This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Combined diesel and diesel" – news ·newspapers ·books ·scholar ·JSTOR(October 2019) (Learn how and when to remove this message) |

Combined diesel and diesel (CODAD) is apropulsion system forships using twodiesel engines to power a singlepropeller shaft.
| Combined marine propulsion |
|---|
Combined diesel or gas (CODOG) |
Agearbox andclutches enable either of the engines or both of them together to drive the shaft. Two advantages over simply using a single, larger diesel engine of the same total power output are that (1) diesel engines have somewhat betterspecific fuel consumption at 75% to 85% max output than they do at only 50% output, and (2) there is a weight and size advantage to using twohigher-speed engines compared to a single lower-speed engine, even with the slightly larger gearbox system.
Passenger and Car Ferry Ships
Containerships
Coast Guard Offshore General-Purpose Cutters
Coast Guard Offshore Security Patrol Cutters
Coast Guard Multi-mission Cutters
Coast Guard Interceptor Cutters
Coast Guard Security Cutters
Patrol Corvettes / Navy OPVs
Corvettes
Frigates
LSDs (landing ships, dock)
LPDs (landing platforms, dock)
Amphibious Flat-topped Ships
FACs (fast attack-craft)
Cruise Ships