Coming down the original Sherman Hill main, Gas Turbine Electric (GTEL) 21 rolls the last miles toward Cheyenne. On the day after Christmas, 1965, UP’s motive power department has already made up its mind to get rid of the big 8,500-hp turbines. The price of once cheap Bunker C fuel is creeping up, and all 30 are starting to spend more time in the shops with turbine blade problems. In exactly four years to the day, the last of the Big Blows will make its final run. Still, it ‘s fun while it lasts: One of these monsters can roar along at 65 mph, producing more tractive effort than a Big Boy, and mu’d with any combination of diesels, can lead motive power consists of staggering power.