The Big Boy Steam Locomotive

The Big Boy Steam Locomotive

For a train aficionado the Age of Steam evokes nostalgia for a bygone era. The Age of Steam begins with static engines and then tip-toes into moving locomotives, but culminated in giant, massive, yet intricate moving machines. Even if you never lived through that steam locomotive age, a big steam locomotive is seen as something of great might and beauty… even something that for Americans brings feelings of patriotism and passion for the United States’ place in the world. It’s because these engines are massive, loud, you can see them working hard, just like the American spirit… and their heyday was in the 1940s and 1950s when the United States was heavily involved in world affairs during World War II and immediately after. Citizens of other early-industrialized countries of the world have the same feelings when seeing the popular steam locomotives of their history. Steam locomotives are popular the world over and a case could be made that countries, like Great Britain, other than the USA do a better job of preserving steam from their heyday, but in the United States there is a steam preservation story that has made headlines and will continue to do so.

Big Boy and Steam go together in the public’s mind

If the public loves the steam engine, there is no steam engine that looms larger in the public’s mind than the Union Pacific Big Boy. The name “Big Boy” has an interesting history: The locomotive began as a Union Pacific effort to pull longer trains faster with fewer engines some of the obstacles facing the “Overland Route”, specifically Sherman Hill and the Wasatch Mountains. Designed with that goal in mind, the new Union Pacific 4000 series of steam locomotives was to be called the Wasatch class. It would have been a fitting name.  But this is a huge locomotive, and during construction at the American Locomotive Company’s Locomotive Works In Schenectady New York, a worker put chalk to steel and wrote “Big Boy” on the bare boiler. The name stuck.

Where can you find out more about the Big Boy? You can find out much more at

The 4000 series, the Big Boys of the Union Pacific, were not all that numerous. Only 25 were made. But, the Union Pacific made sure to use the full public relations value of this huge locomotive – it even appeared on its own television show.

The Big Boy is called that for a reason….

The engine is massive. It is what is called a 4-8-8-4 wheel arrangement. That means 4 pilot wheels, two on each side, with 8 driving wheels, four on each side, immediately behind, then another 8 driving heels, four on each side, followed by 4 trailing wheels to support the massive firebox under the cab. it was a massive machine capable of 3000 horsepower and 135,000 pounds of tractive effort, a measure of pulling power. And that’s just the engine itself, the tender, carrying the locomotives coal and water, needed 14 wheels, 7 on each side, to carry the load.

The engine was built to run at speeds up to 80 mph, although they would never operate at that speed. The overdesign was done to ensure that the rotating parts would not be damaged while operating, and its highest speed reported during a test was 72 mph.

The new engine was so big that the railroad had to install new 135-foot turntables at servicing points and bridges had to be strengthened. The Big Boy was the largest engine that could operate on an existing standard gauge railroad. It is really something to see!

Where can I see these monsters as they were- in action in the 1940s and 1950s? The most complete video collection is available at

Even so, what in 2018 could bring this locomotive back to the public’s consciousness? several have been restored and are on static displays throughout the country including Cheyenne Wyoming, the location of the Union Pacific steam shops, Steamtown, a National Historical Park in Scranton Pennsylvania. The National Railroad Museum in Green Bay Wisconsin, and until recently at RailGiants Train Museum in Pomona California. The engine at Pomona was number 4014, about in the middle of the 25 locomotive run for the 4000 series.

Bringing a Big Boy back to Operating Condition

The Union Pacific operates a steam program that features historic Union Pacific steam engines. Those engines are run for the benefit of shippers, employees and Union Pacific public relations. A lot of time and money has been spent to operate number 844, a Northern class locomotive, and number 3985, a Challenger class locomotive. But Union Pacific’s steam heritage has always been the Big Boy, so in 2014 Union Pacific traded the RailGiants Train Museum for Big Boy 4014. The train museum is not connected to the national rail network and so Union Pacific had to lay track over a parking lot to get her to the nearest rail.

The Union Pacific made a load of Big Boy 4014, taking her by rail from California over the Sierra Nevada mountains over the high plains back to Cheyenne, Wyoming and the Union Pacific Steam Shops. There it is undergoing a complete teardown and rebuild. Big Boy 4014 is scheduled to run for the public again in 2019.

Watch for lines of railfans along a Union Pacific rail line near you!

Railfans around the world await the unveiling of Big Boy 4014. and no doubt, Union Pacific will receive the public relations for the rails again. Big Boy 4014 will be making appearances and towns all across, and maybe since East on a publicity tour. This engine has for over 70 years ignited curiosity and affection from not only railfans, but a public that enjoys nostalgia.

Where can you see a Big Boy on display?

If you are not able to see 4014 running on a line near you, you can still see these massive machines as they are available at museums around the country.  Of the 25 Big Boys, 17 engines were scrapped and 8 have been preserved, all, except lucky 4014, are currently on static display in various museums throughout America: two of the engines are displayed indoors after lengthy outdoor displays. Only four of the locomotives are displayed along original historic Union Pacific lines (Cheyenne, Wyo.; Denver; Omaha, Neb.; and Pomona, Calif.), while two, in Dallas and St. Louis, are now on UP’s map after mergers enlarged the system. You can see which engine ended up in which museum, at the “Preservation Page”.

Fan Favorite Big Boy Videos?

Considering that only 25 engines were ever built, there has been a considerable amount of film taken of them! By far the most complete collection of film on the Big Boy series is the Pentrex “Union Pacific Big Boy Collection“. It features photos and film from each of the 25 Big Boys. Pentrex also has compiled 4 Union Pacific public relations films, plus the television drama and put them out as “Big Boy Combo, Part 1” and “Big Boy Combo, Part 2“. RailfanDepot carries a money-saving double, complete, set of those films put out on DVD by Pentrex, you can see that here. Finally, you can see Big Boy 4014 as she travels from Pomona through California or her way to Cheyenne.  See the trip with “Big Boy 4014 Update” or see that and some early restoration news with Trains Magazine’s “4014, on the Road to Restoration“.

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