Harry Guy Traver (November 25, 1877 – September 27, 1961) was an American engineer and early roller coaster designer. As the founder of the Traver Circle Swing Company and Traver Engineering Company, he was responsible for the production of gentle amusement rides like the Circle Swing, Tumble Bug, and Auto Ride. His roller coasters became legendary for their unique twisted layouts and thrilling, swooped turns. At a time when most coasters were built from wood, Traver was the first coaster builder to utilize steel for the primary structural material.[1] He also built the first motorized fire engine in New York City.[2][3]