Engineering:Combined diesel and diesel

Short description: Two-compression-ignition-engine, one-drive shaft propulsion

Principle of a CODAD propulsion system

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.

CODAD vessels

• Guaicamacuto-class patrol boat
• Type 31 frigate
• Steregushchiy-class corvette
• Jose Rizal-class frigate
• Frégates de taille intermédiaire
• Type 054A Frigate
• Doha-class corvette
• MV Piano Land (formerly MV Oriana)
• Tamandaré-class frigate
• Formidable-class frigate
• M/F Povl Anker