Steamtown in Scranton, Pennsylvania

Steaming Through History: Exploring the Railroads at Steamtown National Historic Site

by Celeste Lipford and Terry Lipford - last updated on 7/20/2024

The Union Pacific 4012 engine, also known as the Big Boy, is a legendary steam locomotive that holds a special place in railroad history. Built in 1941 by the American Locomotive Company, it was part of the Union Pacific Railroad's fleet of massive articulated steam locomotives designed for hauling heavy freight trains over long distances. The Big Boy locomotives were the largest steam engines ever built, measuring over 132 feet long and weighing over 1.2 million pounds. With a 4-8-8-4 wheel arrangement, they boasted immense power and pulling capacity.

One of 25 built, No. 4012 is one of eight of its type to survive the advent of the diesel era. Referred to as an "articulated" locomotive, because it has more than one set of drivers, Big Boy weighs 1,250,000 pounds (570,000 kg). This locomotive worked for 21 years hauling freight between Cheyenne, Wyoming, and Ogden, Utah, logging over 1,000,000 miles (1,600,000 km) before its retirement in 1962.

In 1923, the "Big Boy" emerged from the fires of American industrial might. Designed to conquer the treacherous grades of the Rocky Mountains, this behemoth boasted unmatched power and sheer size. Its boiler housed a furnace the size of a small house, and its wheels pounded the tracks with the force of a battering ram.

For decades, the 4012 reigned supreme over the rails. It hauled heavy freight through blizzards and scorching heat, connecting communities and fueling the nation's industrial engine. Its rhythmic chug, a hypnotic song of steel and steam, became a familiar melody across the American landscape.

The 4012's story isn't just about power and speed. It's also a testament to American resilience. During World War II, these "Big Boys" became the unsung heroes of the home front, hauling vital war supplies across vast distances. They kept the wheels of industry turning and played a crucial role in securing victory.

The Steamtown Scranton PA Roundhouse stands as an iconic structure, a testament to the golden age of steam locomotives. Nestled in the heart of Scranton, Pennsylvania, this magnificent roundhouse has captured the imagination of railroad enthusiasts and visitors alike. With its impressive 22-stall design, the roundhouse served as a hub for locomotive maintenance and repair during its operational days.

When the Steamtown Park was under development, the National Park Service decided to use the existing portions of the Roundhouse (dating from 1902, 1917, and 1937) as a part of the Museum Complex, while adding a Visitor Center, Theater, Technology Museum, and History Museum. The Roundhouse was adaptively rehabilitated to allow Steamtown's mechanics to care for the locomotives with light-duty maintenance and repairs.

In the center area of the round house, there is a "turn table" that allowed the Railroad engineers to bring in equipment and then be able to select which round house shop the equipment would be placed into. The round house is essentially a number of large "garages" where repairs or maintenance work took place.