UP 3985 Test Run in 2010

UP 3985  Test Run in 2010 | Train Fanatics Videos

Before the renovation of UP #844 and #4014 Big Boy, UP #3985 was the largest operating steam locomotive in the world.

Built specifically to take on long, steep grades , the #3985 Challenger was designed to pull freight without the benefit of helper engines.

Both UP #4014 “Big Boy” 4-8-8-4, and UP’s #3985 Challenger 4-6-6-4 are based at Union Pacific’s steam shop in Cheyenne, Wyoming.

As of January 2020, The Union Pacific Steam Shop retired UP #3985 for a second time and has since has announced plans to donate Challenger No. #3985 to the non-profit Railroading Heritage of Midwest America (RRHMA) who plans to restore it back to operating condition.

Some quick facts about the UP #3985 Challenger

  • Builder – American Locomotive Works – 1943
  • Wheel configuration – 4-6-6-4
  • Locomotive and tender weight – 1,073,900 lbs
  • Tractive effort – 97,350 lbf
  • Nicknamed – Challenger

Let us know if you have ever seen #3985 in action. We would love to hear about your experience!

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