The Canadian Coast Guard and three Princess Cruises’ ships participated in a project initiated and partially funded by the Western Marine Community's Pacific Coast Marine Review Panel (PACMAR) to test an Automatic Identification System (AIS) in British Columbia waters during the summer of 1999. The objective of the test was to gain operational experience with AIS and to formulate recommendations on ways to integrate AIS in bridge team operations. This report details participants, the test plan, the technology used, findings of the test and participants’ evaluation of alternative ways of integration of AIS information in Electronic Chart Display and Information System (ECDIS).
The intended audiences for this report are ECDIS developers planning to extend their product to include AIS as proposed by IMO, ITU, IEC, IALA, etc.
The report is also intended to be used by members of the IALA committee charged with setting standards for integration of AIS into bridge operations.
The key participants in this project were the Canadian Coast Guard (CCG), Princess Cruises, Meteor Communications Corporation (MCC), Transas Marine (TM ), British Columbia Coast Pilots, Transport Canada Marine Safety, British Columbia Ministry of Forests (MoF), PACMAR and Marine Management Consulting.
The author of this report directed the project with assistance and support from all stake holders.
The opinions expressed in this report represent, to the best of my knowledge, those of the bridge teams (including pilots) involved in the test.
A color copy of this report can be obtained for US$5.00 by writing to:
Fred W. Pot
Principal
Marine Management Consulting
3837 31st Avenue West
Seattle, WA 98199-1713
(206) 301-9626
(206) 283-7108 Fax
fpot@home.com
or by downloading the report from www.chamber-of-shipping.com
at no charge.
- Participating Vessels
- Test Plan
- Log of Encounters
- Scheduled Rendez-vous
- Technology
| Name |
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(Knots) |
(m) |
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| CCG705 |
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| CROWN PRINCESS |
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| REGAL PRINCESS |
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| SKY PRINCESS |
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During a 2 week period the bridge teams of CROWN, REGAL and SKY recorded all encounters with AIS equipped ships. Apart from each other, they encountered Canadian Coast Guard vessels, tugs (& barges) participating in the International Tug of Opportunity System (ITOS) and British Columbia-, Washington State- and Seaspan Coastal Intermodal Company's ferries (See Chapter IV B for REGAL PRINCESS log).
A rendez-vous between CCG705 and all three participating cruise ships took place at Seymour Narrows on August 30, 1999 specifically to test AIS in an area where, due to topographical boundaries, radar cannot be used for collision avoidance. CCG705 adjusted its speed to rendez-vous with cruise ships at a point just South of Seymour Narrows. Cruise ships provided CCG705 with updates of their ETA at the rendez-vous point via VHF.
- The transponders used for this
test were made by Meteor Communications Corporation of Kent, Washington,
USA. They operate at a frequency of 44.5 MHz. Except for those on ITOS
tugs, all transponders were set to send out position updates every 30 seconds.
On CCG705, the transponder's built-in Global Positioning System (GPS) was used. On cruise ships, the transponder was provided with a National Marine Electronics Association (NMEA) 183 standard feed from the ship’s Differential GPS (DGPS).
On CCG705 the ECDIS, developed by Offshore Systems Limited of Vancouver, BC, Canada, was modified to be able to recognize AIS position updates in the transponder’s native protocol.
On the cruise ships, the ECDIS system, developed by Transas Marine ( TM ) of Southampton, UK, received AIS type 2 position updates in the format proposed by IMO, ITU, IALA, IEC, etc. In the absence of type 5 messages, that provide particulars, AIS targets were labeled with the identification code of the transmitting transponder in hexadecimal format, i.e. CCG705's target was labeled "000002C1". Bridge teams had to translate these codes into target names and particulars through a listing of all AIS equipped ships (see Chapter VI).
Apart from regular ARPA targets, TM’s ECDIS showed AIS targets as triangular icons with a straight line vector representing its last received position, Course over Ground (COG) and Speed over Ground (SOG). AIS targets also showed a one minute track history (trail). AIS targets, for which no updates were received within 40 seconds, were dropped from the ECDIS screen. AIS targets were not dead-reckoned to their current position, nor were ARPA and AIS icons for the same target consolidated into a single target. Figure 1 shows the situation as seen on REGAL PRINCESS’ ECDIS. The target with green label "000002C1" represents CCG705, target "00000368" represents SKY PRINCESS.
Figure 1 (Click on ECDIS Screen to enlarge)
Initial set-up of the transponders, their un-interruptable power supplies (UPS), their antenna’s, their interfaces with DGPS and with ECDIS, along with configuring them as well as the ECDIS systems was surprisingly time consuming and required several experts to board each ship. The technology is so new that "plug-n-play" was not possible and at least 40 man hours were used per ship for set-up, configuration and testing. Once installed, however, the bridge teams reported that they were maintenance free.
