Round-up respectively roundup (in proper nouns also: RoundUp or Round Up) is an amusement ride consisting of a circular horizontal platform with vertical cage like wall around the edge. The platform is attached to a motor on a hydraulic arm. The ride starts out by spinning until the centrifugal force is enough to push riders against the wall. At that time, the friction between the riders' backs and the walls is enough to hold them against the wall. Then, the arm raises the horizontal platform to a vertical position in which riders, instead of spinning horizontally, are now spinning vertically.
The ride spins for a predetermined cycle until an automatic timer releases the hydraulic fluid from the arm causing the platform to return to its horizontal position. The operator may be required to manually control the spin of the ride such that the ride's exit aligns correctly with the exit gate. Most Round ups require the rider to be at least 42 inches tall.
This ride is made by various manufacturers. Huss made a lager version of a Round Up called UFO.