Here's the Biggest Steam Locomotive in the World Flying Down the Rails

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Union Pacific 4014, also known as the largest steam locomotive in the world, also known as a Union Pacific “Big Boy,” is racing to Ogden, Utah, to make it in time for the 150th anniversary celebrations of the transcontinental railroad. Here it is flying down the tracks.

UP 4014 is one of only 25 Big Boys ever built, and is the only one running thanks to a years-long restoration effort by Union Pacific. Weighing over a million pounds, it was originally designed to haul freight over the Wasatch Mountains (themselves a section of the Rockies), and its approximately 6,300 horsepower could propel it up to 80 mph.

Two big boys hitched together to pull an especially heavy load of 90 cars in 1958.
Two big boys hitched together to pull an especially heavy load of 90 cars in 1958.
Photo: Otto Perry (Denver Public Library)

While the Big Boy is the star of my heart just by virtue of being over a million pounds of steel moving more quickly than a million pounds of steel should ever reasonably move, you can see in the video above that it’s joined by another steam locomotive known as UP 844. That particular train was originally designed for high-speed passenger service. Unlike the Big Boy, it’ll gleefully demonstrate that speed all day when it’s unhitched from a freight train and running free:

There’s just something about big steam locomotives hustling quickly that breaks my brain. Those massive connecting rods along the drive wheels, each one weighing a couple thousand pounds (per forums), just shouldn’t move that fast. And yet they do.


If you happen to be in Wyoming this week, as I’m sure tons of normal people are, Union Pacific has posted the Big Boy’s schedule online so you can check it out in person.