METHOD OF OPERATING A WATERBORNE VESSEL
The invention relates to a method of operating a waterborne vessel propelled by at least one mechanical transmission azimuth thruster comprising a driveline connecting a motor located inside the hull of the vessel to a propeller (1) mounted to an outboard azimuth unit of the azimuth thruster, which azimuth unit is arranged to be rotated to any horizontal angle and which driveline comprises a generally vertical shaft (2) and a generally horizontal shaft (3) which is connected to the vertical shaft via a bevel gearing (4) comprising a first bevel gear (5) mounted on the vertical shaft and a cooperating second bevel gear (6) mounted on the horizontal shaft, which motor is drivingly connected to the vertical shaft and which horizontal shaft is drivingly connected to the propeller. The method comprises the steps of, during a first period of time, operating the azimuth thruster utilising a first load direction of the bevel gearing; and, during a second period of time after the first period of time, operating the azimuth thruster utilising a second load direction of the bevel gearing, which second load direction is opposite to the first load direction. The invention also relates to a mechanical transmission azimuth thruster for implementing the method.