WWW.SHIPSANDOIL.COM

PIC OF THE DAY

SHIP INFO

FEATURES

NEWS AND VIEWS

PUBLICATIONS

WEBCAM


 


 



 


 

 

 

OFFSHORE TECHNOLOGY AND THE KURSK

Not for the first time has the versatility and technological capability of the offshore support fleet astounded the military - although in this case the military were the Russian Navy and their own much more limited capability was exposed to the world.

It only comes as a surprise to those not familiar with the offshore oil industry and the demands it places on ships and those crewing them, that the Navies of the world do not have the same level of technology available and their personnel often lack the same levels of skill and experience.

Back in the 1970s when the industry in the North Sea was in its infancy those interested in the level of support which might be provided by the British merchant service to the Navy were extremely surprised by the capabilities of the supply vessel fleet. Even then the average anchor handler had about 7000 bhp available which was the same power as that provided for a medium sized merchant ship. They could hover on the spot for moderate periods of time and move in any direction at will, and they had a range which would allow them to steam to the other side of the world without refuelling.

In 1982 a number of support vessels went to the Falklands either with the Navy or immediately after the war. Most noteworthy was the Stena Seaspread, a diving and maintenance vessel which was taken to the Falklands to act as a floating workshop for the warships. Its manoeuvrability was such that it is rumoured that the warships stayed still and then the Stena Seaspread would move alongside and its workshops and cranage were a revelation to the military. Admiralty pattern moorings were also required for the fleet in Stanley Harbour a task which took an admiralty mooring vessel several weeks to complete back home. The Wimpey Seahorse an 8000 horsepower anchor-handler laid moorings in hours instead of days, amazing everybody. The admiralty bought a few old Seaforth ships for training purposes and commissioned their own diving ship, but it seems that neither of these projects was successful, which some attribute to communication difficulties between the officers and the crew.

The Seaway Eagle, which we believe was originally a cable ship, has even greater capabilities than the Stena Seaspread, and modern positioning systems allow these craft to use GPS and place themselves within a few meters of any position on the earth's surface.

Seagle2S.jpg (32909 bytes)

The Seaway Eagle was, we believe, origin- ally built as a cable laying vessel which accounts for the strange bow shape. In this picture the large construction crane can be seen. The moonpool from which the diving bell is deployed is in the centre of the ship. This minimises the effects of the sea and swell.

The helideck is in front of the bridge on top of the accommodation.

Since the working limit for air divers is about 100 ft, almost all diving ships are provided with a hyper-baric habitat in which up to 12 divers can live under pressure for a considerable time. This allows on-shift divers to work on the seabed and those off shift to rest without the problems associated with decompression. For the Seaway Eagle placing three divers on the seabed in a precise location and putting them to work was easy.

A more modern addition to the armoury of offshore subsea equipment is the ROV - remotely operated vehicle - which is a small submarine provided with thrusters and with a camera and in many cases manipulators, to allow it to do work. ROVs are operated from the mother ships by pilots The Seaway Eagle has at least one of these, and it is thanks to the ROV hovering close to the divers that the pictures of them at work on the escape hatch were available. It also looked as if the ROV was used to release the hatch and it is most probable that once the special tool was made for the hatch valve, it was the ROV which transported it from the surface to the divers waiting below. 

wpe1.jpg (9070 bytes)

This diagram hopefully shows the relationship between the ship and the divers and the ROV. The diving bell hangs directly beneath the mother vessel. It has an internal hatch which ensures that the pressure is stable regardless of depth.

One diver remains inside the bell and looks after the umbilicals to the others. These contain breathing gas, communications and suit heating. Two divers are at work. They stay down for several hours at a time.

The ROV is also connected to an umbilical directly back to the mother ship. This is not a unique capability. There are possibly dozens of ships capable of providing this precise service.

It seems from the reports in the press that no matter when the Seaway Eagle had arrived after the first couple of days there would have been nothing she and her divers could have done, and one assumes that even if they had been successful in fixing the hatch, the submarine being carried on the Normand Pioneer would still have been required. One must hope that if there is ever a next time, the Russians will be more concerned for the saving of lives than the saving of face.