Kennywood's Jack Rabbit, built in 1920 by coaster designers John Miller and Harry Baker under the supervision of Charles J. Mach, is one of the world's oldest operating roller coasters and a longtime Pittsburgh-area institution. This 2,132-foot wooden coaster, constructed at a cost of $50,000, features four drops into a natural ravine and is especially known for its 68-foot, 6-inch double dip after an uncommon mid-course lift hill. It was Kennywood's first coaster to use Miller's patented underfriction wheels, which locked the train to the track and made steeper, more daring drops possible. When it opened on June 18, 1920, it included a dark tunnel around the lower back turn that was removed during the 1940s and later restored before the 1991 season. It is also noted for its classic Edward Vettel Sr.-designed trains with stationary lap-bars, which replaced the original open-front trains in 1951, and it has remained one of Kennywood's most popular coasters for more than 90 years.
