Definitions

roller_coaster

Roller coaster

The roller coaster is a popular amusement ride developed for amusement parks and modern theme parks. LaMarcus Adna Thompson patented the first coasters on January 20, 1885. In essence a specialized railroad system, a roller coaster consists of a track that rises in designed patterns, sometimes with one or more inversions (such as vertical loops) that turn the rider briefly upside down. The track does not necessarily have to be a complete circuit, as shuttle roller coasters exhibit. Most roller coasters have multiple cars in which passengers sit and are restrained. An entire set of cars hooked together is called a train. Some roller coasters, notably Wild Mouse roller coasters, run with single cars.

In what may be a practical application, NASA has announced that it will build one to help astronauts escape the Ares I launch pad in an emergency.

Etymology

There are several explanations of the name roller coaster. It is said to have originated from an early American design where slides or ramps were fitted with rollers over which a sled would coast. This design was abandoned in favor of fitting the wheels to the sled or other vehicles, but the name endured.

Another explanation is that it originated from a ride located in a roller skating rink in Haverhill, Massachusetts in 1887. A toboggan-like sled was raised to the top of a track which consisted of hundreds of rollers. This Roller Toboggan then took off down gently rolling hills to the floor. The inventors of this ride, Stephen E. Jackman and Byron B. Floyd, claim that they were the first to use the term "roller coaster."

The term jet coaster is used for roller coasters in Japan, where such amusement park rides are very popular.

History

"Russian Mountains"

The oldest roller coasters descended from the so-called Russian Mountains, which were specially constructed hills of ice, located especially around Saint Petersburg. Built in the 17th century, the slides were built to a height of between 70 Some historians say the first real roller coaster was built under the orders of Russia's Catherine the Grhe Gardens of Oranienbaum (today Lomonosov) in Saint Petersburg in the year 1784. Other historians believe that the first roller coaster was built by the French. The Les Montagnes Russes à Belleville (The Russian Mountains of Belleville) constructed in Paris in 1812 and the Promenades Aériennes both featured wheeled cars securely locked to the track, guide rails to keep them on course, and higher speeds.

Scenic gravity railroads

In 1827, a mining company in Summit Hill, Pennsylvania constructed the Mauch Chunk gravity railroad, an 8.7mi (14km) downhill track used to deliver coal to Mauch Chunk (now known as Jim Thorpe), Pennsylvania. By the 1850s, the "Gravity Road" (as it became known) was providing rides to thrill-seekers for 50 cents a ride. Railway companies used similar tracks to provide amusement on days when ridership was low.

Using this idea as a basis, LaMarcus Adna Thompson began work on a gravity Switchback Railway that opened at Coney Island in Brooklyn, New York in 1884. Passengers climbed to the top of a platform and rode a bench-like car down the track up to the top of another tower where the vehicle was switched to a return track and the passengers took the return trip. This track design was soon replaced with an oval complete circuit. In 1885, Phillip Hinkle introduced the first full-circuit coaster with a lift hill, the Gravity Pleasure Road, which was soon the most popular attraction at Coney Island. Not to be outdone, in 1886 LaMarcus Adna Thompson patented his design of roller coaster that included dark tunnels with painted scenery. "Scenic Railways" were to be found in amusement parks across the county.

Popularity, decline and revival

By 1912, the first underfriction roller coaster had been developed by John Miller. Soon, roller coasters spread to amusement parks all around the world. Perhaps the best known historical roller coaster, The Cyclone, was opened at Coney Island in 1927.

The Great Depression marked the end of the first golden age of roller coasters, and theme parks in general went into decline. This 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 has continued to this day.

Steel roller coasters

In 1959, the Disneyland theme park introduced a new design breakthrough with the Matterhorn Bobsleds. This was the first roller coaster to use a tubular steel track. Unlike conventional rails set on wooden railroad ties, tubular steel can be bent in any direction, which allows designers to incorporate loops, corkscrews, and many other maneuvers into their designs. Most modern roller coasters are made of steel, although wooden coasters are still being built.

New designs and technologies are pushing the limits of what can be experienced on the newest coasters. Electromagnetically-launched coasters are examples of such technologies..

Mechanics

The cars on a typical roller coaster are not self-powered. Instead, a standard full circuit coaster is pulled up with a chain or cable along the lift hill to the first peak of the coaster track. The potential energy accumulated by the rise in height is transferred to kinetic energy as the cars race down the first downward slope. Kinetic energy is then converted back into potential energy as the train moves up again to the second peak. This hill is necessarily lower, as some mechanical energy is lost to friction.

