When you see this post’s title you may wonder, when would I need to do that. The scenario is a rare one, however, what if a school bus crash causes significant crumpling of the roof effectively trapping the driver and students that are towards the front of the bus. Here’s an option for school bus roof removal involving a coordinated effort with firefighters and a heavy wrecker.
Involving heavy wreckers at our extrication scenes involves prior training for the coordination to work best in addition to calling for them early when an incident may benefit from the extra lifting capabilities.
Pre – Wrecker Arrival
If it is determined that lifting the roof will provide best access to the victims, firefighters can start prepping the school bus for the heavy wrecker while its enroute to the scene. Below are some steps to complete:
- Remove the windshield
- Cut both A posts low (more on this later)
- Cut the B, C, D, E …posts anywhere on both sides. Ensure to cut the window frames. Remove the glass.(The number of posts is determined by where you want the roof to hinge)
- Cut the main entrance door frame so it is not connected to the roof
- Cut the mirror posts on the high side
- Chock the wheels
When the Wrecker Arrives
It is important to leave room directly in front of the school bus for the wrecker. Wreckers with a rear tow bar will be backed in and stopped shorter than those without. In a scenario with a Type C school bus, the rear tow bar can be lowered onto the hood of the bus effectively preventing movement during the lift. (See the video below).
If the wrecker doesn’t have a rear tow bar, then it will be backed into position where the front frame of the bus can be married to the stabilizing jacks of the wrecker preventing movement during the lift. This type of set-up will be needed for Type D school buses.
As the wrecker is stabilizing the front of the bus, the boom can be extended and the cables slacked. Firefighters with chains wrapped around the A posts should be ready to clip into the wrecker cables. Earlier when it was mentioned to cut the A posts low, it was to leave enough structure for the chain wrap as seen in the picture below.
Making the Lift
Once the wrecker has the front of the bus locked down to prevent movement, the cables are attached to the chains around the A posts, all the cuts are made, and the operations boss & wrecker operator are ready…then the lift can be made to remove the roof. It is important to stress to the wrecker operator that this lift needs to be smooth.
If your wondering about a relief cut at the hinge point, here is what we have found during training.
- Stringers running front to back are the main strength of the roof. They will bend at the hinge point without a relief cut if the front of the bus is rock solid.
- Making a relief cut takes additional time and personnel, which are often limited.
- The lift can be smooth without a relief cut.
One of the biggest keys to a good coordinated operation is training with your local wrecker operators.
Pass it on!