The Kamewa VLWJ235s will up the current largest waterjet size of 2m diameter to 2.35m and will feature a new construction method. The VLWJ235 is divided into a series of elements, with the inlet duct integrated into the hull structure. To this and to the transom is bolted the impeller chamber. Outboard of this is the guide vane chamber and the steering and reversing unit, which is operated by a hydraulic steering actuator located inside the vessel and stem that protrudes downward from the compartment over the jet units. The impeller shaft is supported by a water lubricated bearing in the guidevain chamber, has the seal box at its inboard end on the inlet duct, and is supported within the hull by a split bearing.

The massive thrust is taken by a separate thrust block in the hull, connected to the impeller shaft by a stub shaft and coupling.

For Rolls Royce, the VLWJ235 is the latest product of a waterjet research project studying powers of up to 50 MW to understand the upper limits of power likely to be needed for fast vessels in the next few years.

MJ Information No: 17906