The Bigboy is a type 4-8-8-4 locomotive, which means that it has 4 smaller wheels at the front to keep the engine on the tracks, 8 large driver wheels (68 inches in diameter), 8 more large driver wheels, and 4 smaller wheels to hold up the firebox at the back end of the engine. Even more remarkable, the Bigboy is “articulated”, which means that the front 12 wheels are mounted to a frame that pivots independently of the rest of the engine. This allows it to go around corners that are sharper than what a similar sized non-articulated engine could negotiate. The Bigboy is 132 feet 9-3/4 inches long and weighs 1,208,750 pounds. Fully loaded, it carries 28 tons of coal and 25,000 gallons of water.
A total of 25 Bigboys were built in the early 1940’s. They were used by the Union Pacific Railroad to haul coal out of the Powder River Basin in Wyoming. This coal was used in endless quantities in the blast furnaces and power plants that drove American industry during WWII.
Bigboy line drawing by Larry Murchinson, used with permission (click to enlarge).
Of the 8 Bigboys that still exist, I have visited and photographed 7 of the survivors. No Bigboy is currently in running condition. In the late 1990’s, #4018 was slated to be restored to run in a movie. She was actually moved around at the Age Of Steam museum to put her in a position to be towed out for restoration. Fortunately, the project collapsed before the #4018 was moved out of the museum and tore down--the museum likely could not have afforded to put her back together and move her back to the museum. Even if a Bigboy is restored to operation, there is very little track in the US that can support its enormous weight.
