that when corrections or new charting editions are sent to the ship the conversion process can take a long time during which time the ECDIS cannot be used. To overcome this the manufacturers are increasingly offering a service to convert the ENC data to SENC ashore. In a recent paper,  Dr. Fosco Bianchetti (President & CEO of C-Map) detailed the problems associated with the ENC’s and the conversion process within and ECDIS and why he believes that the conversion to SENC should be undertaken ashore rather than on board the ship. The following is an edited extract from his paper which can be found at the following link: www.thsoa.org/hy99/A_5.pdf

“The problem is that the SENC is generated by the ECDIS, and never tested before being used by the ECDIS itself. It may be argued that the SENC Compiler, as part of a type-approved ECDIS, has undergone a severe testing procedure and is therefore assumed to be robust, reliable and exact. Nevertheless there is always a certain degree of uncertainty in format conversion, that could result in partial data loading, unexpected behaviour of the ECDIS, or  a system crash.  Also, the conversion of a large amount of data may be a lengthy affair, and could absorb a large part of the ECDIS resources, maybe right in the moment in which the system is performing a critical computation or analysis. The lack of official ENC’s makes things worse. Even if a number of Hydrographic Offices have started ambitious programs of ENC production, very few official electronic charts in S-57/3 format currently available. The result is that ECDIS users have to supplement ENC data with non-ENC electronic charts. This is the concept of the so-called “dual-fuel ECDIS. Since the ECDIS operates in non-equivalent mode when using non-ENC charts, S-52 and the IMO Performance Standards require that these are not mixed with the ENC and therefore, they must be loaded in the ECDIS into a separate storage area (‘Non-ENC information’ in the diagram) and must remain clearly distinguishable from official charts even after compilation in the SENC. It must be stressed that quality of non-ENC charts may vary to a large extent, and their format may be very different from S-57/3 and this adds further complications (and potential problems) to the task of the SENC Compiler that has to blend various electronic charts with different features into a single database”.

In order to address these issues, not surprisingly, C-MAP have come up with a solution in the latest version of their product known as CM 93/3 which produces the SENC format ashore in a format which I understand has type approval from DNV. Dr Bianchetti explains.

The advantages of this approach are obvious. All format conversions, as well as the difficult task of harmonising and merging data from different sources, are performed at C-MAP facilities, under strictly controlled conditions, and not by the ECDIS installed on board. All data delivered to ships is double checked in advance, in the format in which it will be actually used by the ECDIS, to ensure that it is fully functional and does not contain ‘unwanted surprises’. Any error affecting the source electronic charts is detected (and, if possible, corrected) by C-MAP, instead of being just passed off to the user. As regards the theoretical issue of whether the original ENC in S-57/3 format should be physically present in the ECDIS or not, there are a number of considerations that could mitigate such requirement, or lead to a different interpretation of it:

• The only purpose for the ENC to exist on board is generating the SENC. In fact, whatever operation performed by the ECDIS on electronic chart data pertains to the SENC, not the ENC. Therefore, existence of the ENC in the ECDIS is purposeless, if the conversion to SENC has been already performed under controlled conditions, by a SENC compiler that is part of a type-approved ECDIS.
• S-52 and the IMO PS require that data is not downgraded in accuracy and/or contents during the conversion from ENC to SENC, meaning that ENC and SENC are logically equivalent to each other. At this point, any ENC stored in the ECDIS would represent a mere duplication of the corresponding SENC.
• Based on the above consideration, the theoretical requirement of having the ENC physically present in the ECDIS could be fulfilled by the capability of the SENC compiler to perform a back conversion (i.e. from SENC to ENC).

An approved ECDIS chart. Note the crowded screen!

Operation

When an ECDIS is switched on the watchkeeper is presented with a “standard display” which will consist of the largest scale available in the SENC for the displayed area. The navigator can then build on that display and taylor it to his own watch keeping needs. The specifications require that the ECDIS can be returned to the standard display by means of a “single operator action”.

However, this standard display will not show all the features that you would expect to see on the paper chart. For example features such as submarine cables and spot depths aren’t there and although navigation marks are shown their characteristics aren’t so the navigator needs to know how to access and display this important additional data from the menu system.

For passage planning the navigator first needs to ensure that the ECDIS contains all the necessary charts for the passage and it is here that an interesting argument has developed between a chart supplier and the UKHO. In 2009 an authorised Dutch ENC supply company introduced a sort of “pay as you go” charging plan called ENCTrack that basically permitted free access to all ENC’s but only required the ship owner to pay licence fee for those he actually used on passage.

The UKHO, along with some other approved HO’s halted the launch of this service on the basis that the licensing of any chart should start on the commencement of the planning process; that is, “when it is ‘first used’ in the vital and mandated process of assessing the data available to enable a voyage plan to be prepared”.

In contrast, ‘ENCTrack’ considers the chart’s ‘first use’ to be when the vessel is passing through the chart region, not when the mariner starts his planning process with those same charts.  The UKHO argument is that when preparing a passage plan a navigating officer is making informed decisions affecting ship safety from consulting all the charts and the embedded additional information relevant to his plan so licences should be purchased for all the charts not just for a narrow track over which the vessel actually passes. However, not all HO’s agree with the UKHO position on this and consequently at the time of writing Datema have launched a limited ENCTrack service with those HO’s.  Interestingly, despite the objections, Datema have recently won an award as a “Value Added” reseller of ENC’s. This case highlights just one of the many issues that need to be resolved within the next two years.

Once the navigator has the relevant charts he can now set his waypoints and save the passage in the database and  should back this up in case of failure of the primary system. He can then set the safe depth parameters and the ECDIS can then be set to highlight the appropriate contours for the passage. Undertaking the passage and the quirks of ECDIS for navigation will be covered in part 2 in the April issue.

Don’t forget to pay!                   photo: N Allen

Of course, having the shiny new ECDIS with the relevant chart folios is only the initial element of chart work since the ENCs stored in a SENC require regularly updating. and it is here that some further unresolved complications arise. Updating data can either be made by sending a CD ROM by post, or by data transfer using satellite or mobile phone. Because of the large size of files associated with the updates the latter mode, although preferable is currently expensive, also upon receipt, data transferred by satellite or mobile phone must be burnt on to a CD ROM before the ENC can be updated. The CD ROM is necessary for keeping a hard copy of the update available. The cheaper option of updating by post,  apart from the obvious problem of time delays, also could result in some updates being missed.  This is serious because updates are sequential and if one is missing the update procedure can not be completed until the missing previous updates have been applied.

Even when the CD is received on board there is evidence that the updating process is not always simple and can take considerable time. It also appears that on many systems there is no confirmation that the update has been successful without the navigator having to subsequently check in the folio database for each chart affected which represents a total waste of a busy watchkeeper’s time and totally annuls one of the fundamental advantages claimed for ECDIS.

For urgent navigation warnings  ECDIS specifications require that they can be manually updated but again I understand that on many systems this can be a time consuming and fiddly process with no standard input procedure. These problems are well known and the following somewhat alarming information is taken from the latest (January 2010) ECDIS guidance CD issued by the UKHO:

Updates for UKHO ENCs are issued weekly in line with UKHO policy for all its navigational charts, paper and electronic. Due to unforeseen technical difficulties, ENC updates may occasionally be issued late and consequently may not be synchronised with the corresponding Notices to Mariners and updates for paper and ARCS charts. Updates are issued for all Permanent Chart-Correcting and Preliminary Notices to Mariners. However, it may not always be possible to issue updates for Temporary Notices to Mariners, especially those that cover large geographical areas and are not chart specific. Mariners should consult the paper weekly Notices to Mariners booklet or the UKHO website, http://www.nms.ukho.gov.uk/, for details of these Notices to Mariners.

So it appears we have a situation where the ECDIS updates may not contain the latest warnings and may even be missing some altogether! I wonder just how many officers have either the time or inclination to check the printed weekly NtM’s to check that their ECDIS information is complete? My estimation would be zero!

Another worrying aspect of the updating process is that once applied these are not shown in the traditional manner associated with paper charts but with a new symbology of a polygon with an exclamation mark in it placed in the general area of the notice. The notice will only appear on the “recommended” range scale for a particular ENC so won’t appear if the display is zoomed in or out! The following is again from the UKHO:

The display shows red polygons around the locations of NMs, along with the NM number. T&P NMs are shown with the NM number used in the Admiralty NM Bulletin, including the (T) or (P) designator. EP NMs are shown with (EP) in the number and using numbers that do not conflict with existing paper NMs. All NMs are linked to specific ENCs and will only display when the linked ENC is displayed. This means that as the user zooms in or out to scales at which the NM is no longer relevant, it will be removed from the screen.

Attached to each polygon is the full text of the NM, which can be viewed using the ECDIS pick report. In addition, complex NMs have an attached diagram or picture that helps explain the situation and is available directly from the ECDIS.

So we currently have a situation where the ECDIS NtM’s aren’t synchronised with the printed NtM’s and the information is displayed in an unfamiliar format that has to be interrogated to reveal its content. Feedback from users also reveals concerns that these polygons add further clutter to an already crowded display especially if they contain information not relevant to their particular vessel.

System Stability

An ECDIS is a computer and as such its stability is dependent upon the processing power available. Like all computers, over a period of time the ECDIS memory will fill up and require clearing out. As the memory fill then processing of information will slow and sometimes freeze and the ECDIS will require a re-boot. Obviously this is far from ideal if the vessel is in a busy shipping lane when such computer “issues” occur.

Additional Navigational Information

As part of an integrated system an ECDIS can be interfaced to overlay Radar and AIS data on the charted. Other items such as passage planning tools can be added to the ECDIS database and accessed as required. However, information software is not automatically supplied with the ENC so has to be purchased separately at additional cost. Examples of planning overlays are tide and weather information, sailing directions, port arrival information etc. The disadvantage of such services is that they are often produced by different software providers so the incompatibility problems associated with any computer software on different platforms can arise and of course additional software uses up memory and processing power. To combat this the ECDIS suppliers are increasingly offering such additional software packages specifically tailored to their equipment.

The striped lines on this ECDIS diplay alert the user that he is not using the “recommended” scale!

Training

As can be gleaned from all the aforementioned factors, the safe and efficient operation of ECDIS requires officers to not only be aware of the basic principles of ECDIS operation but they must also be fully conversant with their particular installation.

So, with an estimated 500,000 officers requiring such training before 2018, how is the Industry addressing this training issue? Well as is traditional for the Maritime world the situation is confusing because there is currently no mandatory IMO requirement for watchkeepers to attend ECDIS courses. However, under STCW95  a navigation officer must possess “a thorough knowledge of and ability to use navigational charts and publications…” He must show “..evidence of skills and ability to prepare for and conduct a passage, including interpretation and applying information from charts”.

In an annexe to the STCW95 requirements ECDIS is classified as a “chart” so under the ISM code ship owners have an obligation to ensure that their officers are trained to use ECDIS. Consequently, there is a requirement that all the watchkeepers serving on board any ship which has replaced its paper charts with an approved ECDIS system must have been formally trained in its use. Despite not formally requiring training, the IMO have proposed a syllabus for ECDIS courses and the major navigational institutions are now offering generic ECDIS courses but which currently vary in length between two and five days. Considering how traditional chartwork formed such a major element of a navigator’s training there is increasing concern that the existing courses are woefully inadequate for a watchkeeper to practically comply with the STCW95 requirements. These concerns are enhanced by the generic nature of these courses which cover the basic principles ECDIS but cannot possibly provide  an officer with the necessary competencies required to operate a particular manufacturer’s ECDIS. Since the regulations leave the manufacturers free to decide how the SENC information is displayed and the multitude of functions accessed, we are entering the age of ECDIS with a similar incompatible and confusing variety of ECDIS operating systems as currently exists with the myriad of radar operating systems on today’s bridges!

The IMO are currently proposing that ECDIS training will be a specific requirement in the revised STCW code, scheduled for adoption this year but again this will be generic rather than type specific and so will probably just serve to formalise the existing ad-hoc training courses.

The best ship owners are addressing these issues by sending their officers on type specific courses under their ISM compliance requirements but even such well trained officers may not be fully competent to use another manufacturer’s equipment if he transfers to another ship or company.

Other ship owners are sending officers for the basic training but passing the buck back to the ship by issuing ISM instructions that watchkeepers must familiarise themselves with the ECDIS using the manufacturers handbook. Since some of these can be over 500 pages in length and not easily understood, even by officers who have the advantage of English as a first language such training methodology is unlikely to provide the requisite competency. At the bottom end of the scale the vast majority of ship owners are awaiting the mandatory carriage dates for their fleets and somewhat unsurprisingly there is a growing concern that the authorised training establishments will not be able to cope with the last minute rush! I am already aware of one company which having purchased a coastal tanker from an owner who had fitted an ECDIS system had placed paper charts on board rather than incur the cost of sending the new officers on a training course. Another reason might have been that his crew agency were unable to supply ECDIS trained officers who, if available at all, are no doubt currently at a premium!

Given the track record of some crew supply agencies I think that we can expect to see a lot of forged ECDIS certificates appearing in the near future.

What about pilots?

Given all the complexities of ECDIS and the myriad of different operating systems the advice to pilots is that an ECDIS should never be used as the primary navigation tool for pilotage.

Finally my thanks go to Harry Gale of the Nautical Institute for permission to freely use information from the NI publication “From paper charts to ECDIS” which is the best publication on ECDIS available at this time. See my review in the April 2009 issue.

JCB

PS This article has been compiled from a wide variety of different sources and so my interpretation may not be totally correct. Please let me know if you find any errors in order that I can correct them accordingly.

]]> http://www.pilotmag.co.uk/2010/03/09/ecdis-electronic-chart-display-and-information-system-part1-how-ecdis-works/feed/ 0 http://www.pilotmag.co.uk/2009/12/23/the-bristol-channel-sailing-pilot-skiffs/ http://www.pilotmag.co.uk/2009/12/23/the-bristol-channel-sailing-pilot-skiffs/#comments Wed, 23 Dec 2009 12:06:46 +0000 JCB http://www.pilotmag.co.uk/?p=2297 In the October 2007 issue I ran a feature on the pilot gigs of Cornwall and the Isles of Scilly. That feature was based on information contained within a, long since out of print, book called “Azook” by Keith Harris who kindly permitted me to freely use his research for my article. In addition to the gigs, the waters of South West England were also frequented by another famous pilot craft, the Bristol Channel sailing skiff, or cutter as it now more commonly known as. Despite the ongoing massive popularity of this sailing design, the only authoritative book on the craft was written in the 1970’s by Peter Stuckey. The book was updated and re-published in 1999 but again has long since been out of print and used copies rarely appear and attract very high prices. At the time of writing there is one copy on the internet in the USA with an asking price of $216! In what was probably my best investment in recent years, I purchased a copy in 1999 when it was republished and Peter Stuckey has kindly granted me permission to use extracts from the book for this article. As an introduction, I cannot better Peter’s own which dedicates the book to: those brave men of the Bristol Channel who, with their stout boats, went seeking “downalong”

The Pilotage History

In order to better understand the role of the Bristol Channel skiff it is useful to understand the pilotage area that they covered since the pilots also served vessels trading to ports in S Wales as well as Bristol. The picture however is not as clear cut as the name suggests because due to the competition between pilots in those days there are records in the Welsh ports of their own pilots and in a further complication, the Bristol Channel pilots were not based in Bristol at all but at the small village of Pill at the mouth of the river Avon.

The records of pilotage out of Pill go back to 1497 when barge master James Ray was appointed by the Mayor and Corporation of Bristol to pilot John Cabot’s Mathew on its historic voyage to the New World. Pill subsequently became the centre for Bristol Channel pilots but the relationship between Pill and Bristol was not a happy one and this strained relationship could probably fill a book of its own so suffice to note for period covered by this article that the pilots operated under the Bristol Channel Pilotage Act of 1807 from which the following extract defines the pilotage area as;

from a certain Place about Four Miles Eastward of King Road and so down the River Severn and Bristol Channel to the two small islands called the Stipe Holmes and the Flat Holmes … (and their authority shall) be extended to the Appointment of Pilots for the conducting of Ships and Vessels into and out of and upon the whole of the Bristol Channel, and the several Ports, Harbours and Creeks belonging to and issuing from the same … (that is) all Vessels passing up and down and upon the Bristol Channel to and from the Eastward of Lundy Island, and in or upon the several creeks of the said Channels.

The fact that theirs was a tough life can appreciated by the photo of Pill pilots and “Westernmen” taken around 1880!

Pill Pilots & “Westernmen c 1880

The Sailing Skiffs

There are no historical records of skiffs and their construction prior to the early 19th century but like many craft the evolution would have been gradual over the centuries to met the three main requirements of speed, seaworthiness and ease of handling. The very nature of pilotage in those days where pilots were in direct competition with each other would have meant that any design element which gave a new boat the edge over existing boats would have been incorporated by others and there is no doubt that this constant drive to gain advantage over others is what caused these remarkable vessels to not only become the best sailing craft of their day but also for the design to be still one that is world renowned as one of the best blue water sailing craft in the 21st Century.

The earliest reliable record is from the 1795 Register of Ships which was instigated by the Corporation of Bristol that year and lists 12 Skiffs and provides their tonnage which ranged between 14 and 24 tons but no other details. Other records from the early 19th Century provide more details of some skiffs still surviving from the 1780’s & 90’s and the lengths of the craft ranged between 33 ft (10m) and 40 ft (12.2m). The sail plans weren’t recorded but the skiff James and Samuel which is listed in the 1795 register was sold in 1812 and the equipment included 1 mainsail, 2 foresails, 4 jibs, 1 squaresail, 1 gaff topsail and 1 topmast steering sail.

The earliest photograph of a skiff is that of the Trial which belonged to pilot T Vowles (1847 -78). and shows the squaresail yard which was seemingly a common feature on the early skiffs..

The Trial : An early skiff

It may be thought that detailed plans would exist for the cutters, especially those built in the late 19th and early 20th century, but such plans are virtually non existent because the construction lines were either taken from existing hulls or from half hull models. Also there was no “standard” model with lengths generally varying between 40ft ( 2.2m) and 50 ft (15.2m). Despite the variation in length the method of construction and timber used was fairly standard and the construction was usually of English oak, English elm and pitch pine with interior fittings of teak. Despite the lack of detailed drawings there is the following specification for the Kindly Light, a cutter built for Barry pilot Lewis Alexander dated1911:

General Dimensions: 52ft overall, 141/2 ft. beam, about 81/2 ft. draught. Length of keel, 38ft. Vessel to be built with round forefoot and elliptic stem. Cabin to be fitted with 2 berths and usual lockers. Forecastle fitted with 2 berths, lockers and racks for sails. Materials to be the best of their respective description and to be fitted in a workmanlike manner.

Keel: To be of English elm. (Generally the elm keels were in one length and about 18 inches deep and 6 inches wide)

Stem & Stem Posts: Of English oak.

Floors, frames, stanchions and beams: Of oak.

Keelson: Of pitch pine.

Planking: 1 oak plank round top, pitch pine to bilge, stout elm bilge 21/2 inch, remainder of plank of elm or pitch pine l1/2inch.

Rails: To be of elm or oak with greenheart capping.

Decks: Best yellow pine.

Fastenings: To be galvanized iron.

Masts: To be cutter-rigged with pole size as required.

Bowsprit, boom, gaff, topsail yard, two oars, boat hook. Booming out spar. Ironwork on Keel: Ballast iron.

Rigging: Three shrouds each side of 2in wire, forestay 31/2 inch wire running tackle.

Sails: One mainsail, one foresail, two topsails, three jibs, one balloon foresail, one spinnaker.

Painting: Vessel to be scraped, cemented and concreted up to bilge, to have two coats oil paint, two coats paint on bottom and top sides. Cabin to be varnished, forecastle to be grained.

Brasses for rudder head and collar for trunk and head of stem post.

Sundries and Utensils: Four plates, four mugs, cooking stove, knives, forks and spoons, saucepans etc. Foghorn, bulb flashlight, Morse lamp, combination lamp, water tank 60 gallons, table in forecastle. A

As an interesting note, I understand that Kindly Light still exists and is currently being fully restored in time for her centenary.

The performance of any sailing vessel is as dependent upon the cut and set of her sails but especially for pilots since their livelihood depended upon getting out to the boarding ground ahead of the competition.

The mainsail was of cotton in summer and flax in winter and they were fitted with four sets of reef points and were loose footed.  An indication of the extreme conditions that these craft had to work in, when set to the fourth set, the gaff jaws were almost down to the boom gooseneck. Later, some cutters were fitted with roller-reefing and so were laced to a wooden jackstay or ‘combe’ along the boom. The disadvantage of this reefing was that as the sail was rolled the leech exerted a load on the boom between the gooseneck and mainsheet and the stronger the wind the greater the stress. However, the risk of a broken boom was more than offset by the ease of handling.

The number of headsails carried depended largely on the affluence of the owner, but in all boats it was usual to have a working foresail, which had two sets of reef-points, a balloon foresail and three jibs, namely the large jib or ‘spinnaker’, working or ‘slave’ jib and storm or ‘spitfire’ jib. One or more topsails were also carried

Pilots didn’t normally tan or ‘cutch’ their sails as it was essential that their number or port initial should stand out clearly, but one Welsh pilot apparently carried a tanned jackyard topsail for reasons of strategy. When cruising amongst the numerous tan-sailed fishing craft, he would set this tanned topsail to disguise himself as one of them, and work out to the westward of a rival cutter, resetting his normal sail when the advantage had been gained. Some pilots made their own sails using skills gained on deep-water sailing ships during their required ‘sea-time’ .

When steamships made their appearance the pilots rapidly exploited the possibility of using the ship to tow the skiff back to port in order for it to be available immediately for the next job! This resulted in the unique structural fitting of heavy towing bits being added to the foredeck of the craft.  Somewhat understandably, the crews apparently hated being towed because with the ship steaming at full speed it was exhausting to keep the skiff under control with the foredeck awash!! Pilot Frank Trott actually fitted a proper tug’s towing hook to the fore side of his cutter Marguerite.  Marguerite is also still sailing today.

