Combined diesel or gas

File:CODOG-diagram.png

Principle of a CODOG arrangement

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 frigates or corvettes.

System

For every propeller shaft there is one diesel engine for cruising speed and one geared gas turbine for high speed dashes. Both are connected to the shaft with clutches; only one system is driving the ship, in contrast to combined diesel and gas (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

• MGB 2009, 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
• s of the Indian Navy
• s of the Brazilian Navy
• Template:BNS of the Bangladesh Navy
• s of the Russian and Vietnamese Navies
• 118 WallyPower, luxury yacht
• Type 052D destroyers of the Chinese Navy

Bibliography

• Friedman, Norman (1993). "Propulsion". In Gardiner, Robert & Friedman, Norman (eds.). Navies in the Nuclear Age. London: Conway Maritime Press. pp. 199–210. ISBN 1-55750-613-2.