The Union Pacific Big Boy is a type of simple articulated 4-8-8-4 steam locomotive manufactured by the American Locomotive Company (ALCO) between 1941 and 1944 and operated by the Union Pacific …

Big Boy No. 4014 is the world’s largest operating steam locomotive. Of the eight remaining Big Boys in existence today, No. 4014 is the only one still in operation. Twenty-five Big Boys were commissioned …

Feb 25, 2025 · Few steam locomotives compare to Union Pacific's (UP) colossus 4-8-8-4 " Big Boy." It was designed during the zenith of seam technology and earned celebrity status as soon as the first …

Produced from 1941 to 1944 by the American Locomotive Company of Schenectady, N.Y., exclusively for the Union Pacific Railroad, the Big Boy locomotives were designed primarily to handle heavy …

May 7, 2024 · Discover more about the history of the Cheyenne’s Union Pacific Big Boy, the largest steam locomotive in the world. Read about facts, schedules, and more.

Explore the history and features of Big Boy steam engines. Learn about their manufacturing, operation, and preservation efforts.

Jun 18, 2025 · The world's largest operating steam locomotive — Union Pacific Railroad's Big Boy No. 4014 — is scheduled to make two stops in Colorado during a limited 2025 tour.

Built in November 1941 by the American Locomotive Company in Schenectady, New York, it was assigned to haul heavy freight trains in the Wasatch mountain range.

Sep 16, 2021 · The "Big Boys" were built for power. They did the work of three smaller engines, pulling 120-car, 3800 ton freight trains at forty miles per hour in the mountains of Utah and Wyoming.

Dec 26, 2024 · Referred to as the 4-8-8-4 for the locomotive's wheel configuration, the Big Boy was lauded in the industry and press as the most powerful, heaviest and longest steam locomotive ever …