This article needs additional citations for verification. Please help improve this article by adding 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 template message)
| Combined marine propulsion |
|---|
|
CODOG |
Combined diesel and diesel (CODAD) is a propulsion system for ships using two diesel engines to power a single propeller shaft. A gearbox and clutches 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 better specific 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 two higher-speed engines compared to a single lower-speed engine, even with the slightly larger gearbox system.