Although the British Columbia Ministry of Forests operates a net work of MCC transponders for fire fighting purposes with several base stations near BC waters, it was not used to extend the range of AIS by relaying AIS updates. All observations were of ship-to-ship nature.
- Range
- Encounters with other AIS equipped ships
- Labeling AIS Targets
- Rate of Turn information
- Display a target's route & destination
- Target Particulars and Voyage Data
- Normal active working ECDIS screen
- Target Highlights
- Target Particulars
- Dead-reckoning AIS targets
- Target Consolidation
- Inter Ship E-mail
- Display Navigational Aids
- Transmit current environmental conditions via AIS
- Relaying target information
- Use AIS to receive Differential GPS corrections
- AIS versus VTS
Despite interference from 200+ m high cliffs at Seymour Narrows that impeded radar detection, initial, mostly intermittent, AIS position updates were being received over an hour before rendez-vous at a range of 30 to 40 NM. Updates were being received at a regular 30 second interval by all participants about 30 minutes before rendez-vous at a range of 14 to 16 NM.
Bridge teams expressed a preference for receiving reliable AIS updates about 30 minutes before Time of Closest Approach (TCPA), irrespective of the speed of the target.
ARPA targets of AIS equipped ships were
acquired as late as just a few minutes before rendez-vous due to topographical
boundaries.
The following log of encounters with other AIS equipped ships between 14 and 28 August was submitted by the bridge team of REGAL PRINCESS
| Date |
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Target | Location |
| 14 August 1999 |
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Tug Suiattle | South of Cracoft Island |
| 15 August 1999 |
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Spirit of BC | Between Vancouver |
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Tug Suiattle | and Cape Mudge | |
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Crown Princess | ||
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SS Crusader | ||
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Evco Buccaneer | ||
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Sovereign | Close to Pine Island | |
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Queen of North | ||
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DASH 7 aircraft | ||
| 16 August 1999 |
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Tanu | Hecate Strait |
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Pilot boat | ||
| 21 August 1999 |
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Queen of Chiliwack | Charlotte Strait |
| 22 August 1999 |
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Spirit of BC | Between Sabine Strait |
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John P. Tully | And Cape Mudge | |
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Carrier Princess | ||
| 28 August 1999 |
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Queen of North | Queen Sound |
Although there was no consensus as to how to label AIS targets, all bridge teams agreed that the label should be very short to minimize on-screen clutter. Suggested options included display of an abbreviated vessel name or its radio callsign. In either case, the full name and other particulars should be presented on screen by clicking on a target’s label.
One of the bridge teams preferred to use some of the ECDIS screen to show an AIS target’s rate of turn, if it is available, followed by a P or an S, particularly for targets with a Time of Closest Approach (TCPA) of less than 10 minutes. Most bridge teams, however, preferred to avoid the this "clutter". The option to curve the (COG/SOG) vector emanating from an AIS target to reflect its rate of turn was rejected mostly because bridge teams felt uncomfortable with curved vectors.
If a ship has an ECDIS, uses it for route planning and uses NMEA standard sentences over a connection between ECDIS and AIS, then it could include the currently active route in the periodic AIS voyage details update. A target’s current portion of its route could then be displayed on ECDIS.
Bridge teams felt, however, that this information
would be too unreliable to be worth cluttering the ECDIS screen with.
Again to reduce clutter on the active ECDIS screen, bridge teams preferred three levels of information about AIS targets as follows:
This should display AIS target’s icon position and its course and speed vector. For target tracking and to assist with contacting vessels by VHF radio, AIS targets should be labeled with their callsign or an short abbreviation of their name in small print.
By clicking on the label of a target on the active ECDIS screen, a small new window should open, preferably on a part of the ECDIS screen that is not part of the active chart, with the course, speed, range, bearing, CPA, TCPA, rate of turn, ship type, LoA and full name as well as a "More…" button.
Clicking on "More…" button, the Target Highlights window should expand it to provide additional particulars including voyage data such as destination, Estimated Time of Arrival (ETA), draft, hazardous cargo information, unusual maneuvering limitations, towed barge(s) information, etc. and vessel’s own particulars.
Bridge teams felt that it would not be appropriate to dead-reckon an AIS target to place it on the screen in its most likely current position for more than just a few seconds from its last reported position, COG, SOG and rate of turn.
To reduce screen clutter, bridge teams preferred that ARPA A, ARPA B and AIS icons of the same target be consolidated into a single icon. To avoid operator error, rule based automatic consolidation was generally preferred over manual selection of icons to be consolidated.
Consolidation rules should dead-reckon
the (delayed) AIS icon to its expected current position, determine which
icons
to consolidate and how much weight to assign to the attributes of each
icon for averaging purposes.
