This kind of power transmission is used by locomotives (see that article for details), used for pulling or pushing trains. Diesel-electric powerplants have also been used in submarines and surface ships and some land vehicles. In some high-efficiency applications, electrical energy may be stored in rechargeable batteries, in which case these vehicles can be considered as a class of hybrid electric vehicle.
The first diesel motorship was also the first diesel-electric ship, the Russian tanker Vandal from Branobel, which was launched in 1903. Steamturbine-electric propulsion is in use at least since the 1920s (Tennessee class battleships), the practice of using diesel-electric powerplants in surface ships has been a more recent development. The Finnish "coastal defence ship " Ilmarinen, laid down in 1929, was among the first surface ships to use diesel-electric transmission. Later the technology was used in diesel powered icebreakers.
Some modern ships, including cruise ships and icebreakers, use electric motors in pods called azimuth thrusters underneath to allow for 360° rotation, meaning that the ships are far more maneuverable.
Some vehicles also use gas turbines in the same way. In fact, some use a combination: the Queen Mary 2 has a set of diesel engines in the bottom of the ship plus a gas turbine near the top exhaust tower. All are used for generating electrical power, and none of the ship's propellers are directly connected to any engines.
Some Soviet submarines had three propellers, and could be used in a variety of ways: each running on its diesel engine; either the central one or the outer two could each be connected to a diesel engine with or without the other propeller running on electric; or the engines could via snorkel be recharging the batteries while the central propeller was quietly running on its electric motor; or all three could be running on electric motors.
The diesel engine performance was critical for a conventional submarine's success. Navies imported and copied successful designs. The Germans had some excellent diesel designs for their U-boats, but they also had some designs which were not so good. The Americans had a similar history; their last diesel engine design was radial in form, its driveshaft axis angled vertically. These designs were subsequently abandoned. Older submarines had to be cut in half through the engine room and proven engines installed in a lengthened hull section to replace the unreliable but space-efficient designed engine. Since the correction, European submarine diesels have shown advances.
Modern diesel-electric submarines don't have a direct connection of the diesel engine to the propeller anymore: The usually single propeller is driven directly by an electric motor. Two or more diesel-generators provide electric energy for loading the batteries and/or driving the electric motor. This mechanically insulates the noisy engine compartment from the outer pressure hull and reduces the acoustic signature of the submarine. Even some nuclear submarines decouple their reactor room this way, e.g. all French classes, like the Rubis and Redoutable and the Chinese Type 093 class, have turbo-electric propulsion.
The batteries, carried generally on top of the bus (although some hybrid models are indistinguishable from conventional models, as shown to the right), are charged both by the diesel engine and by capturing energy from braking action. Diesel-electric hybrid buses are generally quieter than conventional (only-petroleum) diesel buses.
See Hybrid trucks
Diesel-electric propulsion was tried on some military vehicles, such as tanks. One example was the ill-fated Maus tank. Currently no tank uses this principle for movement, but it's quite common to train the turret and/or guns with electric motors powered by diesel or turbine APUs.
The U.S. military is considering a replacement for its HMMWV utility vehicle which would use a diesel-electric propulsion system. Such a vehicle could operate its electrical systems for an extended period without running the engine, due to the large battery reserves. When stealth is desired, it could drive using only electrical power for a limited time.
Charged up: Diesel-electric propulsion offers many advantages for a variety of operators. (Boats & Gear: Diesel-Electric Propulsion).(boat building)
Apr 01, 2002; Control. You just gotta have it. For example, if you're a ferry captain approaching a dock while fighting wind and tide, the...
Electrified: many operators are sold on the benefits of diesel-electric power. (Vessel Report: Offshore Service Vessels).
May 01, 2003; One of the biggest knocks against using diesel-electric propulsion instead of direct-drive power is the installation cost....