Combined diesel-electric and gas


Combined diesel-electric and gas
Combined
marine
propulsion

CODOG
CODAG
CODLAG
CODAD
COSAG
COGOG
COGAG
COGAS
CONAS

Principle of a CODLAG propulsion system

Combined diesel-electric and gas (CODLAG) is a modification of the combined diesel and gas propulsion system for ships.

A CODLAG system employs electric motors which are connected to the propeller shafts (usually 2). The motors are powered by diesel generators. For higher speeds, a gas turbine powers the shafts via a cross-connecting gearbox; for cruise speed, the drive train of the turbine is disengaged with clutches.

This arrangement combines the diesel engines used for propulsion and for electric power generation, greatly reducing service cost, since it reduces the number of different diesel engines and electric motors, requiring considerably less maintenance. Also electric motors work efficiently over a wide range of revolutions and can be connected directly to the propeller shaft so that simpler gearboxes can be used to combine the mechanical output of turbine and diesel-electric systems.

Another advantage of the diesel-electric transmission is that without the need of a mechanical connection, the diesel generators can be decoupled acoustically from the hull of the ship, making it less noisy. This has been used extensively by military submarines but surface naval vessels like anti-submarine vessels will benefit as well. Usually CODLAG ships are equipped with rechargeable batteries like diesel-electric submarines as well, allowing them to maneuver in silence without any heavy machinery running.

Integrated electric propulsion (IEP)

Integrated electric propulsion in the Type 45 destroyer
(GT: gas turbine; DG: diesel generator)

A system which uses both diesel engines and gas turbines to generate electricity for electric motors, where there is no mechanical transmission from either to the propellers, is not classified as CODLAG, but as integrated electric propulsion (IEP) or integrated full electric propulsion (IFEP). Such an arrangement is in use on passenger ships like RMS Queen Mary 2, with a pool of diesel generators for the base load and turbo generators for peak power, and on warships such as the Royal Navy's Type 45 destroyer and the upcoming Zumwalt-class destroyer (DDG-1000/DD(X)).

List of CODLAG ships

See also


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Combined diesel and gas — Combined marine propulsion CODOG CODAG CODLAG CODAD COSAG COGOG COGAG COGAS CONAS Combined diesel and gas (CODAG) is a type of propulsion system for ships which need a maximum speed that is considerably faster than their cruise speed,… …   Wikipedia

  • Electric vehicle — Sustainable energy Renewable energy …   Wikipedia

  • Electric boat — This article is about electrically powered boats in general. For the company called Electric Boat , see General Dynamics Electric Boat. Passenger solar boat Solifleur, Switzerland 1995 While a significant majority of water vessels are powered by… …   Wikipedia

  • Diesel engine — Diesel engines in a museum Diesel generator on an oil tanker …   Wikipedia

  • Combined gas and steam — Combined marine propulsion CODOG CODAG CODLAG CODAD COSAG COGOG COGAG COGAS CONAS …   Wikipedia

  • Electric power transmission — Electric transmission redirects here. For vehicle transmissions, see diesel electric transmission. 400 kV high tension transmission lines near Madrid Electric power transmission or high voltage electric transmission is the bulk transfer of… …   Wikipedia

  • Gas turbine — Microturbine redirects here. For turbines in electricity, see Small wind turbine. For turbines driven by the flow of gas, see Turbine. A typical axial flow gas turbine turbojet, the J85, sectioned for display. Flow is left to right, multistage… …   Wikipedia

  • Combined cycle — Thermodynamics …   Wikipedia

  • Diesel generator — A Cummins diesel generator of 500kVA in a tourist resort in Egypt …   Wikipedia

  • Diesel locomotive — Three styles of diesel locomotive body: cab unit, hood unit and box cab. These locomotives are operated by Pacific National in Australia …   Wikipedia


We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.