Bourbon Dolphin capsizes

Ok Walrus has the gog / gob and girting.
Shark jaws, karmfork, AH Tong all do the same thing though in different ways, they are used for holding a wire or chain so that the deck crew can connect / disconnect / work with, if the winch operator on the barge / rig is known to do random actions their use can prevent the vessel being girted as rigging a gog / gob when you are anchor handling is not often an option.
The use of the shark jaws as a gob does restrict the handling of the vessel.

I have experienced being dragged astern at speed and the vessel digging her stern in and trying to turn, only having the wire locked in the shark jaws prevented the vessel being girted, the anchor was at the roller and ended up on the quarter for awhile, as the winch operator was not listening to the radio we dumped the wire, letting the brake go takes awhile sometimes...

www.karmoy-winch.no/anchorhandling.htm has picture of Karm fork

 

If I'm not mistaken Ulstein use odim winches and I also think they make or used to make there own shark jaws and towing pins. http://www.odim.com/

They used there own winches until they sold the enginefactory, automation, winch, proppeler, steearing gear to vickers now rolls royce.

Looking at the ulstein homepages they seam eager to find the reason for this to hapend.

I remember the old ulstein I was on had high stabilety witch was estremly uncomfertable. I moved to quickly so you had only a thin layer off pink skin left on your back after trying to sleep so that there is a chance stabilety is secrafised for comfort in later designs.

 

All the funny words...

OK, this is really interesting.... What I see so far:

1. A need to control the tow horizontally where it comes aboard astern, to prevent it shifting to the side, and forcing the hull to roll or capsize.

2. A need to hold a tow while working on rigging or disconnecting it from a winch.

3. A need to disconnect the tow quickly in an emergency situation. Reid's Primer mentions having a cutting torch set ready to go to cut a cable. Wow, that makes for a cliff-hanger of a movie, as the tow suddenly sinks and starts to pull the stern under...

Are these about right?? How do the "words" / devices fit these needs?

I'm getting another G.H. Reid book on Shiphandling With Tugs. Is there something good about the offshore rig support ships? I know a book is a long way from the open ocean, but it's all I can do right now.

Starting in August I'll get to know people who are working offshore in the South China Sea for Phillips, British Petroleum etc. I'd like to have a clue about those kinds of operations.

 

Gas Axe ready to cut the wire - jesus you'd need a bloody big gas axe to cut thru' a 54 mm wire!!! Knock the brake off and let it run is slightly better!

Rigger remember the old pelican hooks or was that afore your time! **** they were heavy! especially with a deck crew of mate and two! the fun thing was taking the pin out! with a ton of bouy updeck it tended to make you very nippy! released it with the tugger whinch until that pulled out and then it was aimed swings of a sledge! Used to get brown trousers out of that bit quite regularly as it was the mates job if it went wrong (and it frequently did) went through a six month period in the north sea were they killed 7 guys! 6 of them were mates! Started to look for another job after that, running out of luck! these days the mate gets to drive rather than jump around the deck! How times change! And those forks have really made life on deck safer too!

Yes Terry there is something good about the Oil Support Industry but I can't remember what (apart from the buzz!) Bit like combat without the chance of firing back but knowing roughly when your going to get it!!!!

 

You see, most people don't know a thing about what it's like out there!

Hell, I've at least been on the water, built a couple boats, interested in Tugs to where I bought a couple books on them. But it became clear real fast in this discussion that I had No Idea!

I'm hoping to get an invite, maybe as a Photographer, on some of the support ships out of the Shenzhen area. Supposedly quite a few parents of the kids in the school Mary Alice will be teaching at are BP and Phillips employees. That don't mean they go offshore, I imagine, but the guys that do can't be far away...

I bet lots of them will immediately react to the words "Bourbon Dolphin" !

 

In addition to books go to Mr. Ebbe Holsting's site and study the A.H. steps + his second site with great pictures. State of the art !!! One of these pictures below shows the 'size' & 'weight' the crew is struggling with.

www.menkent.dk/anchorhandling.html
www.menkent.dk/picassister.html

Although these anchors are big, the deck scantling can deal with them. That is why I don't think damage stability was involved (no report of collision). Beside the compartments and tanks below are like a Navy destroyer. Sure the fwd E.R. vents got flooded but only around 60-80 deg. into the roll over and after intact stability was lost.

We are dealing with 2 hulls here. Hull moving forward: nice focsle with "big slab sides" as Lazeyjack says and plenty of Intact righting energy. Hull moving backward you are looking at a barge with low freeboard and a deck that is easily swamped. If that stern deck is pulled under and heeling to one side your waterplane moment of inertia & KMt is decreasing fast. Your focsle Righting Energy comes in too late.