With this function enabled, a pick list of short, traffic situation oriented messages ("Intend to pass you port-to-port") should appear in a window as soon as an AIS target is selected with a mouse click. These messages would be pre-formatted, and require no keyboard entry to select and send. The message should be sent to the AIS target ship as soon as one of these messages has been selected and the selection confirmed.
A blinking circle around the icon of the sender should indicate arrival of an incoming traffic message from an AIS target. Clicking within this circle should send a confirmation of receipt to the sender and open both the message and a pick list of standard replies ("OK"). The standard replies appearing on the pick-list should depend on the nature of the original message. A reply should reference the original message. To avoid distraction, standard messages and replies should not be customizable and become "chatty".
Bridge teams felt that inter ship e-mail
may reduce the need for inter ship or ship to VTS (reporting) VHF communications.
However, they, unanimously, felt that the use of email messaging cannot
be allowed to distract the Officer of the Watch (OOW) from maintaining
a visual or radar watch (which can be accomplished while simultaneously
communicating via VHF). Bridge teams also noted that adding another task
to the duties of an already busy OOW was undesirable.
Bridge teams felt it would be useful to display new hazards, out of place buoys, demarcation of traffic separation zones, etc. on-screen. These "stationary icons" should be of a different type and should be identified as such on the ECDIS screen. A VTS Center could broadcast the AIS information for these stationary targets without actually equipping them with an AIS transponder.
Bridge teams felt that AIS should be used to provide them with actual real-time visibility and wind data as well as actual currents observed at surface and at say 5 m from surface in critical passes like Seymour Narrows. EDIS should show a special type of icon for points where actual real-time conditions are available. Clicking on such an icon should open a window with these observations, preferably outside of the active chart.
Bridge teams felt that a radar supported VTS center should broadcast all its ARPA targets (SOLAS and non-SOLAS vessels) via AIS and add target particulars where possible. Bridge teams didn’t feel comfortable asking AIS equipped ships to do the same, because they could be transmitting unreliable ARPA target information. Asking AIS equipped ships (and VTS centers not supported by shore based radar) to relay AIS target information would be less problematic.
If automatic target consolidation is not effective, relayed targets could clutter the ECDIS screen. To avoid clutter, bridge teams probably would need an option to turn off display of relayed targets.
Relaying target information would allow
bridge teams of AIS equipped ships to acquire targets (and target particulars)
well before they could do so as ARPA targets. This information would provide
them with advance knowledge and a more complete picture of the imminent
traffic situation than they could acquired by ship borne radar alone.
Bridge teams felt that this would be useful in areas where direct receipt of Differential correction signals is not available, for instance due to topographical boundaries. The system should, however, use this only as a back-up to direct receipt of differential GPS corrections.
- Bridge teams felt that AIS, once
it achieved near 100% participation, will provide them with a complete
view of the immediate traffic situation and put them in a better position
to assess the situation. Shore-based VTS operators will also have a better
picture of the traffic situation, and there is potential for reduction
of VHF radio interaction between VTS and participating vessels.
Even the limited version of AIS that was tested, proved itself to bridge teams as a useful aid to navigation. They mentioned "seeing" a BC ferry in the Frasier river well before it crossed the shipping lane in the Straits of Georgia and "seeing" what the pilot boat at the Pine Island pilot station is up to, as examples. Bridge teams strongly support efforts to equip as many vessels as possible with AIS. As one officer put it "we want to avoid colliding with any vessel of any size". To entice owners of smaller non-SOLAS vessels to install AIS, simple, affordable transponders should be made available and features should be added that are designed to appeal to them.
This test of AIS was made possible by many people who put in long hours to make it work and to properly evaluate it. Following is an (incomplete) list of organizations and people that contributed to the success of this trial. Thank you:
- Meteor Communications Corporation, Inc. and especially Jay Creech for supplying equipment, expertise, assistance and funding
- The British Columbia Ministry of Forests and especially John Flanagan, Mike Becksted and Martin Torn for supplying equipment, expertise, assistance and funding
- The Canadian Coast Guard and especially Mike Doutaz and Marc Lanthier for contributing CCG705 and for assistance and funding
- Princess Cruises and especially the Communications Officers and the Bridge Teams of CROWN PRINCESS, REGAL PRINCESS and SKY PRINCESS for expertise, assistance, for cabling and for funding the test
- The Chamber of Shipping of British Columbia and especially Ron Cartwright, Joe Bienert and Rose Bray for expertise and assistance
- PACMAR and especially Ed Monteiro for expertise, assistance and funding
- Transas Marine (USA), Inc. and especially Larry DeGraff and Keith Rowlett for expertise, assistance and funding
- The British Columbia Pilots Ltd. and especially Dwight Ruddick for expertise and assistance
- Transport Canada Marine Safety and especially Bill Nash and John Yeung for expertise and assistance