The new Wärtsilä Steerable Thruster series (WST) is being introduced to replace the company's Modular Thruster and Compact Thruster series, while the new Wärtsilä Transverse Thruster series (WTT) is replacing the current range of transverse thrusters. The new products have been developed in response to changing market demands, requiring competitive thruster products which are more efficient and cover a wider power range.
This major product development project was launched by Wärtsilä's Propulsion R&D already in 2011. The latest insights in thruster design were implemented using state-of-the-art numerical simulation tools. The first product to enter the pilot phase is a 4500 kW under water (de)-mountable steerable thruster, the WST-45-U, which began its pilot phase in summer 2013. Two more products, the WST-14 and the WTT-11, are scheduled to begin their pilot phase before the end of this year. Wärtsilä will continue the introduction of different sizes of thrusters in the coming years based on market requirements and customer priorities.
The new thrusters are available for various types of vessel depending on the size and features of the product. For example, the WST-45-U is designed mainly for the offshore drilling market; the WST-14 is intended for tugs up to 45tBP, inland waterway vessels, and for river/sea going cargo ships. This thruster is compatible with both medium speed and high speed (1800 rpm) diesel engines. The WTT-11 is a 1100 kW tunnel thruster designed mainly for merchant cargo vessels.
The new WST and WTT units come with several added features, such as an increased power range, an 8° tilted propeller gearbox, and a new Wärtsilä Thruster Nozzle for the thrusters designed for offshore drilling. The new thrusters intended for tug boat applications also have the new nozzle, which improves performance and has a high level of system integration as well. The new tunnel thrusters are more compact and efficient than earlier versions.
"The marine sector is undergoing a period of significant change and technological advancement, and this next generation Wärtsilä thruster portfolio has been developed in line with these trends by utilizing the latest calculation tools and model testing to secure the hydrodynamic leadership of the products. The new products are even more efficient and reliable than earlier, as well as being lighter and easier to install," says Mr Arto Lehtinen, Vice President Propulsion, Wärtsilä Ship Power.