Xcelerator

Xcelerator
Knott's Berry Farm
Location	Knott's Berry Farm
Park section	The Boardwalk
Status	Operating
Opening date	June 22, 2002
Cost	$13,000,000 USD
General statistics
Type	Steel – Launched
Manufacturer	Intamin AG
Designer	Werner Stengel
Model	Accelerator Coaster
Track layout	Dual Overbank Figure 8
Lift/launch system	Hydraulic launch
Inversions	0
Duration	1:02 (22 seconds from launch to brakes)
Max vertical angle	90°
Capacity	1330 riders per hour
Acceleration	0 − 82 mph in 2.3 seconds
Xcelerator at RCDB

Xcelerator is a steel launched roller coaster at Knott's Berry Farm in Buena Park, California. Xcelerator was Intamin AG's first hydraulically-launched coaster. It is the 9th fastest ride in the world. Xcelerator is the fourth Intamin installation at Knott's. The other three were: The Sky Cabin, Bigfoot Rapids, and Perilous Plunge.

The Ride

Xcelerator's powerful hydraulic catapult motor accelerates the train to 82 MPH in 2.3 seconds. It only uses 157 feet of track to launch the train. The twin hydraulic catapult motor achieves a maximum of 10,500 horsepower each while accelerating the train. Xcelerator's hydraulic motor system has the mechanical capability of accelerating vehicles to a speed of 117 miles-per-hour or more, though it only needs to hit 82. In order for a train to launch, it must "drift" back to "hook" into the catch car. A pin on the third car will drop, the brakes will lower while the train rolls back to hook, and the pin will then hook into the catch car -- which is over 7 feet long. Once connected, the motor will pull the catch car over nylon runners and launch the train. In order to stop the catch car, it passes over its own set of magnetic brakes. If the train is lightly loaded, the motor has to work harder to attain launch speed. Often the catch car may over shoot its ending position and down itself if it cannot attain the speed within parameters. The train must also clear the launch track within three seconds, or the ride will down itself and produce a short shot.

After launch, the train then crests a 205 ft tophat element, soars through two overbanked turns, and glides to a smooth stop over mounted magnetic brakes. The magnetic braking system consists of mounted magnetic calipers on the trains themselves, and copper alloy fins mounted onto the track. These alloy fins on the launch lower when launching as to not interfere with the train during launch, then to slow the train in case of a short shot, they raise section by section after the train has passed them. Other than several brake fins on the brake block, all other fins are stationary and cannot be lowered. Vehicles are traveling at approximately 67 miles-per-hour when entering final block section (brake run).

The Trains

Xcelerator's Red Train exits the first overbanked turn.

The ride has two trains: Purple Train and Red Train. The trains themselves have spring loaded wheel assemblies and are standard Intamin trains with specially crafted shells to make them look like 1957 Chevrolet Bel Air convertibles. Xcelerator's red train was originally a different color. When Xcelerator first opened, the red train was all yellow with red flames along the side. During one of the ride's rehabs, the yellow-colored train was repainted red and given orange flames, closely mimicking the style of the Purple Train. Each train is 5 cars long and holds 20 passengers. A maximum of 2 trains may be operated at any given time. During the slow season, it's not uncommon to see only one train in use; but during the summer and peak season, both trains are normally used.

Restraints

Xcelerator's trains use hydraulically-operated T-Bar lapbar restraints. These restraints appeared on Intamin's earlier accelerator coasters, but over-the-shoulder restraints are now the norm on any new accelerator coaster due to safety concerns. Xcelerator also has special meters installed on its restraints. The meter must show all green in order for a guest to ride. If the meter shows red, the guest cannot ride the attraction. The attraction also has seatbelts, which must be buckled before an operator pulls down on the lapbar. Failure to do so slows the load time of the attraction considerably.

Limitations

Short Shots

File:Xcelerator at Knott's.JPG

A train nearly stalls at the top of the hill.

Every once in a while, a train will not attain enough speed to make it over the initial 205 foot tophat element. Instead, the train will partially ascend the tower, stall, and then roll back into magnetic brake fins situated on the launch track. This is known as a short shot or rollback, and is part of the normal design of the ride. A rollback can cause Xcelerator to close for an indefinite amount of time while the ride is reset and a sufficient number of test launches are performed. While rain is usually the biggest culprit, it is not the only variable that will produce a short shot. Weight, frequency of launching, outside temperature, and overheating will also produce a short shot as on most Intamin attractions.

Weather

Xcelerator will not operate in the rain -- not even a drizzle. This is to prevent rollbacks due to hydroplaning on the launch track. Track usually needs to dry until maintenance has cleared it to operate again before the first test shot is made. This is to reduce the chance of a short shot.

Progression To Taller And Faster

Xcelerator's former Yellow Train (since repainted) cruises to a smooth stop on the magnetic brake run.

Xcelerator laid the groundwork for taller and faster rides such as Top Thrill Dragster and Kingda Ka, coasters both passing the 400 foot mark and 100 mph mark. While successful in doing this, modifications were made to the larger models before being built. Top Thrill and Ka both use dual loading stations to speed up dispatching times, as well as larger more powerful motors. Though a very similar sized coaster named Stealth at Thorpe Park, UK has the same height and speed speficiations as Xcelerator, sans the overbank turns. Lower powered coasters have been built as well, such as Rita at Alton Towers.

Miscellania

• Xcelerator has recently appeared on a Channel 4 ident.
• Xcelerator appeared on Smash Lab in an episode about Magnetic Braking
• Xcelerator appeared in the movie Knocked Up

External links

• Xcelerator Pictures on Ultimate Rollercoaster.com.