Marine gas turbine power transmission

Claim 1

A marine gas turbine engine comprising: a gas generator and a power turbine arranged to drive a propeller through a gear box, said gas generator including low and high pressure compressors and low and high pressure turbines respectively coupled to said low and high pressure compressors; a fluid coupling for selectively coupling said low pressure turbine and said power turbine; said power turbine having a first mode of operation to be driven in a first direction of rotation by exhaust gases of said low pressure turbine when said low pressure turbine and said power turbine are uncoupled by said fluid coupling; said power turbine having a second mode of operation to be driven in an opposite direction of rotation by said low pressure turbine when said low pressure turbine and said power turbine are coupled by said fluid coupling; and said low pressure compressor and said low pressure turbine each having exhaust means enabling compressor delivery air and low pressure turbine exhaust gases to exhaust to atmosphere when said power turbine is operational in said second mode by being coupled to said low pressure turbine.