HO4-6-6-4 CSA-2 Challenger Locomotive, UP #3820 (ATHG-1029)

HO Scale Union Pacific CSA-2 Challenger Locomotive, UP 3820, is a highly detailed HO model of the famous 4-6-6-4 Challenger articulated locomotive. It’s designed for serious HO-scale railroading, letting hobbyists add authentic Union Pacific power to their layouts and enjoy a true-to-life steam-era centerpiece.

Road-number-specific features reproduce prototype detail, including a Worthington feedwater heater on the 3820 variant, a large sand dome, satin paint finish, and blackened side rods, along with illuminated number boards and headlights that adjust with direction. The model offers cab and boiler details, adjustable top vents, and pivoting front and rear engines to handle HO curves, with current pickup on all driving wheels for reliable operation. Sound-equipped versions include a tender-mounted DCC decoder with SoundTraxx Tsunami2 sound, dual cube speakers, and full DCC functionality; in DC mode engine, whistle and bell sounds still operate, and all functions remain NMRA-compatible in DCC mode with programmable CVs and a CV chart included for slow-speed control and MU lashups.