N Scale UP GTEL 8500 HP “Big Blow” Turbine, Coal Operation

Rivet Counter N Scale Union Pacific GTEL 8500 HP “Big Blow” Turbine #9
These are the hallmarks of the Union Pacific Railroad’s unique GTEL 8500 Horsepower Turbine locomotives. Often called “Big Blows” because of their deafening noise, they roamed the less populated landscape between Council Bluffs, IA and Ogden, UT. 30 three unit sets were built between 1958 and 1961 and all were retired by the early 1970s.
Beginning in the 1950s, the Union Pacific Railroad sought higher and higher horsepower ratings from its locomotives to help move increasingly heavier and longer trains. Gas-Turbine Electric Locomotive (GTEL) technology promised much higher horsepower ratings over the diesel-electric locomotive designs of the time. General Electric (GE) and American Locomotive Co. (Alco) built the first GTEL design, a double-ended, 4,500 horsepower, B+B-B+B unit, delivered as UP #50 in 1949. This groundbreaking design would kick off the “Turbine Era” on the UP, which saw GE building successively larger and more powerful GTELs that would power UP’s hottest trains over the next two decades.
All of those factors and lessons learned over the years would result in the ultimate GTEL design, the 8,500HP “Super Turbines” ordered in 1955. Indeed, design changes and technological improvements didn’t see the first of these units delivered until August 1958. These “C-C” (six-axle) units, numbered UP 1-15, with a second group, UP 16-30 also added to the order books, represented the pinnacle of the GTEL design from GE. Boasting 8,500HP, these units were built in a three-unit configuration, with an “A”, or Control Unit, which housed the operator’s cab, electrical control equipment, radiators, dynamic brakes, and a small 8-cylinder Bessemer-Cooper prime mover for hostling and auxiliaries. The semi-permanently coupled trailing “B”, or Turbine Unit, housed the heart of the machine: a GE 10-chamber centrifugal-flow gas turbine, coupled to a pair of 3,500HP electrical generators, which in turn powered all twelve powered axles under the pair of units.
The turbine engines were complex pieces of machinery compared to a typical diesel prime mover, in particular the delicate turbine fan blades. These factors, along with advances in diesel-electric locomotive horsepower, and limitations on where the GTELs could operate, saw the first of the Big Blows, UP 1-4, retired in August 1968, after scarcely 10 years of service. Their numbers continued to dwindle over the last few years of the decade, with UP #7 holding the distinction of being the last Big Blow to operate, pulling its last train on December 26th, 1969. All were officially retired by February 1970, closing out the loud and exciting Turbine Era on the Union Pacific.