UP Rolls Out 9000 Class Union Pacific Steam Locomotives
Union Pacific developed the 9000 Class locomotive to improve speed and pulling power. The locomotive had a running speed of 50 miles per hour, compared to the 40-miles-per-hour standard of the day. It hauled freight primarily between Council Bluffs, Iowa, and Green River, Wyo., over Sherman Hill. The unusual 3-cylinder 4-12-2 had the longest rigid wheelbase of any U.S. steam locomotive. It was used only by UP, largely because the wheel arrangement could not negotiate tight curves on many other railroads. The 9000 Class was retired in 1955.