Union Pacific Heritage Fleet Operations

UP Big Boy 4014

UP: A return to steam for Big Boy 4014

One of the largest and perhaps most famous steam locomotives ever built—Union Pacific’s articulated 4-8-8-4 “Big Boy” No. 4014—will be restored to operating condition by UP’s Cheyenne, Wyo.-based Heritage Fleet Operations within the next five years. 4014 will join UP’s two other famous steam locomotives—4-6-6-4 Challenger 3985 and 4-8-4 Northern 844—in excursion service when her restoration is completed. She will become the world’s largest operational steam locomotive.