Combined diesel or gas (CODOG) is a type of propulsion system for ships that need a maximum speed that is considerably faster than their cruise speed, particularly warships like modern

frigate A frigate () is a type of warship. In different eras, the roles and capabilities of ships classified as frigates have varied somewhat. The name frigate in the 17th to early 18th centuries was given to any full-rigged ship built for speed and ...

s or

corvette A corvette is a small warship. It is traditionally the smallest class of vessel considered to be a proper (or " rated") warship. The warship class above the corvette is that of the frigate, while the class below was historically that of the slo ...

s. For every propeller shaft there is one diesel engine for cruising speed and one

geared A gear is a rotating circular machine part having cut teeth or, in the case of a cogwheel or gearwheel, inserted teeth (called ''cogs''), which mesh with another (compatible) toothed part to transmit (convert) torque and speed. The basic pr ...

gas turbine for high speed dashes. Both are connected to the shaft with

clutch A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...

es; only one system is driving the ship, in contrast to CODAG systems that can use the combined power output of both. The advantage of CODOG is a simpler gearing compared to CODAG, but it needs either more powerful or additional gas turbines to achieve the same maximum power output. The disadvantage of CODOG is that the fuel consumption at high speed is poor compared to CODAG.

CODOG vessels

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, a modified Motor Gun Boat of the Royal Navy (1947), and *The two German torpedo boats ''Pfeil'' and ''Strahl'' (''Vosper'' class, 1963-65) *The US Navy s (built 1966-1971) *The US Coast Guard s (from 1967) *s of the Royal Canadian Navy *s, and *s of the German Navy *s of the Philippine Navy *s of the Royal Australian Navy (RAN) and Royal New Zealand Navy (RNZN) *other MEKO type frigates or corvettes *s of the Royal Danish Navy *s of the South Korean Navy *s of the

Swedish Navy The Swedish Navy ( sv, Svenska marinen) is the naval branch of the Swedish Armed Forces. It is composed of surface and submarine naval units – the Fleet () – as well as marine units, the Amphibious Corps (). In Swedish, vessels o ...

*s of the Indian Navy *s of the Brazilian Navy * of the Bangladesh Navy *{{sclass2, Gepard, frigate, 1s of the Russian and Vietnamese Navies *''

118 WallyPower 118 WallyPower, christened ''Galeocerdo'', is a luxury motor yacht with a maximum speed of , produced by Wally Yachts. The yacht is narrow and angular in design with black glass housing, driven by three Vericor TF50 gas turbines generating , each ...

'', luxury yacht Marine propulsion