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The roller coaster (or simply coaster) is a popular thrill ride developed for amusement parks and modern
theme parks. LaMarcus Adna Thompson patented the first roller coaster
on January 20, 1885. In essence a
specialised railroad system, a coaster consists of a track that rises and falls in specially designed patterns, sometimes with one or more inversions (the most
common being loops) that turns the rider briefly
upside down. The track does not necessarily have to be a complete circuit (the antonym of complete circuit is "shuttle"), though
some purists insist that it must to be a true coaster. (Note that not all thrill rides that run on a track are roller coasters).
Most coasters have cars for two, four, or six passengers each, in which the passengers sit to travel around the circuit. An
entire set of cars hooked together is referred to as a train.
Mechanics
The cars on a roller coaster are not self-powered. A standard full-circuit lift-powered coaster works like this: After leaving
the boarding area (station), the train is pulled up to the first peak of the coaster track with a chain or cable lift. Then
potential energy becomes kinetic energy as the cars race down the first downward slope.
Kinetic energy is converted back into potential energy as the train moves up again to the second peak. This is necessarily lower
as some mechanical energy is lost due to friction. Then the train goes down again,
and up, and so on. However, not all coasters run this way. The train may be set into motion by a launch mechanism (of which there are several types).
Some coasters move back and forth along the same section of track. These rollercoasters are called shuttles because of this
motion and usually run the circuit once with riders facing fowards and then backwards through the same course.
A properly designed roller coaster will have enough kinetic, or moving, energy to complete the entire course, at the end of
which brakes bring the train to a complete stop and a set of tires pushes it into the station.
Blocking
Some roller coasters have the ability to run two or more trains at once. These rides use a block system, which
prevents the trains from colliding. Block systems work by having the track divided into multiple blocks. Only one train is
permitted to be in a block at once. At the end of each block, there must be a section of track where a train can be stopped if
necessary. This can be done multiple ways, including holding it in the station, stopping the lift hill, or using brakes in the
middle or end of the circuit. Sensors at the end of each block detect when a train passes, so the computer running the ride can
tell which blocks are occupied. When the computer detects a train about to travel into an occupied block, it uses whatever method
is available (close brakes, stop lift hill, etc.) to keep it from entering. This can cause a cascade effect when multiple trains become stopped at the end of each block.
History
The first prototype roller coasters were based on gravity switchback trains developed in the 1880s. These primitive coasters were run to provide amusement by railroad companies on weekends when ridership was
lower. By 1912, the first underfriction coaster was developed by John
Miller, often called the Thomas Edison of roller coasters. Soon,
roller coasters spread to amusement parks all around the United States
and the rest of the world. Perhaps the most well known historical roller coaster, the Cyclone, was opened at Steeplechase Park at
Coney Island in Brooklyn, New York in 1927. Like the Cyclone, all early roller
coasters were made of wood. Many old wooden roller coasters are still operational, at parks such as Kennywood near Pittsburgh,
Pennsylvania and Blackpool Pleasure Beach,
England, UK.
The Great Depression marked the end of the first golden age of
roller coasters. Theme parks in general went into a decline that lasted until 1972, when
the Racer was built at Kings Island in Mason, Ohio (near Cincinnati). Designed by John
Allen, the instant success of the Racer began a second golden age, which continues through this writing 2003.
In 1959, the recently-opened Disneyland theme park introduced a new design breakthrough in
roller coasters with the Matterhorn Bobsleds. This was the first roller coaster to use a tubular steel track. Unlike
conventional wooden rails, tubular steel can be bent in any direction, which allows designers to incorporate loops, corkscrews,
and many other manoeuvres into their designs. Most modern roller coasters are made of steel but wooden roller coasters are still
being built.
Some of the major variations in contemporary roller coaster design involve the modification of the car. Some seat the
passenger in a bodyless frame, with the passenger's legs dangling in the air and providing a less-obstructed view of the ground,
thus providing an extra scare to the passengers. Another variation involves cars that have the riders in a standing position
(though still heavily strapped in). Finally, some rollercoasters spend some or all of their travel time with the passengers
sitting in the opposite direction to their travel, so they cannot see what direction the coaster will travel next.
In 1992, the first inverted track roller coaster opened at Six Flags Great
America in Gurnee, Illinois. As of 2003, the roller coaster holding the records for greatest speed and height is Top Thrill Dragster at Cedar Point near Sandusky, Ohio, with a top speed
of 120 mi/h (193.2 km/h) and a 420 foot (128.1 m)
vertical hill. New roller coaster designs and state of the art technology push the physical limits on what type of experiences
can be had on the newest coasters.
Safety
Because roller-coasters are intended to feel risky, accidents, such as the September, 2003 fatality at the seemingly
tame Walt Disney World Big Thunder Mountain, attract public attention.
Statistically, roller coasters are very safe. The U.S. Consumer Product Safety Commission estimates that 134 park guests
required hospitalization in 2001 and that fatalities related to amusement rides average two per year. According to a study
commissioned by Six Flags, 319 million people visited parks in 2001. The study concluded that a visitor has a in one-and-a-half
billion chance of being fatally injured, and that the injury rates for children's wagons, golf, and folding lawn chairs are
higher than for amusement rides.
Nevertheless, accidents do occur. Regulations vary from authority to authority. Thus in the USA, California requires amusement
parks to report any ride-related accident that requires an emergency-room visit, while Florida exempts parks whose parent
companies employ more than 1000 people from having to report any accidents at all. Rep. Edward Markey of Massachusetts has
introduced legislation that would give oversight of rides to the Consumer Product Safety Commission (CPSC).
In 1999, a rider who weighed more than 400 pounds (180 kg) was unable to close his lap bar properly and was thrown from the
Superman coaster at Six Flags Darien Lake, sustaining serious injuries. Despite this, a similar accident occurred in 2004 when a
230 pound (100 kg) man with cerebral palsy was permitted to board the Superman coaster at Six Flags New England and, on the last
turn of the ride, was thrown from his seat and killed. Critics maintain that, despite the generally good safety record, accidents
are occurring that are preventable.
In recent years, controversy has arisen about the safety of the increasingly extreme rides. There have been suggestions that
these may be subjecting passengers to G-forces and torsional accelerations that may be capable of causing brain injuries. In
2003 the Brain Injury Association of America
concluded in a report that "There is evidence that roller coaster
rides pose a health risk to some people some of the time. Equally evident is that the overwhelming majority of riders will suffer
no ill effects."
Types of roller coasters
- Wooden coasters
- Virginia Reel roller coasters
- Side Friction roller coasters
- Steel roller coasters
- Inverted roller coasters
- Stand-up roller coasters
- Flying roller coasters
- Spinning
roller coasters
- Suspended Swing roller coasters
- Floorless
roller coasters
- Side Friction roller coasters
- Shuttle
roller coasters
- Wild
Mouse roller coasters
- Moebius Loop roller coasters
- Racing roller
coasters
- Duelling
roller coasters
- Out
and Back roller coasters
- Twister
roller coasters
- Figure 8
roller coasters
- Launched
roller coasters
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