The SRT is an electrically operated thruster system without a gearbox or propeller shaft. The stator of the electric motor is integrated into the outer part of a tunnel and the blades are fastened to the inside of the rotor. The result is a quiet, space and weight-saving drive capable of transmitting electric power directly into propulsion without the transmission losses and noise caused by a gearbox.
The optimised hydrodynamic design with blades inside leads to a considerable reduction in cavitation.