(Courtesy Wärtsilä)Offshore staff
HELSINKI, Finland – Wärtsilä has supplied what it claims are the world’s largest retractable thrusters ever made for Heerema’s semisubmersible crane vessel Sleipnir.
The four 5500 kW forward retractable WST-65RU thrusters feature a combination of retractable and underwater mountable functionality. The thrusters installed at the aft of the vessel are 5500 kW Wärtsilä WST-65U underwater mountable steerable thrusters.
According to the company, the underwater demounting capability of all eight thrusters means that neither dry docking nor the use of a habitat is necessary should the thrusters need to be exchanged. They are equipped with its anti-pollution face type shaft seals, which have been selected primarily because of the challenging environments in which the thrusters will operate. The outboard parts of the thrusters are completely interchangeable.
Lauri Tiainen, Director, Thrusters and Propulsion Control Systems, Wärtsilä Marine, said: “These are the largest thrusters in our portfolio, and we are particularly pleased with the impressive first-installation performance of the WST-65RU retractable thrusters, which were designed in close cooperation with our customer Heerema Offshore Services especially for this SSCV.
“The eight-degrees tilted propeller shaft solution, that is a feature of our underwater mountable thrusters, significantly reduces the interaction between the thrusters and the hull, and by exceeding the design specifications during the sea trials, we demonstrated the efficiency of this solution.”
In addition to the thrusters, Wärtsilä also supplied auxiliaries for steering and lubrication, the control units, and its comprehensive propulsion condition monitoring service.
Sembcorp Marine’s Tuas Boulevard Yard in Singapore built the 722-ft (220-m) long, eight-legged vessel.
The Sleipnir is on its maiden voyage to southern Spain, where the vessel will be prepared for its first installation project in the Mediterranean.