page_title: Union Pacific GTELs
section_title: Prototype
hierarchical_section_title: Union Pacific GTELs / Prototype
caption_attribution_description: Diagram of an Alco-GE 4500 hp gas turbine electric locomotive in development and tested by Union Pacific. The diagram shows an engine that has a cab at both ends. Union Pacific purchased units similar to this but with only one cab after "test driving" a a locomotive constructed from this diagram.
context_page_description: The Union Pacific GTELs were a series of gas turbine-electric locomotives built by Alco-GE and General Electric between 1952-1961 and operated by the Union Pacific Railroad from 1952 to 1970.
context_section_description: Union Pacific had long sought the biggest and best locomotives. In the 1930s, a pair of steam turbine locomotives were tried but rejected. Before World War II, Union Pacific had been adding diesels to its roster, but none pulled road freight trains. The idea of using four diesels to equal the power of a steam locomotive was unappealing, so the search began for something bigger. General Electric had been building gas turbines for aircraft and proposed using something similar on a locomotive. Union Pacific thought maintenance costs for a locomotive were largely independent of its power, so a smaller number of more powerful locomotives would save money.
  Union Pacific decided the best way for the turbine locomotives to realize their potential would be to put them on mainline freight trains. The long runs and relatively high speeds would maximize the turbines' efficiency.
  After Union Pacific expressed interest, GE built a prototype, GE 101, completed in November 1948. After tests in the Northeast during June 1949, it was renumbered UP 50. Painted in Union Pacific Armour Yellow, UP 50 began a round of tests. Union Pacific never took ownership of this locomotive, however. This was one of the few internal combustion locomotives in North America that had a cab at each end. The cabs themselves resembled the FA units being built by Alco-GE at that time. The sides of the locomotive had numerous air intake louvers that could be opened and closed in varying patterns.
  UP 50 was a carbody unit with a B+B-B+B wheel arrangement – four two-axle trucks, with pairs connected by span bolsters. The turbine produced 4,800 hp (3.6 MW), of which 4,500 hp (3.4 MW) was available for traction. This power output was more than double that of diesel-electric units of that era.
  For starting, the unit's auxiliary diesel generator would power a set of windings in the gas turbine's main generator, causing the generator to rotate. The generator's rotation would begin to spin up the turbine, at which point diesel fuel would be used to start combustion. A steam generator would heat and liquefy the turbine's primary fuel supply (heavy Bunker C oil).  When the turbine and fuel oil reached their minimum operating temperatures, the fuel to the turbine would be switched from diesel to the primary fuel.
  This machine weighed 500,000 lb (230,000 kg) and was over 80 ft (24 m) long.
  The turbines were delivered in three main groups after extensive testing of the prototype. Union Pacific intended to use the turbines to replace its Big Boy steam locomotives, which were scheduled to be taken out of service.
caption: GE diagram of a turbine locomotive.
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