Train (roller coaster)

A roller coaster train describes the vehicle(s) 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 around the track -- the same reason as for a railroad train. Individual cars often vary in design and can carry anywhere from one to eight or more passengers each.

Basic safety features

Roller coaster trains have wheels that run on the sides (side friction or guide wheels) and underneath the track (upstop wheels) as well as on top of it (road wheels), these lock the train to the tracks and prevent it from jumping the track. The side wheels can be mounted on the outside or inside of the train, depending on the manufacturer (although outside-mounted wheels are more common). The wheels are sometimes located between the cars, as well as at the front and rear of the entire train.

Roller coaster trains also have restraints that keep the passengers in their seats. Restraints are of two major types, lapbar and over-the-shoulder. Most roller coasters also have a seatbelt that acts as a safety device. On over-the-shoulder restraints, this seatbelt is mostly used to hold the main restraint down.

Lapbar restraints consist of a padded bar mounted to the floor or side of the train that swings backwards into the rider's lap. These restraints are usually found on roller coasters that lack inversions. Some inverting roller coasters, notably ones created by Anton Schwarzkopf safely operate without the need for shoulder restraints. Lapbar restraints, like buzz bars give the rider much greater freedom of movement than over-the-shoulder restraints, enhancing the feeling of danger. However, lapbar restraints are not quite as safe as over-the-shoulder restraints, as evidenced by several accidents. Some roller coasters have had their lapbar restraints replaced with over-the-shoulder restraints. Others have had shoulder restaints replaced with lap bar restraints, allowing for a more comfortable ride. Some roller coasters (usually wooden roller coasters) also include seatbelts in addition to a lap bar.

Over-the-shoulder restraints, the most common type, consist of a roughly U-shaped padded bar mounted to the top of each seat that swings downward. Almost all roller coasters that have inversions have this type of restraint. Additionally, all Inverted roller coasters and Floorless roller coasters have this type of restraint, as there is simply no place to mount a lapbar restraint. One disadvantage of over-the-shoulder restraints is that they can provide discomfort to the rider (known among coaster enthusiasts as "headbanging"), especially on rougher roller coasters.

However, there is one operating roller coaster that does not have either of these safety features: "Leap-The-Dips", the world's oldest operating roller coaster and North America's last surviving side friction roller coaster. As a side friction coaster, it does not have wheels under the track. Rather, it runs in a trough with wheels that run along the sides of the through to keep the train in place and is only held on by gravity Additionally, "Leap-The-Dips" simply does not require restraints as it is only 41 ft (12.5 m) high and has an average speed of only 10 mph (16 km/h). Until early 2006, the Rollercoaster at Blackpool Pleasure Beach in the UK also operated without any restaints, although seatbelts were added to the ride in the 2007 Season. During 2008, trains form the Big Dipper Rollercoaster were installed on the ride. "Rollercoaster" now operates with lapbars, although the original train is still stored on the transfer track in the station.

Physics

In general, the longer a roller coaster train becomes, the more momentum it gains throughout the ride's course. A roller coaster train that is fully loaded will also have more momentum than one that is empty or nearly empty.