Xcelerator

Xcelerator is a steel launched roller coaster at Knott's Berry Farm in Buena Park, California. The ride was Intamin's first hydraulically launched coaster, while also the fourth Intamin installation at Knott's, alongside The Sky Cabin, Bigfoot Rapids, and Perilous Plunge (removed in 2012). As of late 2017, Xcelerator temporarily closed for maintenance and will reopen at an unknown date.The rideXcelerator's powerful hydraulic catapult motor accelerates the train to 82mi/h in 2.3 seconds (about 1.62 g). It only uses 157ft of track to launch the train. The twin hydraulic catapult motor achieves a maximum of each while accelerating the train. Xcelerator's hydraulic motor system has the mechanical capability of accelerating vehicles to a speed of 117mi/h 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. Twenty-four volts are used to demagnetize a pin underneath the third car, causing it to drop. At the same time, two bellows actuators fill up with air, causing the two drive tires holding the train in place, at the train's rear, to retract. The brakes will lower while the train rolls back to hook, and the pin will then hook into the catch car—which is over 7ft 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 overshoot 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 shortshot. From the time the launch begins, the train has 8.25 seconds to pass over a proximity switch (Hall effect sensor) near the bottom of the first valley, thus clearing the starting block. If the train does not pass over the switch within the given time frame, the ride will down itself.