06/17/2026
What is a Big Boy?
The Big Boy was one of the largest and most powerful steam locomotives ever built. It was designed in the 1940s for the Union Pacific Railroad to haul extremely heavy freight trains over steep mountain grades without the need for helper locomotives. Only 25 were built, and today just eight survive. Of those, Big Boy No. 4014 is the only one still operating.
What was the 4014–4012 reunion?
Big Boy No. 4014 is the world’s only operational Big Boy. Big Boy No. 4012 is a preserved, non-operating locomotive on display at Steamtown National Historic Site.
In 2026, as part of America’s 250th anniversary celebrations, 4014 made its first-ever tour of the Northeastern United States and visited Scranton, Pennsylvania. This allowed 4014 and 4012 to stand side by side, creating a historic reunion of two Big Boys.
For railroad enthusiasts, it was a once-in-a-lifetime event: the only operating Big Boy meeting one of its preserved sister locomotives. Thousands of fans gathered to witness and photograph the reunion. #250