CODOG
CODAG
CODLAG
CODAD
COSAG
COGOG
COGAG
COGAS
CONAS
Combined gas or gas (COGOG) is a propulsion system for ships using gas turbine engines. A high efficiency, low output turbine is used for cruising speeds with a high output turbine being used for high-speed operations. A clutch allows either turbine to be selected, but there is no gearbox to allow operation of both turbines at once. This has the advantage of not requiring heavy, expensive and potentially unreliable gearboxes.
The reason that a smaller turbine is used for cruising is that a small turbine running at 100% power is more fuel efficient than a bigger turbine running at 50% power.
The system is currently used in the 3 ships of the Russian Navy's Slava class cruisers, and in the Royal Navy Type 42 destroyers.
HMS Exmouth (F84) of the Royal Navy was converted to COGOG propulsion as a test bed for its use in later British ships.
Famous quotes containing the words combined and/or gas:
“A multitude of causes unknown to former times are now acting with a combined force to blunt the discriminating powers of the mind, and unfitting it for all voluntary exertion to reduce it to a state of almost savage torpor.”
—William Wordsworth (1770–1850)
“Droning a drowsy syncopated tune,
Rocking back and forth to a mellow croon,
I heard a Negro play.
Down on Lenox Avenue the other night
By the pale dull pallor of an old gas light”
—Langston Hughes (1902–1967)