ATHG97971 Union Pacific UP 4-6-6-4 Challenger Steam Locomotive #3985 Steam-Engine Molded in two colors

Molded in two colors

The only previous RTR model was produced for ‘TT’ gauge in the late-1950s

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Choice of BR 1976-82 or post-preservation main line locos

The packaging has been carefully designed so that once you have removed the pots

ATHG97971 Union Pacific UP 4-6-6-4 Challenger Steam Locomotive #3985 Steam-Engine Molded in two colorsUnion Pacific In the spring of 1941 UP locomotive designers began working on a locomotive to team up with the new 4 8 8 4 Big Boy's then under construction at Alco. The Big Boy's were designed to pull heavy freights up the Wasatch Range in Utah to the division point at Green River, WY. What was needed was a locomotive to take over at that point that could speed the freights eastward across the Wyoming Division. Building on their experience with the