As early as the 15th century, Russians were using nature as their roller coaster; carving as large as 70-foot slides and sleds out of the frozen terrain. Adapting that idea, Pennsylvania coal miners used a roller coaster-type track to transport heavy coal. La Marcus Thomspon saw something in these applications, leading him to develop the first roller coaster for entertainment in the United States at Coney Island in New York. The entertainment ride industry became widespread and, with the inventions of John Miller, a roller coaster safety innovator, was a thrilling, yet safe option for riders.
Compressed Air Brakes
Brakes with compressed air are used at the end of each roller coaster ride so people may get off. The braking system used on most roller coasters can be computer-operated or manually overridden when necessary. Some designs allow for two coaster cars to run on the same track simultaneously. An adequate compressed air break system allowing operators to manually stop the cars must be in place for safety measures to prevent the two coaster cars from colliding. A "block system" is used to separate the parts of the track and designate the areas in which air brakes can be put in place.
Safety Chain Dog
John Miller, an innovator in roller coaster safety, developed an invention to keep the coaster cars from falling backward down steep slopes with an invention called the safety chain dog, also referred to as the safety ratchet. If the lift chain used to pull coaster cars up large slopes becomes loose or broken, chain dogs, or metal "stairs," are designed to catch the cars and secure them to avoid a runaway coaster. The infamous "clickety-clack" sound often heard at the beginning of roller coaster rides is actually a safety feature hard at work.
"Upstop," or under-friction wheels, are another of John Miller's safety innovations. In 1919, Miller saw a need to construct an extra set of wheels on the undercarriage of coasters to keep riders safe during the experience if the coaster were to stop; even while inverted. These wheels "hug" the coaster track and prevent the cars from dislodging themselves, even at high speeds, sharp turns or in loops.
A century of safety technology has been programmed into the computers running roller coasters today. The removal of human operation alleviates error caused by careless mistakes, distraction or purposeful harm. This drastically reduces the potential dangers to riders.
Harness and Safety Belts
The most noticeable safety feature to riders are lap belts, lap bars and harnesses. These safety features vary by coaster and design but are often electronically held in place over the rider's shoulders or waist using a locking mechanism and are not released by the operator until the ride has come to a stop. Lap belts, similar to seat belts, are used in less-thrilling rides such as children's rides or those that do not reach high speeds and are not inverted.