Launched roller coaster

The launched roller coaster is a modern form of roller coaster which has risen to prominence within 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 (LIM), Linear Synchronous Motors (LSM), catapults, or other mechanisms employing hydraulic or pneumatic power. These are some of the fastest rides in the world.

Launched coasters mainly feature improved speed, and capability to accommodate more "thrilling" layouts. These coasters, however, can be less reliable than traditional chain-lifted coasters, and are considered to require heavier maintenance.

Electromagnetic

LIM / LSM

LIM and LSM coasters use propulsion via electromagnets, which utilize large amounts of electricity to propel the coaster train along its track into the ride elements (e.g. inversions, twists, turns and short drops). Four design companies managing these types of rides are Vekoma Industries, Intamin AG, Premier Rides and Maurer Söhne.

Cedar Point in Sandusky, Ohio has two LIM/LSM launched coasters, "Wicked Twister", and "Maverick". Unlike most LSM coasters, "Maverick" has a relatively short drop (only around 100 feet), and LSM's are incorporated in two areas: One is the lift hill itself (drastically shortening the time needed to ascend the hill), the other is inside a 400' tunnel.

Lagoon in Farmington, Utah has one LIM/LSM launched coaster, "Wicked". It is 110 feet tall in the vertical drop and it goes at a speed of around 65 to 70 miles an hour.
Valleyfair in Shakopee, Minnesota has a steel LIM/LSM "impulse" coaster called "Steel Venom".

Dorney Park & Wildwater Kingdom in Allentown, Pennsylvania, also has 1 LIM/LSM launched "impulse" coaster, "Voodoo". This coaster is of the same type as "Wicked Twister", though it only has one twist instead of two. A vertical straight section is used instead. Before being moved to Dorney Park from Geauga Lake , Voodoo was named "Superman: Ultimate Escape", and "Steel Venom".

The amusement park chain Six Flags in the United States of America has 9 examples of such rides:
*"Superman The Escape" 415 ft (127 m), Six Flags Magic Mountain, Valencia, California
*"Mr. Freeze" 218 ft (67 m), Six Flags Over Texas, Arlington, Texas
*"Mr. Freeze" 218 ft (67 m), Six Flags St. Louis, Eureka, Missouri
*"" 200 feet (61 m), Six Flags Great Adventure, Jackson Township, New Jersey (2 coasters running side by side) (defunct as of 2007)
*"Vertical Velocity" 185 ft (56 m), Six Flags Great America, Gurnee, Illinois
*"" 150 ft (46 m), Six Flags Marine World, Vallejo, California
*"Half Pipe" 98 ft (30 m), Six Flags Elitch Gardens, Denver, Colorado
*"The Joker's Jinx" 79 ft (24 m), Six Flags America, Largo, Maryland
*"Poltergeist" 79 ft (24 m), Six Flags Fiesta Texas, San Antonio, Texas

Kings Dominion has six launched roller coasters, four of which are LIM-launched: "Flight of Fear", "Volcano, The Blast Coaster", ""The Italian Job", and the "Back Lot Stunt Coaster". "Flight of Fear", which was also introduced at Kings Island, was one of the first LIM-launched coasters and won an award from the International Association of Amusement Parks and Attractions based on the technology used for its launch. [http://www2.paramountparks.com/kingsisland/attractions/detail.cfm?ai_id=162] The LIM/LSM tower rides are often tall, fast, and until recently were the state of the art in launched coaster design.

Fluid pressure

Hydraulic

Hydraulic-launched roller coasters give the riders high acceleration, yet with improved smoothness, over the electromagnetic and catapult launch mechanisms. The Swiss manufacturer Intamin AG pioneered this new style.

The heart of the system is several (usually eight) powerful hydraulic pumps, each capable of producing 500 horsepower (373 kW).Fact|date=July 2008 Hydraulic fluid is pumped into several hydro-pneumatic accumulators containing two compartments separated by a piston. As the incompressible hydraulic fluid is pumped into one compartment a gas in the other compartment is compressed.

At launch, the fluid under pressure from the accummulators is used to drive a number (typically 16 or 32) of hydraulic motors, which spin a large winch drum that rewinds a cable attached to a catch-car under the train in a matter of seconds. The catch-car moves in a groove in the center of the launch track with the motor at one end, and the waiting train at the other.

