Oklahoma Department of Labor

Brenda Reneau
COMMISSIONER

EXECUTIVE SUMMARY

October 24, 1997


     An April 20, 1997, accident on the Wildcat roller coaster at Bell' s
Amusement Park in Tulsa, Oklahoma, resulted in the death of one person and
injury to five other individuals. The responsibility of investigating the
incident fell to the Oklahoma Department of Labor which, as a result of 
legislative action, has jurisdiction in the matter.

     During the course of the next six months, the Oklahoma Department of 
Labor (ODOL) conducted an intensive and exhaustive investigation. Every 
effort has been made to maintain the integrity of the evidence, eyewitness
statements and employee testimony relevant to the investigation. As the 
largest and most comprehensive investigation ever conducted by this 
agency, the process was methodical, deliberate and cautious. The 
professional services of Zahl-Ford Engineering and Emtech were retained 
to provide technical expertise. Along with ODOL investigators and ride 
inspectors, Zahl-Ford and Emtech performed numerous tests both on-site 
and in a laboratory in our endeavor to determine why the accident occurred
and to develop recommendations designed to prevent such a tragic event 
from occurring in the future. The Zahl-Ford and Emtech results and 
recommendations are contained in this final report.

     From the onset, the primary cause of the accident appeared to be the
failure of the Wildcat's anti-rollback device. The ODOL set out to 
determine why the coaster's non-redundant safety mechanism failed to 
work as designed.

     Numerous theories were considered and systematically dismissed.
Investigators attempted to recreate the events which are believed to have
contributed to the accident. Answers were sought to many questions, 
chiefly, how did the black car prematurely disengage the chain 
necessitating the use of the anti-rollback device on the chain hill?

     A number of contributing factors were present at the time of the 
accident. The "chain dog" which engages the chain at the base of hill was
located higher on the black car than the other Wildcat cars. The wheels 
on the black car were newer with less wear which increased the height of 
the "chain dog" in relation to the chain. The "chain dog" had been removed
and sanded down after it had apparently pulled the chain off the sprocket 
one week before the accident. The chain, itself, differed from other 
Wildcat roller coasters still in operation in that it would 'lay over' 
after clearing the sprocket at the base of the hill.

     Other concerns centered around maintenance and maintenance personnel.
Bell's Amusement Park doesn't possess a copy of the Wildcat 's Operating 
Instructions. The park had no written record of repairs or routine 
maintenance performed on the Wildcat prior to buying it and didn't 
maintain records of repair or maintenance conducted during their 
ownership of the ride. Maintenance workers had no formal mechanical or
technical training in amusement rides. The park's maintenance supervisor
testified he had no established procedure or protocol for verifying work 
performed or the quality of the job. 

     The Wildcat's manufacturer, Schwarzkopf GmbH, no longer makes roller 
coasters. Unable to find some parts or to cannibalize other roller coasters
for parts, Bell's personnel began fabricating unavailable parts on-site. 
This practice contributed the primary factor for failure to prevent the 
accident. Bell's chose a plastic material of dissimilar properties for use
in the car's anti-rollback device. On April 20, 1997, the Nylatron plastic 
insert fabricated in Bell's maintenance shop shattered, allowing the car 
and its three occupants to free-fall backwards down the chain hill. The 
inappropriately brittle material is wear resistant, but it is not 
recommended by its manufacturer for use in non-redundant safety devices
like the Wildcat's anti-rollback device.

     The investigation brought to light other concerns which have been 
addressed in this report. The testimony of park employees indicates no 
formal training exists for ride operators. The park personnel office 
contains no record of employee training or proof of an employee's 
competency and ability to properly operate a given ride. The ODOL 
Safety Standards division has implemented some steps in an effort to
reduce the individual, personal risk associated with amusement park rides.
The Amusement Ride Safety Act requires at least one ride inspection, 
annually. The ODOL is already exceeding this minimum. In addition, to 
inspecting and certifying rides before the start of the State Fairs in 
Oklahoma City and Tulsa, the ODOL instituted a surveillance program for 
the two events. During a 20 day period, 58 re-inspections were performed 
resulting in 69 additional repair orders. Inspectors also issued 23 
operational warnings which included: disregarding height restrictions, 
undermanned rides; and, operator inattention.

     The report contains recommendations which will require either 
legislative or administrative action to affect change. The amusement 
ride industry is highly unregulated. It is unlikely the efforts of the 
Oklahoma Department of Labor, alone, will have much impact outside our
jurisdiction. Although Oklahoma has among the most stringent amusement 
ride laws and rules in the country, it was not enough to prevent a tragic
event from occurring. The general public may have on a false sense of 
security regarding amusement rides. The lack of national standards should
not be considered lightly in an industry which charges admission to 
"safely" scare its patrons. Accidents can happen and safety is neither a 
certainty nor a guarantee.