Combined diesel and diesel

Combined diesel and diesel (CODAD) is a propulsion system for ships using two diesel engines to power a single propeller shaft.

System
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
Passenger and Car Ferry Ships
 * M/F Povl Anker

Containerships
 * MV ACX Crystal

Coast Guard Offshore General-Purpose Cutters
 * Iwami-class patrol vessel
 * Shiretoko-class patrol vessel
 * Tanjung Datu-class patrol vessel

Coast Guard Offshore Security Patrol Cutters
 * Mizuho-class patrol vessel
 * Ojika-class patrol vessel

Coast Guard Multi-mission Cutters
 * Kunigami-class patrol vessel
 * Teresa Magbanua-class patrol vessel

Coast Guard Interceptor Cutters
 * Aso-class patrol vessel
 * Hateruma-class patrol vessel
 * Hida-class patrol vessel
 * Anping-class cutter
 * Tsurugi-class patrol vessel

Coast Guard Security Cutters
 * Heritage-class cutter
 * Mizuho (PLH-41)
 * Shikishima-class patrol vessel

Patrol Corvettes / Navy OPVs
 * Guaicamacuto-class patrol boat
 * Kedah-class offshore patrol vessel

Corvettes
 * Bung Karno-class corvette
 * Bung Tomo-class corvette
 * Diponegoro-class corvette
 * Doha-class corvette
 * Jacinto-class corvette
 * Kasturi-class corvette
 * Laksamana-class corvette
 * Parchim-class corvette
 * Steregushchiy-class corvette
 * Tuo Chiang-class corvette
 * Type 056 corvette

Frigates
 * Formidable-class frigate
 * Frégates de taille intermédiaire
 * Jose Rizal-class frigate
 * La Fayette-class frigate
 * Lekiu-class frigate
 * Maharaja Lela-class frigate
 * Miguel Malvar-class frigate
 * RN Type-31 Inspiration-class
 * Tamandaré-class frigate
 * Type 054A frigate

LSDs (landing ships, dock)
 * Whidbey Island-class dock landing ship

LPDs (landing platforms, dock)
 * Endurance-class landing platform dock
 * Galicia-class landing platform dock
 * Makassar-class landing platform dock
 * Tarlac-class landing platform dock

Amphibious Flat-topped Ships
 * Dokdo-class amphibious assault ship
 * Ōsumi-class dock landing ship

FACs (fast attack-craft)
 * Clurit-class fast attack craft
 * Cyclone-class coastal patrol ship
 * Sampari-class fast attack craft

Cruise Ships
 * MV Piano Land (formerly MV Oriana)