Roll Over – Stiff Leg

TECHNIQUE, EQUIPMENT, & PLACEMENT

The roll-over stiff leg is an excellent device for up-righting an overturned vehicle, because the compression load on the stiff leg will force the vehicle to turn on its axis. Once the vehicle is on its side, the stiff leg will fall out as you continue the upright.

NOTE

Today, many operators now use PVC, Schedule 80 plastic pipe, instead of using the heavier hard wood 4”x 4”.

Cut in the appropriate manner, a stiff leg can be made quite easily out of a 3 1/2 foot (42”) length of 2 1/2”, Schedule 80 PVC plastic pipe, as illustrated above.Pay special attention to the detail of the notching, as this is the critical part of the design. The use of the roll-over stiff leg is outlined below.

FRONT VIEW

SIDE VIEW

A short piece of chain (1/4” grade 8 alloy); approximately 15” to 18” in length, along with grab hooks at each end (WreckMaster calls this piece of rigging a Sister Chain). This piece of rigging is needed for use in this up-righting procedure. You will be sure to find the roll-over stiff leg a great asset for you and your personnel in the up-righting of passenger cars as well as many uses for recoveries.

POSITIONING THE STIFF LEG

The illustration below is a side view of the one-lane parallel up-righting on a passenger car. The low pull; when used with the roll-over stiff leg, is extremely beneficial when up-righting a vehicle on any slippery surface, such as snow or ice.

The angle of the stiff leg, coupled with the compression load the leg places on the casualty, forces the vehicle to rotate with out sliding.

This is the traditional design and cut used for a roll-over stiff leg made of Schedule 80 PVC pipe. For many years since its introduction, it has been outstanding and an all around success, being an extremely versatile and useful tool in towing, transport and recovery industry.

S.C.E.N.E.

SURVEY

This is the time to figure out how much the casualty weighs, prepare it for up-righting and towing. Fix any issues with the casualty that could create an unsafe tow.

CALCULATE

How much force are we creating? What is the resistance? When doing a roll-over, your resistance on a flat level surface is 50% (as you are raising half the vehicle).

EXPLAIN

Inform the parties on scene your plan to up-right the casualty.

NO’S

Do one final walk-around to make sure that no hooks are tip-loaded or side-loaded. Make sure you do not have any twists in the chain.

EXECUTE

Engage the winch.

ENGAGING THE WINCH

  1. Engage the winch – the car will begin to come up.


  2. Stop once the car lands onto it’s side. Do not let the casualty complete the arc. If it completes the arc the rigging is all underneath the casualty, which could be trapped up in the suspension components of the vehicle.


  3. Break down the rigging. You can attach the small chain to a control arm or frame horn on the high side of the car as it’s sitting on it’s side.


  4. Engage the winch to bring the casualty down to sit in front of your wrecker or carrier.

ROLL OVER – STIFF LEG WITH A CARRIER