The cutter Cymro under tow!  photo N Alexander

The Skiffs at Work

The other important aspect of the skiffs was that handling should be manageable by a cox’n and deck hand so the deck fittings, rigging and layout were designed with the same eye for efficiency as the hull and sail plan.

The mainmast was a stout spar wire shrouds but no backstays, and was usually surmounted by a short fidded topmast which was supported by a topmast forestay and a pair of wire shrouds, but often no spreaders and, again, no topmast backstays. The spars were of pine and very heavy in order to eliminate as much supporting rigging as possible, as in the case of the bowsprit which, although sometimes fitted with an adjustable bobstay wasn’t fitted with shrouds in order to facilitate the frequent adjustments necessary to change jibs or reef jib. The bowsprit was normally shipped through a hole in the bulwark to starboard of the stem post.

Just abaft of the aforementioned bitts was the fore-hatch which gave access to the foc’s'le and forepeak and aft of that a little forward of amidships was the mast. Spare spars and sweeps were stowed fore-and-aft in two vertically mounted iron hoops. Aft of the mast a companion hatch was situated at the fore end of the self draining cockpit.  There was usually just one seat athwart-ships at the after end of the cockpit and as additional useful feature, the cutter Pet had a lavatory pan built into one comer of the cockpit seat!

Behind the cockpit coaming was the mainsheet horse and rudder post. The lower mainsheet block was not on a running traveller but was located at the centre of the horse by two very heavy flanking coil springs, or buffers. These buffers were highly necessary as the cutters were frequently gybed all standing as a standard manoeuvre when working and there was seldom time -or hands -to spare for the refinement of overhauling the sheet to ease the load. Generally speaking, the horse was about 2ft to 2ft 6in in length and was mounted between two very strong iron uprights, just high enough to allow clearance for the tiller arm.

The pilot’s boarding punt was kept on the port side, abaft the main rigging, stowed in chocks right way up. This was usually a clinker-built boat about 13ft length  often painted white so as to be easily identified at night.

Skiffs generally had fairly high bulwarks, of about 1ft 6in to 2ft, with a removable section through which the punt was launched to be rowed to and from the ship, Many punts had a standing wire strop fastened between the inside of the stem and transom at the point of balance, and to get the punt back on board the cutter a burton from the masthead was made fast to the eye in the strop, thus making it comparatively easy to hoist it inboard.

There were a few deadlights flush mounted into the deck to provide daylight below and there were rarely any ventilators ( they got enough fresh air!) fitted so the decks were clear  of obstructions for working.

On station the cutters were required to display a pilot flag which in 1849 became the white over red flag still in use today. At night an all round white light was displayed supplemented by a kerosene flare every 15 minutes with each port having a sequence code for displaying the flare. For example the flare code for Bristol was two shorts and a long. After 1858 the cutters were required to display sidelights at night when underway but contemporary accounts indicate that this was frequently ignored, especially in calms when it was not unusual for cutters to extinguish all their lights and get the sweeps out and row the cutter to gain a Westerly advantage over other cutters. Once a ship was encountered that required the services of the pilot, the ship would heave to while the cutter would work into the lee of the ship and “out punt” to transfer the pilot across for boarding. One man and the pilot would do the rowing whilst the man remaining on board would sail clear single handed and once the pilot had shipped return close under the lee of the ship to  recover the punt and other man. The cutter would then either sail or be towed back to the home port ready for the next run out. Occasionally more than one pilot would be on board so the cutter would remain out on station looking for other work. I refer to both the cutter hands as “men” but it was normally the case that these cutter hands were related to the pilots and were pilot apprentices themselves so there was no on board distinction of cox’n and deck hand

“Out Punt”    Painting by Peter Stuckey

There are some today who question whether the skiffs were actually sailed by two men but  this was definitely the case. Peter Stuckey wrote the book when some of the old sailing pilots were still alive and he undertook interviews which has left us a valuable records of those days. These first hand accounts reveal not just a life of hardship and danger but almost unbelievable accounts of seamanship skills.

The following are extracts from the story of Captain George Buck who served his apprenticeship skiffs in the early 1900’s.

Once we were hove to about 5 miles SW of the Wolf Rock, the wind had died away to a flat calm, the sea like a mirror, very dark without a cloud in the sky and the stars shining in the water the same as in the sky, all the lighthouses showing their lights all around the horizon and the Lizard light flashing in the sky. I was on 12 to 4 watch when a ship’s masthead light came in sight. I took a bearing and saw she would pass a long way to the north of us and, having no wind, the only thing I could do was show the Bristol signal on the flashlight, though as the flashlight was usually used by fishing boats in this area ships generally gave it a wide berth. We were expecting one of Pyman’s ships along, called the Cober, she being five days out from Gibraltar. I decided to call one of the pilots (we had two on board) and when he came on deck I suggested calling the other pilot, launching the punt and pulling as far as possible to get as close as we could, then to show the flashlight and hail her with the megaphone. We pulled until she was abreast of us, still more than a mile away, showed the flashlight and started to hail her, but eventually had to give up and had started to pull back to the skiff when we saw her port light come in sight and she came towards us, and sure enough it was the Cober bound for Bristol. I put the pilot on board and he towed me back to the skiff. The next night we still a flat calm. In the 12 to 4 watch I heard my mate come below and tell the other pilot a ship was in sight a long way to the north. I turned out and suggested another pull, the pilot agreed and this time he took an oar and we made the punt fly through the water, stopping now and again to show the flashlight. We were just deciding to give up when she went hard-a-starboard and steamed towards us. She was bound for Bristol and of course I expected to be towed back to the skiff, but when the pilot suggested this to the captain he told him had lost a blade and a half of his propeller and wanted to make sure of his tide. The pilot looked over the bridge and told me but I did not care, being happy to think we had another ship, and started to row back. After pulling for some time I stopped to see if I could pick up the skiff’s light but with so many stars reflected in the water I could not find it but I could see the Wolf light and knew if I pulled in that direction I was bound to find her. It seemed I had been rowing for hours alone in the world and I started singing to keep myself company. Then I stopped rowing, looked around and saw a light and was close to the skiff. My mate was pleased to see me back and I often wonder how many miles I rowed that night.

….It was very dark as we were approaching Barry entrance when suddenly a blue light (a signal for a pilot), was shown from a large ship at anchor in the roads. We sailed off to her and she was the Everton Grange (twin-screw) bound for Avonmouth. We hailed her, told them to put a ladder over and we would put a pilot on board.

The weather had by now got worse with a strong west wind and confused sea, with the tide ebbing west. The ship was lying across the tide, with the tide running on her lee side at about three knots. This meant we had to keep well to leeward, drop the punt with the pilot and myself, and the man in the skiff would have to get back into the wind, then come back and pick me up. If he lost the wind under her lee the tide would set the skiff down on the ship and do some damage. Everything went along fine. I put the pilot on the ladder and the skiff was coming back to pick me up with sufficient way to take her in to the wind again. I was about to jump aboard with the painter when the pilot hailed us to come back and take the Liverpool pilot in as he wished to catch the first train back to Liverpool in the morning. I rowed back to the ladder and then saw that the skiff had lost the wind and was setting down on the ship and we could do nothing to stop her going alongside. We managed to get a couple of fenders over and she brought up on the ship’s starboard quarter close to the propeller, the tide pinning her there. I made the punt fast to the skiff and asked them to pass us down a rope to heave us clear of the ship’s quarter as every time she rolled she smashed our bulwarks and the propeller was very close. But before we got the rope the propeller started to revolve and we yelled for them to stop it. The engines were stopped right away, they passed us down a rope and as they hove us amidships the pilot looked over the ship’s side and asked what all the shouting was about. I told him we had been close to the propeller and felt sure it had touched our bottom. The pilot, using the ship’s engines, then brought her head to tide and we were able to sail away from her.

I pulled up the floorboards in the steerage to make sure we were not making water as the blades of the propeller had been whizzing round abreast our cockpit. When we found everything was all right we asked if the Liverpool pilot still wanted us to land him. The reply being ‘Yes’, I rowed back to the ladder and took him off. We got alongside the skiff and having hauled the punt on board, set more sail and as we shaped course for Avonmouth I made a pot of tea.The next day the pilot came on board to survey the damage. It was not serious, about six feet of bulwark damaged. We pulled up the floorboards over the pump-well and found she had not made any water. The pilot then asked me why I had been shouting and I told him if he had been on board the skiff with that propeller churning round alongside he also would have done some shouting and I was still of the opinion that the propeller had touched our bottom. About three weeks later we put her on Ilfracombe Strand to scrub and tar her bottom and we found the bottom scored to to a depth of about 1/2 inch over a 3 foot length! It was the only time I was really frightened.

..We were cruising about 30 miles west of Lundy Island in a strong westerly wind and rough sea, expecting the Dominion liner, Manxman. We knew there were no skiffs to the westward of us and if she came along she would be ours. We had three rolls in the mainsail, reefed foresail and storm jib. About midday the pilot decided to run towards the island as the wind was increasing, as sometimes, when blowing hard, the wind would decrease to leeward, but when we got abreast the north end of Lundy the wind increased, so, putting another roll in the mainsail, we decided to run farther up Channel. About 8 pm we rolled the mainsail down with the jaws of the gaff on the mainboom, double reefed the foresail and hove-to, being now between the Nash and Foreland Point.

We never cared to give up the chance of a ship and we were certain if the Manxman came along she would be ours and, being a large ship and loaded, we should manage to board her. At 10 pm the pilot came on deck and the wind seemed to be increasing, with heavy squalls and confused sea, so he told me to put the helm up and run for Barry Roads. This skiff was the old Glance and she would run in any sea and never take any water over the stern. Just before midnight the pilot came on deck again and told me to make a pot of tea and call my mate. This I did and was on my way to the cockpit with a cup for the pilot when I heard a crash and when I got to the cockpit I found that the mainboom had snapped like a carrot. The mainsheet and the end of the boom were towing in the water and the mainsail was in ribbons. We had a difficult job getting the broken piece of boom on board and were afraid it might hit the side and break a plank} but we finally got everything secured and again running before the wind. I thought we should go to Barry but the pilot said we would go to Pill as we would require a new mainsail and mainboom.

Lowering the foresail and jib, we put a spare foresail fore side of the mast, hoisted it up and were away like a scalded cat. When we reached the river we hoisted the reaching foresail aft side of the mast for a mainsail, set the foresail and arrived at Pill just before high water. While we were mooring, the havenmaster’s office hailed the boatman’s shelter to say that the Manxman was in King Road and had asked for a pilot. We had not only lost a mainsail and mainboom but also a good paying ship. That was just the luck of the draw in the days of competitive piloting

This is just a small selection of accounts from George Buck and others in the book but provides a valuable insight into the life of pilots who earned their livelihood from the skiffs. Although several pilots and boatmen lost their lives in this service their losses were remarkably low considering the conditions they suffered and were probably no more than those of other occupations in those times. The testimony as to the seaworthiness of of the skiffs and the relationship between the men and their craft is summed up by George Buck as follows:

….when boarding ships at night during dirty weather, we were always glad when we had the punt back on board. In the daytime we took little notice of the weather and it had to be very bad when we could not board and it was not very often we had to run for shelter. The skiffs were fine craft and in bad weather would heave-to with the fore sheet to windward and the helm lashed a little down and they would work to windward off a lee shore.

Off Duty

The pilots relationship with their skiffs contnued even when they were off duty and racing “Reviews” were held at each port and were enthusiastically supported by the local community. Occasionally the skiffs raced against professional sailing yachts and frequently beat them especially in windy conditions. When on service, speeds of 10 knots were frequently achieved and this speed was often exceeded during racing when the additional sails were set.

Off duty racing.

Ilfracombe was the popular holiday resort for the Bristol Channel and the flat firm sands provided a good place for repairs and sprucing up of the skiffs. The pilots andf crew’s families would be lodged ashore in boarding houses and carnivals and other entertainments were enjoyed by all.

The 21st Century

The remarkable sea keeping qualities of the Bristol Channel skiffs and cutters has ensured their survival, with many original craft having been fully restored and maintained. Although during the latter half of the 20th Century the advent of fibre glass cruising and racing yachts somewhat eclipsed these wonderful craft, in recent years there has been a revival of interest and as well as restorations, lines are being taken from original hulls for new builds. In particular they are increasingly popular for the charter market. In ocean races they continue to win trophies when competing against modern yachts and since 2006 an annual pilot cutter “Review” has been held at St Mawes in Cornwall which is seeing an increase in turnout, despite the economic downturn. Meanwhile the reputation of the design for serious “blue water” cruising remains unsurpassed. Such a legacy is a fitting tribute to those hard working pilots and men who earned their living from these legendary craft.

JCB. With thanks to Peter Stuckey for permission to use extracts from his book.

In contrast, The National Transportation Safety Board (NTSB) report, which has now been published, provides a very detailed account (161 pages!) of the events leading up to the incident and reveals that John Cota’s error was compounded by failures of the bridge team and the failure of the VTS to provide support at a critical time.  Although the report catalogues “Human element” failures, in my opinion it doesn’t identify any actions which could be identified as criminally negligent. It is therefore all the more worrying that in sentencing John Cota to prison, the prosecutors have set a precedent that will encourage other legal teams around the world to criminalise the pilot.

The following analysis is extracted from the NTSB report and press reports from the trial but the opinions expressed in it are my personal views.

The Cosco Busan after the allision with the Bay Bridge.   Photo: NTSB

SUMMARY

On Wednesday, November 7, 2007, about 0830 Pacific standard time, the Hong Kong registered, 901-foot-long containership M/V Cosco Busan allided with the fendering system at the base of the Delta tower of the San Francisco–Oakland Bay Bridge. The ship was outbound from berth 56 in the Port of Oakland, California, and was destined for Busan, South Korea. Contact with the bridge tower created a 212-foot-long by 10-foot-high by 8-foot-deep gash in the forward port side of the ship and breached the Nos. 3 and 4 port fuel tanks and the No. 2 port ballast tank. As a result of the breached fuel tanks, about 53,500 gallons of fuel oil were released into San Francisco Bay. No injuries or fatalities resulted from the accident, but the fuel spill contaminated about 26 miles of shoreline, killed more than 2,500 birds of about 50 species, temporarily closed a fishery on the bay, and delayed the start of the crab-fishing season. Total monetary damages were estimated to be $2.1 million for the ship, $1.5 million for the bridge, and more than $70 million for environmental cleanup. The National Transportation Safety Board determines that the probable cause of the allision of the Cosco Busan with the San Francisco–Oakland Bay Bridge was the failure to safely navigate the vessel in restricted visibility as a result of (1) the pilot’s degraded cognitive performance from his use of impairing prescription medications, (2) the absence of a comprehensive pre-departure master/pilot exchange and a lack of effective communication between the pilot and the master during the accident voyage, and (3) the master’s ineffective oversight of the pilot’s performance and the vessel’s progress. Contributing to the accident was the failure of Fleet Management Ltd. to adequately train the Cosco Busan crewmembers before their initial voyage on the vessel, which included a failure to ensure that the crew understood and complied with the company’s safety management system. Also contributing to the accident was the U.S. Coast Guard’s failure to provide adequate medical oversight of the pilot in view of the medical and medication information that the pilot had reported to the Coast Guard.

NTSB CONCLUSIONS

1. The following were neither causal nor contributory to the accident: wind and current; the vessel propulsion and steering systems; the bridge navigation systems; bridge team response to orders; vessel harbor traffic; navigation aids, including the RACON at the center of the Delta–Echo span; maintenance of a proper lookout; pilot training and experience; and vessel traffic service equipment and operational capability.

2. The California Department of Transportation’s assessment of damage to the San Francisco– Oakland Bay Bridge following the allision was timely and appropriate.

3. The California Department of Transportation’s decision to allow the bridge to remain open to traffic after the allision was appropriate.

4. In this accident, the bridge tower fendering system worked as intended to protect the pier structure and to limit damage to the striking vessel to the area above the waterline.

5. The pilot’s order for hard port rudder at the time of the allision was appropriate and possibly limited the damage to the vessel and the bridge fendering system.

6. Although the pilot had been diagnosed with sleep apnea, he was being treated for the condition, and there was no evidence that he was sleep-deprived at the time of the accident.

7. As evidenced by his prescription history and duty schedule, the pilot was most likely taking a number of medications, the types and dosages of which would be expected to degrade cognitive performance, and these effects were present while the pilot was performing piloting duties, including on the day of the accident.

8. The Cosco Busan pilot, at the time of the allision, experienced reduced cognitive function that affected his ability to interpret data and that degraded his ability to safely pilot the ship under the prevailing conditions, as evidenced by a number of navigational errors that he committed.

9. The pilot and the master of the Cosco Busan failed to engage in a comprehensive master/pilot information exchange before the ship departed the dock and failed to establish and maintain effective communication during the accident voyage, with the result that they were unable to effectively carry out their respective navigation and command responsibilities.

10. The master of the Cosco Busan did not implement several procedures found in the company safety management system related to safe vessel operations, which placed the vessel, the crew, and the environment at risk.

11. The interactions between the pilot and the master on the day of the allision were likely influenced by a disparity in experience between the pilot and the master in navigating the San Francisco Bay and by cultural differences that made the master reluctant to assert authority over the pilot.

12. Because the Cosco Busan master was the only crewmember to have been drug tested in a timely manner, no conclusive evidence exists as to whether the use of illegal drugs by the other crewmembers played a role in the accident.

13. Vessel Traffic Service San Francisco personnel, in the minutes before the allision, provided the pilot with incorrect navigational information that may have confused him about the vessel’s heading.

14. Vessel traffic service communications that identify the vessel, not only the pilot, would enhance the ability of vessel masters and crew to monitor and comprehend vessel traffic service communications.

15. Although Vessel Traffic Service San Francisco personnel should have provided the pilot and the master with unambiguous information about the vessel’s proximity to the Delta tower, the Safety Board could not determine whether such information, had it been provided, would have prevented the allision.

16. The lack of U.S. Coast Guard guidance on the use of vessel traffic service authority limited the ability of Vessel Traffic Service San Francisco personnel to exercise their authority to control or direct vessel movement to minimize risk.

17. Even though the pilot’s personal physician, who prescribed the majority of medications to the pilot, was aware of the pilot’s occupation and his medical history, including his documented history of alcohol dependence, he continued to inappropriately prescribe medications that, either individually or in concert, had a high likelihood of adversely affecting the pilot’s job performance.

18. Although the pilot did not disclose to the physician who conducted his January 2007 medical evaluation all of his medical conditions or medication use, as he was required to do, the physician exercised poor medical oversight on behalf of the California Board of Pilot Commissioners by finding the pilot fit for duty despite having collected sufficient information regarding his multiple medical conditions and medications to call into question his ability to perform his piloting duties safely.

19. Although the pilot did not disclose to the U.S. Coast Guard and the California Board of Pilot Commissioners all of his medical conditions or medication use, as he was required to do, the information he did provide should have been sufficient to prompt the Coast Guard, at a minimum, to conduct additional review of the pilot’s fitness for duty.

20. The U.S. Coast Guard, which had the ultimate responsibility for determining the pilot’s medical qualification for retaining his merchant mariner’s license, should not have allowed the pilot to continue his duties because the pilot was not medically fit.

21. The U.S. Coast Guard’s system of medical oversight of mariners continues to be deficient in that it lacks a requirement for mariners to report changes in their medical status between medical evaluations.

22. Fleet Management Ltd. had failed to adequately train the Cosco Busan crewmembers, who were new to the vessel, who had not worked together previously, and who for the most part were new to the company, and this failure contributed to deficient bridge team performance on the day of the accident.

23. Providing a safety management system manual to the Cosco Busan crew only in English and not also in the vessel’s working language limited the crewmembers’ ability to review and follow the SMS.

24. Fleet Management had not successfully instilled in the Cosco Busan master and crew the importance of following all company safety management system procedures.

25. The failure of the U.S. Coast Guard and the California Department of Fish and Game’s Office of Spill Prevention and Response to quickly quantify and relay an accurate estimate of the quantity of oil spilled to the Unified Command did not affect the overall on-water recovery effort in this accident.

26. The Federal on-scene coordinator failed to aggressively use the resources available to him to obtain timely and accurate information about the extent of the spill in order to fulfill his responsibilities.

27. Effective communication regarding response activities was established and maintained between the oil spill response organizations, the qualified individual, the U.S. Coast Guard, and the Unified Command on the day of the accident.

28. The designated oil spill response organizations’ level of response to the Cosco Busan fuel oil spill was timely and effective.

29. A mechanism for the collection and regular communication among pilot oversight organizations of pilot-related performance data and information regarding pilot oversight and best practices would enhance the ability of those organizations to effectively oversee pilots.

30. Recently implemented international regulations with regard to the protection of fuel oil tanks on nontank vessels will, over time, reduce the likelihood of oil spills in mishaps such as occurred with the Cosco Busan.

Probable Cause

The National Transportation Safety Board determines that the probable cause of the allision of the Cosco Busan with the San Francisco–Oakland Bay Bridge was the failure to safely navigate the vessel in restricted visibility as a result of (1) the pilot’s degraded cognitive performance from his use of impairing prescription medications, (2) the absence of a comprehensive pre-departure master/pilot exchange and a lack of effective communication  between the pilot and the master during the accident voyage, and (3) the master’s ineffective oversight of the pilot’s performance and the vessel’s progress. Contributing to the accident was the failure of Fleet Management Ltd. to adequately train the Cosco Busan crewmembers before the accident voyage, which included a failure to ensure that the crew understood and complied with the company’s safety management system. Also contributing to the accident was the U.S. Coast Guard’s failure to provide adequate medical oversight of the pilot in view of the medical and medication information that the pilot had reported to the Coast Guard.

