Bourbon Dolphin capsizes

Great find RayK. ..... a picture is worth a thousand words!.... 40 min before capsize !!

When they lowered pin A, the chain (330T tension) struck pin B like a massive sledge hammer. With the help of the shape of the whaleback (upward motion), the retaining plate on top of pin B was torn away. The chain jumped to C and D as described by the crew.
I doubt the pin was bent or pulled out. Braatvag stuff is built strong. Hopefully the BD is sitting up or to the side and the ROVs will confirm.

 

Yes, that's the scenario I envisioned. Very different to see it laid out on a photo.

Rayk, thanks for that photo. No pleasure here, but seeing the ship in action a short while before she went over .... I have a much more vivid realization of the incredible job those guys do every day.

 

The UK's Marine Accident Investigation Branch confirmed yesterday that they would not carry out their own inquiry because the incident happened in international waters and the casualty was not British.

"It is outside our jurisdiction", the spokesman said, adding that the agency would only get involved if invited to do so by Norway.

The norwegian government inquiry will be held in private and is expected to report within four to six months.

 

I noticed that the anchor on the deck would probably get in the way if the chain moves to the port staghorn. Could that be a cause for the failing emergency release? Sorry if that sounds stupid, I just wanted to ask.
Regards
Johannpeter

 

Doesn't sound stupid to me. We are all guessing here and trying to understand what happened, with very little info on the table.
Very nice job, Rayk! Keep on searching for info like this!
I recognize my supposition was wrong: Anchor was on deck and there was no cable, but chain over it. Thinking back again.....

Given the apparent angle of the chain when leaving the stern, may we say the horizontal componet of the 330 tons tension could have been bigger or very close to the total bollard pull of the vessel?

 

from my experience that sea state is not scale 7, the tops are only just coming off, abt 15 knots, ah well jus saying hey there are so many stories nice photos

 

As per the stability study posted by smarbight, trim with anchor on deck and 282 tons of chain hanging from the stern (I asume they considered it a vertical load) should be 7.65 ft from the stern, or the like, thus very little freeboard should have been remaining there. I doesn't look like that at Rayk's photo, and, even considering the load is not vertical but angled, I'd dare to say the load, at the precise moment of that image, was not as much as 330 tons. What do you guys think?

 

I just watched the half an hour long documentary on TV, nothing new, but very emotional. One of the crew from Highland (do they all have whiskey names?) told us how the picked up three of the survivors. The weather was not bad, but they noticed the large waves when they launched the lifeboat.

 

when you step from a ship to a boat you notice waves , put the waves on top of the swells seems high in small boat

 

The second skipper (if you say so) from Highland said they wouldn't launch the boat without a good reason in those waves, not just for an emergency exercise for example, but he seemed quite relaxed about the weather.

 

WEATHER AROUND 1200-1400, MATCH PICTURE, as per quote:

The vessel was only a few months old and weather conditions were said to be perfect.

WEATHER AT 1700, TIME OF CAPSIZE, SQUALL BLOWING THROUGH, as per quote:
Syversen said there were six persons on the bridge when the ship capsized "and I flew out. I tried to climb up onto the hull, but was caught in the drag." The wind was blowing at 32 knots, the sea swells were nine meters high and it was three degrees Celsius in the water. Syversen wasn't wearing a life vest.
WEATHER AT TIME OF RESCUE, 1730 +
Once the 14-foot rescue boat was launched Mr Dickson caught sight of three men clinging to a large plastic storage tank with wire frame around it. With winds up to gale force seven and seas of up to three metres the small boat was battered by the elements.

As lazyjack said it looks worst when you are in the drink.
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INFO ON ANCHOR RODE
The vessel was around 5200ft from the rig when it capsized, around the limit of the anchor cable. The mooring leg consisted of rig wire, +/-900m 76mm chain, +/- 900m 84mm chain and anchor.

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Guillermo; My buddies in NOLA tell me the stability calcs are just 'ball park' just to see what happen when you have a 300T leash around your neck. They will refine as more info is made public.

 

Johannpeter,

Your question does not at all "sound stupid". I think you made a very good observation. There was no mention of another anchor on the deck of Bourbon Dolphin in any of the accounts so far. It may not have been considered very important, as the load would be negligible under "normal" circumstances.

If the reported time of this picture is accurate, however, it is possible that what you suggested did happen. When the chain rode up the whaleback and bulwarks, moving forward, it could have caught on the anchor, and that could have restricted it enough to prevent a quick payout when the emergency release was activated.

All of our observations are incomplete as we try to learn more about what happened. What you asked is certainly possible, at least. Thanks for sharing your observation.

 

Thanks for your comments, charmc.

 

I knew she had a anchor onboard since it was writen in the media that she was working on number two.
I did not pay mutch atention to it since I would exspect the crew to talk about it if it was a mather.
Now seeing it I realise that if your in the weelhouse the location off it would be hard to see trough the weelhouse window unless you really want to see it.
A good observation.

 

smartbight,
at our office we are working on the analysis of a similar vessel to BD, just a little bit bigger:
L= 83 m
B= 17,6 m
H= 8,7 m
D = 2862 T (lightship condition)
First thing we realize is the VCG is in our case is 7,1 m for lightship condition (as per a detailed weights study, not stability test derived, this has to be clear) while the one in your 'BD cousin' study is 9,3 m
Moulded depth for our vessel is 8,7 m so we are getting a VCG lower than deck height. In your case 'BD cousin' moulded depth is 8 m, so your estimated VCG is clearly higher than deck height.
We are willing to study the significance of the Tow Tripping Criterion with C4 and C5 coeficients made equal to 1, and whinch tension pull (not the bollard pull) for the worst possible case.
As we do not have expertise in this kind of vessels, we would like to confirm with you the VCG issue, before going any further.
Thanks in advance.
Cheers.