The Big Boy

Locomotive 4023, built in November 1944, was one of 25 articulated Big Boy locomotives designed in Omaha by Union Pacific mechanical officer Otto Jabelmann and his engineering team to support the nation’s entry into World War II. Built for speed, these coal-burning, stoker-fired engines helped secure Union Pacific’s status as the nation’s fastest railroad and primarily hauled heavy eastbound freight trains between Ogden, Utah, and Green River, Wyoming, over a 1.14 percent grade. Known as 4-8-8-4s for their wheel configuration, Big Boys were praised in the industry and press as the most powerful, heaviest, and longest steam locomotives ever built. Despite a running weight of 1.25 million pounds, a Big Boy had pulling power equal to 7,000 horsepower at its 70 miles per hour design speed. The American Locomotive Company in Schenectady, New York, built the first 20 Big Boys in 1941, and 4023 was one of five more built in 1944 under government authority as rail traffic increased with the shift from European to Pacific war operations. After the war, diesel locomotives eventually surpassed the Big Boys. In their final days, they ran between Cheyenne and Laramie over Sherman Hill. Locomotive 4023 made its last run on July 20, 1959, was placed in storage in Cheyenne 11 days later, was officially retired in July 1962 after logging 829,295 miles, and has been displayed in Omaha since 1975.

Omaha, Nebraska · United States