This paper covers recent developments in main propulsion transmissions for naval ships powered by gas turbines in the 15,000 to 30,000 HP class when used either as cruise or boost turbines, driving either fixed or variable pitch propellers.
Both conventional and reversing transmissions are covered. Several recent reversing transmissions schemes are described, such as reversible fluid coupling and torque converters, reversing planetaries, and countershaft transmissions. Key elements for reversing, such as clutches, brakes, and couplings are described and evaluated.
Developments for direct reversal of gas turbine power turbines are discussed in brief.
An assessment is made of the various transmission schemes from the standpoint of size, weight, and performance.
Designs covered include transmissions for current and planned US, British, Dutch, and Canadian naval vessels.