Dec 082014
 

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Seven years ago Bourbon Dolphin capsized during a rig move. It was a tragedy that sent waves thorough the offshore industry but have the lessons been learned?

It is still dark early on the morning of 30th March 2007 in Scalloway, Shetland as Norwegian Captain Oddne Remoy boards the Bourbon Dolphin for the first time. Bourbon Dolphin is less than a year old, painted in the distinctive green and white house colours of Bourbon Offshore Norway. She flies the Norwegian flag.

Remoy is to relieve from the vessel’s existing master, Frank Reiersen, as part of the vessel’s shift – five weeks on and five weeks off and is replacing the ship’s other regular master, Hugo Hansen.  Hansen and Remoy have already discussed Bourbon Dolphin by telephone.

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With Captain Remoy is his 14 year old son David. He is expected to follow his father’s trade, he is on leave from school for work experience. Captain Remoy specially requested to take over the Bourbon Dolphin. He might have thought that being aboard the new, state of the art vessel would be good experience for David.

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Transocean Rather

Remoy meets with the outgoing master, Frank Reiersen, completes a familiarisation checklist and a briefing about the vessel. He also covers the rig move plan, RMP, which emphasises that Bourbon Dolphin will act only as an assist. Reiersen has even underlined the reference in the RMP onboard to the ship and says that the marine superviser for the rig move has agreed that the ship was too small to act as a primary vessel for anchor handling.

All this takes about 90 minutes. With the handover complete, Reiersen disembarks and Remoy is now in command.

The rig move is being handled by a specialist consultancy called Trident, based in the UK. Earlier, Captain Reiersen, the Trident marine supervisor, Sean Johnson, and others involved met to plan the move. Reiersen later recalled that during the meeting he was advised that the expected forces on Bourbon Dolphin would reach 194 tonnes and that he objected that the Bourbon Dolphin’s bollard pull of 180 tonnes, which was inadequate for the job.

Whatever was said, he understood it to mean that Bourbon Dolphin would act only as an assist vessel, grappling anchor cable and helping to relieve the forces on another primary vessel that would actually handle the anchor.

imageJohnson recalled the meeting differently and later said that the plan always included using Bourbon Dolphin as a primary vessel to lift the anchor off the bottom and carry it to a new location. Reiersen and Johnson left the meeting with very different expectations . Reiersen’s expectations are now Captain Remoy’s expectations.

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Anchor 2 aboard Bourbon Dolphin

Shortly after 05.30 lines are let go and the journey to the oil exploration rig Transocean Rather in the British sector of the Rosebank Field begins. She will arrive at 1500 local time. There is a crew of 14 onboard, organised into two watches of five and a day crew of four. None of the bridge officers have significant experience in deep water anchor handling. The depth around Transocean Rather is more than 1,000 metres.

Bourbon Dolphin is heading into an operation that is already underway and considerably overschedule with a master unfamiliar with the vessel and a crew he hasn’t worked with before.

The Rig Move Plan calculated five days and eight hours to completion. Bad weather and equipment failures mean that by 12 April the operation has been underway for 18 days and that is the day when the rig is fully manned for operations.

The pressure is intense.

The Final Day

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Olympic Hercules – struggled to deploy anchor 6

The morning of 12 April and at 0230 another AHTS, Olympic Hercules begins to handle the second to last anchor, Number 6, to a position some 3,000 metres to the south south east of Transocean Rather.

The current was normally around 2.5 knots but this morning seemed stronger, running to nor-nor east to north-east. Significant wave height is 3.5 metres to a maximum of 7 metres with winds of 35 knots.

The tug takes the anchor chain from the rig, to be followed by a wire, but finds it difficult to hold the line even with her lateral thrusters at full and using propeller and rudder.

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The track of the Olympic Hercules

By 0655, as the enormous Bruce anchor is attached to the wire at the stern of Olympic Hercules and dropped overboard, she’s drifted to port by as much as 650 metres and ends up 400 metres off course. It takes the help of another vessel, Vidar Viking, to grapple the chain, a normal part of the process, and the slackening off of the wire from the rig for Olympic Hercules to make enough headway to manoeuvre.

By giving starboard rudder and full speed ahead and use her lateral thrusters, Olympic Hercules manoeuvres against the current and up to the line, listing up to 12 degrees to starboard. The anchor chain shifts between the outer towing-pins.

At 1230 anchor number 6 is successfully deployed in the correct position.

To reduce tension on the rig, the anchors are being laid down in diagonal pairs, so anchor number 2 is to be positioned about 3,000 metres in the opposite direction anchor 6, in other words, north north west of the rig. That is Bourbon Dolphin’s task.

While Olympic Hercules was struggling with anchor 6, Bourbon Dolphin had already begun its work with anchor number 2. anchorcurrent Since around 0920 when the rig chain was connected to her winch, Bourbon Dolphin has been running out chain for the last anchor at about a quarter of a knot.

The rig’s chain runs between the starboard towing pins at her stern on the main deck where the last 18 tonne Bruce anchor awaits deployment.

Fifteen minutes after the bigger and more powerful Olympic Hercules finishes deploying anchor number 6, Bourbon Dolphin completes running out the rig’s 914 metres of chain, attached chain from its own chain locker and continues to try and follow the line to the number 2 anchor position. Her two lateral thrusters are running at full. The Chief Engineer is concerned enough to stay in the engine room after his shift finishes at noon.