NTSB Recommendations

• To the U.S. Coast Guard:
• Propose to the International Maritime Organization that it include a segment on cultural and language differences and their possible influence on mariner performance in its bridge resource management curricula.
• Revise your vessel traffic service policies to ensure that vessel traffic service communications identify the vessel, not only the pilot, when vessels operate in pilotage waters.
• Provide Coast Guard-wide guidance to vessel traffic service personnel that clearly defines expectations for the use of existing authority to direct or control vessel movement when such action is justified in the interest of safety.
• Require mariners to report to the Coast Guard, in a timely manner, any substantive changes in their medical status or medication use that occur between required medical evaluations.
• Establish a mechanism through which representatives of pilot oversight organisations collect and regularly communicate pilot performance data and information regarding pilot oversight and best practices.

To Fleet Management Ltd.:

• When assigning a new crew to a vessel, ensure that all crewmembers are thoroughly familiar with vessel operations and company safety procedures before the vessel departs the port.
• Provide safety management system manuals that are in the working language of a vessel’s crew.

To the American Pilots’ Association:

• Inform your members of the circumstances of this accident, remind them that a pilot card is only a supplement to a verbal master/pilot exchange, and encourage your pilots to include vessel masters and/or the officer in charge of the navigational watch in all discussions and decisions regarding vessel navigation in pilotage waters.

In view of all the factors analysed in the report it is  a seriously alarming development that the pilot has been held solely responsible and condemned as a criminal. As a pilot with 27 years experience some factor evidently caused him to lose situational awareness at a critical point. The medication that he was taking seems to have been a factor in the loss of situational awareness but did this represent a criminal act?  I am no legal expert but I don’t believe that this case should ever have come anywhere near a criminal court. Compare John Cota’s actions with that of a driver of an HGV in Alaska in 2002 whose vehicle collided with a car and killed the two occupants because the driver was watching a film on a DVD player mounted in his cab. That driver faced manslaughter charges but he was acquitted because no law existed prohibiting a driver from operating a DVD in the view of a driver and there are many other cases of road drivers causing death and destruction and walking away unpunished.

In frightening contrast (and I mean to be alarmist here!), the prosecutors in John Cota’s trial were determined to condemn the pilot and this now has set a precedent for any pilot who may be unfortunate enough to have the conduct of a vessel which is involved in an incident that results in pollution or death.  An exaggeration?  Take careful note of these accounts from the trial:

In papers filed in court, prosecutors told the judge that Captain Cota should receive a sentence of incarceration because he was “guilty of far more than a mere slip-up or an otherwise innocuous mistake that yielded unforeseeably grave damage. Rather, he made a series of intentional and negligent acts and omissions, both before and leading up to the incident that produced a disaster that, as widespread as it was, could have had even worse consequences.”

“Captain Cota abandoned ship by not following required safety procedures which then resulted in an environmental disaster”

“The court’s sentence of John Cota should serve as a deterrent to shipping companies and mariners who think violating the environmental laws that protect our nation’s waterways will go undetected or unpunished,” said Joseph P. Russoniello, U.S. Attorney for the Northern District of California. “They will be vigorously prosecuted.”

Imposing a prison sentence rather than a fine, U.S. District Judge Susan Illston said, “I know there is a lot of blame to go around and there were a lot of authors in this tragedy, but I think Captain Cota was right in the middle of that.”

She stated that Congress had made it a crime to engage in negligence resulting in an oil spill “in order to protect the environment against the very kinds of things that have happened here.”

John Cota’s legal team are of the opinion that, by criminalising the pilot, the lessons of the Cosco Busan accident will not be learnt and have identified the following failures that contributed to the disaster:

• The Cosco Busan’s master, Captain Sun, failed to adequately supervise his crew and exercise any responsibility for ensuring the safe navigation of the vessel even though under well-established international law, the master is always in charge of his ship and the pilot acts only as his advisor;

• The Cosco Busan’s master ultimately gave the final approval to sail;
• The crew failed to take fixes at frequent intervals as required by international law, and at least every 5 minutes as required by Fleet Management’s policies, to ensure the safe navigation of the vessel in a congested area such as the San Francisco Bay;
• No one told Captain Cota that the electronic chart on the Cosco Busan was not IMO certified, and therefore should not be used in place of the paper chart;
• The fog signals on the Delta and Echo Towers were not working and cannot be heard at any time on the ship’s bridge recorder;
• The master did not know how to operate his ship’s electronic chart system and failed to either admit his ignorance or ask for help.  As a result, when Captain Cota twice asked him for assistance, the master “guessed” at the meaning of the red symbols, first telling Captain Cota they were “lights on . . . bridge” and later, after VTS called, confirmed they marked the “center of the bridge”;
• The crew falsified various checklists and work logs (i.e., the work logs reflected that the crew was getting more rest than was actually the case);
• At the master’s direction, the crew collaborated on their “story,” and continued to be less than forthcoming even though the government gave them immunity from prosecution.  The master in particular made statements under oath at various times that he later repudiated during his Rule 15 deposition.
• The master never told Captain Cota that he did not know or understand the symbols on his electronic chart or that he could have “queried” the symbols and learned that they were the red/green/red buoys in front of the Delta Tower;
• At the direction of Fleet Management’s Superintendents, the crew falsified documents after the accident to make it appear that the ship’s records were “complete” for the upcoming audit and/or government investigation;
• The Chief Officer abandoned his post at the bow of the ship and went to the mess hall to have a “meal and a smoke” shortly before the accident and later lied about this fact to the Coast Guard;
• The crew aboard the vessel, including the master, failed to adequately perform its duties in violation of international law—in particular, there was no pre-departure passage planning and none of the mandatory bridge team management procedures were followed
• The master failed to direct his crew to prepare a berth-to-berth passage plan prior to departing the Port of Oakland even though Fleet Management’s own policies required such a plan;
• The master failed to place a dedicated lookout on the bridge on the morning of November 7, 2007;
• The radars aboard the Cosco Busan were not properly tuned: the gain had been turned up considerably to compensate for the anti-clutter device that was mistakenly left in auto-mode by the master while his ship was in the Bay;
• The master also violated international law when he claimed not to know that the Cosco Busan’s intended route to sea was through the Delta-Echo span of the Bay Bridge or that the course drawn by his crew on his ship’s paper chart was not through the center of the span but was much closer to the Delta bridge tower
• Fleet Management’s Superintendents, who were on board the ship on November 7, 2007 before the ship sailed, and the ship’s master, failed to recognize the need to take any extra precautions or even consider delaying the ship’s departure given the foggy conditions that morning
• The master claimed not to know that his ship was headed in the direction of the Delta Tower because he allegedly did not know how the pilot intended to direct the ship through the Bay Bridge as it departed its berth in Oakland
• VTS failed to give a warning that the Cosco Busan was heading toward the Delta Tower of the Bay Bridge.  Had a warning been given even within the last minute or so, the ship could have safely traveled through the Charlie-Delta span;
• VTS failed to follow its standing orders and mission statement to “coordinate the safe and efficient transit of vessels in San Francisco Bay in an effort to prevent accidents” by either making recommendations or issuing directions “to control the movement of vessels in order to [protect] . . . the environment

A STATEMENT FROM JOHN COTA

Following sentencing, John Cota issued the following statement through his legal team:

Today marks the first time in over 200 years of maritime history of the United States that the government has sent a Bar Pilot to prison for an accident.

Captain John Cota, a man who literally grew up on the San Francisco Bay, is devastated by the events of November 7, 2007.   Having spent over 27 years as a Bar Pilot, and having worked on the waterfront since he was 12, Captain Cota is deeply tied to the Bay.  For the rest of his life, Captain Cota will bear the stigma of his role in the November 7, 2007 oil spill.

Captain Cota apologizes for his actions.

Sending a hardworking man to prison, who was just trying to do his job, for errors in judgment, is a very tough life lesson that Captain Cota wishes on no one.

Captain Cota hopes people understand that many factors – not just his actions – contributed to the cause of this tragic event.  Yet, he alone has been singled out for prosecution, and he alone will be going to prison.

Captain Cota accepts his share of responsibility.  But for lessons to be learned and carried forward to prevent this type of incident from ever occurring again – the multiple errors of all involved must be recognized.  To date, this has not been done.  Even the NTSB investigation was woefully inadequate and missed key evidence and critical facts.

The ship’s managers share in the responsibility for this accident by having:

• Allowed an unseaworthy ship to sail, with a vessel manned by a poorly-trained crew, supervised by an incompetent master; and
• Generated false documents after the accident to cover up its misdeeds.

The United States Coast Guard Vessel Traffic Service (“VTS”) also shares in the responsibility for this accident.  VTS made the conscious decision not to warn the Cosco Busan that it was heading straight for the Bay Bridge Tower in the fog.

It is baffling why these vessel traffic professionals sat silent in their control tower and did nothing to try to keep this tragic accident from happening.  There is persuasive expert opinion that there was ample time for VTS to warn, and had it done so, even within the last minute or so, there was still time for the ship to avoid hitting the bridge. The government must review its own procedures, in addition to prosecuting others, to make sure we never have a similar incident in the future.

In the end, Captain Cota hopes that this process is not just about blaming and punishing one man, but about finding solutions to making the Bay a safer place.  Captain Cota appreciates the support he has received from family and friends.

DOES ALL THIS AFFECT UK PILOTS?

What happens in the USA inevitably sets a precedent for court cases here in the UK so the answer is yes and the only way that any pilot can defend himself is to ensure that procedures, especially the Master / pilot exchange are as comprehensive as possible. Can’t be bothered? Take careful note of the following court statement:

Where it is possible to guard against a foreseeable risk, which, though perhaps not great, nevertheless cannot be called remote or fanciful, by adopting a means, which involves little difficulty or expense, the failure to adopt such means will in general be negligent.

As Australian pilot and senior IMPA Vice president observes:

The primary defence against negligence claims is “due diligence.” This really means that a reasonable person (in the eyes of a court) in the same position would have undertaken certain procedures and processes to ensure whatever it is that did happen, on the balance of probabilities, shouldn’t have happened.

This means that the courts could ask, “what could have guarded against the risk of the accident occurring?“. The answer is, “A proper Master / Pilot exchange  including a passage plan with contingencies that would enable a shared mental model by the bridge team (what we all know as BRM).” To which the courts could then ask the following question, “how much does it cost to have a proper MPX and produce a passage plan?”…..to which the answer is, “two minutes of time and about 20 cents for a sheet of paper”

AND FINALLY….

Just in case you still doubt that criminalization of pilots is just something that happens in the USA, the following has been received from EMPA:

On 1st August 2004 Capt Calvi boarded the Cruise Ferry ‘Danielle Casanova’

to help the Captain berthing in Marseilles harbour.  Due to sudden weather

changes and the constriction of the area the ship hit a pontoon with a

residual speed (less than ½ knot), after avoiding a collision with another

ferry and dropping an emergency anchor.  Unfortunately there were passengers

boarding another ferry moored on the opposite side of the pontoon.  During

the collision, the pontoon chains were broken and a car fell into the water

resulting in one fatality. After many years of investigation Captain Calvi

is facing charges for his conduct and he is now involved in a criminal

prosecution, together with the Ferry’s Captain, Gérard Bouvier.

JCB

The full NTSB report can be downloaded from:

www.ntsb.gov/publictn/2009/MAR0901.pdf

In fog. proceed with caution and obey the COLREGS!                                   Photo: MAIB

Fog has always been one of the elements to cause most concern to the mariner, especially in coastal waters, and in the days before radar the prudent navigator would frequently stop or anchor and wait until the fog cleared before continuing on passage. Similarly, once in pilotage waters, pilots would also anchor and await clearer visibility rather than risk a collision or grounding by continuing on passage. The advent of radar enabled vessels to proceed in fog and, as watchkeepers became familiar with using it, vessels were able to maintain schedules and then commercial pressures to proceed at full speed regardless of the visibility inevitably impinged upon safety. A series of fog related disasters led to new Collision Regulations (COLREGS) which dramatically reduced collisions and groundings in fog and these fog rules are also applicable in pilotage waters. As radar and GPS technology improved and with VTS able to provide traffic overviews, the primary limiting factor became the ability of tugs to manoeuvre vessels but although vessels requiring tug assistance were unable to proceed, other vessels continued to navigate normally in order to maintain schedules. The very nature of pilotage waters results in reduced safety parameters and these are obviously further eroded in fog. Four MAIB investigations have taken place during the last three years into fog related incidents, one of which resulted in a tragic loss of three lives and so all pilots would be well advised to read the full reports and take careful note of the findings.

The following are the “synopsis” and “conclusions” from the MAIB reports. The relevant sections within the full text are shown in brackets.

SKAGEN & SAMSKIP COURIER

Read the full MAIB report HERE

In June 2006, the general cargo ship Skagern and the container ship Samskip Courier collided in the Humber estuary in dense fog. Samskip Courier sustained minor damage to her bow but Skagern was extensively damaged forward and required major repairs.

Skagern had embarked her pilot Spurn light float and following the master/pilot exchange the vessel proceeded inbound towards King George Dock, Hull at a speed of 11.5 kts.

Samskip Courier had embarked a pilot at King George Dock, and after leaving the dock proceeded seaward at speeds of up to 12.5kts, in thick fog.

Both pilots were experienced and aware that the vessels would meet each other at some point; they had talked to each other on mobile telephones, and VTS also informed them of each other’s location. The vessels acquired each other on radar when some 2 miles apart but neither vessel plotted the other on radar as they converged.

VHF radio communications between the two pilots, together with the radar images, revealed that the vessels were on a collision course. The subsequent attempts at emergency avoidance were unsuccessful, and the ships collided head-on.

The ensuing MAIB investigation identified contributing factors to the accident which included:

• Failure to apply long established collision avoidance methods by the masters and pilots of both vessels.

• Pilot /master relationships: the masters’ over reliance on the pilots.

• Poor interaction and communications among the bridge teams.

• Loss of situational awareness by Samskip Courier’s pilot.

• The positioning of Sand End light float.

• Use of mobile telephones on the bridge.

Tracks of Samskip Courier & Skagen prior to the collision                               MAIB

CONCLUSIONS

3.1 SAFETY ISSUES

1. Humber Estuary Services’(HES) Port and Vessel Information System (PAVIS) recorded erroneous information about the master of Samskip Courier’s PEC status. [2.6]

2. Neither master exercised his right to take the con of their ships when it became apparent that a serious situation was developing. This was due to a misplaced trust in the pilots’ experience and ability. [2.8]

3. The bridge manning levels on both vessels were inadequate for the prevailing circumstances and conditions. There was little guidance given on watch manning levels in Samskip Courier’s BPM. [2.9]

4. Neither pilot queried the bridge manning levels on their respective vessels.[2.9]

5. Masters frequently take the opportunity to relax their vigilance when they have a pilot on board. [2.9]

6. Bridge team management was weak on both ships. No briefing or discussion of individual’s roles took place after the pilots boarded. [2.10]

7. Both pilots took over the con of their respective vessels without any formal andover taking place. [2.10]

8. The pilot master exchange on Samskip Courier was inadequate with neither the pilot or master giving each other enough information. [2.10] [2.11]

9. There was poor bridge teamwork and interaction, more so on Samskip Courier, culminating in a failure of the groups to operate as a team and in particular, monitor and question the actions of the pilots. [2.10]

10. There were repeated failures of key personnel to communicate with each other throughout. This impinged upon bridge team interaction. [2.11]

11. VHF radio familiarisation did not take place on Samskip Courier despite there being adequate time to do so whilst the ship was in the lock. This ultimately led to the pilot losing situational awareness at a crucial time. [2.12]

12. Pilots’ mobile telephones were used as the means of communication between the two vessels before and after the accident, resulting in the masters being excluded from the information exchange regarding their own ships. [2.13]

13. There was a failure to apply established collision avoidance measures by the pilots and masters of both vessels, namely:

• The vessels were travelling at an unsafe speed for the prevailing circumstances and conditions.

• There was a failure to determine early risk of collision by using systematic radar plotting or long range scanning techniques.

• Evasive actions to avoid collision were inadequate.

• Samskip Courier strayed from her side of the channel

• Accepted radar navigation principles for the prevailing circumstances were not applied.

• Restricted visibility sound signals were not used despite the prevailing conditions. [2.14]

14. The excessive speeds were possibly indicative of complacency through habitual risk-taking and a failure to perceive approaching danger. [2.15]

15. The vessels were steered from buoy to buoy using radar as the primary means of navigation without applying parallel indexing, long range scanning or clearing bearings. [2.17]

16. Positional information was not queried or relayed by the master of Samskip Courier to the pilot. [2.17]

17. Samskip Courier’s radar had a mapping facility which, if used appropriately, would have helped maintain situational awareness and possibly prevent the accident. [2.17]

18. Sand End light float was not best placed to indicate the proximities of the navigational channel. [2.18]

19. Both masters and pilots failed to take positive decisive action when it became apparent a serious situation had developed. [2.19]

20. The ship masters did not verbally query the actions of their pilots thus interfering with the process of them taking the con away from the pilots. [2.19]

21. The pilot of Samskip Courier misjudged the effect the tide and consequentially kept too far to Skagern’s side of the channel. [2.20]

22. Samskip Courier did not standby the stricken vessel, Skagern, until other assistance arrived. [2.21]57

RECOMMENDATIONS

The Port Marine Safety Code Steering Group is recommended to:

2007/121 Promulgate to pilots, by way of Port Authorities, a reminder on the importance of abiding by the International Collision Regulations at all times, and in particular Rule 6, Safe Speed, when navigating in confined waters in restricted visibility.

2007/122 Promulgate to Port Authorities the need for pilots to maintain dialogue with the bridge team regarding the conduct and execution of the passage plan, thus ensuring the team is kept fully involved, and informed, at all times.

2007/123 Highlight to Port Authorities the risks in using mobile telephones for passing operational information. They should emphasise the need for pilots to use mobile telephones only under controlled situations, and avoid the exchange of operational information which should more appropriately be transmitted by radio.

ABP Humber Estuary Services is recommended to:

2007/124 Discourage its pilots from using mobile telephones for discussing operational matters pertinent to the safe navigation of vessels when VHF radio is available.

The International Chamber of Shipping is recommended to:

2007/125 Through its member organisations, emphasise the need for shipowners to ensure masters are given clear guidelines which detail the importance of effective dialogue with pilots, and identifies the need for masters to challenge or question decisions or actions taken by pilots at an early stage so that, when required, effective corrective action can be taken to prevent accidents.

SEA EXPRESS & ALASKA RAINBOW

www.maib.gov.uk/cms_resources/Sea%20Express%201_Alaska%20Rainbow.pdf

SYNOPSIS

At 1138 (UTC) on 3 February 2007, the high speed ferry Sea Express 1 and the general cargo vessel Alaska Rainbow collided on the River Mersey in thick fog. The collision holed the starboard hull of the ferry, causing her to list and trim significantly within seconds. Alaska Rainbow was bound for Birkenhead Docks. Two tugs were attached before the vessel arrived off the lock. Here, the pilot turned the vessel to stem the tide and await the scheduled docking time, and for the visibility to clear enough for a safe approach to be made.

Sea Express 1 was bound for Liverpool Landing Stage. At 1033, as Sea Express 1 approached the Bar Light Buoy, the trainee captain made contact with Mersey Radio (VTS), who passed the positions of other traffic and advice that visibility in the river was poor. No mention was made of Alaska Rainbow.

Sea Express 1 proceeded inwards, reducing her speed over the ground to about 7 knots. At 1138, in the vicinity of Alfred Lock, Sea Express 1 took action to avoid Alaska Rainbow’s forward tug, which had suddenly appeared out of the fog directly ahead. Seconds later Alaska Rainbow appeared, and Sea Express 1 took further avoiding action. However, this was too late, and Sea Express 1’s starboard quarter and Alaska Rainbow’s bow collided. The collision tore a large hole in the starboard hull of Sea Express 1, immediately flooding the engine room and jet pump room effectively disabling the vessel. Sea Express 1 was towed to the Liverpool Landing Stage, where the passengers were disembarked.

Mersey Docks and Harbour Company (MDHC) and Isle of Man Steam Packet Company Limited (IMSPCL) have taken a number of actions following the accident, particularly with respect to VTS operations, pilotage training and the allocation of bridge team duties in preparation for type rating examinations.

Sea Express 1 being towed to the Liverpool Landing Stage                             Photo: MAIB

Conclusions

Factors related to Sea Express 1:

-A ground stabilised radar display was not used in the confined waters of a river transit, thereby making it difficult for the operator to distinguish moving targets from land radar returns. [2.2.1]

-The initial communication made by Sea Express 1’s captain to VTS lacked urgency and detail as to the seriousness of the situation, thereby delaying an appropriate external emergency response. [2.5.5]

-The allocation of bridge team duties in preparation for the type rating examination was unclear, resulting in the presence of other vessels in the vicinity to be missed during the period immediately leading up to the collision. [2.2.1] [2.2.2] [2.2.3]

Factors related to Alaska Rainbow:

-The pilot did not proactively communicate with Sea Express 1 and VTS at an early stage to ensure that all parties were aware of the hazard that Alaska Rainbow presented to other traffic, resulting unnecessarily in the development of a close quarters situation. [2.3.1]

-The pilot was not proactive in requiring support, and neither the master nor the OOW was proactive in providing support to the pilot, thereby unnecessarily increasing the pilot’s workload. [2.3.3]

-Neither the pilot nor the master ordered fog signals to be sounded, thereby omitting a means by which Sea Express 1 might have been alerted to the presence of Alaska Rainbow. [2.2.2]

-The pilot was insufficiently practiced in maintaining Alaska Rainbow’s position in the prevailing circumstances, resulting in the vessel moving significantly between the west bank and mid-river. [2.3.2]

Factors related to the VTS station:

-No fog routine was in place, thereby preventing a closer watch on vessel movements being maintained to ensure safe traffic flow at times of restricted visibility. [2.4.3] [2.4.4]

-The VTS duty staff were expected to absorb the additional workload that operation in restricted visibility demands; an independent audit of the Port of Liverpool’s safety management system might have identified this shortfall. [2.4.5]

-A review of the Mersey Channel Collision Rules on the sound signals required of vessels manoeuvring in close proximity during periods of restricted visibility would appear to be appropriate. [2.2.2]

-The VTSOs were not proactive in ascertaining further information following the initial report of the collision and in notifying Liverpool Coastguard, thereby delaying an appropriate emergency response. [2.5.4] [2.5.5]

-Additional workload created by the VTSOs having to take pilotage bookings at a time when performance of their normal duties was at a peak, had the potential to result in the VTSO responsible for the Information Service becoming distracted. [2.4.2]

-Specific risks associated with the carriage of passengers had not been separately assessed, particularly with regard to emergency response. [2.5.4]

RECOMMENDATIONS

The Isle of Man Steam Packet Company Limited is recommended to:

2007/185 Review its Safety Management System with particular respect to:

• using ground stabilised radar display in the confined waters of a river transit;

• improving external communications in the event of an emergency in terms of urgency and detail.

