Snatch Straps & Ropes

What is a snatch strap/rope?

A snatch strap/rope is a piece of equipment used to help in the recovery of a stuck vehicle. They can stretch by approximately 20%-30% under load, depending on the type of material used. This stretching property allows the strap/rope to store kinetic energy, which is used to pull the stuck vehicle free. Snatch straps/rope is usually 9m long, but slightly shorter ones are available and if you contact the right supplier you can get it up to 100m long.

A typical 9m 8ton snatch strap, I have a few of these.

A typical 9m 12ton snatch rope. This is what i use and highly recommend.

A typical 9m 16ton snatch rope.

Technical terminology:

The correct names for the strap and rope is:

KERS – Kinetic Energy Recovery Strap

KERR – Kinetic Energy Recovery Rope

Ratings:

The snatch strap/rope comes in different ratings, the most common for off-road use are 8ton-18ton. The rating depends on the weight of the vehicle, and you must remember the higher the rating, the more energy it takes to stretch the strap/rope. If you use a too heavy snatch strap/rope on a too light vehicle, it will not have enough energy to stretch the strap/rope and the effect will be a much more violent recovery operation. On the other hand, if the rope is not rated high enough, the recovery vehicle will build up too much energy and break the strap.

Attachment to the vehicle:

A snatch strap/rope must be attached to correctly rated recovery points on both vehicles. It is essential that proper rated recovery points be used, as snatch straps store dangerous amounts of kinetic energy when under load, and numerous fatalities have resulted from improper use, such as attaching to towbars or towballs not designed to be used as recovery points. The idea is that should something fail, it should be the softest thing in the system, i.e. the strap/rope. A breaking tow ball or shackle will be accelerated to over 300km/h should it break close to the strap/rope’s full rating, which means it will easily kill you and pass through body panels, windows and radiators with relative ease. This doesn’t mean the breaking strap is completely safe, because just the energy in the strap is enough to put a dent in a body panel or seriously injure you.

Safety Precautions:

As a further precaution besides the correctly rated recovery points, you can lay another strap or heavy blanket over the strap to arrest it and absorb some of the energy should it break.

To protect against recovery point breakages, attach a safety strap to the snatch strap/rope and to a seperate recovery point on the vehicle.

An example of a safety strap attach to the vehicle ans the snatch strap.

Ropes and straps I use for safety.

If you attach the strap to the vehicle with an open recovery hook, do not use a shackle as the breaking strap will send the shackle flying towards the vehicle and if the hook is at bottom of the chassis the shackle can fly through underneath the vehicle and injure or kill someone.

This is what I mean by "open" recovery hook.

It is highly advised that you keep spectators at least 1.5 times the strap length away. If you are the spectator and the neccesary safety precautions have not been taken…run for cover!

If a shackle needs to be used to attach the strap/rope to a closed recovery point, make use of a correctly rated bow shackle. I suggest you use a 4.75ton bow shackle.

The correct 4.75ton bow shackle to be used.

Joining Straps:

NEVER use a shackle to join 2 straps, it is extremely dangerous and there have been fatal accidents where the one strap broke and the shackle struck a bystander or driver.

Loop the one strap through the other as per the pics and then place any kind of soft and light material between the 2 straps. The “spacer” between the straps will aid you when you need to take the straps apart. Do not use something heavy as that will again become a dangerous projectile.

Joining 2 strap with some shurbs acting as the spacer.

How to use it:

The snatch strap/rope is laid out on the ground in the direction the bogged vehicle is to be recovered (either forwards or backwards), with an “S” bend in the middle. The recovery vehicle then drives off, and the strap begins to stretch, building up kinetic energy, until the force keeping the vehicle bogged is overcome, at which point the stuck vehicle is pulled forward. Start off slowly on your first attempt as you don’t want the stuck vehicle to fly through the air. Build up the speed on each succesive pull as needed until the vehicle becomes unstuck.

The science behind it all:

Kinetic energy = Velocity^2(squared) x1/2 Mass

This means if a 2 ton(2000kg) land cruiser drives at 10km/h(2.78m/s) it will produce:

(2.78^2)x(1/2 x 2000)=7728.4 Joules of energy

Taking a 1000kg/g Suzuki at the same speed, gives us:

(2.78^2)x(1/2 x 1000) = 3864.2 Joules of energy

If we double the Suzuki’s speed to 20km/h, we get the following:

(5.56^2)x(1/2 x 1000) = 15 456.8 Joules of energy

This means eventhough the Suzuki is half the weight of the Land Cruiser, at double the speed it produces double the kinetic energy of the Land Cruiser and 4 times more energy it had at half the speed.

You need to be very careful when increasing the speed at which you do the recovery and don’t go too fast as the energy produced is 4 times more at double the speed.

A few myths about snatch straps:

-Some say you have to leave the strap/rope to recovery after each recovery. That is nonsense, although it does loose a little bit of stretch after the first recovery, it is not enough to prevent you from doing successive recoveries.

-Some say a strap is worn out after 10 recoveries. This is also nonsense, the life of the strap isn’t down to specific numbers, it all depends on how it was treated through it’s life and how violent the recoveries have been. I have straps that have done more than 100 recoveries and still work well. The snatch ropes will usually last much longer as the stretch is not due to the material used, but the actual weave of the fibres.

What I recommend:

I’ve recently started using snatch ropes instead of snatch straps and now I can only recommend the rope for superior performance. Yes, the strap does take up less space, but the performance of the rope is worth the extra space it takes up. I use a 12ton rated rope which is sufficient for recovering all the types of vehicles that join me on 4×4 trips.

I’ve got a good supplier for snatch ropes at a reasonable price, so if you are interested, please contact me. I can also supply shackles and safety straps if need be and I actually recommend the safety straps as well.