Pipelay, construction vessel design takes shipshape turn

May 21, 2007
Designs for future heavy-lift pipelay vessels and deepwater construction vessels are taking on increasingly shipshape characteristics, as contractors seek to increase their operational flexibility through faster vessels.

Designs for future heavy-lift pipelay vessels and deepwater construction vessels are taking on increasingly shipshape characteristics, as contractors seek to increase their operational flexibility through faster vessels.

Larsen & Toubro Ltd., Mumbai, together with SapuraCrest Petroleum Bhd, Selangor, Malaysia, in early May ordered a new-generation S2500 heavy-lift pipelay vessel designed by Sea of Solutions, part of Offshore Ship Designers Group, the Netherlands.

The $138 million vessel will enter service in 2009. ASL Marine, Singapore, will build it.

Sea of Solutions customized its Seabarge 3000 design in creating the S2500. The more shipshape hull with bulbous bow increases transit speed and generates additional space for the mooring system without affecting dynamic positioning layout.

The S2500 has a 10-point mooring system and can be upgraded to DP.

The design incorporates a center firing line with six single-joint welding stations to optimize pipelaying operations. The vessel is also equipped with a 3,000-ton single post crane.

Another company pursuing a more shipshaped design in its next vessel is Heerema Marine Contractors, which announced in November 2006 that it was investing $1 billion in a new Class III dynamic position system deepwater construction vessel of its own design.

The new vessel will be 220 m long, 88 m wide, and 44 m deep. It will have a maximum speed of 20 knots; up to four times the speed of Heerema’s current deepwater construction vessels, according to the company.

The vessel will include facilities for 550 people, upgradeable to 750 people. Payload is 25,000 tonnes and power generation capacity will be of 75 Mw.

The vessel will have dual crane capacity of 15,000 tonnes. Its J-Lay tower and deepwater lowering equipment will allow it to install pipelines and structures in water 200-3,500 m deep, with a maximum 32-in. pipeline OD. Tension capacity of 2,000 tonnes doubles that of Heerema’s DCV Balder.

Heerema expects the vessel to enter service in 2010.

Arctic, Asia-Pacific

The new vessel’s design and speed will allow it to undertake offshore construction in the Arctic. Heerema is locating the cranes, J-Lay tower, and other installation equipment on the vessel in a manner designed to minimize the effects of the Arctic environment. The hull and thrusters are also being designed to withstand arctic conditions, according to Heerema.

Heerema has targeted both the Barents Sea and Beaufort Sea as areas of future growth. Heerema also expects that the new vessel’s speed will increase the company’s ability to pursue business in the Asia-Pacific region, by either simply reaching the area more quickly following completion of work elsewhere or allowing it to station one of its current vessels in that region instead of the Atlantic Basin.

Heerema intends to order key long-lead components, such as the cranes and J-Lay Tower this summer and is in talks with potential suppliers.