Roller coaster

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The track of a typical roller coaster. This track scheme is loosely based on the Crystal Beach Cyclone.

The roller coaster (sometimes known as a jet coaster in Japan) is a popular amusement 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 designed patterns, sometimes with one or more inversions (the most common being loops) that turn 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. (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 called a train. Some roller coasters, notably Wild Mouse roller coasters, run with single cars.

In what may be the first practical application of the roller coaster, NASA has announced that it will build one to help astronauts escape the Ares I launch pad in an emergency. [1]

Mechanics

The cars on a typical roller coaster are not self-powered. Instead, a standard full-circuit lift-powered coaster is pulled up with a chain or cable along the lift hill to the first peak of the coaster track. 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 on and on.

However, not all coasters run this way. The train may be set into motion by a launch mechanism (flywheel launch, linear induction motors, linear synchronous motors, hydraulic launch, compressed air launch, drive tire, etc). Some coasters move back and forth along the same section of track; these roller coasters are called shuttles because of this motion and usually run the circuit once with riders moving forwards and then backwards through the same course. Some roller coasters are powered by a kind of locomotive. A properly designed roller coaster 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 coaster. A powered coaster is a roller coaster type ride that instead of being powered by gravity, uses one or more motors in the cars to propel the trains along the course.

File:Roller Coaster-Movie World Australia.jpg
The Road Runner roller coaster at Movie World, Australia

Blocking

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 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.

History

The Scenic Railway at Luna Park (Melbourne, Australia), the world's oldest continually-operating rollercoaster, built in 1912.

The earliest roller coasters descended from Russian winter sled rides held on specially constructed hills of ice, especially around St Petersburg. Built in the 18th century, the slides were built to a height of between 70 and 80 feet, consisted of a 50 degree drop, and were reinforced by wooden supports. By the late 1700s, their popularity was such that entrepreneurs elsewhere began copying the idea, using wheeled cars built on tracks. One such company was Les Montagnes Russes à Belleville which constructed and operated a gravity track in Paris from 1812. The first loop track was probably also built in Paris from an English design in 1846, with a single-person wheeled sled running through a 13-foot diameter loop. None of these tracks were complete circuits. To this day, a number of languages (Danish, French, Portuguese, Spanish) use the equivalent of Russian mountains to refer to roller coasters.

The famous all-wooden roller coaster, built in 1951, dominates the Linnanmäki amusement park in Helsinki, Finland.

In 1827, a mining company in Summit Hill, Pennsylvania constructed the Mauch Chunk gravity railroad, a 14-kilometre downhill track used to deliver coal (and a miner to operate the mine train's brake) to Mauch Chunk. By the 1850s, the "Gravity Road" (as it became known) was providing rides to thrillseekers 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 a closed-circuit switchback railway. His gravity ride opened at Coney Island in 1884. [2]. In 1885, Phillip Hinkle introduced the concept of the "lift hill."

As roller coasters grew in popularity, experimentation in coaster dynamics took off. As early as the 1880s, the concept of a vertical loop was explored, and in 1895 the concept came into fruition with The Flip Flap, located at Sea Lion Park in Brooklyn, and shortly afterward with the "Loop-the-Loop" at Olentangy Park near Columbus, Ohio. The rides were incredibly dangerous, and many passengers suffered whiplash. Both were soon dismantled, and looping coasters had to wait for over a half century before making a safer reappearance.

Kingda Ka, the world's tallest and fastest roller coaster, located at Six Flags Great Adventure in New Jersey. (see Notable Roller Coasters)

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 best known historical roller coaster, The Cyclone, was opened 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. The oldest operating roller coaster is Leap the Dips at Lakemont Park in Pennsylvania, a side friction roller coaster built in 1902.

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 (2007).

In 1959, the 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 maneuvers into their designs. Most modern roller coasters are made of steel but wooden roller coasters are still being built.

The first modern-day roller coaster to perform a 360-degree inverting element was the Corkscrew located at Knott's Berry Farm in Buena Park, California, which opened in 1975 and was designed by Arrow Dynamics of Utah.

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. For example, coasters like the Incredible Hulk Coaster feature launched lift hills to create a unique experience.

Riding Expedition GeForce

Safety

Because roller coasters are intended to feel risky, accidents such as the September 5, 2003 fatality at the seemingly tame 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. [3] In fact, driving to the amusement park has a higher risk of injury than riding the rides at the amusement park. It is not unusual for park management to pay higher insurance premiums for carousels than they do for roller coasters.

Many safety systems are implemented within rollercoaster systems. The key to the mechanical fail safes is the control of the coasters operating computers: programmable logic controllers (often called PLCs). Most rollercoasters 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's 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).

Many ride accidents are caused by riders or ride operators not following safety directions properly, but in extremely rare cases riders can be injured by mechanical failures. One such example was the 2006 de-railing of one car on the Wild Thing roller coaster at Valleyfair!.

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." [4]

A similar report in 2005 linked roller coasters and other thrill rides with potentially triggering abnormal heart conditions that could lead to death. [5] Autopsies have shown that recent deaths at various Disney parks, Anheuser-Busch parks, and Six Flags parks were due to previously undetected heart ailments.

Popular United States Roller Coasters

The tallest roller coaster in the world is the Kingda Ka, built in 2005 at Six Flags Great Adventure in Jackson, New Jersey. It's 456 feet high, and is also the world's fastest roller coaster, reaching speeds of up to 128 miles per hour.

The world's next tallest (and also the next fastest) roller coaster is the Top Thrill Dragster, erected in 2003 at Cedar Point in Sandusky, Ohio. It measures 420 feet in height and reaches speeds of up to 120 miles per hour.

Cedar Point also features the longest STEEL roller coaster in the United States (5th longest in the world). The Millenium Force, built in 2000, measures 6,595 feet in length.

