A new semi-submersible crane vessel (NSCV) to be built at the Sembcorp Marine Tuas Boulevard Yard in Singapore will feature a broad scope of Wärtsilä products, systems and solutions. The vessel is being built on behalf of Netherlands based Heerema Offshore Services and when completed will be the largest of its type, and the third largest vessel overall, in the world. The contract with Wärtsilä was placed in October.
“We have a long standing relationship with Wärtsilä propulsion solutions on other vessels in our fleet and look forward to successfully continuing this relationship. We have every confidence that these state-of-the-art thrusters are the right choice for this vessel, which is destined for offshore projects worldwide,” says Sipke Schuurmans, Heerema Offshore Services.
Accurate positioning of the vessel will be ensured by eight 5500kW Wärtsilä Underwater Mountable thrusters, four of which are also retractable. Wärtsilä has developed these four forward retractable thrusters specifically for this project, and given them the type indication WST-65RU. They feature a unique combination of retractable and underwater mountable functionality. The thrusters installed at the aft of the vessel are WST-65U underwater mountable thrusters. The outboard parts of both types are completely interchangeable. The underwater demounting capability of all eight thrusters means that neither dry docking, nor the use of a habitat is necessary in order to exchange the thrusters. The thrusters are equipped with Wärtsilä Oceanguard anti-pollution face type seals, which have been selected primarily because of the challenging environments in which these thrusters will operate.
In addition to the thrusters, the full scope of supply includes auxiliaries for steering and lubrication, the control units, and Wärtsilä’s Propulsion Condition Monitoring Service (PCMS). Wärtsilä will also supply comprehensive centrifugal pump packages. Delivery of the Wärtsilä equipment will commence at the end of 2016.
“Once again, Wärtsilä’s unmatched offering to the marine sector is emphasised with this multi product contract to one of the largest vessels ever to be built. For a large vessel of this type involved in offshore construction work, efficient dynamic positioning is a major requirement. The eight degree tilted propeller shaft solution that is a feature of the Wärtsilä Underwater Mountable thrusters, significantly reduces the interaction between the thrusters and the hull, thereby notably enhancing the vessel’s dynamic positioning performance. This feature, together with the retractability of the thrusters, was extremely important in the award of this valuable contract,” says Arto Lehtinen, Vice President, Propulsion, Wärtsilä Marine Solutions.
The new vessel will be equipped with two cranes of 10,000 tonnes lifting capacity, which is beyond any heavy crane lifting that the marine contracting market currently offer its customers. The NSCV will be self-propelled with a transit speed of 10 knots.