N 4-6-6-4 Union Pacific #3976 Model Locomotive (ATH25544)

Union Pacific N-scale 4-6-6-4 Challenger Locomotive, UP 3976. This detailed, ready-to-run N-scale model recreates the Union Pacific's 4-6-6-4 Challenger from the late 1940s into the 1950s, giving model railroaders an authentic centerpiece for their layouts. The UP two-tone gray paint with yellow lettering and striping reflects the era’s passenger-service appearance, and the model is configured as an oil burner with a dual smoke stack for period accuracy.

Designed for realism, the model is NCC-ready with Quick Plug plug-and-play electronics and is scaled from prototype drawings and measurements. It features a full cab interior with a boiler backhead and printed gauges, individually applied piping and valves, and operating eccentric cranks. Lighting includes LED headlights and directional number boards, with see-through running boards and cab windows, plus McHenry scale knuckle couplers and a heavy die-cast frame for traction. A five-pole motor with a flywheel provides smooth operation, and pivoting front and rear engines accommodate curves as tight as 11 inches, with a minimum recommended radius of 15 inches. Sound-equipped versions include a tender-mounted DCC decoder with SoundTraxx Tsunami2 sound, working in both DC and DCC modes, with CV adjustments and an included CV chart.