Rollback (roller coaster)
Encyclopedia
Launched roller coaster
The launched roller coaster is a modern form of roller coaster which has increased in use in the last decade. In place of a traditional chain lift, the launched coaster initiates a ride with high amounts of acceleration via one or series of Linear Induction Motors , Linear Synchronous Motors ,...
when the train
Train (roller coaster)
A roller coaster train or car 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...
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
Brake run
A brake run on a roller coaster is any section of track meant to slow or stop a roller coaster train. 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...
on the launch track
Launch track
The launch track is the section of a launched roller coaster in which the train is accelerated to its full speed in a matter of seconds. A launch track is always straight and is usually banked upwards slightly, so that a train would roll backwards to the station in the event of a loss of power.A...
. Any roller coaster on which it is possible for a rollback to occur will have these brakes. Intamin, a manufacturer of roller-coasters, refers to the 'rollback' as a 'short shot.'
Most coasters contain at least one anti-rollback device to prevent a train from rolling backwards while ascending the main lift. This is typically with chain-driven lifts, not hydraulic launchers such as Kingda Ka or Top Thrill Dragster.
Rollbacks are most common (though still quite rare) on the world's three largest launched roller coasters, Kingda Ka
Kingda Ka
Kingda Ka is a roller coaster located at Six Flags Great Adventure in Jackson, New Jersey, USA. It is the world's tallest roller coaster, and was the world's fastest until Formula Rossa opened in November 2010. The train is launched by a hydraulic launch mechanism to in 3.5 seconds. At the end of...
at Six Flags Great Adventure
Six Flags Great Adventure
Six Flags Great Adventure is a theme park in Jackson Township, New Jersey, owned by Six Flags Entertainment Corp., the world's largest amusement park corporation...
, Top Thrill Dragster
Top Thrill Dragster
Top Thrill Dragster is a steel, Hydraulic-launched roller coaster located at Cedar Point in Sandusky, Ohio. It was the first "Strata Coaster", loosely defined as a complete circuit coaster that is over tall. It was built by Intamin and debuted to the public on May 4, 2003...
at Cedar Point
Cedar Point
Cedar Point is a 364 acre amusement park located in Sandusky, Ohio, United States on a narrow peninsula jutting into Lake Erie. Cedar Point is the only amusement park with four roller coasters that are taller than...
and Stealth
Stealth (roller coaster)
Stealth is a steel roller coaster built by Intamin of Switzerland. The coaster is located in the Amity Cove area of Thorpe Park in Surrey, England, UK and opened in 2006. The ride reaches a maximum height of 62.5 m...
at Thorpe Park
Thorpe Park
Thorpe Park is a theme park located in Chertsey, Surrey, England, UK. It was built in 1979 on the site of a gravel pit which was partially flooded, the intention of creating a water based theme for the park. The park's first large roller coaster, Colossus, was added in 2002...
, although rollbacks are common on other launched roller coasters of the same type, such as Xcelerator
Xcelerator
Xcelerator is a steel launched roller coaster at Knott's Berry Farm in Buena Park, California. Xcelerator was Intamin's first hydraulically-launched coaster. Xcelerator is the fourth Intamin installation at Knott's...
at Knott's Berry Farm
Knott's Berry Farm
Knott's Berry Farm is a theme park in Buena Park, California, now owned by Cedar Fair Entertainment Company, and a line of jams, jellies, preserves, and other specialty food, now part of The J. M. Smucker Company based in Placentia, California....
and Storm Runner
Storm Runner
Storm Runner is an Intamin steel launched roller coaster at Hersheypark. It was constructed in 2004 and was the third Intamin Accelerator Coaster. It reaches a height of 150 ft and catapults riders from 0 to 72 mph in 2 seconds. It features a top hat and three inversions, a dual...
at Hershey Park.
There are several factors that can cause a rollback:
- Unusual wind gusts could slow the train down enough to cause it to roll back.
- Cold weather increases frictionFrictionFriction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...
in the wheels. - A rollback will often occur during the first few test launches each day, as the launch motor has not been sufficiently warmed up by this point. Intentional rollbacks are sometimes conducted during testing.
- Fewer passengers on the ride reduces the momentum and could cause a rollback.
While the general public may not realize that rollbacks usually are completely safe and that coasters are designed with them in mind, many coaster enthusiasts look forward to being in one. Being in a rollback essentially gives riders a ride and a half, as the train will be launched again after the rollback (although, when a rollback occurs with people on the train, it will first be brought back to the station to give the guests the option of getting off the ride). This is less of an incentive in parks that charge an overall admission fee and don't charge for individual rides.
In a video of a rollback on Stealth
Stealth (roller coaster)
Stealth is a steel roller coaster built by Intamin of Switzerland. The coaster is located in the Amity Cove area of Thorpe Park in Surrey, England, UK and opened in 2006. The ride reaches a maximum height of 62.5 m...
at Thorpe Park
Thorpe Park
Thorpe Park is a theme park located in Chertsey, Surrey, England, UK. It was built in 1979 on the site of a gravel pit which was partially flooded, the intention of creating a water based theme for the park. The park's first large roller coaster, Colossus, was added in 2002...
, the train is seen to reach slightly over halfway over the midpoint at the top. The train proceeded to roll back, due to an insufficiently powerful launch, combined with an uneven distribution of weight on the train in April 2006. Stealth also had a rollback in March 2008 due to strong winds.
Very rarely, a train is launched with just enough speed to reach the track's highest point, resulting in the train getting stuck on the top. This results in neither a full ride nor a rollback. This happened three times on Top Thrill Dragster
Top Thrill Dragster
Top Thrill Dragster is a steel, Hydraulic-launched roller coaster located at Cedar Point in Sandusky, Ohio. It was the first "Strata Coaster", loosely defined as a complete circuit coaster that is over tall. It was built by Intamin and debuted to the public on May 4, 2003...
; All three times, a ride mechanic had to take an elevator to the top, and give the train a small push so it could complete the ride. http://www.xtremecoastin.com/videos/misc_videos/ttdstuck_2005.htm It has also happened on Stealth
Stealth (roller coaster)
Stealth is a steel roller coaster built by Intamin of Switzerland. The coaster is located in the Amity Cove area of Thorpe Park in Surrey, England, UK and opened in 2006. The ride reaches a maximum height of 62.5 m...
at Thorpe Park
Thorpe Park
Thorpe Park is a theme park located in Chertsey, Surrey, England, UK. It was built in 1979 on the site of a gravel pit which was partially flooded, the intention of creating a water based theme for the park. The park's first large roller coaster, Colossus, was added in 2002...
during early morning tests.