More Power!
The Union Pacific had a penchant for experimental, high power locomotives.
This is the GE GTEL, turbine electric rated at 10,000hp… the worlds most powerful single locomotive. They used these for getting loads over the mountains of Wyoming near their base of operations. While the locomotive worked OK, it was so damn loud that none dared send it through an urban area. It sounded like a jet airliner at takeoff. So the GTELs were relegated to wilderness mountain areas to deliver trains before the locomotive was abandoned.
http://www.railpictures.net/photo/516286