Built for Union Pacific between 1936 and 1943, the 4-6-6-4 steam engines known as "Challengers" were used primarily in freight service, but a few did haul passenger trains in California and Oregon. Only 105 were built, though its technical innovations did lead to its successor, the legendary "Big Boys."
Equipped for DCC & Sound, this top-quality HO scale model of the museum-displayed #3977 Challenger features Rolling Thunder audio, chuffing smoke and synchronized sound, an accompanying tender, whistle smoke, an opening pilot door, separately applied parts (including handrails, ladders, a brass bell, and more), operating cab roof vents, RP25 metal wheels, a detailed undercarriage, and magnetically operating knuckle couplers. Minimum radius of 18". Measures approximately 17" long with tender.