StianM says:
"I remember the old Ulstein I was on had high stability witch was extremely uncomfortable. It moved too quickly so you had only a thin layer off pink skin left on your back after trying to sleep so that there is a chance stability is sacrificed for comfort in later designs." As an 'old salt' you are on the right track, but I would rather have my 'behind' raw than admiring fishes through the 'panoramic' P.H. windows turned 'aquarium'.

As a designer of this type of vessels; I cringe looking at the superstructure+pilot house+ bigcrane+lifeboats that high. Looking good for a cruise ship! but an ocean going tug ? doing A.H. work ???? Glad my name is not on the Trim & Stability Booklet. You can meet minimum required stability criteria and structural scantling and end up with a lousy tug.

 

So far, the statement I found in the Glasgow newspaper is the closest thing to an eyewitness statement addressing the cause of the capsize. If this is accurate then it was a case of girding, as was the capsizing I witnessed personally (post # 23). Assuming for discussion that this statement is reasonably accurate, the question becomes: what force would be strong and rapid enough to cause a sudden turn and force the cable out of the "mechanism at the rear of the deck which held it"? It sounds like something like a karmfork/towing pin was in use. The words "jump" and "turn sharply" have me wondering if the anchor cable or chain snagged on a part of the rig, something on the bottom, etc. I suggest this because from the account it would seem that the force was both sudden and at a large angle to the tug's direction of pull. Snagging seems to explain both, in my opinion, which is not expert in this area.

Another question might be why the winch wasn't immediately allowed to spool to relieve the pressure....that is meant as an informational question only, no criticism intended at all. As Terry said, those of us who have not worked on an AHTS have no idea of how quickly or in how many ways things can go badly. The anchor handling website mentioned by smartbight says, in one of the photo captions, that for things to go exactly according to the standard procedure was the exception, not the norm. Looking at those photos of the anchors and towing gear, and thinking of pictures I was shown by some drilling rig crew I met along the Gulf coast in Texas, it seems, as Walrus mentioned, that all too often something goes wrong quickly, giant forces are turned loose in non-designed ways, and the men have to catch it quickly, sometimes in seconds, or it causes a disaster, as happened here. All those who work on the sea deserve respect for the skill and courage they show daily.

 

Ebbe Holsting has done an amazing thing with his site! I feel I'm starting to get the feel of this, if not the actual scope. This stuff is HUGE!

Going thru Ebbe's step-by-step it seems that the intention is to never leave the anchor chain untensioned, slipping around on the bottom. In fact, it seems the anchor chain is, ideally, not touching bottom during the retrieval or positioning of an anchor.

It seems something went very wrong here. As Charlie said, "it seems, as Walrus mentioned, that all too often something goes wrong quickly, giant forces are turned loose in non-designed ways, and the men have to catch it quickly, sometimes in seconds, or it causes a disaster, as happened here."

Someday, we'll understand what went wrong. And hopefully, procedures will be designed to prevent it happening again.

 

Hi Charmac, just on what you put up - "rapid enough to cause a sudden turn and force the cable out of the "mechanism at the rear of the deck which held it"? It sounds like something like a karmfork/towing pin was in use. "

Well if the spring in the karmfork failed the wire / chain could have come out, have had it happen just after the Chief engineer saying that it was impossible. The springs do fail, 2 new ships with the springs on each karmfork failing within 6months of commissioning, I have had pins made up to prevent the wire / chain getting loose when the crew are working them, but it gets fitted manually, and if left in once the crew have cleared the deck there is no way of releasing the gear.
I prefer the triplex shark jaws but they have their own weaknesses, ie wear and tear can prevent them locking in the safe position for the guys to work them.
I am very interested in finding out what has happened here as this is not the first instance of a vessel going over when anchor handling. More / adjustments to the regulations may be needed as with out them the companies will only comply with what is there.

A question - Water tight doors fitted below the main deck line, should they be able to be remotely controlled or just have an indicator on them and to rely on them being closed by the crew using them?

Walrus I have been lucky enough to avoid having to use pelican hooks, still carry them incase the other gear fails, saying that unless it was critical to do the job I would stand off as very few crew have any experience using them where I have been working.

