Offshore developments move further offshore, into deeper waters with more extreme weather conditions, the challenge of providing operations and maintenance (O&M) support safely and cost effectively grows. The Fjellstrand WindServer is one of the new generation of offshore service vessels who will be meeting these needs.
Fjellstrand will build two 30 m and four 25 m trimarans for Danish shipping company World Marine Offshore. The vessels will have a service speed of 25 knots and the capacity to carry 25 and 12 service personnel, respectively. They are scheduled to enter service in March 2013. Germanischer Lloyd (GL) will class the vessels.
Four Engines
The Fjellstrand WindServer, includes a number of innovative features which have been designed to improve access to offshore installations in rough weather, improve fuel efficiency, ensure the safety of the personnel on board, and reduce running costs. The vessels will be equipped with four engines that power two controllable pitch propellers, giving improved operational flexibility while ensuring redundant capacity.
Stability without Motion Control Systems
The vessels will be equipped with ballasting systems allowing them to shift between a rough weather SWATH mode and a light weight transit mode. A fixed stabilisation foil adds to the design’s stability – one of a set of permanently integrated motion damping devices that are part of the hull concept and designed to reduce construction and maintenance costs by avoiding complex active motion control systems.
Tank Testing
The WindServer was one of thirteen shortlisted concepts in the Carbon Trust’s Offshore Wind Accelerator access competition. The competition was designed to enhance the safety of workers transferred to offshore wind turbines and increase turbine availability by identifying and developing new access systems. The programme allowed Fjellstrand to undertake extensive tank testing on the new hull form, demonstrating its stability and seakeeping ability in high seas states at both high speeds and stopped.
Image: The WindServer 25 and 30 (Courtesy of Fjellstrand AS)
