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Snatch Recovery Techniques


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Use this information at your own risk

Towballs are NOT recovery points and can KILL! Don't use them! EVER!

Snatch recovery kills mother of three (Aug 2011)

Make sure your tyres have the correct pressures, reduce them if you need to. Try using a shovel first.

One pound = .45 kilograms. A Patrol can weight more than three (3) tonnes (3,000kg or 6500lb), without a trailer.

Snatch recoveries are dangerous. Make sure anyone not directly involved is well clear of the recovery.

Snatch straps store kinetic energy and are designed to stretch and release energy under tension, similar to an elastic band. When the tow vehicle drives away energy is stored in the strap. As energy increases in the strap the resistance of the bogged vehicle is overcome and "snatched" out.

Now you're stuck.

  • Assess the risks.
  • Make sure everyone is safe.
  • Secure the vehicle.
  • Assess the situation. Sand, mud, depth, incline, weight. Every situation is different.
  • Ask for advice.
  • Can you dig out, lighten the load, lower tyre pressure?
  • Two vehicles, One boss.

The figures below are a generalisation. They assume no assistance from the stuck vehicle.

Incline

  • 15deg slope add 25% to the vehicle weight.
  • 30deg slope add 50%.
  • 45deg slope add 75%.

Decline is the opposite.

If you're bogged up to the bottom of the wheel rim then about 100% of vehicle weight will be required in force for the recovery. Up to the hubs, 200% (exceeds all snatch strap ratings). Up to the chassis, 300% (hope you've got a winch).

Worst case scenario. Bogged to the chassis on a 45% slope. 15.7 tonnes or 35,000lb force required. Snatch that!

SAFETY FIRST

Who is in charge? Commonly the stuck driver is in charge and is best able to decide when the recovery is complete. Good communication is vital, use UHF if you have one, and make sure hand signals and voice commands are clear in case something goes wrong. It may be that someone else needs to be in charge (tow driver or spotter) for what ever reason. Have a plan agreed on.

NEVER step over a strap (or cable) once connected to both vehicles.

Use cable dampeners and rated "Bow" shackes (the one below is stamped WLL 4.7t). The Safety Shackle is also shown and is a good option. Dampeners absorb a portion of the energy released when a strap breaks. They are easily fitted with velcro to hold the two halves together over the strap and pockets to add weight.

post-21-0-79014500-1337039328_thumb.jpgpost-21-0-39349200-1337039958_thumb.jpg post-21-0-01556600-1337837902_thumb.jpg

Don't fully tighten the bow shackle pin, instead, once finger tight back off 1/4 to 1/2 a turn. Make sure the strap is not twisted. Twists can create pinch points and reduce strap performance. The strap should have about a one metre fold between the two connected, stationary, vehicles.

When performing recoveries using snatch straps, don't just attach a strap and go "hell for leather" in an attempt to recover a vehicle. The first and foremost thing you should do is start slowly and see if all that is needed is a simple tow. If that isn't sufficient, then more effort can be applied incrementally.

At some point, reason should be applied and winching considered, or connect two vehicles for added traction and weight. Unfortunately, some people love going at things like a bull at a gate and then wonder why things went wrong.

Make sure everyone knows the plan. The bogged vehicle should be in gear and ready to accelerate when the snatch begins. The tow vehicle drives away gently (like at the traffic lights) and continues accelerating. The bogged vehicle accelerates as the strap tensions. As soon as the bogged vehicle is recovered, stop. Try not to run over the strap, they can be difficult to remove from tailshafts etc.

Should you join two snatch straps? Traditional method pic removed. I like the "new" method better.

Anything else?

Edited by twisty
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That photo shows the traditional way that most sources show how to attach two straps, but it's not really ideal, especially if one uses a piece of timber lying around and it turns out not to be sturdy enough. If the timber breaks, the two snatch straps ends will bind so tightly, it will be almost impossible to undo. I'll take some photos tomorrow showing how to do a better join that can never bind if the joiner breaks. I'll also add a knot that everyone should be familiar with, as it's the most versatile knot to use in just about any situation.

Cheers

Ray

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A lot of articles don't recommend joining snatch straps together, but I suspect that the main reason for that is because if not done correctly, it could become a severe safety hazard. That said, this is how I've been joining snatch straps for as long as I can rememeber and have never had an issue. Yes, I've broken straps, but the join has never failed (other than one time when a piece of wood wasn't as sturdy as thought, but no damage resulted).

Compared to the method shown in the previous photograph, this joining method is quick and easy (one strap can already be connected to the vehicle to be towed), is as strong as any other method and will never bind:

strap1.jpg

strap2.jpg

strap3.jpg

strap4.jpg

strap5.jpg

There is another way to also do this by bringing the first loop back on itself and pulling part of the strap through its own loop, but this is the easiest, especially if you have a fairly stiff strap.

One thing that I forgot to mention is how to use a shackle correctly. Whenever attaching a snatch strap (or winch cable for that matter) to a shackle (a properly rated one), you should finger tighten the shackle pin until it locks and then back off a quarter turn. If you fail to do this, have a spanner handy, as you will not be able to undo the shackle pin by hand.

Also, a knot that everyone should know how to tie is the bowline. A bowline is basically a loop that is easy to tie, will never bind and will retain approx 95% of the strength of the original material. It's useful for any sized rope, or string for that matter, and if you should break a snatch strap (which more often than not occurs near the stitching), you can use a bow line to create a temporary loop. This is a link to perhaps the most visual demonstration I've seen on how to tie a bowline:

http://www.animatedk...imatedknots.com

Here's a static image of the four parts to tying a bowline. I always find it easier to tie a bowline by having the loop uppermost in your hand:

knots3b.gif

Cheers

Ray

Edited by Ray!
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Does anyone have any pics of a snatch recovery? Links to good/bad/extreme examples?

edit. Yeah gts thanks ... I know, youtube (there a just so many). I thought members might have some favourites they'd like to share.

Edited by twisty
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can you use a tree trunk protector as a bridle strap? seems to be differing opinions on the net.. im guessing by connecting the bridle/TTP to my two front recovery points after slipping the snatch strap eyelet through it would be pretty good..

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Thanks. I am going to do that from now on when I get snatched out, seems like it will put a lot less stress on the chasis than snatching from a single point.

Slightly OT but is it the same when winching, ie better to use a bridle, or is one point OK?

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Whenever getting snatched,or snatching, do it gently first. If bogged to the chassis, even snatching won't usually work.

Winching is always gentler, so it doesn't create the sudden stress that snatching does and the stress is usually taken up by the winch.

More often than not, it depends on the angle of pull that puts stress on components.

Cheers

Ray

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to add to Rays oint above

I would recomend for anyone actualy buying new shackls to get 3 piece bow shackles .

not the 2 piece type ( shackle and a threaded pin that screws into the shackle ) 2 piece are a pain . they tighens them selfs up ( even when backed of 1/2 a turn or wil become loose ) .

Get the 3 piece one's . ( seperate Shackle , Pin and Nut .) one of these with a safety clip ( or split pin if your real keen ) is heeps better . they will not tighten or loosen up . and Seem to be the only accepted standard most places I work these days . ( for above said reasons )

I've got mostly these in my recovery gear these days and havn't had any trouble loosing the nut for the shackle .

you can do what I've done and used 2.5mm s/s braided wire ( Fishing trace ) to attach the Pin / Shackle / and safety clip together .

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