Back 4th-Dimension-Coaster German Montaña rusa de cuarta dimensión Spanish Montagnes russes quadridimensionnelles French 4次元コースター Japanese Vierdimensionale achtbaan Dutch 4th Dimension roller coaster SIMPLE
| Fourth-dimension roller coaster | |
|---|---|
 'X2' (formerly 'X') was the first fourth-dimension roller coaster in the world. | |
| Status | In production |
| First manufactured | 2002 |
| No. of installations | 18 |
| Manufacturers | Arrow Dynamics (discontinued), S&S Worldwide, and Intamin |
| Riders per row | 4 |
| Restraint Style | Over-the-shoulder |
A fourth-dimension roller coaster is a type of steel roller coaster where riders are rotated independently of the track's orientation about a horizontal axis perpendicular to the track. This feature allows riders to experience inversions without the track rotating upside down. Some fourth-dimension roller coasters are controlled, with seats that rotate based on the spacing of two additional rails on the track. Others are free-spinning, where the seats flip primarily due to forces exerted by the ride's elements, offering a different experience during each ride.