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Collision in fog
Janine
Posted: Friday, May 21, 2010 8:45 PM
Joined: 02/05/2008
Posts: 386


Dockwalk magazine's regular column, What Went Wrong by Kelly Sanford, highlights a different marine accident each month, focusing on the lessons learned. We've received feedback that some readers would like to comment on it. So we're republishing it in the forum so you can have your say.

The June 2010 column recounts a story of two vessels that collided in foggy conditions


As the seasons change and many boats head for New England and the Pacific Northwest, it’s a good time to examine the perils of radar navigation in dense fog conditions. The details of the following incident are taken from a UK Marine Accident Investigation Branch report.

 

Two vessels were in UK coastal waters in poor visibility at around1200h. The mate was on watch and the captain was below deck on both vessels. At the time of the accident, Vessel A was exhibiting normal running lights. When taking over the watch, the mate modified the radar from a six-mile range with ship’s-head-up to a north-up display without range rings. The radio was monitoring 16 with the volume turned up and both the autopilot and watch alarms were operational. The course setting was 008° and the vessel was making eight knots. Despite thick fog conditions, no fog signal was being sounded because it was not normal practice unless there was traffic in the immediate area.

 

The mate on Vessel B modified the radar from a six-mile range, ship’s head-up and rings displayed to a personal preference setting of three miles range off-center with an a head range of 4.5 miles. The VHF was monitoring 16 with the volume up; autopilot and watch alarms were both active, but again, no fog signal was being sounded. Vessel A was on a course of 185° and was making eight knots.

 

Aboard Vessel B, the mate observed a radar target (Vessel A) to starboard at about four miles, which he monitored with the electronic bearing line (EBL) and Variable Range Marker (VRM). The mate calculated that the other vessel was on a nearly reciprocal heading and would pass on his starboard side at a range of about five cables (approximately half a nautical mile). He was also monitoring an overtaking vessel passing to his port side at a range of about one mile (Vessel C).

 

At this same time, the mate on Vessel A noted radar targets on each side of his heading. According to the report, “His interpretation of the situation was that the vessel on the port bow had an obligation to keep out of his way, while he was required to keep out of the way of the vessel on his starboard bow.” He then decided to make a slight course alteration to starboard and assumed the vessel to his port would do likewise.

 

When the CPA was 3.5 miles, Vessel A made radio contact on 16 and said, “The two vessels either side of the vessel heading north, please let me know your intentions.” He heard a single reply, “Yes, I can see you.”He then observed Vessel C turn to starboard and pass safely behind Vessel B – which still appeared to be on a steady bearing.

 

At a range of 2.5 miles, Vessel A again tried unsuccessfully to make contact with Vessel B on the VHF and so made a minor course adjustment to starboard. When the mate aboard Vessel B fixed his position and found himself starboard of his planned track, he made a minor course adjustment to port. However, the mate aboard Vessel A calculated Vessel B coming down his bearing line and made yet another minor adjustment to starboard, which he announced on 16. Unknowingly, they were incrementally turning towards each other as they progressed.

 

At about one mile, the mate on Vessel A switched to manual steering. The report states, “Shortly afterwards, he altered course further to 083° and then saw the other vessel end on at about 45° on the port bow. He called on the VHF, ‘I am going hard to starboard,’ and then applied full starboard helm.” None of these radio communiqués was heard by Vessel B. Vessel B suddenly saw the port side of Vessel A, changed to manual steering and turned hard to starboard, but it was too late to avoid collision. Fortunately, the damage to both vessels was above the waterline, which allowed them to return to port safely without injuries or pollution.

The Mariner’s Alerting and Reporting Scheme report contained these conclusions:

·         Though many officers like the radar display setting with ship’s-head-up, it limits the accuracy of monitoring other vessel’s movements. “As mariners are told over and over again, ‘Assumptions shall not be made on the basis of scanty information, especially scanty radar information.’”

·         The mate aboard Vessel B failed to establish that a risk of collision existed.

·         The mate aboard Vessel A failed to appreciate that both vessels had an obligation to alter course to avoid the collision. “Although he eventually altered course… he should have acted sooner and more boldly.”

·         Vessel A placed too much importance and lulled himself into a false sense of security in trying to communicate intentions on the VHF rather than adept, mutual compliance with Collision Regulations.

·         Vessel A made several small alterations to starboard, whereas one, bold alteration would have been more obvious. Even on impact, neither vessel reduced speed leading into a close quarter situation.

·         Neither vessel had a dedicated lookout posted despite the poor visibility conditions.

·         Although sound signal regulations are throwbacks to the days before advanced electronics, sophisticated radar and ARPA, and despite the fact that they may annoy guests on deck, they still play a vital role at sea. Investigations into incidents like this one often reveal that the vessels involved were not making required sound signals.

