Union Pacific 3700 Challenger Steam Locomotive (DCC-Sound)

Union Pacific 3700 Challenger Steam Locomotive (DCC-Sound)

1:160 scale model produced by Minitrix. This model is ready-to-run straight out of the box and would make a excellent addition to any model railway collection.

Features:

• DCC Sound Model
• This model mainly operates in USA
• This model is decorated in Union Pacific company markings
• This model is best suited to 261mm radius curves

Details

Long overshadowed by the famous “Big Boys,” the Union Pacific Challenger locomotives were no less imposing. During the steam era, the UP faced steep gradients and sharp curves along the transcontinental line through the Rocky Mountains, requiring frequent helper and pusher engines, especially on heavy freight trains. By the mid-1930s, the six-coupled locomotives of the 9000 series had reached their limits. To meet the challenge, UP developed a powerful articulated locomotive with two engines, capable of higher power and improved curve negotiation.

Constructed by the American Locomotive Company (ALCO), the first (2'C)C2' h4 Challengers were delivered in 1936. Each engine had six driving axles powering four cylinders, with two leading and two trailing axles per engine to support a massive boiler and firebox. At 37 meters long and over 450 tons, these locomotives delivered 5,000 hp and could reach 110 km/h, making them suitable for both freight and heavy passenger service. The name “Challenger” reflected the locomotive’s readiness to take on any challenge.

UP ultimately acquired 105 Challengers in five series from 1936 to 1944, with later models producing nearly 6,000 hp and featuring larger tenders, smoke deflectors, two-tone paint schemes, and oil firing. Many coal-fired Challengers were also converted to oil from 1941 onwards, with renumbering to 3700–3717 for distinction. Their shorter length compared to Big Boys made them more versatile and essential to UP operations before dieselization.