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DVL3 - saisie le 16/03/2017

MTH is proud to introduce the UP "Baby" 4500 turbine locomotives, with all the same detailing and features of its bigger brother, the Veranda. Variable intensity smoke, a broad range of sounds, turbine crew conversations, remotely controlled couplers, operating Mars light, built in DCC decoder, and die-cast metal construction, twin flywheel-equipped motors, and four traction tires to provide pulling power all culminate in a model that rivals the prototype.

In the late 1940s, even as it was building diesels in partnership with Alco, General Electric was experimenting with ways to apply its aircraft jet engine technology to railroading. Its gas turbine electric (GTEL) was basically a diesel engine with a large turbine replacing the diesel as the prime mover. In a turbine, intake air is compressed by spinning turbine blades and fed into combustion chambers, where fuel is added and ignited, as in a jet engine. The hot exhaust gases spin the blades of another turbine that powers one or more generators, which produce electricity to power diesel-type traction motors. Compared with diesels of the period, GE's GTEL put three times as much power (4500hp) in one locomotive, had significantly fewer moving parts, and did not vibrate like a diesel. The major drawback was a voracious appetite for fuel.

Undeterred by the failure of its steam turbine prototypes, GE pursued the development of a gas turbine engine, and in June of 1949 UP added the prototype to their roster for further testing. Locomotives #51-60 were then ordered by UP in March of 1951. In their first year of operation the locomotives averaged approximately 4.2 gallons of total fuel per 1,000 gross ton-miles. Union Pacific's president A.E.(Art) Stoddard referred to the locomotives as "jet propulsion on wheels", claiming the turbine gas engines "might well revolutionize American railroading". The Baby 4500hp turbines demonstrated the locomotives' ability to go faster than diesel engines and appeared, at the time, to be the more economical choice.

While not intended for passenger use, on occasion the gas turbine 4500 locomotive pulled in a streamlined passenger train after a diesel engine would break down. Although the locomotive was not designed for multiple unit operation, they were occasionally double headed, even through long tunnel routes where recirculation of exhaust gases could pose problems. After two years of testing GE's prototype, the Union Pacific ordered its first ten GTELs in 1951. The engines were designed to burn Bunker C oil, a byproduct of petroleum distillation that was almost considered waste material. The low cost of Bunker C more than compensated for the turbines' high consumption, although the oil was so thick it had to be heated to 240 degrees Fahrenheit to flow though the fuel system. In 1955 auxiliary fuel tenders were added to the locomotives. This additional 24,000 gallons of oil allowed the engines to make longer runs, increasing monthly mileage.

Averaging around 10,000 miles a month (400 turbine operating hours), the locomotive also contained a 250hp diesel engine, which was used to bring the turbine engine up to its firing speed of 700RPM. This allowed the engine to then run fans, pumps, cooling motors, auxiliaries, and allowed the locomotive to move around terminals when running light. Unfortunately, by the early 1960s, the turbines' use of Bunker C fuel had changed from an advantage to a problem. The plastics industry had found new uses for the former waste product and its price skyrocketed. At the same time, the corrosive nature of the fuel led many of the turbines to develop engine problems. The Verandas were retired in 1963-64 in favor of newer 8500hp Big Blows, and the UP's entire turbine program was finished by 1970.