Let's say a tractor trailer has flipped on its side on the shoulder of a busy interstate. The crowd is gathering around and all eyes are on you and your crew. Are you in control? I don't mean just psychologically. I mean, are you in control of the entire process, from initial lift to the tractor-trailer being set (gently) on the ground? If you can't say with absolute confidence, "Yes, Justin, I'm in control," this post is for you.
As I often say, "If you're not in control of the load, the load is in control of you." The best way to control the load when uprighting a tractor-trailer is to use a control vehicle—an additional recovery vehicle that controls the descent of the casualty from the balance point to the ground. Here is a quick overview of the important parts of the process.
DETERMINE THE WEIGHT OF CONTROL VEHICLE YOU NEED. The weight of your control vehicle depends on the weight of the casualty you're uprighting and the conditions the casualty is under. If the tractor-trailer weighs 40,000 lbs and is on a level surface, the total weight you need to upright is 50% of that (20,000 lbs), and the control vehicle you select will need to be able to create enough resistance to slow the tractor-trailer's descent. (Check out this post for a refresher on calculating resistance in towing and recovery.)
CHOOSE YOUR RECOVERY STRAP CAREFULLY. The strap needs to have enough length to prevent the control vehicle from being pulled into the tractor-trailer after it's been uprighted.
USE WEAR PADS. These should be installed at the points where the strap comes in contact with the trailer body to protect your straps from damage.
USE CRIBBING TO CHOCK THE WHEELS OF THE TRACTOR-TRAILER. Properly installed cribbing will ensure there's no movement once the tractor-trailer is uprighted.
ENSURE THERE'S NO SLACK IN THE STRAP AS THE TRACTOR-TRAILER IS LIFTED. This is the job of the operator in the control vehicle, who keeps slack out of the strap from the initial lift up to the balance point.
MAINTAIN PRESSURE ON THE CONTROL VEHICLE'S BRAKE PEDAL. This will enable the operator in the control vehicle to gently control the tractor-trailer's descent. The amount of pressure is up to the operator.
PUT THE CONTROL VEHICLE IN GEAR. This isn't always necessary, but will be needed if the control vehicle is on a grade or soft surface, to prevent the recovery vehicles from having to pull the control vehicle up to the balance point.
BE PREPARED FOR THE EFFECT OF WEIGHT TRANSFER. As the tractor-trailer approaches the balance point, more weight wants to transfer to the ground.
DON'T CATCH OR HOLD THE CASUALTY ONCE IT'S REACHED THE BALANCE POINT. The transfer of responsibility from the operators in the recovery vehicles to the operator in the control vehicle at the balance point needs to be as smooth as possible. Delaying the casualty's descent once it's reached the balance point can cause severe damage to the rail of a delicate trailer.
Uprighting a tractor-trailer isn't something a towing and recovery operator wants to do for the first time under the watchful gaze of the truck driver, incident responders and curious onlookers. Practice in private first, to perfect your technique.
Don't have a spare tractor-trailer laying around to practice on? We do. WreckMaster Level 4/5 Advanced Techniques courses are offered across North America. Enroll and practice with us!