rmoore
05-04-2005, 10:50 AM
Received this question from a British fire officer. They had a BMW convertible crash into a large tree in a residential neighborhood. The two deployable rollbars fired off and were in the UP position when the rescue crew arrived. The question is as follows;
-----Original Message-----
Is it safe to remove or cut the deployed roll protection devices to speed extrication of a casualty.
My Reply:
Yes. Once deployed, the steel rollbars are locked into position. Some deploy with compressed gas. Some deploy mechanically. Regardless, once in the UP position, you can consider them just like a fixed roll bar or roll cage on a vehicle and work with it or remove it without incident.
The BMW's roll bar system deployed in your incident because the car was airborne as it struck the tree. The sensor knew that, detected the weightlessness, and deployed the rollbars. Also, when the front struck the tree with such force, the rear of the vehicle will typically come upward instantaneously. That would have also tripped the rollbar sensors if the car were at ground level.
-----Original Message-----
Is it safe to remove or cut the deployed roll protection devices to speed extrication of a casualty.
My Reply:
Yes. Once deployed, the steel rollbars are locked into position. Some deploy with compressed gas. Some deploy mechanically. Regardless, once in the UP position, you can consider them just like a fixed roll bar or roll cage on a vehicle and work with it or remove it without incident.
The BMW's roll bar system deployed in your incident because the car was airborne as it struck the tree. The sensor knew that, detected the weightlessness, and deployed the rollbars. Also, when the front struck the tree with such force, the rear of the vehicle will typically come upward instantaneously. That would have also tripped the rollbar sensors if the car were at ground level.