Rocks & mirror
Encyclopedia of Marine and Energy Technology



A propulsor that consists of a water inlet channel with inlet located in the bottom of the ship, a pump that accelerates the water and a nozzle. In concept, it is a ducted propeller where the duct has been prolonged and integrated into the vessel structure. The water is accelerated by an axial or mixed flow pump and thrust out of the stern through a nozzle. Behind the nozzle, a steering and reversing bucket is mounted. It is controlled by hydraulic rams. Water jet units with main steering function are also regarded as steering gear for the vessel.

The reversal of the thrust is achieved by a reversing bucket. Moving the bucket into the jet stream and thereby deflecting it forward, reverses the thrust. The bucket can be gradually inserted into the jet stream, so that only a part of the jet is deflected. This way, the thrust can be controlled continuously from full ahead to full stern just by adjusting the position of the bucket
1. Shaft

2. Thrust bearing block

3. Duct

4. Impeller

5. Impeller housing

6. Stator housing

7. Discharge nozzle

8. Steering nozzle

9. Hydraulic actuators

10. Reversing bucket

Waterjet Waterjet Waterjet
Download the Encyclopedia