Build Date: December, 1941 Builder: ALCO, Schenectady, NY Current Status: Static Road: Union Pacific Configuration: 4-8-8-4 Union Pacific's route across the Wahsatch mountains in southwest Wyoming and northern Utah provided a significant obstacle to moving freight. As steam locomotive technology progressed, Union Pacific ordered larger, faster and more powerful locomotives: 2-8-8-0s in 1918, the three-cylinder 4-12-2s in 1926, then 4-6-6-4s in 1937, and ultimately a locomotive which could move freight over steep Sherman Hill unassisted and maintain a fast schedule. In 1941, Union Pacific received the first out of an eventual 25 locomotives dubbed "big boys," the last five of which were delivered in 1944. At the time, the 4000 class were the longest and among the heaviest, most powerful steam locomotives in the world. Big Boy 4018 was in service and assigned to Wyoming's Cheyenne-Green River territory in September of 1957, having received its final repairs at the Cheyenne shops in April of 1957. By October of 1957 engine 4018 was stored serviceable at Green River. 1958 saw several 4000s in service on the Cheyenne-Laramie segment only. As a result some 4000s ended up stored at Laramie at the end of 1958, and the last six 4000s located at Cheyenne were placed into service for just 15 days in 1959. Union Pacific 4018 was officially retired in 1962 and donated in 1964, traveling from Wyoming to Kansas City, then south via the Santa Fe into Dallas. In 1998 the museum was approached with a proposal to restore 4018 to operation for a feature film which did not materialize. Union Pacific 4018 remains on static display at the Age of Steam as it has been since 1964. There are no plans for an operational restoration. http://www.dallasrailwaymuseum.com/bigboy.html http://www.dallasrailwaymuseum.com/Big%20Boy%20Whistle.wma The Big Boys were built for power. They did the work of three smaller engines, pulling 120-car, 3800 ton freight trains at forty miles per hour in the mountains of Utah and Wyoming. With power though, comes weight - larger cylinders, pistons, drive rods, boiler and firebox. Steam locomotive manufacturers added more wheels with idlers and powered drive wheels. The extra wheels added length. Long engines had difficulty squeezing through the sharp track curves, especially in the mountains. A Swiss designer, Anatole Mallet (1837-1919) added a "hinge" to the middle of a locomotive to allow it to "flex" slightly. Two pairs of cylinders supplied power to the two sets of drive wheels. The Big Boys were built in Schenectady, New York by the American Locomotive Company (ALCo) to the Union Pacific's design. ALCo delivered the first batch of 20 - including #4012 in the Steamtown NHS collection - in 1941 and the remaining 5 in 1944. Big Boys had over one mile of tubes and flues inside the boiler. Their firebox grate measured 150 square feet. The Big Boys had sixteen drive wheels, each measuring 68 inches. From coupler to coupler they measured 132 feet 9 inches. The tender held 24,000 gallons of water and 28 tons of coal and the engine and tender weighed 1,189,500 pounds in working order. The engines well deserved the name 'Big Boy' which was written on one of the drive rods by an unknown worker at ALCo. http://www.nps.gov/archive/stea/bigboy.htm I had the chance to talk with the Amtrak engineer and he showed me back to the engine.standing within 2 feet of a 16 cyclinder diesel engine running was a treat.raw power to say the least. this same Amtrak just past close to my house the same day as I took this picture thanks for viewing and comments. have a wonderful weekend