This remarkable mechanism was a simple condensing engine. It was finished in 1876 requiring seven months to build. It furnished power for running the machinery at the Philadelphia Centennial Exposition in 1876. It was purchased by George Pullman in 1880and was moved from Providence RI where it had been in storage after the run of the Centennial Exposition to Pullman, requiring a train of thirty-five cars to transport it. It was shaped like the capital letter A and from the floor to the top of the walking beam was forty feet. The cylinders were forty inches in diameter affording a ten-foot stroke. The diameter of the crankshaft was eighteen inches and twelve feet long. The diameter of the large gear (fly) wheel was thirty feet with a face of 24 inches and was the largest gear wheel in the world. The gear wheel meshed into a pinion wheel that powered 3268 feet of main power shafting located in tunnels 4-5 feet below grade in tunnel. From the main power shaft, approximately 13,000' of overhead shafting and two miles of belting applied to the machinery in the car shop. The engine was capable of developing 2500 horsepower.
When the engine was started at the Centennial exposition in Philadelphia's Fairmont Park by President Grant and Emperor Don Pedro III of Brazil, they were supported by a choir of 1000 singing Handel's Hallelujah Chorus, a band of 150 pieces playing the Centennial March composed by Richard Wagner, followed by 100 gun salute.
The engine was started by Florence Pullman on April 2, 1881, and ran until the fall of 1910, when it was scrapped after electricity replaced steam as the power source. Portions of the foundation of the original engine house and power shaft tunnels located below grade are still visible on the site.
The engine house at the Pullman Factory was located east (to the rear) of the North Factory wing in a room 40' square and 66' high. Wide aisles around the engine platform were providing for visitor on sight seeing tours of the factory works. The cost of engine was $77,000.