Have there ever been gas turbine-powered railroad locomotives?

Yes, there were also four attempts in the UK. the first was a project begun by the Great Western Railway, delivered from Brown Boveri in Switzerland in 1950, two years after the railways were nationalised. It had two six-wheeled bogies of the A1A-A1A layout. It was followed the next year by a larger machine - still on six-wheeled bogies, but of the Co-Co layout - built by Metropolitan Vickers in the UK. The first locomotive was effectively withdrawn from service by the end of the 1950s, latterly serving as a mobile power supply vehicle at the British Railways Locomotive Testing Plant at Rugby until 1960. It then spent five years in store before being returned to Switzerland, where it became a mobile laboratory on the Swiss Federal Railways.

The second locomotive was withdrawn from service in 1958, when it was returned to the manufacturers in Manchester and converted into an A1A-A1A electric locomotive for driver training duties on the West Coast main line, which was at that time being electrified. It saw occasional use after 1961 until officially withdrawn in 1968, although it was not cut up for scrap until 1972.

These first two prototypes used electric transmission, but in 1959, the Vulcan Foundry produced a gas turbine locomotive with mechanical transmission. It was of a curious layout, being similar in configuration to a 4-6-0 steam tender locomotive, having a leading bogie and six coupled wheels, with a separate tender carrying the train heating boiler and fuel tanks. It was tested over the British railway network for about two years, but was never BR property.

The final attempt at gas turbine traction was with the experimental 'Advanced Passenger Train', of 1972. This was the first 'tilting train', designed to reach speeds of 150mph on conventional tracks. It had two power cars with two passenger carriages in between. It never ran in public service - it wasn't intended to, and the 'production' units were electrically powered. Problems were encountered with the reliability of the tilting mechanism and - like so many other British inventions and innovations - the government chickened out of the cost of further research, leaving the Italians to successfully develop tilting train technology.

The conclusion of all of these experiments was that gas turbines are only useful for railway traction in situations where the locomotives are running at full power for long periods - once the power output is reduced, the fuel consumption increases exponentially.

The UP was the only American railroad to try them. They didn't work out to well. Other countries have used them too. http://www.up.com/aboutup/special_trains/gas-turbi... http://en.wikipedia.org/wiki/Gas_turbine_locomotiv...