 

 


Koru International
Posted: Tuesday, May 25, 2010 7:32 PM
Joined: 07/10/2008
Posts: 9


I realize that as Captains, we have many esponsibilities. The most important being safety of all passengers. To have 'poor' visibility on not be on the bridge is beyond me. It was 1200. Were the respective Captains having lunch below? Could they not have taken lunch on the bridge? Also, especially when the weather is bad, I encourage more eyes up top, with the known fact that if you see it, say it. No hesitation. Help your watchstander as much as possible. No music gets played when the conditions are bad. That's when you need to be able to hear everything. With regard to their actions it truly surprises me that neither one of them altered speed. At all. That is the second rule when in doubt, the first being contact via VHF. When noone responded, vessel A should have immediately slowed until intentions were clear. In addition, I always teach that course changes should be deliberate. Let the other vessel know your intentions. Then you can ease back over when and if you feel comfortable. I have done this many times with my mate in very close quarters so that she can see how well it works to convey my message to the other vessel. It seems as though inexperience in many ways and insufficient traing was the culprit here.
14Freedom
Posted: Tuesday, May 25, 2010 11:45 PM
Joined: 16/04/2009
Posts: 155


"Despite thick fog conditions, no fog signal was being sounded because it was not normal practice unless there was traffic in the immediate area."
Hey All,
"The mate aboard Vessel B failed to establish that a risk of collision existed.
·         The mate aboard Vessel A failed to appreciate that both vessels had an obligation to alter course to avoid the collision. “Although he eventually altered course… he should have acted sooner and more boldly.”

·         Vessel A placed too much importance and lulled himself into a false sense of security in trying to communicate intentions on the VHF rather than adept, mutual compliance with Collision Regulations.

·         Vessel A made several small alterations to starboard, whereas one, bold alteration would have been more obvious. Even on impact, neither vessel reduced speed leading into a close quarter situation.

·         Neither vessel had a dedicated lookout posted despite the poor visibility conditions."



DUH...COLREGS are there for a reason, some just never learn.
Good thing no one was injured and they both made safe port. Both vessels Captains and Mates should be held liable. I couldn't imagine going to sea with such inept crew.

ATB-
The Slacker

Henning
Posted: Wednesday, May 26, 2010 1:29 AM
Joined: 01/06/2008
Posts: 1049


One thing that wasn't mentioned in the report was whether the vessels were all AIS equipped or nor. Without AIS or some other method of positive identification, VHF communications are of dubious value when multiple vessels exist in close proximity. No mention was made of how the vessels identified each other. As to "where was the captain?", he may have been asleep and not been called. This is one of the reasons my standing orders include "The moment you start to suspect there is a questionable situation arising or any doubt in your mind over anything that is going on is the time to wake me, do not wait until we're in a bind. I'll never fault you for for getting me up early in a developing situation even if it turns out to be nothing."

On another note, this type of situation is also why the captains cabin should always be in very close proximity to the wheelhouse, not down below as I see on many boats.

As for no fog signals, not much of an excuse there, most boats are fitted with automatic signaling devices. The passengers on deck will understand when you explain to them "This is first and foremost a ship at sea, and that signal is required and vital to your safety."

Marc
Posted: Wednesday, May 26, 2010 5:18 AM
Joined: 03/07/2009
Posts: 4


I am basing these comments on the article as reproduced by Dockwalk above and not the full MARS report so my apologies if I am wrong but I think each of us is (or should be) well aware of the errors made and the report covers these issues sufficiently that I see no point in reitterating them.  My concern lies with some of the replies. Comments made by others imply that the captain should always be on the bridge and that as it was midday he was probably having lunch are not particularly helpful.  The article gives no indication of how long this period of reduced visibility had existed, is the captain supposed to remain on the bridge indefinitlely without rest to the detriment of his ability and concentration?  If you are a Med/Caribbean captain, fog may be such a rarity that you have forgotten it can last for days, not hours. I thought the general gyst of the MARS report was that wrong assumptions were made, I would suggest you extend this to your own thinking too.
2. The same person commented that the "first rule is contact via VHF".  Strange, not according to all the COLREGS books I have.  In fact, nowhere in COLREGS does it advise to contact via VHF in any close quarters situation, as time and time again, this has historically resulted in misunderstandings and collisions.  I agree with Henning that AIS is useful in determining which vessel is which but until it is compulsory fit on ALL vessels that could show on a radar screen, it is still extremely unreliable.  All decisions should be based upon the rules as set out, not on your own variations of them or how are we all supposed to respond.

Powerabout
Posted: Monday, December 13, 2010 1:29 PM
Joined: 22/11/2009
Posts: 14


In the commercial world you are taught to slow down in a close quarters fog.Which may mean you end up bow to bow and stopped.
Any other answer in your orals and you will fail

 
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