Not all rides feature a lift hill, however. The train may be set into motion by a launch mechanism such as a flywheel launch, linear induction motors, linear synchronous motors, hydraulic launch, compressed air launch or drive tire. Such launched coasters are capable of reaching higher speeds in a shorter length of track than those featuring a conventional lift hill. Some roller coasters move back and forth along the same section of track; these are known as shuttles and usually run the circuit once with riders moving forwards and then backwards through the same course.

A properly designed ride under good conditions 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 it is pushed into the station. A brake run at the end of the circuit is the most common method of bringing the roller coaster ride to a stop. One notable exception is a powered roller coaster. These rides, instead of being powered by gravity, use one or more motors in the cars to propel the trains along the course.

If a continuous-circuit coaster does not have enough kinetic energy to completely travel the course after descending from its highest point (as can happen with high winds or increased friction), the train can valley: that is, roll backwards and forwards along the track, until all kinetic energy has been released. The train will then come to a complete stop in the middle of the track. This, however, works somewhat differently on a launched coaster. When a train launcher does not have enough potential energy to launch the train to the top of an incline, the train is said to "roll back." On some modern coasters, such as Top Thrill Dragster at Cedar Point in Sandusky, Ohio, and Stealth at Thorpe Park in Surrey, UK this is an occurrence highly sought after by many coaster enthusiasts.

Timing

Most large 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. In a block system, the track is divided into several sections, or blocks. Only one train at a time is permitted in each block. At the end of each block, there is a section of track where a train can be stopped if necessary (either by preventing dispatch from the station, closing brakes, or stopping a lift). Sensors at the end of each block detect when a train passes so that the computer running the ride is aware of which blocks are occupied. When the computer detects a train about to travel into an already occupied block, it uses whatever method is available to keep it from entering. The trains are fully automated. The above can cause a cascade effect when multiple trains become stopped at the end of each block. In order to prevent this problem, ride operators follow set procedures regarding when to release a newly-loaded train from the station. One common pattern, used on rides with two trains, is to do the following: hold train #1 (which has just finished the ride) right outside the station, release train #2 (which has loaded while #1 was running), and then allow #1 into the station to unload safely.

Safety

Because roller coasters are intended to feel risky, accidents such as the September 5, 2003 fatality at the Disneyland Big Thunder Mountain Railroad, 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 one 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. In fact, driving to the amusement park has a much higher risk of injury than riding the rides at the amusement park.

Many safety systems are implemented within roller coaster systems. The key to the mechanical fail safes is the control of the roller coaster's operating computers: programmable logic controllers (often called PLCs). Most roller coasters run with three separate PLCs; however, only one PLC is required to detect a fault for the ride's fail-safes to be activated. This is often the reason that the ride trains may stop on the lift or the brake runs, yet after a short time the ride starts again without any obvious maintenance by staff. It is likely in such a case that one of the PLCs detected a fault by mistake, and the ride operator only needed to restart the ride.

Nevertheless, accidents do occur. Regulations vary from one authority to another. 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. Ed Markey of Massachusetts has introduced legislation that would give oversight of rides to the Consumer Product Safety Commission (CPSC).

Ride accidents can be caused by riders or ride operators not following safety directions properly, but in extremely rare cases riders can be injured by mechanical failures.

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 translational and rotational 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."

A similar report in 2005 linked roller coasters and other thrill rides with potentially triggering abnormal heart conditions that could lead to death. Autopsies have shown that recent deaths at various Disney parks, Anheuser-Busch parks, and Six Flags parks were due to previously undetected heart ailments.

Physics

Roller coaster design is a science, as well as an art: the designer must use knowledge of kinematics to avoid overstressing the human body and building an uncomfortable or dangerous ride. The acceleration is a significant design parameter, as is the rate of change of acceleration, jerk. Jerk is often used in engineering as some precision or fragile objects—such as passengers—need time to sense stress changes and adjust their muscle tension to avoid injuries such as whiplash. Designers also have to incorporate gravitational forces into their design. On a roller coaster, humans have certain limits of G-forces that they can endure. Positive vertical forces (ones that push riders down into the seat) can be withstood the easiest, with forces almost going into the 6 G (six times the force of gravity) range. Negative vertical forces (a type of force that, if balanced with gravity correctly, will give the sensation of weightlessness), a force on a roller coaster in which the car crests a hill or similar element, and the riders are pushed out of their seat from centrifugal force. Designers normally don't exceed -1.5 to -2 G-forces in this type of force because it is the hardest for riders to endure. Lateral G-forces are also experienced on almost every ride ever built. This is the force that throws the rider toward one side of the seat when going around a curve. Normal lateral forces on a roller coaster usually don't exceed 1.5 Gs, though some have been recorded as 1.8. Lateral forces can cause an uncomfortable, rough feeling on a roller coaster if there is too much force.

