This Broadway Limited HO Scale UP Class Post-1947 CSA-2 Early 4-6-6-4 Challenger Brass Hybrid steam locomotive is based on the huge articulated mallets used by Union Pacific to move tonnage across its mainline over Sherman Hill from Ogden to Wasatch, Utah as well as on tough grades systemwide. The Union Pacific Challengers were simple articulated 4-6-6-4 steam locomotives built by American Locomotive Company for the UP. 105 of these locomotives were built between 1936 and 1943. The Challengers were 122′ (37m) long, weighed 284,800 kg, and operated over most of the Union Pacific system, primarily in freight service. The excellent Challenger design allowed for increased speed on mountain grades compared to UP′s previous articulated steam locomotives. This BLI model is of the Class CSA-2 Challenger, commonly called an ′early challenger′. This models has a post-1947 appearance, after the locomotives were renumbered from 3900 to 3800 series and has three appropriate detail variations: four road numbers with the as-delivered front engine, four road numbers with a rebuilt front engine, and two road numbers with an integral cast cylinder front engine. All are oil-burners with 19,000 gallon cylindrical tenders. This Stealth Series no-sound/DCC-ready model operates on DC out of the box, or you can easily install a DCC decoder of choice. Stealth Series models are DCC-ready with a standard MTC21 pin on the DC motherboard. Out of the box, front and rear lights are directional, and other lights are always ON with track power. Additionally, some lighting functions may be missing depending on your choice of aftermarket decoder. It also features a built-in speaker so you won′t have to add one later. Other features include a heavy die cast chassis and select roadname-specific details. Its wheels are profiled to operate on Code 70 and larger rail and curves of 22′ radius, but larger curves are recommended. The Early 4-6-6-4 Challenger is one of many Broadway Limited HO Scale locomotives.