2007/186 Ensure that the passenger safety instruction card illustrates the lifejacket to be found under the seat for which the card is provided.

J.G.Goumas (Shipping) Co. S.A. is recommended to:

2007/187 Ensure its masters are given clear guidelines which detail the importance of effective dialogue with pilots and identify the need for the ship’s bridge team to:

• be proactive in providing support to pilots;

• challenge decisions or actions taken by pilots at an early stage so that, when required, effective corrective action can be taken to prevent accidents.

Mersey Docks and Harbour Company is recommended to:

2007/188 Complete its review of compliance with the requirements of the PMSC with particular reference to:

• VTS operations, ensuring that an effective fog routine is established and that the VTS station is sufficiently manned to absorb the additional workload that operation in restricted visibility demands, and that VTSOs are proactive in ascertaining further information in the event of incident;

• Pilotage best practice, highlighting the need for pilots to proactively communicate with approaching vessels and VTS at an early stage to avoid unnecessary development of a close quarters situation; to be proactive in requiring support from the ship’s bridge team; and to sound appropriate fog signals in restricted visibility.

2007/189 Following satisfactory completion of its review into PMSC compliance, invite the MCA to conduct a PMSC verification visit to the Port of Liverpool.

2007/190 Review the Mersey Channel Collision Rules with respect to sound signals required by vessels manoeuvring in close proximity during periods of restricted visibility.

AUDACITY & LEONIS

www.maib.gov.uk/cms_resources/Audacity_Leonis.pdf

SYNOPSIS

At 1351 on 14 April 2007, the UK registered product tanker Audacity was involved in a collision with the Panama registered general cargo ship Leonis, in very poor visibility, in the precautionary area at the entrance to the River Humber. Both vessels sustained damage to their bows. Fortunately there were no injuries and no pollution was caused. Audacity had been outward bound from Immingham Oil Terminal and was approaching the precautionary area in order to disembark her pilot. Leonis had entered the precautionary area from seaward and had just completed embarking her pilot. The MAIB investigation found that the operation of the bridge team on Audacity was inadequate, and the extent of the VTS area and VTS powers was not clearly understood by the VTS operators. The investigation identified contributing factors to the accident; these included:

• The pilots and bridge teams, on both vessels, did not make a full assessment of the

risk of collision.

• VTS procedures for managing traffic in the precautionary area were insufficient.

• VTS operators were unaware of the poor visibility in parts of the VTS area.

• Humber VTS did not have a formal operating procedure for periods of reduced visibility.

• Communications were poor.

• The Port Authority misunderstood how risk assessment could be used to improve the effectiveness of the VTS operations. As a result of this accident, Associated British Ports Humber Estuary Services (ABP HES) has taken several actions to improve the performance of the VTS, pilots and pilot boarding operations.

The VTS view showing a dangerous situation developing                                        Photo: MAIB

Safety issues directly contributing to the accident which have resulted in recommendations

1. The procedure for a pilot/coxswain briefing prior to embarking the vessel was

not conducted efficiently. The radar equipment available in the launch was liable

to severe shadow effect while close to vessels, making the identification of navigational markers unreliable. [2.11]

Other safety issues identified during the investigation also leading to recommendations

1. From historical data, incidents in the Humber Estuary are occurring more frequently than weighted in their current risk matrix. This indicates the risk is greater than initially allowed for or that the safety barriers are insufficient or ineffective. [2.3 / 2.5.2]

2. There were no detailed marine policies applied throughout the group, which made the auditing of ports within the ABP group for compliance with the PMSC more difficult. [2.5.1]

3. Risk analysis should be reviewed as a matter of routine after any serious incident to ensure the effectiveness of the safety barriers or to evaluate the need for additional barriers. [2.5.1]

Safety issues identified during the investigation which have

not resulted in recommendations but have been addressed

1. Due to a combination of circumstances the VTS operator allowed Leonis to drift into a dangerous position close to the exit from the outbound TSS. This action was compounded by the lack of traffic information to either Leonis or Audacity about the position of the other. [2.10.1 / 2.10.4]

2. Main Highway’s transit of the precautionary area, at speed, and with substantial alterations of course during the pilot boarding operation, was not good seamanship, nor was it commented on by VTS. [2.8.1]

3. The powers of the AHM to give advice and guidance to vessels operating inside the VTS area, but outside the port limits, were not fully understood, and there was reluctance for operators to issue proactive information to vessels within the precautionary area. [2.6.1 / 2.10.1]

4. It was incumbent on VTS to ensure that its plan for boarding of pilots recognized the need for vessels arriving at the boarding area to be properly separated both geographically and in time. [2.6.2]

5. The VDR recording from Leonis was incomplete, and information regarding helm and engine status was not recorded. There were no procedures in the SMS for the use and maintenance of VDR equipment. [2.4]

36

6. Routine information broadcasts, including visibility reports, were made every 2

hours. Although several reports of reduced visibility were received, no formal re-assessment was made of the visibility in the estuary and no additional broadcasts were made. There were no formal reduced visibility procedures and no requirements for reduced visibility to be reported. [2.6.2]

7. Humber VTS had no formal procedures for the preservation of records in the event of an incident. [2.6.3]

8. Leonis altered course towards the northwest because both master and pilot were unaware of the presence of Audacity. As a result, no assessment of the risk of collision was made before manoeuvring. [2.7.1 / 2.7.4]

9. ARPA was not used effectively on either vessel to assess risk of collision. By the time the ARPA was used on Leonis, it was too late for it to provide reliable information. [2.7.4 / 2.9.5]

10. Effectively, no-one held the con on the bridge of Audacity because both the master and pilot had deferred to the other, there was no discussion or questioning of the intentions of Leonis, and at a critical time they involved themselves with tasks that were inappropriate given the impending close quarters situation.

[2.9.1 / 2.9.2]

11. The bridge on Audacity was insufficiently manned in the circumstances and conditions. It did not comply with company requirements or HES instructions to pilots, however no additional resources were requested by the pilot. [2.9.2]

12. Despite advising the pilot of Leonis that he would take action and come to the south, the pilot of Audacity did not alter course. This lack of action was not questioned by the master or the VTS operator, and the pilot of Audacity did not advise Leonis’s pilot that he no longer intended to act as agreed. [2.9.2 / 2.10.3]

13. The communication between all parties involved was unclear and prone to misunderstanding, and use of standard marine phrases was not practised. [2.10]

14. VTS operators did not consider they were able to give advice and guidance to vessels with pilots on board. It was considered that the pilot would know what he was doing and that the operator did not need to be further involved once a pilot was on board. [2.10.2]

15. Communications from the VTS operator and P/L Venus were ambiguous and confusing. They were not result orientated and did not use identifier markers. Requests for specific information were inappropriately answered. [2.10.5 / 2.11]

Recommendations

UK Major Ports Group and British Ports Association are recommended to:

2008/103 Inform their members of the MAIB’s advice that they should consider how best to review how pilots can be helped to gain proper orientation of the traffic and navigational situation prior to boarding vessels to conduct acts of pilotage.

Associated British Ports Group is recommended to:

2008/104 Develop Group Marine Policies covering headline issues which can be implemented throughout the ports within the Group. Such policies should encompass, but not be limited to, training, risk assessment, and development and promulgation of best practice.

2008/105 Develop an auditing process to verify compliance with the group marine policies, including procedures which track the status of audit findings until agreed

corrective actions have been implemented.

LOSS OF TUG FLYING PHANTOM WHILST TOWING THE RED JASMINE IN FOG.

www.maib.gov.uk/cms_resources/Flying%20Phantom.pdf

SYNOPSIS

On 19 December 2007, the tug Flying Phantom was girted and sank while acting as a bow tug. She was assisting the bulk carrier Red Jasmine during a transit of the River Clyde in thick fog. Three of the tug’s four crew were lost; only the mate managed to escape from the tug’s wheelhouse and was subsequently rescued.

After Flying Phantom’s tow line had parted during the capsize, the pilot on board Red Jasmine completed the transit to the berth safely, in the thick fog, with only a stern tug to assist him.

The investigation has identified a number of factors which contributed to the accident,

including:

• The emergency release system for the towing winch on board Flying Phantom had operated, but not quickly enough to prevent the tug from capsizing.

• There were no defined operational limits or procedures for the tug operators when assisting/towing in restricted visibility.

• The routine observed by the tug’s crew prior to towing or entering fog was ineffective, resulting in the watertight engine room door being left open and the crew not being used in the most effective manner once the fog was encountered.

• The port risk assessment was poor, and the few control measures that had been put in place after a previous similar serious accident in thick fog proved ineffective.

• The port’s reliance on their ISO9001 quality management system audits to highlight safety concerns was fatally flawed.

• The lack of an individual to fulfil the role of “designated person” had resulted in major shortcomings in the port’s safety management system being overlooked.

• UK ports appear to have been failing to learn lessons from accidents at other ports.

• The lack of an accepted international industry standard for tug tow line emergency release systems.

CONCLUSIONS

Safety issues directly contributing to the accident which

have resulted in recommendations

1. Although the tow line emergency release mechanism operated after the mate activated the system, it did not act quickly enough to prevent the girting of Flying

Phantom. [2.4.1].

2. Towing winches are not generally regarded as equipment that should be the subject of class surveys. Additionally, there is no clear standard defining the time or loading within which the towing winch brake should release. [2.4.3]

3. There were no defined limits for tug towing operations in restricted visibility. If fog was encountered, there was no appropriate procedure or training provided to ensure tug crews could continue to operate safely. [2.5]

4. In the event of encountering fog, the bridge ergonomics of Flying Phantom were not suited to conducting blind pilotage operations. [2.5]

5. There were no formal pre-towing checks to ensure the necessary preparations had been completed prior to towing. This resulted in the engine room watertight door being open, which reduced the tug’s residual stability and, therefore, her ability to right herself when experiencing a heeling load. [2.6.1]

6. Once Flying Phantom had entered the fog bank, her personnel were not used to best advantage to ensure the vessel navigated safely in the narrow confines of the

River Clyde. [2.6.2]

7. Clydeport had no effective system for assessing the risk of fog. Although the area in which the accident occurred was known to be susceptible to fog, there was no reliable means of detecting the arrival of fog on the River Clyde, or warning river users of its presence. [2.7.3]

8. While a procedure for operating in restricted visibility was provided in the port’s safety management system, it was ineffective. Specifically, although a lay-by berth was detailed for consideration, it was not appropriate for a vessel of Red Jasmine’s size, and the pilot had little choice other than to continue to the ship’s intended destination, at Shieldhall Riverside Quay [2.7.4]

9. Clydeport’s risk assessment was immature, and many of the control and counter measures put in place were ineffective. It is vital that a comprehensive review of the port’s risk assessment is conducted urgently by an independent marine expert to rectify this position. [2.8.1]

10. Many of the recommendations from the Abu Agila accident, which occurred in thick fog, were not followed up, and the subsequent control measures were not implemented or were ineffective. [2.8.2]

11. There were a number of inconsistencies and conflicts within Clydeport’s SMS documentation. These had the potential to cause confusion and permitted too much flexibility in interpretation. [2.8.3]

12. Clydeport’s ISO9001 audits were not effective at highlighting any gaps in safety procedures or the adequacy of the safety procedures in place. Furthermore, the audit approach did not provide a means of checking that the underpinning risk assessments were adequate. [2.8.4]

13. Clydeport’s board was receiving a false impression of the safety performance of the port by relying on the ISO9001 system acting as the designated person. Given the safety management system shortcomings identified in this investigation, it is considered essential that Clydeport needs to appoint an appropriately qualified individual to the post of designated person under the Port Marine Safety Code. [2.8.5]

Safety issues identified during the investigation which have

not resulted in recommendations but have been addressed

1. The liferaft painter was attached to the tug directly without a weak link. Although having no bearing on this accident, if Flying Phantom had been lost in deeper water, the liferaft, even if it had inflated, would have been lost with the tug. [1.7.7]

2. Lessons from an accident at one port are not always being learnt by other. [2.9]

Recommendations

Clydeport Ltd is recommended to:

2008/161 Appoint an appropriately qualified individual to the post of designated person under the Port Marine Safety Code.

2008/162 Conduct an urgent review of its port risk assessment and safety management system to ensure:

• Requirements, conditions, controls and operational limitations for the safe transit of large vessels on the Clyde are clearly defined.

• Ambiguities or conflicts within its SMS documentation are removed.

• The company’s SMS is subject to routine audits by an independent and appropriately qualified marine professional.

• Limitations and/or working procedures relating to the operation of tugs in restricted visibility are agreed with the port tug operators and incorporated into standard operating procedures.

Lloyd’s Register is recommended to:

2008/163 Take forward a proposal to IACS to develop a standard for tug tow line winch emergency release systems, to ensure tow lines can be released effectively when under significant loads in an emergency.

Svitzer Marine Ltd. in association with the BTA is recommended to:

2008/164 Derive limitations and associated necessary guidelines and training for the operation of tugs in restricted visibility. Ensure that ports and pilots are aware of such limitations and guidelines.

The British Tugowners Association is recommended to:

2008/165 Highlight to its members the importance of tug crews’ emergency preparedness, including:

• maintaining watertight integrity

• functionality of tow line emergency release systems

• limitations and procedures for operating in restricted visibility

As you will be aware, the UKMPA have been involved in the European Maritime Navigation Information Services (MarNIS) project for four years and EMPA have been the project leaders for the development of the Portable Operational Approach and Decision Support System (POADSS) which developed from the Innovative Portable Pilot Assistant (IPPA) project which ran from 2000 – 2003.

Our “front man” on the POADSS project has been Southampton pilot, Nigel Allen who, along with other pilots from within EMPA, has achieved the rare distinction of producing a fully working unit on time and on budget. The project culminated in a successful live demonstration in Lisbon last October and the future now rests with how the manufacturers wish to develop the concept to the requirements of individual pilots and ports. POADSS is a highly sophisticated aid which incorporates the latest technology and although we all know it will never happen it actually has the potential to transfer the whole VTS to the pilot on the bridge. At its current state of development it is somewhat hampered by the necessity to have much of the hardware in a separate Interface Unit (IU) but since this unit has already been downsized within 12 months from a tea trolley (see issue 291 October 2007) it is probably only a matter of time before all the necessary components can be included in a single display unit. Nigel must be congratulated for his unflagging enthusiasm and dedication and Maarten Betlem and the Lisbon pilots also deserve a special mention for successfully concluding a complex project which has been a credit to the professionalism of pilots.

The following article details the key elements of POADSS and has been edited from the detailed final report produced by Dutch pilot, Maarten Betlem.

POADSS within the MarNIS Project  

The work on POADSS was undertaken as part of the MarNIS project under Work Package 4.2 (Port’s safety and infrastructural info on board vessels)

The other Work Package 4.1 in this Cluster was “Modern Vessel Traffic Management” and during the project intensive consultation took place between the two Work Packages to achieve the most beneficial results for both parties.

The MarNIS project is also linked to other European maritime research projects such as WATERMAN and EMBARC.

Initially the acronym POADSS stood for Portable Operational Approach and Docking Support System but Docking was subsequently changed to Decision, to better reflect the project’s aims.

The POADSS unit consists of three main elements, two onboard units and the ashore unit. One onboard unit is an Instrument Unit (IU) and the other is a laptop for displaying the available information and for receiving and transmitting data to and from the shore based unit by means of mobile broadband. Ashore this information exchange is organized by the POADSS Ground Server Station which sources data from VTS, tide / swell gauges etc. Thus, together with its own stored data, an independent comprehensive overview of ship’s static and dynamic information data, as well the surrounding traffic image and environmental conditions results in a comprehensive overview of all relevant parameters of the particular ship on her passage.

What will it do?

Most pilotage units monitor the vessels horizontal position (2D), whilst the POADSS also monitors the vertical position (3D) and all dynamic motions.

In summary, there are 4 main new applications:

• • Integration of an Inertial Measurement Unit (IMU) with Global Navigation Satellite Systems (GNSS) to accurately determine all dynamic movements of the vessel
• • Wireless broadband to exchange information in real time (Web Map Services)
• • Dynamic high density bathymetric data displayed on an electronic chart (enables a true dynamic safety contour)
• • Dynamic Under Keel Clearance (DUKC) software

The POADSS is intended to improve navigational safety and efficiency, reduce voice radio communications, access relevant information to maximise the usability of fairways and thus enhance the efficiency of the overall traffic flow.

POADSS has incorporated as much available ‘off the shelf’ hardware and software as possible in order to facilitate data exchange with the shore server. 

The Shore Server Station provides the following support:

• • VTM Stakeholders;
• • Dynamic Passage Planning and resource management 
• • Information inputs to support Dynamic Passage planning
• • Data logging.

Interoperability with the VTMS centre is a key element and by using Web Map Services (WMS) the overall VTS traffic image can be overlaid on the POADSS Electronic Navigation Chart (ENC).

WMS can also provide real time meteorological and hydrographical conditions along with temporary navigation notices

If the broadband connection is lost AIS information remains available via the vessel’s Pilot Plug Connection.

The Dynamic Under Keel Clearance (DUKC©) module is divided into two elements: predicted and actual. The predicted DUKC, is computed for each ship and passage prior to the passage and stored on the shore server and can be accessed at any time during the passage. The actual DUKC is established with cm accuracy by the POADSS Instrument Unit (IU)using the latest position, heading, speed, heave, roll (heel) and pitch (trim) and displayed on the laptop. Crucial for an accurate DUKC is the exact determination of the onboard position of the POADSS IU in relation to the ship’s dimensions, as well as, the ships stability data and the centre of gravity.

The predicted DUKC and the actual UKC are presented in graphical diagrams 

and comparison of both values will confirm that the actual UKC is within an acceptable safety limit to the predicted  DUKC. In practice the real time UKC is always greater than the predicted UKC because the latter is based on increased parameters to ensure safety.

Functional requirements

The ENC is the most important part of the display since the information must be accurate and not mask other essential information. However operating the POADSS mustn’t distract attention away from the essential task of overall safe navigation and therefore training is of fundamental importance. The POADSS software has therefore been developed to be ‘Port specific’ which results in it being much easier to use whilst piloting. 

Special consideration must also be given to integrating POADSS into the Bridge Resource Management structure in order to reduce the chance of single person error.

System components 

The existing two POADSS units contain the following modules:

The Instrument Unit (IU).

• o Integrated Global Navigational Satellite Systems (GNSS) / Inertial Measurement Unit (IMU) component;
• o Satellite Antenna;
• o RTK Antenna;
• o AIS Unit;
• o Electronic Motherboard;
• o Internal Communication to the User Interface Unit;
• o Battery Pack.

User Interface Unit (Laptop)

•  
  • o Windows XP;
  • o Dedicated Electronic Navigation Chart System/ ECDIS kernel;
  • o External Communication by means of Mobile Broadband to the POADSS Shore Server;
  • o Internal Communication to Instrument Unit by means of a Local Area Network. (WiFi);
  • o Dedicated POADSS software application, divided in:
    • ♣ Information Mode;
    • ♣ Planning Mode;
    • ♣ Navigation Mode;
    • ♣ Docking Mode.

The POADSS Shore Server (PSS) contains

•  
  • o Server 
  • o Network Switch;
  • o Tide data Server;
  • o DUKC Server;
  • o VTS – WMS Server;

The increasing use of Portable Pilotage Units (PPU’s) worldwide has resulted in a growing need for such units to be operated within a legislative framework. Achieving this will require close co-operation with international organisations such as the IMO and IEEC and this will be an important aspect of the implementation of the POADSS. Likewise, the POADSS Server station will need to conform to agreed standards in order to ensure the provision of quality assured information. 

Since this project began, there have been rapid advances in the technology available for stand alone PPU’s carried by pilots and many systems are already capable of accessing much VTS and hydrographic information without the separate IU box.

However, although the matter of PPUs has been raised in IMO NAV and STCW meetings, the IMO has not issued any definitive guidelines or regulations on what constitutes a PPU or how they should be used by Pilots. Currently the only formal requirement is that there must be an AIS “Pilot Plug” installed on the bridge of a ship that can be used by a Pilot with a PPU.

State of the Art

Since this project began, there have been rapid advances in the technology available for stand alone PPU’s carried by pilots and many systems are already capable of accessing much VTS and hydrographic information without the separate IU box.

However, although the matter of PPUs has been raised in IMO NAV and STCW meetings, the IMO has not issued any definitive guidelines or regulations on what constitutes a PPU or how they should be used by Pilots. Currently the only formal requirement is that there must be an AIS “Pilot Plug” installed on the bridge of a ship that can be used by a Pilot with a PPU.

Consultation with pilots

The POADSS project involved consulting with pilots currently using PPU’s which produced the following findings:

•  
  • • Most pilots prefer screen displays that are very simple and pragmatic. In general, little extraneous information is shown other than what is needed for the current situation or task-at-hand. For this reason the interest in having radar imagery or VTS information superimposed on the chart display is very port specific. However, some pilots (particularly river pilots) wanted to predict points for meeting or overtaking other ships. The AIS is crucial for this predictor facility.The display chosen by the pilot may be basic but the software allows the pilot to choose what to show and what to hide.  
  