Types of roller coasters

Today, there are two main types of roller coaster:

Steel coasters are known for their smooth ride and often convoluted shapes that frequently turn riders upside-down via inversions. Wooden coasters are typically renowned by enthusiasts for their rougher ride and "air time" produced by negative G-forces when the train reaches the top of hills along the ride. There are also hybrid roller coasters that combine a steel structure with wood tracks, or a wood structure with steel tracks.

Modern roller coasters take on many different forms. Some designs take their cue from how the rider is positioned to experience the ride. Traditionally, riders sit facing forward in the coaster car, while newer coaster designs have ignored this tradition in the quest for building more exciting, unique ride experiences. Variations such as the stand-up roller coaster and the flying roller coaster position the rider in different ways to provide different experiences. Stand-up coasters involve cars that have the riders in a standing position (though still heavily strapped in). Flying coasters have the riders hanging below the track face-down with their chests and feet strapped in. Vekoma "Flying Dutchman" coasters have the riders starting out sitting above the track, then they fully recline so that the riders are looking at the sky. Eventually, they twist into the "flying" position. B&M flying coasters have the riders hanging below the track like in an inverted (hanging) coaster. To go into the flight position, the section of the car where the riders' feet are is raised to the track. That way, they start in the flight position. In addition to changing rider viewpoint, some roller coaster designs also focus on track styles to make the ride fresh and different from other coasters.

See Roller coaster elements for the various parts of a roller coaster and the types of thrill elements that go into making each roller coaster unique.

By train type

By track layout

By mechanics

By height

Several height-related names have been used by parks and manufacturers for marketing their roller coasters. While often used among coaster fans, their definitions are not always agreed upon, nor are the terms necessarily accepted industry wide.

A megacoaster is usually defined as a complete-circuit roller coaster with a lift hill or drop between and high. The world's first megacoaster was Magnum XL-200 at Cedar Point. A coaster with a total elevation change of at least but with no individual ascent or drop of at least , such as Tatsu, is not considered a megacoaster. The term hypercoaster, coined by amusement industry writer Allen Ambrosini, is also used for this height classification, but its usage is more ambiguous as it also refers to a "style" of coaster that is out and back, lacks inversions and is designed with speed and airtime (negative G-forces) in mind. A hypercoaster in this style may or may not fit the height classification; some manufacturers, such as Bollinger & Mabillard and Chance Morgan, use the term for production models both under and over the to range.

A gigacoaster is a complete-circuit roller coaster with a height of between and . The term was coined in 2000 by Cedar Point in conjunction with ridemaker Intamin AG of Switzerland, as a marketing description for their coaster Millennium Force, the first roller coaster to break the threshold. The term is used as a production designation on the Intamin website. The only other gigacoaster in existence, Steel Dragon 2000, also opened in 2000 and holds the record for world's longest roller coaster.

Name Park Manufacturer Status Opened Height
Millennium Force Cedar Point Intamin AG Operating May 13, 2000
Steel Dragon 2000 Nagashima Spa Land Chance Morgan Operating August 1, 2000

A stratacoaster is a complete-circuit roller coaster with a height between and . The term was adopted and attributed by Intamin. Only two stratacoasters have been built worldwide, both using Intamin's hydraulically-launched Accelerator Coaster design. The first was Top Thrill Dragster at Cedar Point, which opened in 2003 and stands at a height of . The second was Kingda Ka at Six Flags Great Adventure, which opened in 2005 with a record-breaking height of .

Tower of Terror at Dreamworld Australia, and Superman: The Escape at Six Flags Magic Mountain, respectively, were the first roller coasters to break the barrier, but are not considered stratacoasters, since they are shuttle roller coasters and their cars go only high.

Name Park Manufacturer Status Opened Height
Top Thrill Dragster Cedar Point Intamin AG Operating May 4, 2003
Kingda Ka Six Flags Great Adventure Intamin AG Operating May 21, 2005

A junior roller coaster is a roller coaster specifically designed for families and children not able to ride the larger rides.

Gallery

Major roller coaster manufacturers

See also

Notes

External links

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