Rolls-Royce’s Promas integrated propeller and rudder system claims to offer gains in propulsive efficiency of between five to fifteen per cent for new builds and retrofits. The resulting benefit in practice depends on a number of factors, so each vessel needs to be considered on its merits however in most cases the payback period lies between 18 to 24 months.. Improvements can be made to FPP and CPP systems with single and multiple propellers. A Promas Lite system can be installed during a scheduled drydocking and can normally be fitted within a week. [More]