Broadway Limited's N Scale Union Pacific 4-6-6-4 Challenger #3977 is a stunning, highly detailed model of one of America's most celebrated articulated steam locomotives. The 4-6-6-4 Challenger was designed by the American Locomotive Company (ALCO) and introduced in 1936 for the Union Pacific Railroad. The Challenger's simple articulated design placed two sets of six driving wheels on a flexible frame, allowing it to negotiate curves while producing approximately 4,500 horsepower for the heaviest freight and passenger assignments.

Union Pacific rostered 105 Challengers, and UP No. 3985 remains in occasional operating condition today as one of the largest operating steam locomotives in the world. This BLI model features Paragon4 Sound/DC/DCC with Rolling Thunder and synchronized puffing smoke.

Key Features:
- N Scale Union Pacific 4-6-6-4 Challenger #3977 ready-to-run steam model
- Paragon4 Sound and Control System with factory-installed integral DCC decoder
- Dual-Mode operation on both standard DC and DCC layouts
- Authentic recorded Challenger steam locomotive sounds
- Synchronized puffing smoke unit with on/off switch
- Back EMF motor control for smooth slow-speed operation
- Built-in GoPack capacitor for reliable operation over imperfect track
- Rolling Thunder functionality for use with bass subwoofer systems
- Die-cast boiler and tender body for maximum tractive effort
- Separately applied handrails, grab irons, ladders, whistle, and brass bell
- Minimum operating radius 11.25 inches