Try www.up.com, for that and much more:

"Union Pacific was the only railroad in the United States to own and operate gas turbine locomotives. The turbine, rather than an internal combustion diesel engine, drove an alternator/generator to supply electricity to electric motors mounted on the axles. Union Pacific's gas turbine fleet totalled 55 locomotives.

The first turbine, No. 50, was built by Alco-GE in 1948 and was tested extensively on UP in 1949. Although it was painted in Union Pacific colors, the railroad never owned No. 50, but it paved the way for the GE turbine fleet which followed. The first ten UP turbines, Nos. 51-60, packing 4,500 horsepower each, were delivered to UP by General Electric in 1952. Fifteen more of these units were ordered in 1954 and numbered 61-75. Thirty units of a larger model, numbered 1-30, were delivered between 1958 and 1961. With a hefty 8,500 horsepower apiece, the last 30 units were the largest locomotives ever built."

I have a very fine model of a Big Boy, pride of my collection, but can't help you with a simulator.