Designed to meet requirements far into the future

12 January 2006

UT 787 CD

The newly developed UT 787 CD design just contracted by Island Offshore is a hypermodern offshore vessel that can place anchors with precision at whatever depth.

Aker Yards, Langsten, will build two vessels of this type, for delivery in 2006 and 2007. The last one is vessel no. 500 built from the UT-Design.

The UT 787 CD design focuses on fuel efficiency in transit and position-keeping modes, together with a high bollard pull and deck machinery suitable for anchor-handling operations in ultra-deep water. 'Clean Design' is the strictest environmental class. The vessel’s impact on the environment will be as small as possible.

Håvard Ulstein, managing director of Island Offshore, says: "The UT 787 CD will enable us to carry out anchor-handling operations in water as deep as anyone wants to go. Because we have an integrated hangar for a work-class ROV, we can also place anchors very precisely using ROV inspection. Using the A-frame and the moonpool, we can position items of equipment weighing 150 tonnes each on the seabed in 2,000m deep water. We're confident that Rolls-Royce has designed a vessel for us that will meet the industry’s requirements far into the future."

The UT787 CD is 78.3m long, has the broad beam of 22m, a bollard pull in the 230 tonne region, and about 900m2 deck area.

All types of offshore supplies can be carried on or under deck. A Rauma Brattvaag 64bar hydraulic main winch of unusual layout has been specified. It has three drums, one extremely large, plus two independently driven smaller drums side by side, each with its own cable lifter almost on the ship’s centreline. There is also a large secondary winch.

Two Bergen BV12 32:40 main engines, each rated at 6,000kW, drive CP propellers in nozzles. A tunnel thruster and a swing-up azimuth thruster are located aft, and the same forward. These azimuth units can supplement the main propellers to increase bollard pull. The vessel has an unusually large electric generating capacity. In addition to two 2,500kW shaft generators, there are two diesel gensets of 1,800kW and one of 600kW. The philosophy is to operate efficiently as a diesel electric vessel in DP mode using thrusters alone, without requiring the main engines to run, and there is the redundancy required to comply with IMO DP2.