HIGHLY DETAILED INFORMATION CAN BE DISPLAYED IF REQUIRED

•  
  • • Transit times varied within the survey group from 45 minutes to 13 hours. From arrival on the bridge the PPU is usually up and running within 2 – 3 minutes but if a pilot has to set up his own DGPS this might add another 2-3 minutes. The GPS antenna is normally clamped onto the railing on the bridge wing and if there are two antennae they are usually placed in a fore and aft fashion, and spaced one to four meters apart. This arrangement and distance are set into the software. If a specialized docking system is deployed, this might take up to 15 minutes to set up but in such cases two pilots are usually employed and one sets the equipment up while the other goes to the bridge.

•  
  • • Few pilots currently use radar integration but in Rotterdam VTS radar information is integrated in the PPU due to the large number of barges not fitted with AIS transponders.

•  
  • • Currently, relatively little VTS-related information is displayed on PPU’s. and digital VTS services are not widely available. This may change with the wider introduction of long range mobile broadband services such as Hyperlan or Wimax in the future..

•  
  • • Precise docking systems are widely used in Europe and Australia but far less so in North America. These systems are relatively expensive (about €50,000) and require that the chart data be large scale and highly accurate (+/- 1 meter or better). 
  

•  
  • • Some pilots specifically mentioned that an important advantage of using PPUs was video playback. Specifically, video playback of a pilot’s recorded voyage data can be useful for reviewing a passage, analysing an incident to establish “lessons learned” and for training.

•  
  • • Some pilotage organizations take training very seriously while others less so. All believe that a minimum level of hands-on training should be a prerequisite for carrying a PPU but there are differing opinions on how much and who should conduct it (e.g., a manufacturer or experienced pilots).
  • • Some pilots expressed their opinion that if mandatory PPU use is implemented there needs to be an agreed system of assessment and that there should be an approved standard operating procedure.
  • • The master must give permission to use the POADSS, in particular if it is using any ships systems such as AIS. 
  • • Civil liability is mostly excluded for the maritime pilot, with the exemption of negligence or flagrant fault. With a normal proper functioning POADSS, the legal position of the pilot isn’t changed with respect to his position without the use of the POADSS. 
  • • The responsibility of the pilot is to use all sources of information available to safely conduct the vessel.
  • • VTS and other organisations are in principle responsible for the content of the data and liable if the content proves to be incorrect. It doesn’t make any difference whether this information comes via the ships sensors (ie VHF) or via the POADSS.

Survey Conclusion

Each pilotage organization had significantly different requirements for a PPU and consequently there is no single “fits all” solution. However, each pilot group had a good understanding of what are their specific requirements were and the overall requirements for PODSS were considered to be that it should:

•  
  • • Be developed for vessels whose dimensions reach the limits of a fairway;
  • • Supply three dimensional position information of the vessel.
  • • Should be capable of undertaking Dynamic Passage Planning (DPP) including prediction of Dynamic Under Keel Clearance and display of the actual UKC. 
  • • Monitor and assess the available position accuracy 
  • • By using the POADSS in conjunction with Dynamic Passage Plan the maximum draft could be considerably increased and tidal windows widened without compromising the safety of the vessel or the safety and efficiency of other traffic. 

POADSS can provide all of the aforementioned requirements and therefore the commercial benefits of POADSS to the shipping industry are potentially considerable.

POADSS Conclusions

1.  
   1. 1. The development and demonstration of the POADSS have been successful and the majority of the determined objectives have been met.
   2. 2. The assembly of the POADSS Instrument Unit requires more research to come to an optimum. Off the shelf units are currently not designed for a portable unit which makes them cumbersome as well to expensive.
   3. 3. The development of Fibre Optic Gyro’s and Micro Electronic Motion Sensors (MEMS) is advanced and it is expected that within the next five years MEMS will be available with the required accuracy, reliability, dimensions, weight and cost for use in the POADSS.
   4. 4. Currently positioning and calibrating the POADSS correctly onboard is complicated.
   5. 5. The development of the POASDSS has resulted in the maximum of applications, which can be included within a PPU.
   6. 6. Resulting from the above the installation of a permanent 3D GNSS/IMU on board should be considered.  However the cost/benefit of the installation needs to be clarified to the ship owner/operator. 
   7. 7. The use of Web Map Services in Lisbon was very successful. The presentation of additional data in the form of graphical layers on top of the ENC is considered as the most efficient way of presenting this kind of information.
   8. 8. The application of Dynamic Under Keel Clearance was also very positively received during the demonstration in Lisbon. The presentation of the computed DUKC ashore with the actual UKC simultaneously on the POADSS laptop is seen as a major step forward for navigating in shallow waters.
   9. 9. All the information/data exchange depends on a reliable wireless broadband link. In Lisbon a commercial broadband link was used which proved to be very good but not perfect. The coverage depends on the number of users and the capacity of the accessible relay stations. It is anticipated that Wimax (see page …)will be implemented in the next few years, but Harbour Authorities and pilots may need to come to special arrangements with the providers or a dedicated Wimax network can be installed. A satellite connection is considered as being too expensive for POADSS applications.
   10. 10. With the development of E-Navigation there is a good opportunity to integrate the POADSS into Integrated Bridge Systems and to install some components of the POADSS onboard. This could possibly result in a dedicated pilotage console within the integrated bridge layout. 

BY HUGUES CAUVIER (QUEBEC PILOT)

Where will she pivot? Photo: JCB

From the day that an officer commences his apprenticeship, the traditional introduction to ship handling instils the concept of a ship’s pivot point into the new recruit. Every navigating officer is therefore aware that a ship pivots around a point approximately 1/3 from the bow when going ahead and 1/4 from the stern when proceeding astern. This knowledge could be proudly revealed to the examiner during the “orals” examination when pushing the battered old wooden ships around books on the examiner’s table. Well, you can now forget those lessons because Canadian pilot Hugues Cauvier has studied the principles involved and the following feature seeks to explain how, in many circumstances, our traditional understanding of the pivot point is incorrect and that an equally important factor is the “Centre of Lateral Resistance” (COLR).

This concept is well illustrated by Hugues using delightfully simple demonstrations involving basic models in a paddling pool on a video stream at the following link

http://ohlinthermotech.com/pivotpoint/

Research centres such as Wallingford and Marin should be afraid!

JCB

PS This article can also be downloaded in pdf format at the following link:

http://www.cpslc.com/understanding_the_pivot_point.pdf

Introduction

The following text brings forward a new understanding of the pivot point’s position shift while handling ships. The proposed method, based on simple physical principles acting in combination, also outlines the limitation of the term “pivot” used to qualify that point. We will start from a basic rule of the thumb, which has been the traditional understanding of the pivot point until recently, and step up to more complex levels giving better explanation of the real-life behaviour of rotating ships.

The current approach highlights the effects that a side force applied on the ship has on the rotation and on the sideways motion of the ship. The author believes that understanding these effects at any stage of manoeuvring is more important than strictly dealing with the pivot point. The text is formatted so the reader can stop his study when he reaches a level that suits his needs or curiosity.

This article will also describe the phenomenon of the ship generated sideways current which effects have become obvious during practical trials made to deepen the understanding of the pivot point.

After the theoretical part, you will find a section covering real life shiphandling situations for some of which the traditional concept of the pivot point has no answer.

Definition: The pivot point (or more precisely the “apparent pivot point”) is that point along the fore and aft axis of a turning ship, that has no sideways movement, having for reference the surface of the water.

Level 1

The traditional theory: the pivot point is nearly at 1/3 ship’s length from the bow when the ship is moving ahead, and between ¼ ship’s length from the stern and the rudder post when going astern. The pivot point is considered to be the centre of leverage for forces acting on the ship.

Level 2

The pivot point is generally at 1/3 ship’s length from the bow when the ship is moving ahead, and between ¼ ship’s length from the stern and the rudder post when going astern. But if a powerful and effective lateral force is applied at one end of the vessel, the position of the pivot point will shift at about 1/3^rd ship’s length from the other end of the ship (relative to the applied force).

Example of an Azipod* driven ship moving astern

A ship fitted with Azipod propulsion is backing slowly from a finger pier (fig. 1). According to the traditional theory, when a third of the vessel is out of the corner, knowing the pivot point when going astern is also clear (fig. 2), the ship should not touch if a 90 degrees kick towards the dock side is given in order to swing the bow open towards the river. In real life, it does not happen since the lateral kick pushes the bigger part of the ship sideways (2/3 rd) having for effect a pivot point approximately 1/3^rd ship’s length from the bow (fig. 3)

*An Azipod driven ship was selected for this example since it can produce very effective side thrust without slowing the sternway. A very efficient tug pushing aft on a conventional ship would have a similar effect.

Level 3

As we have seen in Level 2 the P.P. is not always at 1/3 ship’s length from the bow when the ship is moving ahead, and between ¼ ship’s length from the stern and the rudder post when going astern. If that rule is not always applying, it is simply because it is not a rule.

Here is the major bug in the traditional P.P. theory: imagine that you are pushing laterally on a point very close to the “so called” pivot point, let’s say a little bit forward of it. If that point is really a “pivot”, the part of the vessel forward of the P.P. should move in the direction of the push, and the part of the ship behind the P.P. should swing in the opposite direction. This would be true if the P.P. was a fixed axis and the ship was rotating around it. It does not happen that way because a ship is a floating object that can also bodily drift sideways when submitted to an effective lateral force. When a force is acting close to the “P.P.”, it also pushes this point sideways – together with the ship – so the “pivot point” by this sudden lateral movement is then automatically losing the characteristic that gives it its name.

The position of the apparent pivot point is function of the efficient lateral force(s) applied on the ship. It is not caused by the headway or sternway.

Basic physics principle: sideways motion + rotation

Let’s suppose that you have a bar shape body floating on a friction free surface and you apply a lateral force on it at one end (fig 4). The resulting motion can be decomposed in two parts:

First, a moment of rotation about the centre of gravity (fig. 5). Secondly, a sideways bodily motion (fig. 6). These two results when combined will cause a change of position of the body as per fig. 7 after the force has been applied for a period of time.

We realize that the part of the bar that has not changed position in space, the “apparent pivot point” (fig. 7), is not located at the centre of gravity but some distance off it, away from the end on which a force is applied.

This basic principle applies to ships. It is the main reason why a ship turning has its P.P. at 1/3 ship’s length from the bow, since that ship is submitted to the lateral component of the rudder force. The combined effect of the lateral motion and rotation have for consequence a “P.P.” away from the acting lateral force.

That point that has no sideways movement, having for reference the surface of the water is the “Apparent Pivot Point”. It has no other importance physically speaking. The Apparent Pivot Point is not the centre of leverage of anything.

At port operation speed, the centre of leverage (point of the ship where an effective lateral force causes no rotation) is close to midship. A little more forward if the vessel is trimmed by the head, a little bit more aft if the vessel is trimmed by the stern (a little more means less than 10% ships length). This point is the Center of Lateral Resistance (see level 5.1)

Level 4

From this level on, we will add information that complete the basic principle of Level 3. In depth explanations will be given at Level 5.

- The closer to the centre of the ship (centre of lateral resistance) a force will be acting, the further away at the opposite end of the vessel the apparent pivot point will be. It can even lie outside the ship’s physical limits (see level 5.2).

- Little under keel clearance brings the apparent pivot point closer to the centre of the ship (see level 5.3)

- When a ship is turning, but has no longer forces acting on it, the position of the apparent pivot point follows the traditional pattern: approx. 1/3^rd ship’s length from the bow when the ship is moving ahead, and 1/3^rd ship’s length from the stern when going astern (see level 5.4).

- A bulkier, wider vessel has an apparent pivot point closer to the bow when moving ahead and turning (see level 5.3)

Level 5

This level explains in detail the rules given in level 3 and 4

5.1 Center of lateral resistance vs. apparent pivot point

Let’s make a clear distinction between : the center of lateral resistance and the apparent pivot point.

The center of lateral resistance (COLR):

At a given moment, the COLR of a vessel is that point where, if you apply an “effective” lateral force, no rotation (if the vessel has a steady heading) will occur. Acting on this point, a lateral force has no arm lever, therefore no turning moment, it only pushes the vessel sideways. A force acting ahead of the COLR will rotate the ship in a different direction than the same force acting astern of the COLR would do. The lateral resistance can also be called hydraulic lift.

The position of the COLR depends on:

- the centre of gravity

- the centre of the underwater surface area (hull shape and trim)

- the pressure fields around the hull

1) The starting point of the COLR is a point between the centre of gravity of the ship and the centre of underwater surface area, when these two do not coincide.

2) The position of the centre of the underwater surface for one ship is mainly affected by the trim. A trim by the stern moves the COLR point more aft. A trim by the head moves it more forward

3) The pressure field (bow wave, stern sub-pressure) under headway shifts the COLR forward. This is mainly due to the positive pressure built around the bow (in a forward motion) which creates a more resistant surface for the hull to lean on when pushed sideways. The same principle applies when going astern. For practical shiphandling purposes, the shift of the COLR due to the speed is rarely more than 10% of the ship’s length in the direction of the ship’s movement.

Fig 8

The COLR is the leaning point for arm levers. It is not! the apparent pivot point. Actually these two points almost never coincide.

The “apparent pivot point” (or the pivot point as the mariners know it) :

the point, along the fore and aft axis of the ship, that has no sideways movement, having for reference the surface of the water.

Position of the apparent pivot point:

The position of the apparent pivot point at a given moment depends on:

- the hull underwater resistance to lateral movement,

- the efficient lateral force(s) applied on the vessel and,

- the inertia of rotation of the vessel

In order to estimate the position of the apparent pivot point we must assess how a lateral force will affect:

- the rotation of the vessel

- the sideways movement of the vessel (see level 3: basic physics principle)

For an easier understanding of the following demonstrations, the shiphandler will imagine his vessel being free to move on a non-friction surface.

5.2 The position of the acting lateral force

A lateral force acting away (fig. 9) from the COLR will, for the same angle of rotation, push the COLR relatively less sideways than a force acting closer to the COLR. This results in an apparent pivot point further at the opposite end of the vessel (fig.10). The closer to the COLR the force is acting, the further away to the opposite end the apparent pivot point will be, this can even result in a pivot point outside of the vessel physical limits (fig. 112). This principle is very helpful when using tugs.

5.3 Lateral resistance

As we have seen earlier, the “lift” is the resistance of the water to any lateral movement of the vessel.

The hydraulic lift varies with:

- The shape of the hull: a more profiled (narrow) hull will induce relatively more lift. Let’s compare two ships with the same length, same draft, the first one having twice the beam of the second one. After the ships have developed sideways motion, it is harder to stop the drift of the wider ship (twice heavier) for approximately the same lateral resisting force (L x draught = surface area of the wall of water).

- The under keel clearance: little under keel clearance means more lift (the narrow space under the keel makes it difficult for the water to flow from one side of the ship to the other, so it is harder to push the ship sideways).

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A higher lift means a pivot point closer to the COLR

For the same change of angle, the COLR of a vessel with high lift will drift less sideways than a vessel with low lateral resistance when submitted to a lateral force. This results in an apparent pivot point closer to the COLR for a vessel with high lift than the vessel with low lift.

5.4 Motion of the ship after the lateral force(s) have been applied

The rotation effect

Let’s take again our solid bar free to move on an friction free surface. Let’s push it sideways with with some anti-clockwise rotation. Now stop the force acting on it and watch the resulting movement: The center of gravity is moving to the right and the bar rotates around it. The point that has no speed (having for reference the ice surface) is “P”, the apparent pivot point.

When a ship is being handled at low speed (when the pressure fields on the hull are actually very low), it is mainly due to the above effect that the “apparent pivot point” seems to move astern if the vessel is moving astern and turning, and ahead if the vessel is moving ahead and turning. The other factor affecting it is :

The ship generated sideways current

Level 6

The ship generated sideways current

Let’s consider a ship turning, and moving ahead. The “sweeping” movement of the stern creates a vacuum which in turn drags a mass of water towards the quarter shipside. The outer shipside also pushes a mass of water away. We will call it the ship generated sideways current . Let’s now stop the force creating the turning movement.

The ship, with its rotational inertia, keeps on turning, but the rate of turn will reduce due to water friction. The ship generated sideways current with its own inertia, will catch the stern and continue to push it sideways, while the forward part of the ship is in undisturbed water. This force, acting more or less sideways on the stern contributes in moving the apparent pivot point more forward.

The ship generated sideways current effect is relatively more important on a deeply laden vessel than on a wide light barge. On the latter, the rotation effect will be more noticeable. The result, however, is the same : an apparent pivot point located forward.

Note: The ship generated sideways current can have surprising effects when an efficient side force (strong tug, for example) is applied, at the shoulder on a ship with headway or at the quarter on a ship with sternway, for long periods. The ship can develop a swing in the opposite direction!

http://www.imsf.org/2001AGMPresentations/Genua_paper_1.doc

The similar effect is sometimes observed when leaving a berth with a stream coming from the stern having a tug moored on the quarter and pulling. If the tug is used for a prolonged period to open the stern towards the centre of the river, (with the engines of the ship astern) the forward part of the vessel will be more affected by the ship generated sideways current than the stern. This will cause the bow to go after a while in the same direction as the tug pull.

Kick ahead, hard over while having sternway

What happens after an engine turning astern, causing stern motion, is followed by bold ahead engine movement with rudder hard over. The turbulence around the rudder, caused by the opposite flows of the surrounding water (coming from aft) and the propeller thrust, reduces its efficiency. The ability of a conventional rudder to initiate rotation is then very poor. Most of the propeller thrust kills the sternway, only a little part of it actually pushes the stern sideways.

However, you can, with a powerful twin screw, an azipod or a high efficiency rudder, produce enough efficient lateral force to move the apparent pivot point ahead, as per first basic principle, even with the vessel still having stern way.

Bow thruster efficiency

The poor turning effect of the bow thruster when moving ahead and its good steering properties when moving astern are well known facts. A very interesting article on the efficiency of the bow thruster was published in a Nautical Institute book entitled “Pilotage”. In this article, Captain H. Hensen explains that when the ship starts moving ahead, the high speed stream of water expelled from the thruster bends along the hull (fig. 23). Its high velocity flow creates a low pressure area that “pulls” the bow in a direction opposite to the side we want to thrust it. The result is that the two forces tend to annihilate each other and the net thrust force is very weak.

The bow thruster is simply losing its efficiency as the ship moves forward. The loss of turning effect has therefore little to do with the change of arm lever distance between the thruster and the COLR.

When the vessel is moving astern (fig, 24), the vacuum effect created by the thruster is much less significant since the hull area over which it acts is quite smaller (area between the bow thruster opening and the stem).

Light ship (trimmed by the stern) vs. loaded ship (trimmed by the head)

A light ship is usually trimmed by the stern. Its COLR is relatively more aft than a loaded ship. This results in a shorter arm lever from the rudder to the COLR. At first glance this should lead to less steering efficiency. This short arm lever is overcome by the small inertia of rotation* of the light ship (less mass to control, therefore quicker reaction) for approximately the same steering power (same engine, same ruder, with maybe a little less efficiency if they are not completely water covered).

On loaded ships, the larger inertia of rotation (even if the rudder-COLR arm lever is longer) makes the ship

* For those not familiar with “inertia of rotation”, it is the tendency of a body to keep the same rate of turn if no force is applied on it (which also means to keep a steady course if it is initially steady).

slower to react. The following phenomenon can also complicate steering control, especially when some vessels are even keel or trimmed by the head. The more important underwater area ahead combined with over pressure around the bow of these ships bring the COLR well forward of amidships).

Let’s take the example of a vessel moving north and initiating a turn to starboard (fig. 25). Once the turn is started, the centre of gravity of the vessel has now a new direction, a bit to the left of the initial course, let’s suppose 350°. Because of inertia, the C. of G. wants to keep going that way (350°). Meanwhile the vessel itself has a different orientation, let’s say 030°. This means that relative to the new direction of the C. of G. (350°), the COLR, would be some distance d off to the right. That distance corresponds to an arm lever that can be high enough sometimes to accelerate the rate of turn even with the wheel in midship position. Steering such a ship is like trying to keep the arrow of a wind indicator tail in the wind.

Here is a familiar “land” example that illustrates this effect :

Push a loaded grocery caddie backwards. As soon as some external forces gives it a slight rotating movement, the rate of turn accelerates and the caddie turns completely around.

This happens because the centre of lateral resistance, is at the level of the rear fixed wheels. These fixed wheels prevent the rear part of the caddie from going in the same direction than the C. of G. of the caddie and cause the turning couple.

Steering a ship going astern with tug alongside

It is possible to steer a ship with a tug, even if positioned at approximately ¼ L from the stern where the traditional pivot point supposedly lies when a ship is moving astern. When the tug is pushing, you do not get a bodily movement as traditional theory suggests but a movement of the stern in the direction of the action of the tug. The arm lever is short. The COLR is lying a little aft of midship since the ship is going astern slowly. The rotation produced is small and the side movement important, the apparent pivot point is consequently somewhere between the bow and 1/3L from the bow.

Note : As seen before, if this pushing force is applied long enough for an important ship generated sideways current to appear, the rotation of the vessel may stop and even start in the opposite direction!

Azipods

Azipod driven vessels going astern and turning will best demonstrate the present theory (see level 2).

Their high side thrusting capacity will show a pivot point forward of amidship even if the vessel is going astern (especially at low speed). In fact I foresee the greatest usefulness of the present theory for those who handle azipod and Z-drive ships.

Deep draft container vessel vs. hovercraft

These two means of transportation seem to have very little in common. There is one thing though, that they do have in common: their respective behaviour when submitted to lateral forces can be explained by the present approach.

The hovercraft:

hovercrafts have by definition very little “lift”. They are also usually short vessels. Let’s say

that the air cushion vessel alters course progressively from 000° to 030° without overshooting. The steering flap, creating the lateral force, is relatively close to the COLR, this results in an important side movement for a given course alteration. The absence of lift resistance amplifies this relative sideways motion, the apparent pivot point is subsequently very far from the COLR (fig. 28), actually outside the vessel physical limits.

