Research of The Main Engine Manufacturers' Recommendation on Propeller Design

Abstract

It has been well known among propeller designers that propellers must be designed so as to prevent any possibility of overloading the main engine even the required engine power increases owing to the increased frictional losses on ship's hull and propeller itself during service.
On the other hand, propeller designers recently wonder if an allowable load of the engine is very limited and an allowable overload duration becomes more and more short.
Taking consideration of the above, Propeller and Shafting Committee has made inquiries about their design criteria to the major diesel and steam turbine main propulsion machinery manufacturers in Japan relative to the following items;
1) Main engine allowable operating range of manufacturer's standard.
2) Main engine performance drop by aging.
3) Recommended allowance for propeller design against aging.
4) Relations between propeller rpm drop in service and main engine allowable operating range.
5) Possibility of improving the main engine allowable operating range.