According to Wikipedia:
"The ride structure consisted of three 265-foot-tall towers (81 m) placed in a triangular arrangement. Several high-strength cables ran down from the top of the tower and attached to the ride vehicle, which would sit on the ground when not operating. The three towers were able to sway up to 8 feet (2.4 m) in high winds, or when the cables were stretched during ride operation.
Riders of VertiGo would first be strapped into a triangular car. Two people could sit on each side of the triangle, letting six people to ride at one time. The restraints were designed to make you feel very insecure, and had few places to hold on. The car would rise a few feet off the ground, and then pneumatic air pressure would rocket the riders up at 50 miles/hour, over the three 265-foot-tall towers, almost 300 feet (91 m) in the air."