Hydraulic pumps can be driven by means of main engine or electric motors. In both options, DATA prefers 2 pump units for higher redundancy.When 2 pumps are running together winch can provide full capacity. If one pump is running, winch can provide max. pull but half speed. Hydraulic pumps are variable displacement type and the valve is proportional which provides stepless speed control and minimum heating. Aft and fore winches can be driven by a common hydraulic power unit. Also other hydraulic systems on the vessel can be powered from this unit. Hydraulic power units are equipped with all necessary valves, filters and sea water type heat exchanger. Hydraulic motors on the towing winches are radial piston type with low speed and high torque for heavy duty. Depending on the size of the winch, it is equipped with 1 or 2 hydraulic motors. Hydraulic winches can be 2 speed with dual displacement hydraulic motor. Speed of the winch can be controlled from zero to maximum by means of a proportional joystick on the control panel.