Rolls-Royce has won a contract to supply its Promas Lite propulsion system to the Norwegian ship owner Hurtigruten for their cruise ship MV Richard With. Propeller efficiency improvement for the ship is estimated to be between 11-14 per cent at 15 knots.
MV Richard With: Photo courtesy the owners
Promas Lite is a version of the Rolls-Royce Promas integrated propeller and rudder system which is designed specifically for vessels already in service. It is well known that with advances in propeller design, propeller blade changes, or the fitting of new propellers, can have a significant effect on propulsive efficiency, fuel consumption and, therefore, emissions. With Promas Lite these improvements can be maximised, as the propeller and rudder are treated as a complete system, and further increases in efficiency can be achieved with improved manoeuvrability for only a small increase in cost. First, extensive modelling work is carried out at the Rolls-Royce Hydrodynamic Research Centre in Sw... [More]
There is a patented device claiming to give between 6 to 10 per cent increased efficiency to the propulsion system applying mainly to planning hulls with inboards. The BOSS (Bolt On Shaft System) as it is called, basically is a tube that encloses the immersed part of the propeller shaft and combines it with a seal and thrust bearing that is mounted directly on to the hull. The self contained unit eliminates through hull sealing and alignment difficulties, and allows the gearbox and engine to be mounted free of thrust considerations. The propeller end of the tube is supported by a P-bracket type of arrangement. For the boat builder, installation times are substantially reduced and the built-in watertight shaft seal ensures a dry bilge. For the user, the reduced losses give the benefits of lower fuel consumption, improved range or a higher top speed. It’s available for shaft diameters of one to four inches (25 – 102mm) and is claimed to lower propulsion noise and vibration. [More]