The container ship:

In the case of a deep draught container vessel in shallow water, the position of the “apparent pivot point is at the other end of the spectrum when compared to a hovercraft. As we have seen earlier, a profiled ship’s hull has more lift than a bulky one. This results in less sideways movement when turning and an “apparent pivot point” closer to the COLR. In addition, the small clearance under the keel makes it difficult for the water to flow from one side of the ship to the other, because of this effect, when the ship is turning, the sideways drift is again reduced. This causes the apparent pivot point to lie even closer to the COLR (fig 29).

Trivia question

Now a quick one to see if the lesson is well learned.

A vessel is drifting in a current, her fore and aft axis making 90 degrees with the direction of the current . The anchor is let go with sufficient slack. With five shackles in the water, the brake is screwed tight. The anchor dives in the mud, it holds. The ship starts to swing. Where is the pivot point? At the center of gravity? At the hawse pipe? 1/3L from the bow? 1/4L from the stern? Somewhere else?

Answer: The “apparent pivot” point is about 1/3 to ¼ L from the stern as explained in figs. 4 to 7. Let’s not forget that the apparent pivot point is relative to the sea surface surrounding the vessel. If you consider the movement of the ship over the ground, the pivoting point of the ship will of course be initially in the vicinity of the hawse pipe).

Appendix

Centre of Gravity vs. Centre of Underwater Surface Area

For a body in space where no friction is involved, the arm levers for forces causing rotation have for reference the centre of gravity of the body. For a ship in the water, this is basically true but the real “neutral” point of application for arm levers is also function of the resistance of the underwater surface.

Example: Let’s say we have an homogeneous floating object at rest having the following shape (fig. 30). The centre of gravity “G” and the Centre of underwater Surface “CS” are on the same vertical line. It is also the position of the COLR.

In fig. 31, we have added a large surface stern keel to our floating object. Let’s assume this added surface is very light and causes negligible change of position of the centre of gravity. It is quite easy to see that in fig. 30 if we apply a force acting on G, the floating object will move sideways and no rotation will be induced since there is no arm lever. On the other hand, if you apply the same force on G in fig. 31 there will be an unbalance of the water resistance between the areas forward of G and aft of G. The centre of underwater surface area “CS” being more aft in this case, the COLR (neutral point for arm levers) will actually be located between these two points: the centre of inertia G and the centre of water resistance CS.

Experiments on small scale models

The following experiments have been performed at the Ilawa shiphandling center in Poland in July 2005. These trials, made on a small scale bulk carrier loaded even keel, were recorded and printed by the centre’s high accuracy positioning system.

The goal of the experiment was to apply really effective side force on different points of the ship when she was making way through the water. For this we used a hand pulled towing line oriented at 90 degrees from the ship axis. By using a line, the results are not altered by hull/working force hydraulic interactions (as produced by tugs or bow thrusters).

- When the force is applied on the traditional pivot point (tests 2 and 4), the expected result (traditional theory) of a ship only moving bodily sideways since there is no arm lever, does not occur. There is a moment of rotation, therefore an arm lever. The apparent pivot point is also at the opposite end of the one where the force is applied. This demonstrates again clearly the weakness of traditional theory.

HUGUES CAUVIER: sohu@oricom.ca

In a departure from tradition in order to make attendance more attractive for delegates and their wives, it was decided at the 2006 Conference to move the date of the annual conference from November to May and to find a more central venue. UKMPA Section committee member and Tees pilot Peter Wylie is to be congratulated on finding the Crown Hotel at Harrogate and making all the necessary arrangements for what was a very well supported and successful conference. Having arrived at Harrogate on the eve of the conference the delegates naturally observed merchant navy tradition by merrily socialising and the Hotel catering staff also observed MN tradition by setting off the fire alarms at 0545 the following morning.

Needless to say, your normally fine and dapper representatives were looking decidedly the worse for wear as they shuffled outside to the muster point in the car park!! Of course, as professional seafarers, once fortified by breakfast they were all fully alert and attentive for the conference proceedings. The following is a brief outline of the agenda items discussed. The full minutes are available for members on the UKMPA website.

PROCEEDINGS

PILOTS’ NATIONAL PENSION FUND (PNPF):

Secretariat report: Debbie Marten

Debbie’s report is on page13?

Trustee report: Richard Williamson: (Boston pilot & Chairman of the pilot Trustees)

Richard provided delegates with an overview of the fund and provided detail on the following topics:

Trustees:

Secretariat:

Managers and Advisors:

Meetings:

Membership:

The contributions paid to the Fund

Investments and Strategy:

Triennial Valuation:

The fund is currently undergoing the triennial valuation and Richard explained in detail the new requirements that had replaced the previous Minimum Funding Requirement (MFR).

Legal Issues:

Regarding the responsibilities the existing non pilot members of the fund and their responsibility towards the fund the Trustees had reluctantly had to seek legal advice about who could potentially be made responsible for any deficit and the matter was now the subject of a court case.

During the subsequent Q&A session Richard answered questions regarding the fund and the pending court case.

Richard explained that the case was being brought solely to establish whether or not a liability existed. If, as anticipated, such liabilities were found to exist the specific liabilities of each party would subsequently be analysed and set. In the case of Trust Ports the port’s trustees were unable to commit to payments unless required to do so by a court order. It was even possible that the Government may be liable in that it was the 1987 Act which had caused the problems in the first place. Because this case was unique, any outcome was impossible to predict but the hope was that it would result in a clear allocation of liabilities and that the pensions regulator would then ensure that those liable would honour their commitments .

MAIN CONFERENCE SESSION

CHAIRMAN’S REPORT: Joe Wilson (Tees)

Following one minute’s silence in remembrance of those pilots worldwide who had been killed in service since the last conference, Joe updated the delegates on the latest issues affecting the Association and the key points are in Joe’s report on page 12?

FINANCIAL REPORT: John Pretswell (Forth)

John referred delegates to the financial statements included in the delegates’ papers which are available to members. Membership now stood at 492 pilots from 46 districts.

RULE CHANGES: John Pretswell.

John explained the reason behind the proposed rule changes to rules 4d, 10h, 14c, 15 & 18 which had been previously circulated to the delegates. All the changes were approved unanimously by the delegates.

ELECTION OF OFFICIALS

John oversaw the election / re-election of the Section Committee members and their deputies. The list of SC members is on page 18.

MARITIME & COASTGUARD AGENCY (MCA) Peter Wylie (Tees)

Peter explained that he held the MCA brief for the Association and this involved being on 5 committees.

• UK Safety of Navigation (UKSON)
• VTS (with Jon Stafford {London}).
• National Occupational Standards (NOS) (With Brian Wilson, Belfast) is frustrating in that the process has been stalled for several years, mainly as a result of the Ports’ concerns regarding costs. However, the DfT want it, the MCA want it and so the ports are reluctantly having to accept the concept.
• Port Marine Safety Code (PMSC) steering group: Involved in rewriting the Formal Risk Assessment (FRA) for the Guide to Good Practice (With John Harrison-Nayes, Medway) This is a new Working Group and the MCA had specifically invited UKMPA input. The MCA had drawn up a consultation document and the only two responses were from Peter & John! Such outcomes serve to enhance the reputation of the UKMPA within the MCA & DfT. The ports now have to have comprehensive FRA procedures in place. Another development to emerge from the PMSC steering group is that pilots can send MAIB reports back if they believe that the content is inaccurate.
• PEC’s: It had been agreed (reluctantly by some!) that PEC holders should have a level of competency equivalent to that of a pilot for the same ship especially when working with tugs etc. The result of the work of this sub committee had been M307. The DfT had agreed that PEC’s should only be issued following an assessment by a pilot.

During the subsequent Q&A session the issue of PEC abuse was raised and Peter stated that if the details were passed on to him he would raise the matter directly with the MCA / DfT.

TECHNICAL & TRAINING Gareth Ress (Southampton)

Gareth announced that he would be standing down in November after 4 years as chairman and that Brian Wilson (Belfast) would be taking over the chair. He then provided details of the Committee’s work since the last conference. T&TC had been involved in:

E-navigation: The T&TC continued to monitor events and releases.

Pilot Boarding and Landing Code: After much delay this had now been ratified and published.

SOLAS: was currently looking at the securing of platforms on combination ladders to the ship’s side but no recommendations were expected in the near future.

RNLI : John Nurser (Head of RNLI technical dept) was a regular attendee at the T&T meetings and his expertise on small craft and their fittings was of great value to the committee.

Deep Sea Pilots: Roger Francis had put in valuable hard work on UKSON, VTS, wind farms and the Vessel Monitoring Directive.

Azipilot Project:

Gareth explained that this was an EU funded project being run by Newcastle University to train mariners in the use of marine Azimuthing Control Devices. Other partners in the project were several European shipping companies, nautical colleges and maritime research bodies. Gareth has been joined by Ian Simpson (Harwich) on the project but delegates were requested to notify Gareth or Ian of any others who may wish to participate in any way. Gareth’s Working Group will be involved in establishing current usage, training, on-board operational procedures and the examination of incident reports.

Q&A

There followed a discussion from the floor on azimuth propulsion with several districts handling cruise liners considering it unsatisfactory that manoeuvring was entirely dependent on the Master. Harwich pilots had been on a simulator course which had provided some insight into the manoeuvring techniques involved. In Aberdeen they had been handling vessels fitted with azi-propulsion for nearly 30 years and had developed their own simulators which were frequently used by shipping companies. In their experience, the training given to Masters was not always good and sometimes non existent. Another aspect of azi propulsion was that with the lifespan of bearings limited to a few years it was also essential for pilots to be able to handle failure situations.

NATIONAL OCCUPATIONAL STANDARDS Brian Wilson(Belfast).

Brian expressed frustration at the fact that after 8 years nothing was progressing. The initiative had started with BPIT but following the agenda being handed to the Ports the situation had totally stalled and it was evident that the ports’ just weren’t interested in adopting pilotage standards. Brian suggested that one way forward was for the UKMPA to take over responsibility for the training and authorisation of pilots by means of a form of pilotage commission based on the Dutch model but he urged members to engage in constructive thought as to the best way forward. During the subsequent discussion it was agreed that the principles behind the idea were sound and it was suggested that the UKMPA drafted a !position paper2 to submit to the Government for consideration in the Marine Bill.

MARNIS Nigel Allen (Southampton)

Nigel provided delegates with a brief introduction to the MARNIS project, which is a 20million Euro EU project started in 2004 and now nearing completion

The key area for pilots is the Port Operations and Decision Support System (POADSS) portable pilotage unit. The Cosco Busan allison in the USA had led to calls for such units to be made mandatory and this was likely to accelerate the agenda in Europe.

Nigel provided details of the different units offered by the various manufacturers and informed delegates that the latest units contained more advanced features than a few years ago. The cost, size and weight of units had come down .

With respect to the actual MARNIS project Nigel explained the work packages that he was involved in and in his opinion the technology was now reaching the point where a pilot with a laptop could download all the information currently provided by shore VTS directly to a pilot’s laptop and the port’s VTS system would become a data processing centre (silent VTS).

POADSS had already made amazing advances and the latest version incorporated the following new features:

• Dynamic Under Keel Clearance (DUKC)
• Web Mapping Services (WMS).
• Dynamic Path Prediction. (DPP)

The official “live” demonstration of POADSS will take place in Lisbon on 16^th October. Other MARNIS elements will also be demonstrated around that time.

Nigel concluded the presentation by explaining that the key function of MARNIS was to explore concepts that would integrate the on-board needs with those of shore authorities of the member states.

EMPA Dave Williamson (Liverpool)

Dave had attended the EMPA conference and delegates had been concerned by one speaker from the European Community Ship owners Association (ECSA) who stated that.

• ECSA doesn’t accept the validity of the rejection of Ports Packages 1 & 2
• ECSA doesn’t agree that pilotage represents a safety service
• ECSA considers pilotage to be a monopoly abuse of competition
• ECSA considers Pilotage should only be compulsory after an open risk assessment
• ECSA favours an increased use of PEC’s

Safety Campaign

This had been a joint IMPA, EMPA & UKMPA survey and had received a good response. The replies indicate that around 19% of vessels are non compliant and this can be considered a conservative assessment of the true situation. The concern is that this figure has not improved since the first survey undertaken in 1994. This figure will be brought to the attention of the Commissioners and the European Maritime Safety Agency (EMSA) and other relevant stakeholders.

Competition

This is still a major problem in Denmark, Finland and the Baltic Sea

Technical & Training

Dave provided details of the following areas which the EMPA T&T had been involved with:

• Unmanned Port Traffic Communication System (UnPorTraCS). The unmanned isn’t ashore in the VTS but on board the ship! Basically a new term for shore based pilotage. So far this project hasn’t been supported by EU funding but again EMPA are monitoring the proposals.
• The Azipilot project
• High minimum speed of vessels. Reports have been received of a new containership with a Dead Slow Ahead speed of 12 kts.
• Mooring of large vessels.
• Safe manning and equipment of pilot cutters.
• Motorways of the Sea (MOSES) This is a cross sector transport initiative looking at streamlining transport and removing bottlenecks in the system. For shipping the most serious bottleneck is considered to be the need to slow down to pick up a pilot!

Representation

EMPA is a very effective and respected body with representation on a wide range of maritime related bodies and working groups (including ECSA). Following on from the NOS and ECTS, EMPA are currently producing protocols based on the International Standard for pilotage Organisations (ISPO). These are basically ISO standards for pilots and pilotage and although Dave expressed some concerns they are generally positive for pilots, especially the self employed districts. Full details are available on the EMPA website.

IMPA Don Cockrill (London)

Don had attended the IMPA conference in Cuba with John Pearn. He had stood for election as a Vice President but his application had been defeated. He would be standing again in Bangkok this year and hoped to be elected this time round.

The UK bid to host the 2012 IMPA conference had been successful and plans were already underway. The venue will be the Gorman hotel adjacent to Tower Bridge and although the organisation will be handled by a professional company delegates were invited to participate in the planning and organisation of what promised to be a very prestigious event.

Permanent International Association of Navigation Congresses (PIANC).

Don sat on this body as pilot representative and provided the practical mariner’s input.

E-Navigation

Although the initial flurry of activity regarding e-navigation had calmed down, IALA were deeply involved in promoting the e-nav agenda through IMO and IMPA had a pilot representative on the e-nav committee.

In addition to his IMPA role, Don participated in other UKMPA activities and one new area was assisting Joe Wilson in participating in MAIB investigations. This involvement was not as a UKMPA member but more as an expert providing a pilot’s eye view of an incident but it is an additional and important element in enhancing the professional reputation of the UKMPA. In a similar manner, Don also assists Joe in participating in CHIRP investigations.

INSURANCE Simon Campbell (Forth)

Simon is working with Drew Smith and Circle Insurance to enable pilots to renew policies on line and download their relevant receipts and documentation. The policies had been successful in achieving payouts to pilots in several cases. One case is of particular interest to those who have previously questioned the need for independent insurance since it involved a payout for loss of earnings to an employed pilot who had been de-authorised by his CHA. (see Insurance article on page 17)

SURVEY OF DISTRICTS John Pearn (Milford Haven)

John explained that because all UK ports operated independently the UKMPA needed to collate an overview for each district. 37 replies had been received from 46 districts and this had provided a valuable National overview. Full details of the survey are available for members on the UKMPA website.

HUMBER Barrie Youde Barrister, ex Liverpool pilot)

Barrie Youde’s statement appears on page 7

The HPL members had requested that Barrie pass on their gratitude to all those from the UKMPA who had generously contributed towards the case and Chairman Joe Wilson, paid tribute to Barrie for his tireless dedication in supporting the HPL members which had resulted in such a positive outcome. This was acknowledged by warm applause from the delegates.

WEBSITE

Due to the difficulties involved in maintaining communications through the UNITE office in London Joe was keen to make the website the communication focal point of the Association. He acknowledged that there were problems with the existing site and requests feedback from the districts as to ideas and layout.

FUTURE CONFERENCES

Joe Wilson expressed satisfaction at the number of delegates attending which tended to confirm that the decision to hold the conference at Harrogate had been correct. He proposed that rather than have an Interim Delegates Meeting in 6 months time that there should be a one day conference on the HQS Wellington in May 2009 (Date to be confirmed) with a possible return to Harrogate for a full 2 day conference in 2010.

DAY 2: GUEST SPEAKERS

Following introducing the guest speakers for the day, Joe invited Michael Grey to open the conference..

OPENING SPEECH Michael Grey (Lloyd’s List)

Michael Grey provided the delegates with a very lively and interesting speech which revealed a full depth of knowledge regarding pilotage issues. Michael expressed particular concern regarding the “blame culture” whereby the zero tolerance of any maritime incident was leaving pilots increasingly exposed as an individual upon which all the blame could be piled, even though the incident may have resulted from events outside his control. He concluded by advising pilots that they should use the maritime press to challenge uninformed opinions and that they should also be pro-active in promoting their work by inviting representatives from the various maritime sectors to join them on a trip. “Awareness is a powerful antidote to ignorance”.

The speech was acknowledged by warm applause from the delegates.

(A subsequent article by Michael, based on this presentation. Was published in Lloyd’s List and is available on the pilotmag website)

MAIB Stephen Meyer (Chief Executive MAIB)

Stephen opened his presentation by explaining the role of the MAIB and how it functions.

The sole remit of the MAIB representative is “future safety”. The MAIB have greater powers than the police but this power has only been granted on the understanding that none of the information obtained can be released to any other party or used in any form of court case.

The MAIB is totally opposed to prosecutions of anyone involved in a maritime incident because the “blame culture” results in everybody covering up the causes and remaining silent on legal advice. It should be acknowledged that accidents do happen but there should be sufficient checks and balances to ensure that one mistake doesn’t become a disaster.

Addressing the concern raised in the editorial of the January issue of The Pilot regarding the use of MAIB reports in court proceedings, Stephen explained that whilst the reports inevitably would provide investigators with an indication of where to focus their enquiries, it was up to those bodies to gather the necessary evidence to apportion blame or prosecute. Generally, what is revealed by the MAIB in their report is readily available to others and great care is taken to protect individual anonymity.

There had been a case where a company had commenced disciplinary action on the basis of information contained within a report and the MAIB took immediate action to stop the proceedings which were subsequently dropped.

Another key issue is creating internationally agreed standards for investigations and Stephen has been active in tabling a resolution through IMO to introduce a “Code” on accident investigations that will make it mandatory for all flag states to undertake a thorough investigation, independent of any of those being undertaken by those with vested interests. Stephen has also been active in Europe and a new directive is being drafted for member states to undertake investigations based on the MAIB model.

The MAIB investigate all accidents to UK flagged vessels and any accident occurring in UK waters. In contrast to traditional investigations which assume that the “system” is right and that the “man on the spot” is at fault, the MAIB take a detached view and although the final cause may result from the man on the spot, the fault may lie in the system which may leave the individual unsupported. Pilots are particularly prone to being in this category.

Current areas of concern involve the trend by cruise companies to voyage to remote parts of the world such as the Antarctic and the on-going issues of fatigue, manning and competence, especially on the short sea trade sector. The fishing industry continues to have an unacceptably high casualty rate and the unregulated leisure industry also gives cause for concern.

As for pilotage it is obvious that pilots work in the highest risk element of a vessel’s voyage but as an outsider it is very difficult for a pilot to integrate into a vessel’s “bridge team” however simple or comprehensive that team may be. Regrettably some pilots are reluctant to integrate, display complacency and don’t communicate their intentions, especially with regard to potential risks. Every MAIB investigation into pilotage incidents reveals some element of complacency on behalf of the pilot and Stephen provided some graphic examples from recent incidents to illustrate this point.

The most important aspect of pilotage was a comprehensive master / pilot exchange being undertaken.

In conclusion, Stephen emphasised that pilots must operate to high standards, they should be demanding similar high standards from the bridge team and Stephen considered it the role of the MAIB to ensure that CHA’s recognised their own responsibilities towards ensuring high pilot standards and that they also fully supported the pilots in their difficult role.

Q&A

PEC monitoring?

The MAIB considered it essential that a PEC holder should be assessed for his ship handling expertise and also that the PEC should be ship specific and that the practice of permitting a PEC to be used on multiple ships should be discontinued.

Commercial pressures placed on pilots by CHA’s to handle ships in marginal conditions?

Pilots were rightly involved in undertaking “dynamic” risk assessments which, unlike the air industry, were not easily quantified. There was evidence to indicate that pilots were boarding ships and under pressure to accept riskier situations than they would normally consider acceptable and the MAIB were working towards creating an understanding within the Industry that poor standards are unacceptable. Stephen acknowledged that it would be a slow process.

What powers does the MAIB have to follow up recommendations and ensure enforcement?

The MAIB has no powers of enforcement of recommendations but a recent amendment to the regulations mean that the MAIB can now contact those affected by a recommendation and request information as to how they intend to address them. These contacts and the response are sent to the Secretary of State once per year and are publically available. This has proven to be very successful in ensuring that recommendations are acted upon.

The respondents also have a legal obligation to inform the MAIB if there are subsequently any changes to the written responses but the MAIB doesn’t have the resources to physically check that the recommendations have been acted upon.

In the Prospero (pod propulsion failure) incident in a compulsory pilotage district why did the MAIB consider that the Master rather than the pilot should have been manoeuvring the vessel?

In the opinion of the MAIB it was considered impossible for pilots to be fully conversant with the manoeuvring characteristics of every vessel and therefore in some instances there should be teamwork with the pilot directing the manoeuvre and the Master using the controls to achieve the desired result.

Concern was expressed that the “sharing” of the manoeuvre could result in the pilot not being fully in control at a critical time and the PMSC stated that a CHA should ensure that pilots were trained to be qualified to conduct the vessels to which they may be allocated?

Stephen felt that in the case of specialist vessels, in view of the wide variety of different equipment in use, the term “conduct” needed a realistic interpretation and in his opinion, if the bridge team was experienced and competent in manoeuvring the specialist ships then the pilot needn’t necessarily (and probably couldn’t) be trained to handle them. The pilot should be supported by professional standards on board the ship and the MAIB considered it their role to ensure that onboard standards were raised to ensure such support.

