GE - Aviation: Marine Gears

GE Stock: Jul 8, 2008 at 16:02 ET 28.06 +0.96

engines

Gear/Propulsion Arrangements

Gearing - MS Type, Propulsion - Diesel (CODOD OR CODAD)

A gear of the "MS" type is a single-reduction unit with a multiple-input. It consists of two or more pinions that drive one gear. The input pinions may be positioned at various locations relative to the output shaft to suit the required application.

This arrangement is used primarily to combine two or more diesel engines to drive a single propeller separately (CODOD) or simultaneously (CODAD). Gear elements are double-helical or optional single helical. Single helical gearing will utilize our newest available gear technology derived from our Renk Tacke License.

This gearing can transmit 50,000 hp or more over a wide range of appropriate output speeds.

Gearing - DT Type, Propulsion - Single Gas Turbine

This propulsion configuration primarily uses a single gas turbine to power the propeller through a double-reduction, locked-train gear (DT-Type). The rotating elements consist of one first-reduction pinion, two first-reduction gears, two second-reduction pinions and one second-reduction gear. The input pinion may be positioned at various locations relative to the output shaft to suit the application.

Sealift ships of the U.S. Navy are one example of a ship using this configuration.

This gearing can transmit up to 60,000 hp over a wide range of appropriate output speeds.

Gearing - MD Type, Propulsion - Gas Turbines (COGOG OR COGAG)

This propulsion configuration primarily uses two or more gas turbines to power the propeller, each driving through a double-reduction gear train (MD-Type). The turbines can drive the propeller either separately (COGOG) or simultaneously (COGAG). The rotating elements at each input consist of a first-reduction pinion, a first-reduction gear and a second-reduction pinion driving a common second-reduction gear. The input pinions may be positioned at various locations relative to the output shaft to suit the application.

This gearing can transmit 100,000 hp or more over a wide range of appropriate output speeds.

Gearing - S/DT Types, Propulsion - Diesel & Gas (CODOG) OR (CODAG)

A gas turbine and a diesel engine typically are used either separately (CODOG) or simultaneously (CODAG) to power the ship's propeller. The diesel powers the propeller through a single-reduction gear (S-Type) while the gas turbine powers it through a double-reduction, locked-train gear (DT-Type). The rotating elements of the "DT" type consist of a first-reduction pinion, two first-reduction gears and two second-reduction pinions both driving a second-reduction gear.

The input pinions may be positioned at various locations relative to the output shaft to suit the required application.

This gearing can transmit 50,000 hp or more for powering patrol gunboats, frigates and corvettes.

Gearing - S/D Types, Propulsion - Diesel & Gas (CODOG) OR (CODAG)

The CODOG version of this propulsion configuration splits the power of a gas turbine to drive two propellers at high power/speed or, with the gas turbine off, the propellers are individually driven by two diesel engines at moderate cruise power/speed levels. Power is transmitted from the gas turbine through double-reduction gearing (D-Type) to both propellers and from the diesels through a single reduction (S-Type) gear.

Alternatively, all three prime movers can operate simultaneously (CODAG) in the above manner to drive the two propellers.

Patrol gunboats, frigates and corvettes, which rely on both maximum cruise efficiency and full power capability, use these configurations. This gearing can transmit 50,000 hp or more over a wide range of appropriate output speeds.

Gearing - MDT Type, Propulsion - Gas Turbines (COGOG) OR (COGAG)

This propulsion configuration uses two or more gas turbines to power the propeller, each driving through a double-reduction, locked-train gear (MDT-Type). The turbines can drive the propeller either separately (COGOG) or simultaneously (COGAG). The rotating elements at each input consist of a first-reduction pinion, two first-reduction gears and two second-reduction pinions driving a common second-reduction gear. The input pinions may be positioned at various locations relative to the output shaft to suit the required application.

Applications for this configuration include Navy destroyers (DDG51-class), frigates and auxiliaries.

This gearing can transmit 150,000 hp or more over a wide range of appropriate output speeds.

Gearing - MDT Type, Propulsion - Gas & Steam (COGAS)

This propulsion configuration uses a gas turbine and a lower power, higher speed, steam turbine to power the propeller. Both turbines drive simultaneously through a double-reduction, locked-train gear train (MDT-Type). The rotating elements at each input consist of a first-reduction pinion, two first-reduction gears and two second-reduction pinions driving a common second-reduction gear. The input pinions may be positioned at various locations relative to the output shaft to suit the required application.

Applications for this type of COGAS propulsion can include container ships, auxiliaries and cruise liners.

This gearing can transmit 100,000 hp or more over a wide range of appropriate output speeds.

Gearing - MD Type, Propulsion - Steam Turbines (COSAS)

This propulsion configuration uses two steam turbines to simultaneously power the propeller (COSAS). Each turbine drives through a double-reduction gear (MD-Type). The rotating elements at each input consist of a first-reduction pinion, a first-reduction gear and a second-reduction pinion driving a common second-reduction gear. The input pinions may be positioned at various locations relative to the output shaft.

This gearing can transmit up to 60,000 hp over a wide range of appropriate output speeds.

The LHD-5, 6 & 7 Multi-Purpose Amphibious Assault Ships and high powered commercial ships (LNG Lerici and San Diego Class tankers) are examples of ships with this configuration.

Gearing - MDT Type, Propulsion - Steam Turbines (COSAS)

This propulsion configuration uses two steam turbines to simultaneously power the propeller (COSAS). Each turbine drives through a double-reduction, locked-train gear (MDT-Type). The rotating elements at each input consist of a first-reduction pinion, two first-reduction gears and two second-reduction pinions driving a common second-reduction gear. The input pinions may be positioned at various locations relative to the output shaft.

This gearing can transmit up to 85,000 hp over a wide range of appropriate output speeds.

Aircraft carriers (Nimitz-class), submarines (Los Angeles-class and Trident/Ohio-class), destroyers, frigates, and high-powered commercial vessels are examples of ships with this configuration.

Gearing - S/DT Type, Propulsion - Diesel, Electric or Gas Turbine (CODLOG)

This configuration uses a diesel engine, an electric motor or a gas turbine to power the ship's propeller. The diesel powers the ship efficiently at moderate cruise speeds while the gas turbine is applied for shorter periods of high power/speed and the electric motor for low speed and/or quiet operation.

Single-reduction (S-Type) gearing would be typical for the diesel and electric motor while double-reduction (D or DT-Type) would be used for the gas turbine. DT-Type gearing for the gas turbine that is shown here consists of a first-reduction pinion, two first-reduction gears and two second-reduction pinions both driving a second-reduction gear.

The input pinions may be positioned at various locations relative to the output shaft to suit the required application. Each input can supply a wide range of power to the propeller.

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