9 Subsea Winches designed for Marine Power Systems Ltd

This project involved the design of bespoke Hydraulic Drum Subsea, Mooring and Corner Winches to power the quarter-scale prototype for client Marine Power Systems Ltd’s innovative new wave energy convertor: WaveSub

The only device of its kind, the WaveSub consists of a barge and floating sphere, tethered together by cables. It generates power hydraulically through the spheres which react to the continual orbital motion of waves under the surface of the sea.

The WaveSub has been developed to counter what MPS have identified as the four main challenges of energy generation at sea. Key features include a unique energy capture mechanism, its small size relative to its energy output, easy maintenance and transportation and a depth-adjustability function which ensures optimum energy generation and protection in harsh weather conditions.

Motive Engineering was required to supply 9 Winches suitable for subsea use, with the capability to remain subsea for up to 12 months between services.


The winches produced use pressure compensated hydraulic gearboxes and motors to effectively operate subsea via a separate hydraulic power system. Four of the winches have load monitoring capability, enabling remote observation of winch operations. In conjunction with Marine Power Systems Ltd, Motive engineered and developed the winches from concept through to completion, ensuring all client requirements were met and that any changes to the specification were realised.

Motive personnel were on-hand throughout the project commissioning phase to assist and advise Marine Power Systems Ltd as required, providing full support and back up. Motive has in-house design and engineering departments to provide technical back up long after delivery where required.


Motive attended the unveiling of the WaveSub prototype on 13th October 2017 in Pembroke Dock, Wales. The full-scale WaveSub device will measure 100 metres long and generate 5MW of electricity, enough to power around 5,000 homes.

“Marine Power Systems selected Motive Offshore to supply bespoke subsea hydraulic winches for their WaveSub wave energy converter. Motive were very supportive of the R&D nature of the project and worked closely with Marine Power Systems to ensure that the winches supplied for the WaveSub were suitable for the demanding requirements for the novel renewable energy device.”

Dr. John Chapman, Chief Engineer, Marine Power Systems Ltd