Zipper (ride)

The Zipper is an amusement ride invented by Joseph Brown under Chance Rides in 1968. Popular at carnivals and amusement parks in the United States, Canada, Australia and New Zealand, it features strong vertical G-forces, numerous spins, and a noted sense of unpredictability. Chance Rides has manufactured more than 200 units since the ride's debut.

Most models of the Zipper follow a similar basic format: A long, rotating, oval boom with a cable around its edge that pulls 12 cars around the ride. Except at peak times, most operators will only fill half of the cars at one time with riders. Like most carnival equipment, the ride is designed to be portable; it can be disassembled onto a truck and transported from site to site.

Though a staple of amusement parks and carnivals, the original models of the Zipper garnered a reputation for being unsafe due to their rough nature, and a series of deaths on the rides in the late 1970s after cabin doors came unlatched led to a series of revisions, primarily restructuring of the door lock system. No less, the ride has amassed a cult following over its decades in operation, and was named by Popular Mechanics as one of the strangest amusement park rides in the world.

The Zipper was created by Joseph Brown under Chance Rides in 1968 in Wichita, Kansas, and registered under patent 3,596,905 in 1971. The ride's basic design was based on an earlier ride called The Swooper, invented in 1928, which also featured a series of cars being pulled along a cable around an oblong framework. The central difference between The Swooper and the Zipper was the ability of the Zipper's frame to rotate as the cars travel along it by cable.

The Zipper has a long oblong frame (the boom) that rotates like a Ferris wheel, with free-flipping cars suspended on off-center axes that move around the sides of the boom via a pulley system. Each passenger capsule is essentially a bench seat that snugly fits two people, built into a compartment of metal mesh contoured to protect the riders' entire bodies. The odd, apostrophe-shaped capsules, spaced evenly along the perimeter of the boom, look very much like the rows of interlocking teeth on a zipper, the characteristic for which the ride was named.

The passenger capsules travel around the perimeter of the boom at 4 revolutions per minute (rpm), not particularly fast, but the "flip" around the end of the oblong frame causes a sudden burst of speed and sends the compartments flipping end over end. The boom itself rotates at 7.5 rpm in the same direction as the pulley system. This combined but offset rotation provides each capsule with a unique and unpredictable experience. Zippers rotate both clockwise and counter-clockwise, and most are run with several rotations in each direction constituting "one ride".

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