A
brake run on a
roller coasterThe 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...
is any section of
trackRail tracks are the surface structures that support and guide trains or other rail-guided transportation vehicles.Most familiarly they consist of* two steel rails on which the vehicle wheels run,...
meant to slow or stop a
roller coaster trainA roller coaster train describes the vehicle which transports passengers around a roller coaster's circuit. More specifically, a roller coaster train is made up of two or more "cars" which are connected by some sort of specialized joint. It is called a "train" because the cars follow one another...
. Brake runs may be located anywhere along the circuit of a coaster and may be designed to bring the train to a complete halt or to simply adjust the train's speed. Contrary to some belief, the vast majority of roller coasters do not have any form of braking on the train itself, but rather forms of braking that exist on track sections.
A
brake run on a
roller coasterThe 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...
is any section of
trackRail tracks are the surface structures that support and guide trains or other rail-guided transportation vehicles.Most familiarly they consist of* two steel rails on which the vehicle wheels run,...
meant to slow or stop a
roller coaster trainA roller coaster train describes the vehicle which transports passengers around a roller coaster's circuit. More specifically, a roller coaster train is made up of two or more "cars" which are connected by some sort of specialized joint. It is called a "train" because the cars follow one another...
. Brake runs may be located anywhere along the circuit of a coaster and may be designed to bring the train to a complete halt or to simply adjust the train's speed. Contrary to some belief, the vast majority of roller coasters do not have any form of braking on the train itself, but rather forms of braking that exist on track sections. One notable exception is the scenic railway roller coaster, which relies on an operator to manually control the speed of the train.
On most roller coasters, the brakes are controlled by a computer system, but some older
wooden roller coaster A wooden roller coaster or woodie is most often classified as a roller coaster with laminated steel running rails overlaid upon a wooden track. Occasionally, the structure may be made out of a steel lattice or truss, but the ride remains classified as a wooden roller coaster due to the track design...
s have manually operated brakes. These are controlled by large levers operated by the ride operators.
Trim brakes
Trim brakes are sections of brakes which are intended to adjust a train's speed during its course rather than bring the train to a complete stop. They may be engineered into a ride at its design stages at certain anticipated troubled spots, or later retrofitted once it is discovered that trains transverse certain areas at higher-than-anticipated speeds. Trim brakes are often either added for safety reasons, to lower g-forces in certain areas, or for
maintenancePreventive maintenance has the following meanings:#The care and servicing by personnel for the purpose of maintaining equipment and facilities in satisfactory operating condition by providing for systematic inspection, detection, and correction of incipient failures either before they occur or...
/mechanical reasons, to lower the cost of wear-and-tear (especially on wooden roller coasters) caused by the trains traveling at faster than normal speeds. Usually, a proximity sensor precedes the trim brake in order to identify the current speed of the passing train. From this, the trim will then grab the train's brake fins to modify the train's speed to what the ride sets.
Block brakes
Block brakes are sections of brakes located on any roller coaster wherever more than one train is intended to run. They act as virtual barriers between the trains running on the roller coaster, preventing collisions should one train stop along the course for any reason. Because of this, block brakes must be capable of completely stopping the train (should a vehicle preceding the block stop) and starting a train (after it has been stopped). Block brake sections usually start the train again in one of two ways including a slight downward slope to let gravity take its course, or by the use of drive tires pushing the train out of the block. Like trim brakes, block brakes can also be used to control the speed of the train.
See Timing.
Types of brakes
Various types of braking exist when dealing with roller coasters, some of which have been recently developed due to technological advancements in design.
Skid brakes
Skid brakes essentially involve a long piece of material, often
ceramicA ceramic is an inorganic, non-metallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...
-covered, situated in the middle of the track parallel to the
railRail tracks are the surface structures that support and guide trains or other rail-guided transportation vehicles.Most familiarly they consist of* two steel rails on which the vehicle wheels run,...
s. When the brake is engaged, the skid raises and
frictionFriction is the force resisting the relative lateral motion of solid surfaces, fluid layers, or material elements in contact. It is usually subdivided into several varieties:...
against the underside of the train causes the train to slow and eventually stop. Skid brakes were one of the first advancements in roller coaster braking and are typically not utilized in modern creations with the exception of Twister at Knoebels Amusement Park in Elysburg, PA.
Fin brakes
Fin brakes involve a metal fin being attached to the underside of a train. The track is fitted with two computer-controlled squeezing mechanisms which upon closing, squeeze the fin and either slow or stop the train. Fin brakes are the most common form of brakes on roller coasters today. Sometimes they are thick metal box beams (mostly on
Bolliger & MabillardBolliger & Mabillard Consulting Engineers is a roller coaster design consultancy based in Monthey, Switzerland. The company was founded in 1988 by Walter Bolliger and Claude Mabillard, with Bolliger acting as president and Mabillard as vice-president...
roller coasters) and are engaged when compressed air flows into a metal drum, pushing joints on two sides in order to close shut two parallel brakes that in turn will drag along the box beam. Fin brakes are designed to be fail-safe, so that a loss of power will cause them to engage.
