ASK ARB –
sand recovery

Dear ARB,

I have only just joined 4×4 Action and thank you for a most
informative mag. On a trip down the Hay River Road, I got well and truly stuck in VERY soft sand at the top of a sand dune, unable to reverse or go forward. Having a Warn 9000lb winch and suitable tree some 50m away, my friend and I set up the winch using extension straps, snatch strap and drag chain. On operating the winch nothing happened except a very tight winch cable! With hesitation, I let the clutch out a little and whammy – the Nissan rocketed out. I’m told that you’re not supposed to use the clutch with the winch. My question is, why not? Did I use the wrong technique?

Also, I’d like to share with your readers a housekeeping trick I do for the car. I have a list of EVERY thing that is in each drawer, glove box, tucker box etc in the console. In the heat of the moment when one forgets where items are; just look at the list. This is even handier if other people borrow your car and need the D-shackle, fuses or EPIRB.

Thanks, Peter

Hi Peter,

Amongst 4WDers, what is the right or wrong technique in a recovery situation is always a heated debate. Every situation is different and as such the technique used will have a lot to do with the equipment you have on hand. There is no ‘standard’ that dictates what you can and can’t do, but there are generally accepted methods for winching that are based on safety, and also dedicated and rated equipment for the job.

The situation you found yourself in can be one of the toughest for winch recovery. A vehicle bogged in sand can be the hardest dead weight to move as it will tend to drag through the sand like a grader blade as it is pulled slowly by a winch. From what you described, I’m guessing you were also pulling off a tree that was down a slope which would have an adverse effect on trying to lift the vehicle up out of the sand.

To make the distance to the nearest tree there is nothing wrong with using a drag chain to give extra length to your cable and winch extension strap. But it is the wrong use for a snatch strap. A snatch strap is designed to stretch approximately 20% of its length when used in a snatch recovery. In these situations they rarely meet their peak rated load except possibly for a few seconds before they begin to ‘shrink’ or return to their normal length. However when used in a winch recovery as an extension strap, they can be stretched at close to peak loading and maintain that stretch for the duration of winching… this can permanently stretch the strap and render it useless when called upon to work as a snatch strap.

Using engine drive/clutch to assist in a winch recovery can, as you’ve experienced, help. Although you see this practice used extensively in competition, it is not recommended by winch and recovery equipment manufacturers due to the adverse loads that can be applied to the equipment. When you use engine drive to assist in winching, as the vehicle lurches forward a couple of things can happen. Firstly, the winch cable will lose tension and as the winch may still be operating, this can cause the cable to bundle and tangle. If the vehicle is still not free of the obstacle and you continue to winch, the successive layers will crush the tangled cable, causing flat spots and irreparable damage.

Secondly, if on a steep hill, engine drive can help get over an obstacle, but if no traction is gained on the other side, the vehicle can roll or slide back, causing a shock load to be applied to the cable and other components. Shock loading can cause both cables and extension straps to fail, as they are not designed to give or stretch, and the shock loads can be far greater than the rated load of the equipment. Winches, cables, shackles, drag chains and extension straps are all designed to pull dead loads.

But as I said earlier, every recovery situation is different. In your situation, the fact you stated that ‘the Nissan rocketed out’ suggests the snatch strap may have indeed helped the recovery in that as you have applied drive to the wheels, the elasticity of the loaded strap has helped pull you out. However if a component such as a strap or cable had failed and broken during the recovery, the snatch strap’s energy may have made the situation a lot worse as any projectile like a shackle would have had a lot more damaging force behind it. Using a snatch strap as an extension strap can be very dangerous and is not recommended.

Safety is always the most important factor in any recovery operation and for that reason you should only ever use properly rated and maintained equipment. A better solution for your situation would have been to use a snatch block to help halve the load on the winch and double its pulling power. It’s always easier to say this in hindsight, but you probably didn’t have enough extension to do this. Being prepared for every situation is not always possible.

So did you use the wrong technique by applying drive? Technically yes, but as it is accepted practice in competition… no. You just need to be aware of the danger of possible damage to your equipment and the unsafe environment that may result. It’s in competition that we see the most failures of recovery equipment and that is because of the practices used.

Before you head off on your next trip there are a few things I’d ensure:

A) Check that your snatch strap isn’t permanently stretched. This should be reasonably easy by measuring its current length against its specified length.

B) Consider your destination and the possibility of becoming stuck. Make sure you’ve got the right equipment to get you out safely.

C) Practice makes perfect. Become more familiar with your winch, its capabilities and the accessories that can make it work easier for you. The last place you want to learn the limitations of your equipment is when you are stuck in the middle of nowhere.

Cheers,

Mark ‘Lowmount’ Lowry
(Manager – Product Development & Evaluation)