Turbo-electric transmission

ALCO-General Electric Union Pacific GTELs gas turbine-electric locomotive. X-18 is one of the third series, built 1958–61.

Turbotrains were gas turbine trains built in France 1971–75 and supplied to SNCF, Amtrak and Iranian Railways.

The battleship USS New Mexico, launched in 1917, was the World's first turbo-electric steamship.

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 turning turbines to the slowly-turning propellers or wheels without the need of a heavy and complex gearbox. It also 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.

A disadvantage, shared with the more common diesel-electric powertrain, is that because of the double conversion of mechanical energy to electricity and back, more energy gets lost than with a mechanical transmission.

Ships with turbo-electric drive

USS Langley, the US Navy's first aircraft carrier, was converted to turbo-electric transmission in 1920–22.

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

Warships

Battleships

• Colorado-class battleships
• USS New Mexico
• Tennessee-class battleships

Aircraft carriers

• USS Langley (as re-engined in 1922)
• Lexington-class aircraft carriers

Destroyer escorts

• Buckley-class destroyer escorts

Troop ships

• Admiral W. S. Benson-class transports
• Gilliam-class attack transports

Submarines

• USS Glenard P. Lipscomb
• USS Tullibee

Auxiliary ships

• Suamico-class oilers

Coast Guard cutters

• Tampa-class cutters USCGC Haida, USCGC Modoc, USCGC Mojave and USCGC Tampa

Merchant ships

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

SS Normandie, launched in 1932, was the World's most powerful turbo-electric steamship.

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

RMS Queen Mary 2, launched in 2003, has gas turbines and is the World's largest turbo-electric ship.

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

Ocean liners

• SS California (later SS Uruguay), SS Pennsylvania (later SS Argentina) and SS Virginia (later SS Brazil)
• SS Canberra – the most powerful steam turbo-electric units in a passenger ship, 42,500 shp (31,700 kW) per shaft, 2 shafts
• RMS Mooltan (as re-engined in 1929)
• SS Morro Castle and SS Oriente (later USAT Thomas H. Barry)
• SS Normandie – most powerful steam turbo-electric passenger ship ever, 40,000 shp (30,000 kW) per shaft (50,000 shp at max power), 4 shafts
• SS Potsdam and SS Scharnhorst (later Japanese aircraft carrier Shinyo)
• SS President Cleveland and SS President Wilson (originally planned as Admiral W. S. Benson-class transports)
• SS President Hoover and SS President Coolidge
• RMS Queen Mary 2 – 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
• SS Santa Clara (later USS Susan B. Anthony)
• Strath-class ocean liners RMS Strathnaver and RMS Strathaird
• RMS Viceroy of India

Coastal liners

• SS Princess Marguerite (II) and SS Princess Patricia

Ferries

• TEV Wahine
• TEV Rangatira – one of the World's last steam-powered turbo-electric ships; now scrapped

Cruise ships

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

Banana boats

• SS Darien (as re-engined in about 1930)
• Cargo and passenger liners (later Mizar-class stores ships) SS Antigua, USS Ariel, USS Merak, USS Mizar, USS Talamanca and USS Tarazed
• SS Musa and SS Platano
• SS San Benito, later USS Taurus

General cargo ships

• SS Arauca (later USS Saturn), SS Antilla and SS Orizaba

Oil tankers

• T2 tankers

• 

  Canberra's steam turbine

• 

  driving an alternator

• 

  powering an electric motor

• 

  driving a propeller shaft

See also

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

External links

• Czarnecki, Joseph (31 January 2001). "Turboelectric drive in American Capital Ships". The Naval Technical Board. NavWeaps. 
• Draper, John L (December 1930). "The Paddle Wheel to Electric Drive". Popular Mechanics: 898–902.  — detailed article with drawing and charts on turbo-electric drive for ships and the advantages