While the train inches forward, the pusher moves back from the motor towards the train. Once the pusher connects, the anti-rollback braking system drops beneath the track, giving the train the green light to be launched. The system as a whole is capable of producing up to 20,800 horsepower (15.5 MW) for each launch.Fact|date=July 2008

These launches are considered capable of giving a far greater and smoother acceleration than the LIM/LSM styles. The acceleration from a LIM/LSM launch is greatest at the beginning and dies off rapidly towards the end of the launch, but the acceleration from a hydraulic launch remains nearly constant throughout the launch.

"Superman The Escape", the fastest LIM/LSM coaster, has been measured to reach 100 mph (161 km/h) in 7 seconds, climbing 330 ft (even though the tower is convert|415|ft|m|abbr=on. high) in the process. The first hydraulic launch coaster was "Xcelerator" reaching convert|82|mi/h|km/h|abbr=on in 2.3 seconds. The world's current tallest and fastest coaster "Kingda Ka" at Six Flags Great Adventure, which opened in the spring of 2005 is capable of reaching 128 mph (206 km/h) in 3.5 seconds.

Hydraulic launched rides usually have a tower after the launch, with differing layouts afterwards depending on the park's financial resources. "Top Thrill Dragster" brakes after the tower and "Kingda Ka" features a single convert|130|ft|m|abbr=on hill after the tower, while "Storm Runner" at Hersheypark offers a series of inversions after its 180 foot (55 m) tower drop. "Rita - Queen of Speed" at Alton Towers doesn't have a tower at all, only airtime hills. "Stealth" at "Thorpe Park" has a very large tower that links to the left over the top and then round the track back to the start, this allows for two cars to be on the track at once (one launched & one loading). "Xcelerator" at Knotts Berry Farm offers two overbanked turns after the tower. Along with the height and speed, these coasters, named "Rocket Coasters" in the industry, are considered more comfortable due to a smoother launch than LIM-style launches.

A recent newcomer to the hydraulic launch industry is Vekoma, who recently opened a coaster called "Booster Bike" at Toverland in the Netherlands, said to give riders a sensation of racing on high performance motorcycles over a low twisted layout, at speeds up to 47 mph (75 km/h). The cars imitate real motorcycles, and the riders sit in the same posture as real bikers.

Pneumatic

Hydraulic launch technology faces competition from S&S Power, a leading manufacturer in vertical amusement rides, who in recent years created a new breed of coasters with pneumatic launch power. Their coaster model, the "Thrust Air 2000", was first built in Kings Dominion under the name "Hypersonic XLC". The coaster has been clocked to launch from the rest at station to 80 mph (128 km/h) in 1.8 seconds. The coaster proceeds to ascend a tower at 90 degrees and descends vertically. Another compressed air launched coaster, built in Fuji-Q Highland, is "Dodonpa". This coaster is capable of launching passengers from 0 to 106.9 mph (171 km/h) in 1.8 seconds. The fastest one, Ring°Racer, built at the Nürburgring race course will reach speeds of 135 mph in 2.5 seconds.

Other styles

Catapult

In the catapult launch, a large diesel engine or a dropped weight winds a cable to pull the train until it accelerates to its full speed.

These rides are often not very tall, and usually achieve speeds of 60 mph (96 km/h).

Flywheel

Flywheel launches are used on some Anton Schwarzkopf designed shuttle loop coasters and Zamperla Motocoasters. A large flywheel is spun at high speeds and is attached to a cable that propels the train forward.

Electric Motor and Spring Tension

Arrow Dynamics' Launched Loop coasters, which were popular in the 1970s and 1980s, use a powerful electric motor and tensioned springs to propel a launch car forward. The launch car pushes the train outward to a drop, and then returns to its position. After the train reaches the opposite platform, another catch car works the same way.

Friction Wheels

Another type is launch is by friction wheels. The launch track consists of a series of horizontal tires that pinch the brake fins on the underside of the train. One example of this is the "Incredible Hulk Coaster" at Universal's Islands of Adventure

External links

* [http://schwarzkopf.coaster.net/ESshuttlelooptyp1GF.htm Counterweight] launch system on Schwarzkopf rides
* [http://schwarzkopf.coaster.net/ESshuttlelooptyp2GF.htm Flywheel] launch system on Schwarzkopf rides