Cryogenic engine system

A system comprising:

• an independently operable cryogenic engine having a first motive power output member, and which operates by vaporizing a working fluid in the form of cryogenic liquid, and having a first tank for storing said working fluid;
• at least one working fluid injector for injecting said working fluid from the first tank into the cryogenic engine;
• at least one expander for extracting power from the working fluid by expanding the working fluid;
• a heat exchange fluid tank for storing heat exchange fluid;
• and at least one heat exchange fluid pump for transferring the heat exchange fluid from the heat exchange fluid tank to the cryogenic engine, wherein heat is transferred from the heat exchange fluid to the working fluid to vaporize and expand the working fluid;
• an independently operable heat generating power generation apparatus having a second motive power output member;
• a first transfer means configured to transfer waste heat expelled by the power generation apparatus to the heat exchange fluid tank;
• a transmission system operably connected for receiving motive power inputs from one or other or both the first and the second motive power output members and including a common transmission output operably connected for receiving motive power from the transmission system;
• and
• a controller configured to control the operation of each of the cryogenic engine and the power generation apparatus such as to cause a supply of motive power from one or other or both thereof to said transmission system.