Here's the deal on the Gurnee Edge accident -- I followed this extremely closely when it happened since this was my home park. I have tons of local news articles and newscasts on video tape from when this accident happened.Shockwavegirl wrote:From what I was told when I worked there, is this..
How the ride worked was that the car was lifted up one tower and a set of brakes stopped it and moved it over to the tower that it came down on. What malfunctioned was the brake at the top of the first tower failed and the ride came back down the lift tower. If this is incorrect, I was misinformed by park management.
The original ride control programming had one car start up the tower just as the car before it was released down the slope. This helped improve the rides capacity by keeping cars moving all the time. Before the tower ascent, the ride weighed the car at the bottom of the tower so it could properly adjust the braking force once the car went down the slope. In addition, the ride also measued the velocity of the car as it was coming down the slope to further adjust the braking force required to safely stop the car.
It was raining the day of the accident in Gurnee. When the car at the top of the tower was released, the other car started its ascent. However, the computers detected that the car travelling down the slope was going too fast, causing a fault and shutting down the ride immediately. This stopped the car ascending the tower 2/3s of the way up.
When maintenance attempted to reset and restart the ride, the lift chain broke. Partly due to the rain, but mostly due to under-sized anti-rollback brakes on the lift, the car that was in the tower fell back to the platform.
It did not land on another car. The three boys in the car that fell had internal bruising and were in the hospital for a few days.
After the accident, three things were changed: (1) ride programming was modified such that the car in the tower does not begin its ascent up the tower until the car before it has completed its descent. Therefore, if the ride detects a fault simialr to what happened in Gurnee, the car in the tower is just sitting at the bottom of the lift. (2) The anti-rollback brakes in the tower were replaced with units twice as large as those originally spec'd for the ride. (3) The number of anti-rollback brakes was doubled from 12 to 24.
All FreeFalls, to my knowledge, received these upgrades.
I was totally bummed when they removed The Edge from Gurnee. Official statement was that ridership was down and that the public confidence in the ride was shaky. Personally, I think insurance was a factor and/or that the park simply didn't want the black cloud hanging over them. When I was at the park after The Edge had re-opened, the lines were always pretty long.
The Edge was truly one of the only rides in history that really scared my out of my mind when I first rode it. What rush!