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Compare the track of Bourbon Dolphin with that of Olympic Hercules

By 1300 the thrusters are overheating and the first engineer tries to cool them down with a high pressure air gun. Bourbon Dolphin begins to drift off the line at around 1345, pushed by the weather and the increasing effect of the current on the chain she has pulled from the rig.

By 1417 she’s 1,200 metres from Transocean Rather and is 185 metres off the line and still drifting. At 1430 Bourbon Dolphin asks for the help of Highland Valour to grapple for the chain and take its weight allowing Bourbon Dolphin to get back on line.

It is now about 1445. The chain from the rig is now completely out and attached to the workwire from Bourbon Dolphin. At about 1500 the telephone on the bridge buzzes, it’s the first engineer asking that the thruster be eased off. The Chief Officer refuses the request.

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Highland Valour – A close call with Bourbon Dolphin was unreported

Bourbon Dolphin is loosing its fight against the wind and current, critical equipment is almost continuously overheating. She can’t hold her position and she’s drifting eastwards rapidly towards another anchor position and there’s a danger that she might snag. Nobody tells the rig there’s a problem.

She calls the rig, which sends another vessel, Highland Valour, to assist. She’s to grapple the chain and take the weight, allowing Bourbon Dolphin to get back on line. Fifteen minutes later the Highland Valour has come astern of Bourbon Dolphin, is over the mooring line and ready to grapple.

The Bourbon Dolphin is then 559 metres off the run-out line and her distance from the anchor deployment position has increased to 2,016 metres. Highland Valour sinks the grapple to 900 metres but fails to find the chain. The grapple goes down again, this time to 700 metres and makes contact with the chain.

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Just after 1600 thrusters churn the waters around Bourbon Dolphin

Over the half hour from 1530 to 1600 Bourbon Dolphin makes little headway, just 30 metres but her drift increased from 650 metres to 730 metres. By 1610 Highland Valour succeeds in grappling the chain about 240 metres aft of Bourbon Dolphin. There was powerful tension on her winch, at the same time Bourbon Dolphin registered a fall in tension.

Over the next ten minutes Bourbon Dolphin’s drift increases further to 840 metres off-line and the distance from the anchor deployment position is now 1,970 metres.

Video:Animation of Bourbon Dolphin’s attempt to deploy anchor

Exactly what happens next is confused. At 16.26 Bourbon Dolphin suddenly appears to loose power and drifts at high speed sternwards toward Highland Valour, bringing the vessels within inches of each other. As the two vessels manoeuvre to avoid collision Highland Valour loses its hold on the chain as Bourbon Dolphin comes full ahead and Highland Valour manoeuvres away from her.

Highland Valour asks the rig if a third attempt should be made and is told no. On the rig it was feared that, given the position of Bourbon Dolphin any further attempt to grapple her chain might snag the mooring line of anchor number 3 to the east of her.

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Moments after the close call

Both vessels are told to move westwards away from mooring line 3. By 1647 Bourbon Dolphin is 1,019 metres away from the line but struggles back to 936 metres over the next seven minutes. Nobody tells the rig about the near miss but Captain Oddne Remoy is called to the bridge of Bourbon Dolphin to take command at 1650 and his schoolboy son David probably comes with him.

Also on the bridge is the chief officer, who’s the officer of the watch, both of the ship’s first officers, including Gier Torr Syversen on his first time onboard, and an able seaman. The chief engineer calls the bridge and asks for reduced use of the overheated thrusters.

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30 minutes before capsize, with chain between the starboard towing pins, note chain veering to port.

Bourbon Dolphin has taken on a small but persistent list to port. Anchor chain runs between the inner and outer starboard towing pins but then veers to port, inducing the list to the same side as the heavy Bruce anchor on the main deck.

To try and trim the vessel ballast is pumped from the port to the starboard ballast tanks. There’s a radio conversation with the rig, which suggests attaching the chain to workwire and running it through the pins in an effort to improve manoeuvrability.

Exactly what was said in that conversation isn’t known for sure, but shortly afterwards the inner starboard towing was dropped and the chain smacked hard against the out port towing pin with a loud bang. But the list gets worse, increasing to 30 degrees for 15 seconds before she manages to right herself.

There’s a puff of black smoke from Bourbon Dolphin’s exhaust stack and the electric power flickers off then back on again. There’s a call from the engine room, the starboard engines have stopped.

The list to begins again,this time it doesn’t stop. There’s a warning from Highland Valour to release the chain. At 1708, Bourbon Dolphin capsizes. First Officer Syversen activates the winch emergency release then struggles to open the starboard bridge door. Getting it open he looks back to see Oddne Remoy and his son and the AB falling to the port side of the bridge and the other first officer trying to get into a survival suit.
Video: Visualisation of the last moments of Bourbon Dolphin

Syvrsen makes it out of the door and climbed up onto the starboard railing as the vessel capsized, dragging him under the water. When Syversen surfaces he finds another crewmember clinging to a float.

Five others survived the capsize. David Remoy, the schoolboy who wanted to follow his father’s footsteps, was not one of them. Three bodies were later found, another five remain missing. For the next few days, the Bourbon Dolphin remained afloat, inverted, until, on Sunday, 15 April, she finally sank to the bottom, more than 1,000 metres below.

The loss of the Bourbon Dolphin and half her crew was a national tragedy for Norway and a wake up call for the offshore industry, in its own way as important as the Piper Alpha disaster in 1988. A vast safety net that had been built up over the previous 21 years had failed to protect the lives of the men aboard Bourbon Dolphin.

We’ll be looking at what went wrong in next week’s episode of The Case of the Toppling Tug.

This is Bob Couttie wishing you safe sailing.

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