PROPULSION SYSTEM AND METHOD

摘要

The present invention relates to a propulsion system for vessels and a method for moving a vessel in ice conditions. The system comprises a drive shaft (3), a propeller (4) attached to the drive shaft, a nozzle (5) surrounding the propeller, the nozzle having a water inlet (10) and a water outlet, and rotatable blades or vanes (6) attached to a portion of the drive shaft which projects outside the water inlet for breaking and/or crushing ice before the ice enters into the nozzle. The point of maximum diameter of the blades or vanes is positioned at an axial distance from the plane of the water inlet which is 0.02 to 0.25 times the diameter of the propeller. The rotatable blades or vanes are also having a diameter which is 0.6 to 0.8 times the diameter of the propeller.