CODAD
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 diesel engines have somewhat better specific fuel consumption at 75% to 85% max output than they do at only 50% output, and 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.
Ship classes32
2
2,600 t
107.5 m
25 knots
65
5
8,500 t
141 m
15 knots
65
3
40,000 t
237 m
25 knots
1,100
4
3,300 t
109 m
25 knots
193
4
3,500 t
112.3 m
21.8 knots
47
10
11,394 t
125 m
16 knots
126
2
18,800 t
199 m
23 knots
330
8
1,200 t
80 m
27 knots
23