HO4-6-6-4 CSA-1 Challenger Locomotive UP #3911 (ATHG-1030)

Union Pacific Challenger CSA-1 4-6-6-4 HO-scale steam locomotive with coal tender, UP 3911, is an HO-model designed to faithfully reproduce ALCO's legendary Challenger class for model railroaders. These massive articulated engines were built to haul fast freights and sometimes passenger trains, delivering impressive starting trActive effort and the versatility to tackle tough grades. This model captures the prototype's sheer scale with a satin paint finish and authentic detailing.

In operation, it features illuminated number boards and headlights, pivoting front and rear engines for smooth negotiations of curves, and current pickup on all wheels for reliable performance. The sound-equipped version includes a tender-mounted DCC decoder with SoundTraxx Tsunami2 sound and dual cube speakers for rich, realistic audio—covering chuff, whistle, bell, blow-down and more—operating in both DC and DCC with full DCC functionality. It supports multiple-unit lashups, offers precise slow-speed control, and provides CV adjustments (CV chart included) to tailor performance and sound. A minimum 22-inch radius is recommended, while the articulated drivetrain can negotiate 18-inch curves.