UP 3985

Union Pacific #3985 is the largest operational steam locomotive in the world.

About
3985 was built in 1943 as part of the final batch of 4-6-6-4s for the Union Pacific Railroad. The engine later stopped pulling revenue trains in 1957, but was semi-retired. It was officially retired in 1962, and donated to Cheyenne, Wyoming for display.

In 1979, Union Pacific Employees decided to restore 3985, and the restoration was complete in 1981. Subsequently, the engine performed excursion tours, but as of March 2022 has since been stored in the Union Pacific's Cheyenne roundhouse for the CSX Railroad's 40th Birthday Party. It is now Clinchfield Challenger #676 again for Welcome and Farewell excursions of The CSX Railroad's 40th Birthday for a short time and back to its original identity after that. It is unlikely to ever be operational again.

Surviving Sister Engines

 * UP 3977