Hydraulic propulsion system for boats
HPM, HPH Vetus

In many cases it may be preferable to drive the propeller shaft by means of a hydraulic motor, instead of using the conventional set up of engine and gearbox. One of the major benefits of hydraulic propulsion is that the propulsion engine does not need to be installed in line with the propeller shaft. This means that the engine may be fitted in any suitable place on board, even athwartships. In addition, should the propeller become fouled or touch the bottom due to running aground, the risk of damage to the propeller shaft assembly, the hydraulic motor or the main engine is almost nil. An integrated pressure relief valve ensures that in the event of overloading, the
hydraulic motor is safely bypassed. Particularly in the case of hire craft, this is clearly a great advantage. The hydraulic motor is engaged in a smooth and noiseless manner. The complete assembly is vibration free and the propeller thrust is not transmitted onto the engine, but onto the hydraulic motor instead, which is flexibly mounted on its own bed.