DfT: James Weeden (Ports Division) & Geoff Stokes (Port Liaison Policy Leader:MCA)

James provided an overview of general ports policy and explained that the role of the Government was set the regulatory framework with particular emphasis on the environment and safety and how this had led to the draft Marine Bill to introduce supportive legislation for the PMSC on the following port safety measures:

• General directions to be available to every HA
• Power for the Secretary of State (SoS).to issue directions to a HA to underpin the PMSC.
• Power to remove CHA status from a port that no longer operates commercially should the port request it.
• PEC management to underpin the PMSC and M307 guidelines.
• Power to remove a PEC
• Make it an offence to fraudulently use a PEC
• Extend the officer grading from Master and 1^st mate to enable other officers to obtain PEC
• National Occupational Standards to become mandatory .
• Closure of Harbours.

James concluded his presentation by detailing the consultation process and encouraged delegates to submit responses as key stakeholders.

Q&A

Deep concern was expressed that the PEC proposal to reduce the qualifications from the “bona Fide” Master and First Mate was effectively opening the PEC system to abuse whereby a company could obtain PEC’s for its officers who could then move from ship to ship and effectively provide a competitive pilotage service.

James reassured delegates that there was certainly no intention within the Bill to alter the existing pilotage and PEC regime and that the advantage of producing a “draft” Bill with a 12 week statutory consultation period was that potential anomalies such as the wording of the clause identified by the UKMPA could be addressed and he offered an invitation to the UKMPA to explain their concerns in detail to the DfT team drafting the Bill.

What would happen to the consultation submissions if the Bill was not introduced?

They would be examined in detail and any important factors would be incorporated into the PMSC as an interim measure.

In response to specific concern from delegates over the planned removal of the term “bona fide” in the draft Bill, Geoff Stokes agreed that his personal opinion was that it was not just important that the officer was a bona fide member of the ship’s crew but it was also essential that he should be competent in handling the vessel and that the PEC should therefore be ship specific.

Would the National Occupational Standards be implemented by 2010 as agreed?

James replied that had the Bill been given parliamentary time in the current programme then NOS would have been incorporated by the 2010 deadline but if the Bill was delayed then it was unlikely. However, Geoff emphasised that both the DfT and the MCA were both wanting to progress the NOS implementation.

Joe Wilson concluded this session by thanking James and Geoff for providing the delegates with the clarifications on the important topics and welcomed and accepted the invitation to meet with the DfT to discuss the issues in detail with the relevant officials.

MCA Geoff Stokes (Port Liaison Policy Leader)

Geoff explained the different roles of the MCA and DfT. The DfT devise the policy and the MCA deal with the operational aspect.

As a ex pilot (Dover) Geoff regretted that it takes a serious incident to trigger any change in the maritime world and acknowledged that despite 12 years having passed since the event that triggered the creation of the PMSC it had still not been implemented by all ports. However, despite being voluntary it was now being followed by the majority of ports. The PMSG steering group, which consisted of representatives from the Department, MCA, ports, ship owners and pilots, met twice per year to discuss progress and with respect to the PEC issue this group had produced MN 307 which establishes the procedures and guidelines for PEC’s. In Geoff’s opinion, within a compulsory pilotage district the conduct of the vessel with a PEC should be indistinguishable from one with an authorised pilot on board.

Currently the outstanding items within the PMSC are NOS and the Formal Risk Assessments.

Geoff provided details of other work undertaken by the MCA in support of the PMSC such as verification visits and compliance exercises. Geoff emphasised the importance of the Duty Holder who, if any person is concerned over any matter regarding PMSC compliance, is the person who must be notified if all other avenues have failed prior to contacting the MCA.

With respect to NOS, the MCA fully understood the pilots’ frustration with the lack of progress and were keen to see a pilot qualification introduced as soon as possible.

In response to further concerns over the lack of progress on NOS, James Weeden agreed to raise these issues at a forthcoming meeting with the ports.

Geoff Stokes believed that progress would have to be made because NOS was included in the Bill, the SoS had accepted that standards were essential and most importantly, the MAIB had referred to the Standards in recent reports. The pressure on the ports was therefore at a point where they could no longer afford to delay.

Joe Wilson closed this session by again thanking Geoff & James for their comprehensive responses but requested that Geoff and James advised their department heads that the pilots wanted the standards and that it was the Government’s responsibility to put an end to the 8 years of delay.

P&I CLUBS Andy Kirkham (International Group of P&I Clubs)

Andy opened his presentation by explaining that the International Group was a growing consortium of P&I Clubs and that he worked for the North of England Club. The 13 Clubs which formed the IG now covered nearly 10% of the World’s tonnage.

In detailing the P&I Club structuring Andy referred delegates to the website www.igpandi.org. The group shares information and where there is a particular field of interest to ship owners they set up sub committees. One such group is the Pilotage Sub Committee which looks at “pilot error” claims and with respect to this the IMO resolution A960 and the MPEX document were very important.

In providing an an example that had been classed as “pilot error” where damage had been caused by the engine being put the wrong way during a manoeuvre, delegates intervened to express their opinion that the example chosen was in fact a ship’s error since the pilot had given the correct engine order.

Andy responded that in the opinion of the P&I Clubs, when a pilot arrived on the bridge he became a temporary member of the bridge team and therefore if there was an error made by the bridge team, because the pilot had the conduct of the vessel the P&I Clubs preferred to class the incident as “pilot error” in preference to some long winded grouping such as “pilot as part of the bridge team error”. This remark generated some dissent from the delegates.

Andy then provided some statistics which revealed that the number of claims was falling but the concern was that the costs of each claim were escalating.

The P&I Clubs had welcomed the IMO resolution A960 and IMPA had been very helpful in providing the Clubs with feedback from around the World from pilotage organisations regarding compliance with A960. Andy also emphasised the importance of a formal Master / Pilot exchange and passage planning. P&I Clubs accept that the ship cannot produce a comprehensive berth to berth plan but there should be a basic appreciation of the intended passage by the ship’s bridge team as per the A960 definition.

In the subsequent discussion, the P&I club’s use of the term “pilot error” caused considerable debate. Andy acknowledged that there was a problem with the term and that they were now working with EMPA & IMPA when examining certain cases. Joe Wilson offered the service of the UKMPA Section Committee to provide pilotage input into the claims process and Andy agreed to progress this within the IG.

Other issues discussed were manning and competence and Andy stated that there was a growing pressure to ensure “safe” manning rather than the “minimum” manning parameters which currently provided a commercial advantage to the sub standard end of the industry and penalised the high quality operators.

In conclusion all were agreed that this had been a most constructive session and that closer, regular contact between the P&I Clubs and pilots would be beneficial to both bodies. Joe emphasised his appreciation of Andy attending the conference and being prepared to “put his head above the parapet”.

LEGAL LIABILITIES: Kevin Austen (Barlow, Clyde & Gilbert)

Kevin opened his presentation by displaying some of the negative and sensational press coverage that accompanied any maritime incident.

There was a general but incorrect viewpoint in the Industry that pilots couldn’t be held liable for anything. However, what the ship owner was really interested in was minimising losses and generally their concern was over the fact that CHA’s could limit or absolve themselves from any liability.

Pilots could be held personally liable under civil and criminal law and the real risk to a UK pilot was to be involved in a civil case where he may be subjected to a disciplinary hearing by his CHA and in this case his authorisation may be at risk and this would probably be more punitive than any penalty imposed through a court!

A very important fact regarding liability is that a pilot is only legally a pilot if he actually has the conduct of the vessel. If a Captain takes over to manoeuvre the ship then the pilot wouldn’t be liable in the case of an incident.

Kevin clarified aspects of Limitation of Liability and the difference between “command” and “conduct”..

Turning to criminal law, a pilot could be prosecuted for such offences as manslaughter and pollution. Pilots could also be found criminally liable under the Merchant Shipping Act and an example of this might be criminal proceedings resulting from excessive speed.

Kevin then clarified a few general legal aspects of pilotage such as the decision whether or not to proceed. In fog, case law had ruled that the decision was solely down to the pilot.

Another important aspect was the observance of the collision regulations. Courts always considered these and took a dim view of actions that contravened the COLREGS or bye-laws. Sound signals and keeping a look out became important and arrangements such as “green to green” passing were frowned upon even though they may be common, accepted practice.

If a serious incident occurred then public opinion required an individual to be identified as responsible and self employed pilots could be affected by the new Corporate Manslaughter Act however, Kevin mentioned that no pilot had been successfully prosecuted for a criminal act since the early 19^th century but the “Cosco Busan” case in the USA did look as if it may set a precedent and pilots should be aware that important legal events in the USA inevitably became incorporated into English Law.

Q&A

Should a pilot report to the VTS if the Master has taken over the handling of the ship?

YES! Such a record could be vital should something go wrong.

Would Kevin consider that for employed pilots the CHA’s own cover was adequate and that the separate insurance taken out through the UKMPA was unnecessary?

Kevin was unaware of the cover provided by the UKMPA insurance but was of the opinion that such cover was advisable. Chairman Joe Wilson, made the point that in a case currently being made against a pilot on the Clyde, the UKMPA insurance was essential because the CHA was making a case against the pilot.

]]> http://www.pilotmag.co.uk/2008/09/06/119th-ukmpa-conference/feed/ 0 http://www.pilotmag.co.uk/2008/07/01/squat-part-2-mud-navigation-negative-under-keel-clearance/ http://www.pilotmag.co.uk/2008/07/01/squat-part-2-mud-navigation-negative-under-keel-clearance/#comments Tue, 01 Jul 2008 20:52:02 +0000 JCB http://test.pilotmag.co.uk/?p=207 Whilst wading through the various documents to produce the article on squat in the January issue, I came across several references to the linked topic of muddy water navigation and the concept of negative under keel clearance (UKC).

I must admit that until I read the research I had no understanding of this form of navigation and felt that it must be another theoretical area of research with no feasible practical application because we have enough trouble presenting masters with passage plans using minimum UKC and would therefore have no chance trying to explain to a stressed out Captain that the passage plan would involve navigating through areas where the draft would be greater than the charted depth!! However, there are several ports where the liquid mud in suspension is sufficiently fluid to be navigable and the difference between the echo sounder depth and the solid mud depth can be considerable and therefore the commercial advantage of accurately measuring the navigable mud layer can be considerable. The depth where the navigable mud becomes non navigable is called the “Nautical Bottom”. One major port where this phenomena is present is Zeebrugge and it is therefore in Belgium where most research has been undertaken. As with squat, the maths and physics are complex and the following is therefore an attempt to de-mystify the concept.

Navigable mud can open the operational window for port operations. Photo JCB

To asses the navigability in muddy navigation areas the “nautical bottom” concept was introduced and in 1997 the Permanent International Association of Navigation Congresses (PIANC) formalised the following definition:

The nautical bottom is the level where physical characteristics of the bottom reach a critical limit beyond which contact with a ship’s keel causes either damage or unacceptable effects on controllability and manoeuvrability.

This definition is somewhat vague in that there are so many different ship types that what may be a critical limit for a laden bulk carrier might have no adverse effect on a fine lined containership. Fortunately the researchers have examined different ship types in detail and have concluded that the important factor is the density of the mud in suspension and have established that a density of 1200kg / m3 can safely be navigated by all vessels. However, although the nautical bottom can be established by density its effectiveness as a safe critical parameter is dependent upon the ability to continuously monitor the density of a mud layer and detailed knowledge of ship behaviour in muddy areas. This has been undertaken by, physical tank testing, mathematical modelling and by live trials mainly involving the pilots in Zeebrugge. The following information contains extracts from papers published on the internet by many different establishments but in particular:

Marc Vantorre: Ghent University, IR04 – Division of Maritime Technology

Michael J. Briggs: Coastal and Hydraulics Laboratory, U.S. Army Engineer Research and Development Center

Klemens Uliczka: Federal Waterways Engineering and Research Institute, Hamburg

Pierre Debaillon : Centre d’Etudes Techniques Maritimes Et Fluviales,

DEFINITION OF DEPTHS IN MUDDY AREAS

HYDRODYNAMIC DEPTH:

The exact level of the interface between moving muddy water and stationary mud.

PARAMETRIC DEPTH

The bed level determined by some material parameters e.g. target strength, shear strength etc.

OPERATIONAL DEPTH

The depth of a particular parameter relevant to some specific operation e.g. navigation.

In areas where the mud bed is firm these 3 definitions will coincide.

COMPARISON OF NORMAL SOUNDING DEPTH AND NAUTICAL BOTTOM

As an example of the difference that using the nautical bottom as opposed to normal sounding bottom can make, the following diagram shows real data from surveys on the EMS using different sounding frequencies, with the 210 khz being the standard for sea water and the 15khz to penetrate through to the 1200 interface. The results reveal an additional navigable depth of over two metres in places.

Muddy Navigation Areas

The presence of a fluid mud layer on the bottom of a channel has a significant influence on ship behaviour in general, and sinkage and trim in particular. Two effects play a dominant role:

• The pressure field around the moving hull causes undulations of the water mud interface that modify the distribution of vertical forces over the length of the ship and, therefore, sinkage and trim.

• If the ship’s keel penetrates into the mud layer, the hydrostatic (buoyancy) force acting on the submerged hull increases due to the higher density of the mud.

The interface deformation is a function of many parameters, such as ship speed, layer thickness, mud density and rheology, and the initial UKC with respect to the mud-water interface.

Contact between the ship’s keel and the mud layer depends mainly on the UKC, but is also influenced by the interface undulations and the ship’s sinkage. As a result, both effects are interrelated. Most of the information available on this subject is based on experimental research using models.

Experimental research

One of the major problems for reseach into mud layer navigation is producing an accurate model for the mud behaviour. Mud behaves in a complex manner and its characteristics vary with the depth. The model tests that have been carried out mostly use an artificial mud layer because it is difficult or even impossible to repeat several tests under the same natural mud conditions.

Additional problems with model tests are the scaling effects of the simulated mud with respect to the model and consequently for the port of Zeebrugge a new research program was initiated, consisting of captive manoeuvring tests in Flanders Hydraulics Research shallow water tank and both fast- and real-time simulation runs. The mud layer was simulated by means of a mixture of chlorinated paraffins and petroleum. Most runs were carried out with a model of a 6000 TEU container as this one was the standard type of vessel for the harbour of Zeebrugge at that time. Mud layer thicknesses were varied from 0.75m to 3.00m and under keel clearances referred to the water-mud interface from -12.2% till +21% of draught.

Mud-water Interface Undulations

A ship navigating above fluid mud layers will cause vertical interface motions

(internal waves and undulations) that are influenced by the ship’s forward speed as revealed in the following diagram:

Model tests showing conditions b) & c)

a) At very low speed the interface remains practically undisturbed.

b) At intermediate speed an interface sinkage is observed under the ship’s bow if the fluid mud layer is relatively thick. At a certain time, an internal hydraulic jump, perpendicular to the ship’s longitudinal axis, is observed. The front of this internal jump moves aft with increasing speed.

c) At higher speeds, the internal or interface jump occurs behind the stern

The sinkage for a ship sailing in a muddy bottom condition is decreased relative to the condition in which the mud layer is replaced by a solid bottom. This is because the ship can “feel” the hard bottom more than the softer, less dense, mud layer. If the mud layer is replaced by water (normal conditions without a mud layer) however, the sinkage would decrease relative to the condition with the mud layer. However, this does not take into account the effect of extra buoyancy (i.e., mud is denser than water), but this is only important in very dense mud layers and/or important penetration. In general, the influence on trim is more important than sinkage since the mud layer causes the ship to be dynamically trimmed by the stern over its complete speed range. Thus, the effect of mud layers on average sinkage is only marginal as trim is much more important.

Mathematical modelling

Obviously the results of model tank tests could not be immediately transferred to real ships for trials so the results needed to be transferred for use in a simulator which meant that mathematical models needed to be created. There were many complexities involved in this process and for those of you interested in this aspect of mud navigation full details can be found in the papers within the links at the end of this feature.

ZEEBRUGGE: REAL-TIME SIMULATION RUNS

The final purpose of the research program consisted in ascertaining the actual operational limits for mud navigation by means of live trials. As the pilots play a central role in the navigation to and from Zeebrugge, the input of their experience and assessment in this project was required. For a selection of bottom conditions, a real-time simulation programme was organised with Zeebrugge pilots at the full mission bridge simulator of Flanders Hydraulics Research, Antwerp. All runs were carried out with a container ship (length over all: 300.0 m; beam:40.25 m; draft: 13.5 m) calling at and departing from the harbour of Zeebrugge.

The simulation programme was composed paying attention to several aspects:

· Validation of the mathematical models: is the behaviour of the ship assessed as realistic during the simulation runs? In order to evaluate this aspect, simulations were carried out above a solid bottom and above muddy bottoms with reduced under keel clearance, according to existing or realistic situations.

· Determination of the limits of the controllability: according to the PIANC definition, contact between the nautical bottom and the ship’s keel causes unacceptable effects on controllability and manoeuvrability. In order to make an assessment in these matters, a series of simulation runs was carried out during which contact occurred between the ship’s keel and mud layers with higher density and viscosity.

· Evaluation of the navigability of mud layers: in case it is decided to determine the nautical bottom by means of a density level higher than the present 1.15 t/m³, the ship’s keel will possibly penetrate into mud layers with reduced density and viscosity. The ship’s behaviour in such conditions was assessed by a series of simulation runs.

In total, 63 runs were carried out by 15 pilots during 8 days.

These manoeuvres are typical for large container carriers calling at Zeebrugge, so that a feedback to the pilots’ experience was guaranteed; moreover, a broad range of hydrodynamic conditions (speeds ahead/astern, propeller rpm ahead/astern, drift angles, yaw rates, …) was covered during the simulation runs. During each single run, the bottom characteristics were assumed to be constant over the entire harbour area.

The access channel to the harbour, the Pas van het Zand, is characterised by important tidal currents in the zone beyond the breakwaters; at low tide, the magnitude of cross currents takes values of 2 to 2.5 knots. As these currents greatly affect the shipping traffic arriving and departing from Zeebrugge, realistic current patterns were introduced into the simulation environment.

All manoeuvres were carried out in frequently occurring, moderate wind conditions (SW, 4 Bf); during some runs, more severe winds were applied. Tug assistance was guaranteed by two tugs of 45 ton bollard pull each; during some runs the available tug power was increased.

Qualitative evaluation of the simulation runs

All pilots were requested to complete a questionnaire just after the simulation run; this resulted into a first, very important assessment of the manoeuvres. According to the opinion of a large majority of the pilots, the simulation of the outside view, the ship’s behaviour and the tug assistance could be considered as “good” to “very good”.

After each run, the pilot was asked whether it would be advisable to carry out the manoeuvre in reality. Based on this assessment, the conditions were classified as “acceptable”, “marginal” and “unacceptable”

Analysis based evaluation of the simulation runs

Taking account of the comments of the pilots on the simulated manoeuvres, it was clear that following criteria should be considered for assessing the bottom conditions:

· Speed: Is a departing ship able to reach a speed that is sufficient to compensate for the cross current acting beyond the breakwaters?

· Controllability by own means: Can a departing ship obtain a straight course without extreme use of rudder and propeller?

· Manoeuvrability with tug assistance: Are the ship’s rudder, propeller and the tug assistance sufficient to perform the manoeuvres safely within acceptable time limits?

Based on the pilots’ qualitative assessment, limits were determined to quantify these criteria:

· Speed: in order to keep within the fairway, a departing ship’s speed should be at least 8 knots, and preferably 10 knots. These values were selected as limits for unacceptable, marginal and acceptable conditions.

· For a departing ship’s controllability by own control devices, the standard deviation of the rate of turn to be an adequate indicator. For the different bottom conditions, this value is displayed as a function of the water depth to draft ratio. Taking account of the pilots’ evaluation, values of 5 and 6 deg/min were selected as critical limits.

· In order to evaluate the ship’s manoeuvrability with tug assistance in a quantitative way, the impulse of steering force was introduced, being the time integral of the sum of the lateral rudder and tug induced forces. The values of these impulses were calculated for each sub trajectory, and compared to the pilots’ evaluation of the adequacy of tug assistance. In this way, it was not only possible to quantify the third criterion, but extrapolations to assistance by more or less powerful tugs could be made as well.

CONCLUSIONS

As a result of the analysis of the real-time simulation runs with a small negative under keel clearance, it can be concluded that contact with mud layers of a density of 1,200 kg/m³ or more should be avoided, even if sufficient tug assistance is available.

However using a limit of 1200kg/m³ was considered safe for navigation provided that tugs were available as per the following table:

• 0% under keel clearance using 2 tugs of 30 ton bollard pull and less;
• -7% under keel clearance if 2×45 ton bollard pull tug were available;
• -12% under keel clearance in case of 2×60 ton bollard pull tugs were available.

These conclusions are only valid in moderate wind conditions for 6000 TEU container carriers. However the methodology can be applied to any vessel or harbour. The new critical limit led to the admittance of deeper drafted vessels and an optimization of the maintenance dredging works in the harbour Zeebrugge, without jeopardizing the safety of navigation.

However, a warning was made that pilots should always be aware of the level of the water-mud interface, which should be indicated on the nautical charts as well, for several reasons:

· If the ship’s keel penetrates by more than 10% of her draft into low density mud layers, this may result into unacceptable situations.

· Small positive under keel clearances relative to the mud-water interface may result into a modification of the ship’s behaviour and controllability.

· A major conclusion of the simulation study was the importance of available tug assistance. If insufficient tug power is available contact with the mud layer should be avoided so that the nautical bottom is moved to the mud-water interface; if more powerful tugs can assist the ship, the pilot may decide to allow a larger negative under keel clearance. In the near future, the tracks, controls and tug assistance of deep-drafted containers ships arriving at and departing from Zeebrugge at low tide will be recorded by the pilots in order to provide a feedback to the simulation study. After an evaluation phase, it will be decided whether the new criteria for the determination of the nautical bottom will be applied in practice.

