HO 4-6-6-4 Challenger with DCC & Sound, UP #3976 (ATHG98974)

This HO-scale Union Pacific 4-6-6-4 Challenger with DCC & Sound, road number 3976, brings UP’s WWII-era Challenger power to an HO layout. It pairs a DCC decoder with SoundTraxx Tsunami2 sound for authentic engine performance, synchronized chuff, whistle and other effects, and features illuminated number boards and headlights for realistic operation on both day and night runs.

The model wears a two-tone grey UP livery with yellow lettering and striping, includes an oil burner and dual smokestacks, and features road-number specific detailing such as illuminated cab signals, a tender light, and a detailed boiler backhead with printed gauges. It uses pivoting front and rear engines to handle curves, with current pickup on all wheels and a front coupler pocket for an operating coupler; the minimum radius is 22 inches, with 18-inch curves possible thanks to the articulated design. New features include dual cube speakers, a flickering firebox visible through a see-through door, brighter LED headlights, and an improved loco-to-tender harness. Sound-equipped operation uses a tender-mounted DCC decoder with Tsunami2, working in both DC and DCC with full NMRA-compatible functionality and CV-tunable performance (CV chart included). Historically, the Challenger was designed to move heavy trains at speed and was used in both freight and passenger service, a heritage reflected in this faithful HO model.