Magnetic brakes
- See also Eddy Current Brake.
MagneticIn physics, the term magnetism is used to describe how materials respond on the microscopic level to an applied magnetic field; to categorize the magnetic phase of a material. For example, the most well known form of magnetism is ferromagnetism such that some ferromagnetic materials produce their...
brakes are a relatively new technology that is beginning to gain popularity due to their high degree of safety. Rather than slowing a train via friction (such as fin or skid brakes), which can often be affected by various elements such as rain, magnetic brakes rely completely on certain magnetic properties and resistance. In fact, magnetic brakes never come in contact with the train.
Magnetic brakes are made up of one or two rows of very strong
Neodymium magnetA neodymium magnet , a type of rare-earth magnet, is a permanent magnet made from an alloy of neodymium, iron, and boron to form the Nd2Fe14B tetragonal crystalline structure...
s. When a metal fin (typically copper or a copper/aluminum alloy) passes between the rows of magnets,
eddy currentAn eddy current is an electrical phenomenon discovered by French physicist François Arago in 1824. It is caused when a conductor is exposed to a changing magnetic field due to relative motion of the field source and conductor; or due to variations of the field with time...
s are generated in the fin, which creates a magnetic field opposing the fin's motion. The resultant braking force is directly proportional to the speed at which the fin is moving through the brake element. This very property, however, is also one of magnetic braking's disadvantages in that the eddy force itself can never completely stop a train in ideal condition. This effect of magnetic braking can be explained by an example in which the train's speed is halved as it passes through each set of brakes. The train's speed (in any unit) would initially be 40, then 20, 10, 5, and so on. It is then often necessary to bring the train to a complete stop with an additional set of fin brakes or "kicker wheels" which are simple rubber tires that make contact with the train and effectively park it.
Magnetic brakes can be found in two configurations:
- The brake elements are mounted to the track or alongside the track and the fins are mounted to the underside or sides of the train. This configuration looks similar to frictional fin brakes.
- The fins are mounted to the track and the brake elements are mounted to the underside of the train. This configuration can be found on Intamin's Accelerator Coasters (also known as Rocket Coasters) such as Kingda Ka
Kingda Ka is a roller coaster located at Six Flags Great Adventure in New Jersey, USA. It is the tallest and fastest roller coaster in the world, claiming the titles from Top Thrill Dragster at Cedar Point when it opened on May 20, 2005. The train is launched by a hydraulic launch mechanism to 128...
at Six Flags Great AdventureSix Flags Great Adventure is a theme park in Jackson Township, New Jersey, located from New York City, from Newark and from Philadelphia. It is located next to Six Flags Wild Safari animal park and Hurricane Harbor water park. It serves as the amusement park for one of the biggest and most...
. This configuration is probably less expensive, as far fewer magnets are required.
In terms of pros, magnetic braking is virtually fail-safe because it relies on the basic properties of magnetism and requires no electricity. Magnetic brakes are also completely silent and are much smoother than friction brakes, gradually increasing the braking power so that the people on the ride do not experience any unpleasant feelings. Many modern roller coasters, especially those being manufactured by Intamin, have utilized magnetic braking for several years. Another major roller coaster designer implementing these brakes is Bolliger & Mabillard in 2004 on their
Silver Bullet inverted coaster, making it the first suspended roller coaster to feature magnetic brakes, and again used them on their newer projects. These later applications have proven effectively comfortable and relevant for these inverted coasters which often give the sense of flight. There also exist third party companies such as Magnatar tech. which provide various configurations of the technology to be used to replace and retrofit braking systems on existing roller coasters to increase safety, improve rider comfort, and lower maintenance costs and labor.
However, the main disadvantage of magnetic brakes is that they cannot completely stop a train, so they cannot be used as block brakes. They also cannot be conventionally disengaged like other types of brakes. Instead, the fins or magnets must be retracted so that the fins no longer pass between the magnets. These are the most effective brakes that slow the train quickly, and these are failsafe. Accelerator Coasters, for example, have a series of magnetic brake fins located on the launch track. When the train is launched, the brakes are retracted to allow the train to reach its full speed. After the train is launched, the brake fins are raised to safely slow the train down in the event of a
rollbackA rollback occurs on a launched roller coaster when the train is not launched fast enough to reach the top of the tower. It will roll backwards down the tower, and will be stopped by brakes on the launch track. Any roller coaster on which it is possible for a rollback to occur will have these brakes...
.