Drop in power caused Frontier City roller coaster to stall
A momentary drop in power at Frontier City caused the Silver Bullet roller coaster to leave eight riders stranded nearly 100 feet off the ground earlier this week, but the ride's safety features functioned properly, according to a report on the incident released by the Oklahoma Department of Labor.
The brief loss of power caused a sensor fault that triggered the ride computer's safety measures, according to the report.
"This built-in safety procedure prevents multiple train carts from colliding. The coaster's computer program is designed to shut down the lift if a sensor on the track is triggered," the Department of Labor found in its investigation.
Seven children and one adult were stranded atop the roller coaster for more than an hour on Wednesday and had to be rescued by Oklahoma City firefighters.
The Oklahoma Department of Labor inspects amusement park rides on an annual basis, said Christina Foss, a spokeswoman for the Department of Labor.
State inspectors found no problems with the Silver Bullet during a routine check of Frontier City rides in April, but noted that the ride's brakes should be adjusted as needed.
In 2015, state inspectors called for minor repairs to the coaster after a routine annual inspection.
A new inspection of the Silver Bullet on Thursday found that ride's safety aspects meet the manufacturer's standards and the ride was reopened.
“As a preventative measure, Frontier City maintenance personnel will receive additional safe restart training and a written copy of those procedures will be placed in the computer controller station,” the Oklahoma Department of Labor said in its report on the incident.
Frontier City referred all questions about the Silver Bullet to the Department of Labor on Friday.
Frontier City brought the Silver Bullet from the Texas State Fair during July 1986. It was the park's first looping roller coaster.
Standing at a maximum height of about 82 feet, the Silver Bullet is the tallest roller coaster in Oklahoma.