CODAG
CODAG, short for Combined Diesel And Gas, is a ship propulsion arrangement that uses both diesel engines and a gas turbine to drive a single propeller shaft through a combining gearbox with clutches. In this system, diesels provide economical propulsion at low to moderate speeds, while the gas turbine supplies additional shaft power for high-speed operation. The combining gearbox and clutches allow the prime movers to be engaged separately or together, enabling different operating modes without changing the propeller gear ratios.
Typical modes include diesel-only for efficient cruising, gas turbine-only for high-speed bursts, and full CODAG operation
CODAG is contrasted with CODLAG and CODOG. CODLAG uses diesel-electric generation and a gas turbine driving