Engineering:Turbo-electric transmission

The battleship , launched in 1917, was the world's first turbo-electric battleship.

A turbo-electric transmission uses electric generators to convert the mechanical energy of a turbine (steam or gas) into electric energy and electric motors to convert it back into mechanical energy to power the driveshafts.

Turbo-electric drives are used in some rail locomotives (gas turbines, e.g. with the first TGV) and ships (steam and more recently gas turbines). An advantage of turbo-electric transmission is that it allows the adaptation of high-speed turbines to slow turning propellers or wheels without a heavy and complex gearbox. It has the advantage of being able to provide electricity for the ship or train's other electrical systems, such as lighting, computers, radar, and communications equipment. Other advantages for ships include greater watertight subdivision, quieter operations, and safety (via instant thrust reversal by changing engine direct current polarity) for submarines.

Ships with turbo-electric drive

, the US Navy's first aircraft carrier, was converted in 1920–22 from the collier USS Jupiter. Jupiter was the US Navy's first turbo-electric ship, commissioned in 1913.

, launched in 1960, was the US Navy's first turbo-electric submarine.

Warships

Aircraft carriers

• (gas turbine)

Destroyers

• Type 45 destroyers (gas turbine)

Troop ships

• s
• s

Submarines

• s
• s
• s

Auxiliary ships

• s

Coast Guard cutters

• cutters , , and

Merchant ships

Uruguay. She was launched in 1927 as , the world's first turbo-electric ocean liner.

, launched in 1932

, launched in 1960, was the first ship with alternating current (AC) turbo-electric transmission.

, launched in 2003, has gas turbines and is the world's largest turbo-electric ship.

Arauca (shown here) and her sister ship were launched in 1939. Their propulsion systems suffered significant technical failures on their maiden voyages.

Ocean liners

• (later Uruguay), Pennsylvania (later ) and Virginia (later )
• – the most powerful steam turbo-electric units in a passenger ship, 42,500 shp (31,700 kW) per shaft, 2 shafts
• Monarch of Bermuda (later and Arkadia) and
• (as re-engined in 1929)
• and Oriente (later )
• – most powerful steam turbo-electric passenger ship ever, 40,000 shp (30,000 kW) per shaft (50,000 shp at max power), 4 shafts
• and (later )
• and (originally planned as s)
• and
• – powered by General Electric gas turbines as well as her diesel generators to generate the current for her four Rolls-Royce electric podded azimuth thrusters
• Santa Clara (later )
• Strath-class ocean liners and

Coastal liners

• Cuba (formerly Powhatan), converted to turbo-electric transmission in 1920
• (II) and

Ferries

• – possibly the World's last steam-powered turbo-electric merchant ship; scrapped 2005
• Union Rotorua and Union Rotoiti were both built as gas turbine ships with electric transmission. Rotoiti was subsequently re-engined to diesel.

Cruise ships

• Millennium-class cruise ships Celebrity Constellation, Celebrity Infinity, Celebrity Millennium and Celebrity Summit

Banana boats

• (as re-engined in about 1930)
• Cargo and passenger liners (later s) , , , , and
• and
• San Benito, later

General cargo ships

• Arauca (later ), and

Bulk carriers

• was a lake freighter that was converted to turbo-electric propulsion in 1930.

Oil tankers

• T2 tankers

See also

• Gas turbine-electric locomotive
• Steam turbine-electric locomotive

References

Sources

• Friedman, Norman (1984). U.S. Cruisers: An Illustrated Design History. Annapolis, MD: United States Naval Institute. ISBN 0-87021-739-9. 
• Friedman, Norman (1985). U.S. Battleships: An Illustrated Design History. Annapolis, MD: United States Naval Institute. ISBN 0-87021-715-1. 
• Friedman, Norman (1994). U.S. Submarines Since 1945: An Illustrated Design History. Annapolis, MD: United States Naval Institute. ISBN 1-55750-260-9. 

External links

• Czarnecki, Joseph (31 January 2001). "Turboelectric drive in American Capital Ships". The Naval Technical Board. NavWeaps. http://www.navweaps.com/index_tech/tech-038.htm. 
• Draper, John L (December 1930). "The Paddle Wheel to Electric Drive". Popular Mechanics: 898–902. https://books.google.com/books?id=qOIDAAAAMBAJ&q=Popular+Science+1930+plane+%22Popular+Mechanics%22&pg=PA898.  — detailed article with drawing and charts on turbo-electric drive for ships and the advantages