This Broadway Limited HO Scale Pennsylvania Railroad S1 Duplex is a must-have for your Pennsy steam collection. Affectionately nicknamed "The Big Engine," this iconic locomotive was a groundbreaking experimental duplex designed to showcase the technological advantages of duplex drive wheels. It was the longest (140' 2-1/2") and heaviest (608,170lbs) rigid-frame reciprocating steam locomotive ever built. Built at its own Altoona shops, the engine was numbered 6100 and featured a streamlined exterior designed by the renowned Raymond Loewy. With its unique 6-4-4-6 wheel arrangement, the S1 achieved remarkable speeds for passenger trains by eschewing articulation. After several test runs, it was proudly displayed at the 1939 New York World's Fair, adorned with "American Railroads" lettering on its tender. The engine entered service passenger train service in 1940 hauling prestigious trains such as the Broadway Limited, Liberty Limited, The General, The Trail Blazer and The Golden Arrow. However, its size limited its use to routes with sufficient track clearances, specifically between Chicago, Illinois, and Crestline, Ohio. This detailed brass hybrid model captures the looks and detailing of the prototype. This Stealth Series no-sound/DCC-ready model operates on DC out of the box, or modelers can easily install their 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 selected aftermarket decoder the modeler installs. 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 18" radius but larger curves are recommended. The Class S1 6-4-4-6 Duplex is one of manyBroadway Limited HO Scale locomotives.