WHEN A PROPELLER IS ALSO A PUMP

The first report on an innovative propulsion system developed by Frenchman Oliver de la Roche is presently being published. The hydropulsor system, designed to serve a twin function as a pump and a propulsor, was filed by de la Roche 10 years ago but considered too far fetched for practical application. The Ship Research Institute of Norway has now taken up the idea and initiated serious investigations into the system's possible use. In simple terms the hydropulsor consists of an open-ended box with a plate hinged to a rod inside. By moving the rod up and down, the plate presses water through the box creating more thrust per horsepower unit than equivalent size propellers. The results of the tests go a long way to prove the system's usefulness, especially where a lot of horsepower is needed for towing or precision manoeuvring. Norway is the only country where the French invention has been seriously investigated. They have so far concentrated on the hydrodynamic effects of the device and have yet to learn what will be the optimum design for varying sizes of vessels. Large ships present special problems and much work is still to be done before the Institute solves problems of structure and power transmission. At the same time it seems that the slow-moving plate in the hydropulsor will avoid the cavitation problems common in high capacity propellers. The research carried out by the Institute leaves many questions unanswered, but it has confidence in the system and its ability to take over such propulsion operations as tug boats, oil rigs and big ships where power and not speed is the criterion. (No further information in article.)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/1337152
• Supplemental Notes:
  • Full report available from the Ship Research Institute.
• Corporate Authors:

  Seatrade Publications Limited

  Fairfax House
  Colchester CO1 1RJ, Essex,   England 
• Publication Date: 1974-9

Media Info

• Pagination: p. 81
• Serial:
  • Seatrade
  • Volume: 4
  • Issue Number: 9
  • Publisher: Seatrade Publications, Limited
  • ISSN: 0037-0428

Subject/Index Terms

• TRT Terms: Propulsion; Vehicle power plants
• Uncontrolled Terms: Propulsion systems
• Old TRIS Terms: Hydropropulsors
• Subject Areas: Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00071721
• Record Type: Publication
• Source Agency: Seatrade Publications Limited
• Files: TRIS
• Created Date: Nov 12 1974 12:00AM