Other considerations

Although the above analysis reveals that mud navigation is feasible, such navigation results in other physical effects on the ship. Some of my colleagues who served on freight ferries running regularly to Zeebrugge have informed me that navigating the mud layer doesn’t just keep the hull clear of growth but also removes the paint and dry docking reveals a clean metal hull and the propellers also become highly polished. The other obvious problem is with engine cooling systems which are not designed for cooling by muddy water.

JCB

A tanker in a restricted channel. According to ship squat tables this tanker should be aground! Photo :JCB

All pilots are aware that, at speed, ships display a tendency to sit deeper in the water, a phenomenon officially referred to as “squat”. Despite their being generally aware of squat, most pilots have no respect the squat tables calculated for a particular ship because they frequently indicate that a passage using historically proven safe under keel clearance (UKC) parameters is mathematically impossible! In the majority of ports the UKC parameters were established sometime around the time of Noah and traditional pilot training has meant that rather than relying on mathematical tables, pilots gain an instinctive “feel” for the ship with vibration, high exhaust temperatures or a breaking quarter wash indicating that a vessel’s speed is too high for the existing water depth which usually results in the speed being reduced before a squat induced grounding occurs! A pilot’s knowledge and experience of their own district is therefore considered more reliable than the tables and consequently the number of groundings solely resulting from squat are almost non existent and the only case that I can identify as being totally attributable to squat is the QE2 leaving Massachusetts in august 1992.

So, in theory, ship squat can be disregarded as a serious problem for pilotage navigation but these days the “we’ll pull her back a bit Capt as we go over the shoal” approach is not considered best passage planning practice so, in order that we can factor in squat, it is increasingly necessary to have accurate data regarding the causes and effects of squat.

Squat does exist! This vessel is steaming at about 12.5kts. Draft 7m in water depth 16m. Photo : JCB

As mentioned previously, information provided by the ship’s squat tables rarely tallies with the pilot’s / port’s established passage planning speed / UKC guidelines but there are now two key reasons why pilots must take squat seriously. Firstly, should a pilot be unfortunate enough to be involved in any incident the passage plan and master / pilot exchange will be examined in detail and if a pilot hasn’t discussed the ship squat characteristics with the Master then he will be condemned by the investigators, regardless as to whether or not squat was of relevance to the incident. The second factor is that well trained “bridge teams” now utilise squat tables when calculating safe UKC parameters in their passage plans so the Master / pilot relationship can get off to a frosty start if the pilot breezes up to the bridge and dismisses the bridge team’s squat tables as an irrelevance that can be ignored, especially if he then identifies points during the intended passage where the UKC is likely to be less than the tabulated squat! The intention of this article is to try to increase the overall understanding of the squat phenomena.

Freight Ro-Ro. Draft 6,5m Speed 10 kts UKC approx 8m Photo : JCB

The same ship. Speed 20kts UKC 10m Photo JCB

My interest was triggered by a major feature on ship squat, somewhat alarmingly titled “Don’t Fall Victim To Ship Squat Perils” in the July 2006 issue of the NAUTILUS Telegraph, written by Dr. Barrass FNI whose mathematical calculations and tables are those used throughout the Industry and shipping fleets. In that article Dr. Barrass reproduced tables which indicated that at 10 kts speed through the water a vessel with a high block coefficient such as a tanker or bulk carrier would squat between 1 and 2 metres and that this might be doubled if another vessel was passed in shallow waters. This is clearly an incorrect figure because such vessels have been safely transiting shallow water port approaches using under keel clearances of 0.5m and 1.0 m years before any calculations had been produced to suggest that such parameters were unsafe! I had therefore been planning to write and question Dr. Barrass’ mathematics myself but Houston pilots’ representative, Louis Vest, beat me to it and the following is an extract of his letter:

… we will transit a vessel with 13.7m of draft and 0.6m of under keel clearance. A typical transit speed for such a vessel will be about 10 to 12 knots across the bay.

According to the author’s tables, we should experience about 2m of squat, but we don’t. The ship runs up the channel, the 0.6m under keel clearance doesn’t change, and we deliver the ship safely to her berth. This is not a rare event but a daily occurrence. Contrary to the author’s claim that squat increases in shallow water, squat appears to disappear in very shallow water.

The author also asserts: ‘The presence of another ship in a narrow river (passing, overtaking or simply moored) will also affect squat — so much so that squats can double in value as they pass/ cross the other vessel.’ We make our transits with two-way traffic. In no case has a change in squat been a factor in these meetings. I do believe that squat exists, but squat and ship hydrodynamics in very shallow water are a very poorly understood phenomenon. If the author would like to correspond with me in the interest of clarifying these points, I would be happy to oblige.

Such observations are in accordance with our experience in London and many other major ports such as Rotterdam, also safely undertake passages using low UKC parameters so one would have expected that Dr Barrass would take up the offer of dialogue with the Houston pilots in order to try to understand and resolve the anomalies between the actual and theoretical squat. However, rather than entering into a constructive dialogue, Dr Barrass chose to respond in the December 2006 Telegraph with another article titled “Ship Squat Is A Real Issue In the Real World” where he used his complex formulae to reveal how the Houston pilots totally misunderstood how ships behave in shallow waters and narrow channels and accused them of dangerously negligent navigation practices which couldn’t possible be undertaken without a grounding. Unfortunately, Dr Barrass’ diatribe reveals almost total ignorance of real ship operations with, for example, the following responses to Louis Vest’s comments regarding transit speeds of 10 - 12 kts:

To me, his (Louis) speed appears to be ‘ship speed over the ground.’ This is the speed measured when using GPS. It is not the speed that I use, namely the ‘ship speed relative to the water.’ Louis Vest has mistakenly ignored the speed of current flow. At zero current flow it is not possible in hydrodynamics to have to a ship speeding at 10 to 12 knots along a channel where B/b is about 4 and H/T is about 1.04. In the real world the local port authority would take an extremely dim view of these speeds. Furthermore, the machinery space within an oil tanker would not generate sufficient power to produce these ship speeds along this channel.

With respect to Louis’ comments regarding squat seeming to disappear at slow speeds Dr. Barrass reveals poor research methodology by stating:

This just cannot be so. It defies the laws of physics. It contradicts the laws of the Venturi effect. I have a database of 69 vessels that have gone aground due to ship squat problems. If this quote were true, then we would not have had any grounding such as the Herald of Free Enterprise in 1987, the QE2 in USA in 1992 and the Sea

Empress in 1996.

These are unfortunate examples because only the QE2 grounding was directly attributable to squat and checking on other examples of groundings listed by Dr Barrass as having been caused by squat reveals that at least two ( Tasman Spirit and Diamond Grace) grounded for reasons entirely unrelated to squat and most of the others listed cannot be directly attributed to squat. However, Dr Barrass’ arguments were reinforced by retired Venetian pilot, Sergio Battera MNI who agreed with Dr Barrass that UKC of 0.6m at speeds of 10 – 12 kts would be unsafe and could result in a grounding!

Louis Vest obviously responded and the following extracts highlight the key facts regarding the everyday navigation practices at Houston:

a. Dr Barrass provided a table showing predicted squat of 1-2m for a vessel travelling at 10 knots in a confined channel.

The Houston Ship Channel crosses Galveston Bay for over 30 miles. It is a man-made channel 530ft wide and 45ft deep in a bay whose average depth immediately

outside the channel is around 12’ft, making this a restricted channel.

b. He made the assertion that the predicted squat can double in value as one vessel passes another vessel.

The project depth of the channel is 45ft and the initial dredging was to 47ft, as

measured with tide value = 0. c.

c. Vessels making too great a speed in shallow water will ground due to squat.

We accept ships for transit to Houston with drafts of 45ft at 0 tide, 44ft at -1 tide, etc…

d. The lower the value of underkeel clearance the greater the value of predicted squat.

We transit Galveston Bay at speeds of 10-12 knots in these deep draft vessels.

We do not run aground.

We operate in a two-way traffic environment and do not ground when meeting other vessels, even similarly loaded vessels. These are not calculations or predictions as some have suggested (Capt. Battera of Venice, January Telegraph). They are easily verifiable facts. They are not exceptions or rare occurrences but everyday events in the busiest port in the United States. The fact that our daily practice runs counter to accepted theories of squat is somewhat unfortunate for the scientists who have made this their life work, but it is no less true because of it.

Dr Barrass attempts to discredit my letter in several ways. In one paragraph he insultingly suggests that I am confused about the difference between speed over ground and speed through water. I would like to assure Dr Barrass that we humble seamen, in our crude Neanderthal way, are aware that current affects the speed of a vessel. In another paragraph Dr Barrass suggests that operating vessels at 10-12 knots across the bay is unsafe and irresponsible. The morality of the Houston pilots is not the question. We stand on our safety record. The ship, in a strictly scientific sense,

cannot act irresponsibly. As an inanimate object (regardless of what personality traits she might manifest for her crew) the ship makes her transit in complete innocence of Dr Barrass’s opinion of her conduct. For Dr Barrass to suggest that crossing the

bay at 12 knots is dangerous or irresponsible ignores the substance of the subject, which is that Dr Barrass has published a table that says it can’t be done and yet it is done on a routine basis. Elsewhere in his letter Dr Barrass employs his formulae to

assert that the ship’s machinery is inadequate to propel a vessel through a confined channel at 10-12 knots. Your readers can decide that one for themselves. On one hand you have a formula with B/b = 4 and H/T=1.04 and who knows what. On the other hand there is the vessel herself in one place one moment and a mile away still going strong five minutes later. I personally think Velocity=distance/time trumps Dr

Barrass’s hydrodynamic formulae here. Dr Barrass also uses formulae (not given) to predict that a vessel with a given speed in deep water would have her speed reduced

to about one-third that speed in a confined, shallow channel given the same engine input. In practice, a vessel running very close to the bottom as we are discussing will make about 80% of the posted speed, not 33%. As the underkeel clearance increases

that percentage approaches 100%. For example, a large tanker making turns for 12 knots as indicated in her tables will make about 10 knots. The same tanker outbound in ballast will make 11-11.5 knots. A small coaster with 5-6m of draft will make very close to her indicated speed. Yes, I am allowing for current (see above). In order to burst Dr Barrass’s hopes that a change in water density from fresh water to salt water might explain our miraculous escape from the laws of physics as he interprets them, I would like to point out that Houston is a major oil port and the United States is an oil

importing nation. Most, but not all, of our deep draft transits begin in the salty water of the Gulf of Mexico and terminate in the fresh water of Buffalo Bayou. The claim is made that we would not have had groundings such as the Herald of Free Enterprise, the QE2, and the Sea Empress if not for the effect of squat. According to the official

report, the Sea Empress grounded on rocks due to the pilot’s failure to adequately allow for the set of current across the channel. The Herald was notoriously lost due

to the failure of her crew to secure her bow doors properly. Neither accident was remotely related to squat. The QE2 struck a rock jutting up from much deeper

water all around. While this accident involved squat it is not related to my

observations about squat in a confined channel with a continuous minimum underkeel

clearance.

Now mariners from the ends of the earth (Houston) are telling scientists that their predictions of ship behaviour do not match real world observations. I suggest we

recognise that our knowledge of the hydrodynamics of large vessels in very shallow water is indeed poorly understood. This represents an opportunity to advance our understanding of the world if properly taken.

This situation is obviously unsatisfactory. On the one hand we have pilots safely bringing ships in and out of port with minimum UKC parameters and on the other hand there are the scientific “experts” who have produced tables to prove that what we are doing is impossible. There is no other industry that would not only accept the mathematics without question but also create a safety policy around such poor scientific analysis. I have never met Dr. Barrass and I am sure that he is a very eminent mathematician but I would have thought that rather than publicly accusing the Houston pilots of incompetence and revealing a somewhat alarming ignorance of real ship behaviour, a curious scientist would have undertaken further research to explain the anomalies between the mathematical predictions and real time practical experience. To be fair to Dr Barrass his calculations are reasonably representative of others working on this phenomena and I will at least give him credit for sticking his head above the parapet and stimulating some emotional debate!

So, what is squat?

The Permanent International Association of Navigation Congresses (PIANC) (see Autumn 2007 issue) is now the main forum for squat related issues. This is a positive development because the UKMPA attend the PIANC sessions so pilots’ now have direct input into the discussions. The PIANC papers provide the following definitions of squat. Squat is the reduction in UKC between a vessel at-rest and underway due to the increased flow of water past the moving body. The forward motion of the ship pushes water ahead of it that must return around the sides and under the keel. This water motion induces a relative velocity between the ship and the surrounding water that causes a water level depression in which the ship sinks. The velocity field produces a hydrodynamic pressure change along the ship that is similar to the Bernoulli effect in that kinetic and potential energy must be in balance (Newman 1977). This phenomenon produces a downward vertical force (sinkage, positive downward) and a moment about the transverse axis (trim, positive bow up) that can result in different values at the bow and stern (Figure 1).

Most of the time squat at the bow S_b represents the maximum value, especially for full-form ships such as supertankers. In very narrow channels or canals and for high-speed (fine-form) ships such as Passenger Liners and Containerships, the maximum squat can occur at the stern S_s. The initial trim of the ship also influences the location of the maximum squat. The ship will always experience maximum squat in the same direction as the static trim (Barrass 1995). If trimmed by the bow (stern), maximum squat will occur at the bow (stern). It is the classical “Venturi Effect” as streamlines will move faster under the smaller cross-sectional area at the bow (stern) resulting in lower pressure (i.e., more suction) and increased squat. It is not possible to compensate for increased squat at one end by trimming at the other end.

Factors Governing Squat

Prediction of ship squat depends on ship characteristics and channel configurations. The main ship parameters include ship’s draft, hull block coefficient, and speed through the water. The main channel considerations are proximity of the channel sides and bottom Channel bends and proximity to banks tend to increase squat and muddy bottoms to decrease it. The presence of another ship (passing or moored) can also increase squat.

The most important ship parameter is its speed through the water and generally squat varies as the square of the speed so doubling the speed quadruples the squat.

The most important channel parameter is the water depth and can be ignored if the depth is twice the draft or more.

How is squat calculated?

Consider yourselves lucky that I am not going to reproduce the mathematical formulae used to calculate squat because they are pretty baffling to a simple seaman such as me but for those of you who would like to see them they can be found via the web links I have placed at the end of this article.

The calculations are made for three different shallow water conditions shown above and several specialists have produced mathematical formulae to calculate squat but Dr Barrass’ formula are the most well known and widely used.

However, they all use the same basic concept so produce similar predictions but as highlighted by the exchange between dr. Barrass and the Houston pilots there are seemingly serious anomalies between the predicted squat and the actual squat experienced.

The following are examples of calculated squat from the ten main study groups for a selection of typical vessels illustrating the range between the results. They are for bow squat in an unrestricted channel with an initial UKC of about 2.5m and speed through the water of 11 kts. The name of the research group is in brackets.

250,000 DWT Tanker

Largest squat (Milward) 1,25m

Least squat ( Eryuzlu) 0.50m

(Barrass) 0.80m

65,000 DWT Tanker

Largest squat ( Milward) 1.10m

Least squat (Romisch) 0.43m

(Barrass) 0.90m

Panamax Container Ship

Largest squat (Milward) 0.75m

Least squat (Romisch) 0.20m

(Barrass) 0.30m

As can be seen there is a considerable difference between the various researchers so the allegation by the Houston pilots that squat is a “very poorly understood phenomenon” is fully justified.

Resolving the anomalies.

The existing calculations are nearly all based upon theory or laboratory testing methodology and PIANC has recognized this and produced the following recommendation regarding squat :

PIANC recommends model tests for specific ship and channel conditions, especially if the conditions are new or novel. Many laboratory-based formulas are from captive towed tests that introduce unintended moments that can cause unrealistic trim of the towed models. The current thinking is to use free-floating, remote controlled models for physical model tests. Finally, full scale measurements are always a good check of design stage predictions.

Until very recently the complexities of measuring the real time squat of ships under way were too great to enable any meaningful results. Fortunately the advent of DGPS and other technologies such as tide rate / height monitoring has enabled real time squat measurements to be made by placing specialist equipment on board which can generally produce accuracies to +/-10cm and the latest equipment is capable of accuracies to +/- 1 cm. Much of the pioneering work has been undertaken by the Australian company OMC who have developed and registered as a trade mark the concept of Dynamic Under Keel Clearance (DUKC) ® to permit maximum loadings of bulk carriers. The DUKC® concept doesn’t just allow for squat but also has to factor in the large swells that are a frequent problem in Australia and new Zealand. With dedicated precise instrumentation fitted on board several bulk carriers and precise swell meters and tide gauges sited at critical points along the intended route, data is fed into computers at the loading terminal and these ships are thus loaded to the absolute maximum for the existing conditions. I understand that this loading method has resulted in additional cargo liftings of around 1,500,000 tonnes per annum at just the Hay Point terminal in Queensland alone.

Other real time measurements have been undertaken by the US Army Engineer Research Centre (USACE) and on the Elbe both live trials and specialist model tank tests have been undertaken by the Federal Waterways Engineering and Research institute (BAW).

Results from Real observations and specialist “free” model tank tests.

Although the number of real ship trials is still fairly low there is now real data beginning to emerge that confirms that the existing predictions are over pessimistic which of course comes as no surprise to pilots! Full details of many trials can be obtained via the links at the end of this article but the following are a small sample of results from trials undertaken by the above groups. Please note that these are very basic interpretations from detailed graphs.

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BAWTank test:

Panamax Containership: Draft 12.8m, Initial UKC 5.7m

Speed Squat

10kts 0.3m

12kts 0.4m

14kts 0.7m

Bulk Carrier (350m loa) Draft 14.5m Initial UKC 4.0m

Speed Squat

8kts 0.5m

10kts 0.7m

12kts 1.0m

BAW Live trials.

Data was collected from 9 transits of large container ships on the Elbe. The results reveal an interesting difference between wide and normal transom ships with the wide transom displaying far less squat.

Speed least observed squat largest observed squat

10 kts 0.2m 0.5m

12 kts 0.5m 0.9m

15 kts 0.6m 1.7m

USACE observations

In 1999 the USACE undertook live trials in Charleston. The following is a sample of the results which compares the observed and predicted bow squat.

Predicted squat

Ship Observed Squat Huuska Barrass Romisch

PX Container 0.99m 1.86m 1.99m 0.99

190m Bulk Carrier* 0.53m 1.03m 0.94m 0.66

* Restricted Channel.

OMC Observations

OMC have been undertaking real time trials using very precise measurements. Recently they have completed real time trials for the port of Port Marsden in New Zealand. The results are very detailed because the DUKC® concept also factors in swell and other environmental conditions but as an example, measurements on a 100,000 DWT tanker with a speed through the water of 9 kts in a restricted channel gave an observed squat of about 0.4m.

My own observations

Totally unscientific but with nearly 20 years of piloting ships from small coasters to VLCC’s in restricted channels my personal observations are:

• At speeds of less than 9kts through the water squat is negligible.
• Squat is to be taken seriously if the vessel is passing rapidly from deep to shallow water.
• If a vessel is already in shallow water then the ship and environment will warn you (engine vibration and breaking quarter wave) that you are going too fast before a grounding occurs due to squat
• Modern pitch control propeller systems have overload protection that will prevent excessive speed in shallow waters
• It is important to discuss the UKC with the Captain! He will have been in and out of many ports and will normally have a good understanding of how his ship behaves in shallow waters especially if he has transited the Houston ship canal and played “Texas Chicken” (www.texnews.com/1998/2002/texas/texas_Pilots_Se822.html) after which very little will perturb them!!

Conclusions

Squat is an extremely complex subject and is dependent on many factors including mud*. Practical trials generally reveal the traditional tables to be over estimating squat which of course provides a safety margin. However if they are so inaccurate that they are unrepresentative of reality then they are an alarmist waste of time. What I find difficult to comprehend is that despite many real time observations indicating anomalies in the tables, these tables are still being provided for every ship and potentially introducing conflict in the Master / Pilot exchange. Fortunately most Masters accept that the port’s own established guidelines, applied by properly trained pilots will result in safe transits but the overall situation is unacceptable.

http://chl.erdc.usace.army.mil/library/publications/chetn/pdf/chetn-ix-14.pdf

http://www.omc-international.com/

Dr. Barrass: www.ship-squat.com

*Next quarter I will be examining the linked concept of mud navigation and navigable bottom!

Feedback from Louis Vest:

I’m glad to finally get some support from other pilots. Interestingly, Dr. Barass; after trying to discredit me in the magazine with his second article, has never contacted me about my offer to observe squat (or lack thereof) in Houston. Nor has any other hydrodynamacist. Regarding the reliability of models. Another of my disagreements with the professorial experts has been the validity of observations/tests/predictions based on data obtained from test tank models or mathematical models. Validation of these models is important because ship designs, rudder designs, etc are increasingly made and tested on computers. In some cases portions of sea trials are allowed to be simulated or performed in a test tank. In one of the numerous attempts to verify squat calculations that you described above, the USCOE funded an effort here in Houston. The goal was to install highly accurate GPS units (+/- 2cm)on the bow, stern and beam ends of vessels making Houston transits. The recorded data was to be made available online for investigators to use. Last time I checked no one had done any work on the data. More importantly, there were several ships calling in Houston at the time for which mathmatical models were available; the same models used for generating the graphics of simulators for example. The researchers made the extra effort to record data from these vessels and in at least one instance two vessels met in the channel, both of which were equiped for data recording and both of which had known mathmatical models. When the ships met bridge cameras were used to record the exact timing and sequence of pilot orders during the meeting. (For those who aren’t familiar, a meeting in Houston involves two ships meeting head on until about .5 mile and then swinging right to pass within 60-70 meters of each other in a 160m channel.) After the study, two of the researchers tried to recreate the maneuver on a simulator using the ship models, the recorded sequence of commands, and the recreated channel outlines. The results did not conform to the actual meeting situation. The simulator ships could not recreate the maneuver. The reported the results were significantly different on the simulator from real life. I tried to convince them that a negative result was important and worth an article in one of the leading scientific journels, but they didn’t seem to think so. So. How accurate is simulator training or simulator ship design? It’s not just about squat. Louis Vest.