 

From Shipspotting.com forum:

The loss of the "Bourbon Dolphin" was not as singular an event as sometimes called in the recent days. F.e., on 19th October 2003 a Danish AHT, the "STEVNS POWER", sank whilst operating off the Nigerian Coast. She was at the time moving an anchor, one of 12, that was holding the position of the "CASTORO OTTO", a pipe laying vessel. Unlike the BOURBON DOLPHIN she was not a new vessel, being built in 1976, but the procedure was one she and her crew were largely familiar with and had been doing so regularly for at least two years with the CASTORO OTTO. It is the job of an anchor handler to re-position the anchors that keep a rig or other sea platform in their desired position. The CASTORO OTTO was laying a gas pipe and needed to relocate her anchors. Late that afternoon STEVNS POWER began operations to relocate anchor No.10. She lifted the anchor off the sea bed and indicated she had done so and CASTORO OTTO's winch then began pulling the anchor wire with STEVNS POWER manoeuvring astern as this was done. The tug then executed a turn, necessary to keep the anchor cable following a straight line to the new position for the anchor, when suddenly she heeled over. It appeared that her stern plunged below the surface of the sea and within a minute the vessel was so overpowered by the ingress of water she capsized, leaving just her bow sticking out of the water. None of her 11 crew survived the tragedy. A subsequent inquiry concluded that factors which had contributed to the loss of the vessel and her crew included: Lack of proper safety procedures between the pipe laying vessel and STEVNS POWER, the practice of having very little freeboard aft to allow easier lifting of the anchor buoy, the turning manoeuvre and the speed at which the anchor line was pulled in from the client ship. The tug was going astern too fast. Open hatches and perhaps open watertight doors (the heat in the region probably meant crew left doors open instead of closing them as is normal practice during anchor handling) There were other factors that could have contributed, but the inquiry did not have sufficient evidence to establish if they did: these included the anchor wires snagging, failure of steering gear (the STEVNS POWER had had problems with this before the incident), lack of experience on part of the navigator at the helm at the time or fatigue on his part. The report also concluded with a warning to crews not to wish for speedier, but safer operations. A few minutes saving was not worth the risks involved. The tragedy focussed minds on how potentially dangerous anchor handling is. Here were experienced hands on a vessel that had performed such tasks over and over again, often many times in a day, and in the relatively calm waters off the African coast.
Every day in our waters these vessels, with the expertise of their masters and crew, bravely carry out their duties in seas that can be hostile indeed. The general public never give such matters a second thought, nor do many shipping buffs for that matter, and whether or no the BOURBON DOLPHIN tragedy proves to have any similarities with the one in 2003, we must always remember that it can take just one minute for any operation to change from routine to disaster

 

I hope you read Norvegian.

 

Very good posts, smartbight, thanks a lot.
I do not read Norwegian, but having a look at the nice explicative sketch, I find something is missing there: a line fixed to the oil rig has been mentioned by witnesses as being involved in the accident. This doesn't appear in the sketch.

An anchor weighing 18 tonnes plus the weight of the rode, how much is that with nowadays materials for the rode? Is that enough to turn turtle a ship like this just by pulling from the side, as in the drawings? The anchor seemed as not being holding tight at the bottom, but hanging from stern or aboard. Slippage has been mentioned. Could hanging side weights have been the only cause? Sounds strange to me. Could you quantify this effect for us, simulating it for one of the AHTSVs or OSVs you have designed?

Witnesses' reports seem to me to imply a different situation, something like the ship having the anchor hanging from the stern or on deck, and at the same time having the rode (or another line) attached to the drilling rig. A quick turning maneouvre made the attached line to pull hard from the side, this heeling the ship and inducing slippage of whatever not fixed items on deck and the hanged anchor coming also to the side, all contributing to the capsizing. Am I right in this interpretation?

I agree with you low freeboard astern and high structures forward decisively influence stability, absolutely, even more if there is an accentuated stern trim situation as to inmerse the deck aft, but if I'm not wrong this situation has not been clearly reported in this case. I still think we cannot discard a heeling induced massive flooding into supposed WT spaces under or at main deck level, as playing a significative role in this capsizing. Watertight integrity depends strongly on crew actions or omissions. Riggertroy question on remote controlled openings is a very good one.

Cheers.

 

Is this drawing accurate?

Ebbe Holsting's description of anchor handling on a similar new ship never shows an anchor and rode being winched like this drawing shows. Only the anchored ship/rig would be pulling the rode end with the anchor on the bottom.

The Anchor-handling ship, from Ebbe's details, lifts the anchor by a chaser wire. An anchor with the round chaser is shown here: http://www.menkent.dk/assistpics/anchor.jpg

Ebbe shows the chaser wire lifting the anchor itself directly here: http://www.menkent.dk/anchorhandling7.html

What was the Bourbon Dolphin doing at the time? Was it re-positioning the anchor, with the rode still attached to the rig? Could it have snagged on bottom?

I have only questions, no answers!

 

If I understand it right the rode is 160kg/m, the wire (to controll the angle of the anchor) is 30kg/m. The drawing indicates a depth of 1000 meter. This means 200 tonns of rode+wire, but the text sais 300 tonns for anchor+rode+wire. I suppose that means approx 1500 meter of rode+wire. I can't see in the drawing where the wire was attaced.

Tomorrow night, Wednsday April 25, at 22.30 Norwegian Broadcasting will show a documentary, maybe with some new info.