The world's longest roller coaster of any kind is a wooden contraption, also in Ohio, at Paramount's King's Island in King's Mill. Constructed in 1979, the coaster known as The Beast is 7,400 feet long.

Leap the Dips at Lakemont Park in Altoona, Pennsylvania, is the world's oldest operating roller coaster. It opened in 1902, and after being closed for several years, was restored and re-opened in 1999. Leap the Dips is an old-style "side friction" roller coaster, the only one of its kind in North America.


Types of Roller Coasters

File:BGT Montu coasterfanatics.jpg
Montu. A popular Inverted roller coaster at Busch Gardens Africa. (see Notable Roller Coasters)
File:Lethal Weapon Ride Track.JPG
"Lethal Weapon - The Ride" at Warner Bros. Movie World is among the first steel inverted roller coasters in Australia

Today, there are two main types of roller coasters: Steel roller coasters and Wooden roller coasters (also called 'Woodies'). Steel coasters are known for their smooth ride and often convoluted shapes that frequently turn riders upside-down via inversions known as loops, corkscrews, pretzels, and other descriptive names. Wooden coasters are fondly looked at by coaster enthusiasts for their more rough ride and "air time" produced by negative G-forces when the coaster car reaches the top of some hills along the ride. Much debate can be had regarding which coaster type is better, as they both have their pros and cons.

Regardless of the type of roller coaster being built, coasters come in a multitude of designs. Some designs take their cue from how the rider is positioned to experience the ride. Traditionally, coaster 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 for the riders. 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 roller coasters 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 addition to changing the rider's viewpoint, coaster designs also focus on track styles to make the ride fresh and different from other coasters.

One method of designing a coaster is to select one item from each of the different coaster options: height, rider experience, track design, and launch mechanics. These four elements combine to make a unique coaster for the park.

(See Notable roller coasters for coasters that are known to be first in each category.)

Height-specific

Some names, originated by Cedar Point, have been used by the park for marketing their roller coasters. While occasionally used among coaster fans they are not industry accepted terms.

  • Stratacoaster - When Cedar Point announced Top Thrill Dragster in 2003 the park used the term Stratacoaster in their press materials to describe a roller coaster that was 400 feet tall. Top Thrill Dragster and Kingda Ka are the only roller coasters that have been associated with this term.
  • Gigacoaster - Used by Cedar Point and manufacturer Intamin AG to market and describe the Millennium Force roller coaster. Cedar Point claimed the term referred to a roller coaster that broke the 300-foot mark. The term is actually used as a production designation on the Intamin AG website.
  • Hypercoaster is a term not coined by Cedar Point, but instead by amusement industry writer Allen Ambrosini. One definition of a hypercoaster is a coaster that is built for speed and airtime, while a second definition is of a coaster with an initial drop of between 200 and 299 feet tall. Some manufacturers, such as Bollinger & Mabillard and Chance Morgan use this term for production models both over and under 200 feet tall.
  • Junior roller coaster. A roller coaster specifically designed for families and children not able to ride the larger rides.

Physics of Roller coasters

Roller coaster design is a science as well as an art, the designer must use knowledge of kinematics to avoid stressing the human body and making an uncomfortable ride.

The acceleration is a significant design tool, as is the rate of change of acceleration - Jerk - and the rate of change of Jerk - Snap

Jerk is often used in engineering, especially when building roller coasters. Some precision or fragile objects—such as passengers, who need time to sense stress changes and adjust their muscle tension, or suffer, e.g., whiplash—can be safely subjected not only to a maximum acceleration, but also to a maximum jerk. Jerk may be considered when the excitation of vibrations is a concern.

Neuroscience of Roller coasters

Roller coasters are well known for being amusement devices, in the sense that a rider of a roller coaster will go through a multitude of different emotions whilst riding, most notably fright and excitement, but will ultimately end up with a feeling of having been thrilled. This thrill and happiness that occurs after completing the experience happens due to the release of Epinephrine (Adrenaline) into the blood, invoked by the Fight or Flight response as the rider is scared by the coaster; and due to the release of Dopamine in the brain that occurs as a result of the brain rewarding the rider for having survived the experience; which is why the more extreme a coaster is, the more scary it is and the more it throws the rider around, the larger the resulting dopamine and adrenaline rush will be, and the more enjoyable the experience will be.

Many Roller coaster riders do not enjoy the experience, normally feeling that the terror and discomfort they experienced during the anticipation of riding and the actual riding of the roller coaster to be a price not worth paying for the positive feeling invoked. Different people enjoy the feelings of adrenaline to different extents as well, where an adrenaline junkie will favour the experience much more than someone who is not used to the feeling.

Roller coaster manufacturers

See also

References

  1. ^ Chris Bergin (November 3, 2006). "NASA will build Rollercoaster for Ares I escape". NASA Spaceflight.com. Archived from the original on 1 January 2007. Retrieved 2007-01-08.
  2. ^ Sheedy, Chris (January 7, 2007). "Icons - In the Beginning... Roller-Coaster". Sunday Life (weekly supplemental magazine included in The Sun-Herald). John Fairfax Publications Pty Ltd. p. 10.
  3. ^ Levine, Arthur. "White Knuckles Are the Worst of It". themeparks.about.com. Retrieved 2007-01-08.
  4. ^ Blue Ribbon Panel (February 25, 2003). "Blue Ribbon Panel Review of the Correlation between Brain Injury and Roller Coaster Rides - Final Report". Retrieved 2007-01-08. {{cite journal}}: Cite journal requires |journal= (help)
  5. ^ Laino, Charlene (November 16, 2005). "Roller Coasters: Safe for the Heart?". WebMD.com. Retrieved 2007-01-08. {{cite news}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

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