One of the locomotives, The Challenger Union Pacific 3985, was built in 1943 and is the little sister to "The Big Boy." ... Union Pacific 5511 was built in 1923 and hasn't run since 1956.

The Challenger Union Pacific 3985, Centennial Union Pacific 6936 and Union Pacific 5511 are the locomotives that are being donated to RRHMA.

CHEYENNE – The Union Pacific steam crew has been busy preparing the Challenger No. 3985, along with the TTT-6 steam locomotive No. 5511 and Centennial diesel locomotive No. 6936, for ...

OMAHA, Neb. (AP) — Union Pacific will spend more than $1 billion to upgrade 600 of its old diesel locomotives over the next three years and make them more efficient, but regulators still want it ...