{{Short description|Compression-ignition engine plus turbine connected to one drive shaft}} {{More citations needed|date=February 2024}} [[File:CODOG-diagram.png|thumb|right|Principle of a CODOG arrangement]] '''Combined diesel or gas''' ('''CODOG''') is a type of [[marine propulsion|propulsion]] system for [[ship]]s that need a maximum speed that is considerably faster than their cruise speed, particularly [[warship]]s like modern [[frigate]]s or [[corvette]]s.
==System== {{Combined-marine-propulsion}} For every [[propeller shaft]] there is one [[diesel engine]] for cruising speed and one [[transmission (mechanics)|geared]] [[gas turbine]] for high speed dashes. Both are connected to the shaft with [[clutch]]es; 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.<ref>Friedman, p. 206</ref> 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 efficiency|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]] {{sclass|Asheville|gunboat|1}}s (built 1966-1971) *The [[United States Coast Guard| US Coast Guard]] {{sclass|Hamilton|cutter|1}}s (from 1967) *{{sclass|Halifax|frigate|1}}s of the [[Royal Canadian Navy]] *{{sclass|Bremen|frigate|1}}s, and *{{sclass|Brandenburg|frigate|1}}s of the [[German Navy]] *{{sclass|Gregorio del Pilar|frigate|1}}s of the Philippine Navy *{{sclass|Anzac|frigate|1}}s of the [[Royal Australian Navy]] (RAN) and [[Royal New Zealand Navy]] (RNZN) *other [[MEKO]] type frigates or corvettes *{{sclass|Peder Skram|frigate|1}}s of the [[Royal Danish Navy]] *{{sclass|Pohang|corvette|1}}s of the [[South Korean Navy]] *{{sclass|Visby|corvette|1}}s of the [[Swedish Navy]] *{{sclass|Shivalik|frigate|1}}s of the [[Indian Navy]] *{{sclass|Niterói|frigate|1}}s of the Brazilian Navy *{{BNS|Bangabandhu}} of the Bangladesh Navy *{{sclass2|Gepard|frigate|1}}s of the [[Russian Navy|Russian]] and [[Vietnamese Navy|Vietnamese]] Navies *''[[118 WallyPower]]'', luxury yacht *[[Type 052D destroyer|Type 052D destroyers]] of the [[People's Liberation Army Navy|Chinese Navy]]
==Citations== {{Reflist}}
==Bibliography== *{{cite book |editor1-last=Gardiner |editor1-first=Robert |editor2-last=Friedman |editor2-first=Norman |title=Navies in the Nuclear Age |date=1993 |publisher=Conway Maritime Press |location=London |isbn=1-55750-613-2|author-link=Norman Friedman|name-list-style=amp|chapter=Propulsion|last1=Friedman|first1=Norman|pages=199–210}}
[[Category:Marine propulsion]]