Skip to main content




Thursday, March 7, 2019 

Wärtsilä has upgraded its LJX series of modular waterjets for greater efficiency with low levels of cavitation and underwater noise.

Following this upgrade, the company’s modular waterjets will be redesignated as the Wärtsilä WXJ series. The development is based on a new axial pump design, which boosts performance with an increased thrust of as much as 3%, while the improved cavitation margins help reduce environmental impact by lowering noise levels. This is in line with Wärtsilä’s Smart Marine vision to offer the maritime industry a new era of ultra-high efficiency, improved safety, and reduced environmental impact.

The new WXJ pump, which is an integral part of the waterjet technology, has been tested in computational fluid dynamic (CFD) simulation and model testing. With this upgrade, Wärtsilä is now positioned to supply global markets, including China and other Asian countries, with highly efficient waterjet solutions.

“We have been able to keep the notable benefits from the LJX-series, and the interface between the waterjet and the vessel remains identical to that of the LJX. Similarly, the small transom interface dimensions, and best in class weight are unchanged, but overall performance is now improved,” said Leendert Muilwijk, GM Product Group Waterjets at Wärtsilä.

“As the leader in the large waterjet market, Wärtsilä is committed to creating innovative solutions and the further development of existing products in order to serve our customers even better. The new Wärtsilä WXJ modular waterjets represent the state-of-the-art in this field, delivering outstanding benefits and performance,” said Sander van Oosterhout, Wärtsilä’s Product Director Waterjets.

The Wärtsilä WXJ modular waterjets are aimed at various market sectors, including high-speed ferries, frigates and other fast speed naval vessels, yachts, shallow draft vessels, large fast crew vessels, and large fast supply vessels.

Wärtsilä axial waterjets are single stage, compact, high performance systems that combine mixed flow properties with an axial construction. This results in less space being needed on the vessel’s transom, and increased waterjet cavitation margins for optimum flexibility. For naval architects, the axial jet technology creates the possibility to apply a larger power density onto narrower hulls in order to achieve high performance.

Unlike a non-axial design, the Wärtsilä waterjet does not expand in a radial direction downstream. As the water flow is directed through the pump along the most efficient path, it is easier to fit the jet to the available transom space. The reduced transom size decreases the weight of the installation. These weight optimisations and savings can be as high as 20% compared to non-axial jet designs.

Thanks to the increased pump cavitation margin of 35% and the lower impeller tip speed, more power can be introduced to the pump during manoeuvring. This results in a 15% higher manoeuvring thrust and faster response to acceleration. Operating flexibility is improved thanks to the combination of the reduced number of shaft lines and the higher loads of the remaining engines.

Reader Comments (0)

There are currently no comments on this article. Why not be the first and leave your thoughts below.

Leave Your Comment

Please keep your comment on topic, any inappropriate comments may be removed.

Return to index

Web Analytics