Snatch Strap Question

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Originally Posted by Slunnie

I'm pretty sure that winch extention straps are not static like a chain etc. They still give by a fair bit, though thats not a property that are designed for.

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I was trying to give a very boad brush stroke picture of different items used in recovery. A chain will stretch under load, not much but it will stretch.

Winch lines stretch under load. Winch extension straps ideally would not stretch, but in practise they do.

The exact class that you put things in will always be up for debate.

Maybe it would have been better if I used a ultra stiff to ultra elastic class structure.

The static to dynamic classes come from rope terminology which i am familar with.

Regards

Brendan

The winch straps stretch by something like 10% though, where a snatch strap is something like 15-20%. A lot of people treat them as something that is totally inflexible where that couldn't be further from the way they are.

Pretty much anything used for recovery, rescue, caving etc will have some give.
With static lines it should be no more than 10% maximum and should actually break if stretched more than 20%. Basically for rope rescue a static rope should not stretch more than 3% with an 80kg load and more than 10% with a 375kg load and will fail if stretched more than 20%. Winch extension straps etc are static.
A dynamic rope could be anywhere from 5% to 20% stretch depending on the type and use. Average climbing rope is 6%-10%. Snatch straps are dynamic and usually 15-20%.
Obviously chain and wire rope should have no real visible stretch to the naked eye, but will stretch up to 5% with no real damage.

How much give do you want? I noticed in the mag review loom straps have more give - I took this to be a good thing. Also one of them had 50% more give than the others.

Should I get the stretchiest for softer launchings, or is too much a bad thing?

Cheers, Steve

The big thing for most recoverys is having the right strap for the job, as a strap stretch's it stores energy which then aids in pulling the stuck vehicle out, to strong a strap and you get no assistence from it, it becomes just one vehicle dragging another out, to weak and it won't be able to pull against the recovering vehicle and may snap. The rating of the strap should also be based on the tow vehicle not the vehicle being recoverd, ie do you think a sierra would put any stretch in a 11,000kg strap if it were trying to pull a patrol out of a bog, with a lower rated strap that the sierra could effectivly "work" the amount of pulling power available would go up as the strap is also working not just the car.
For a D2 i would suggest an 8k strap for pretty much most things (bearing in mind that they do have a lifespan) and an 11k strap for those times when all vehicles may be fully loaded.

I've a D3, so an 11,000KG strap is needed. But even in that size I can get some which barely stretch 2m, the OL one is 3.7m (or similar). I'm thinking that I should get the OL one as the extra stretch is a good feature.

I'm annoyed that the mag noted findings regarding stretch but didn't comment on the meaning of this data.

Cheers, Steve

Be wary as stretch is not always the answer. This can infact highlight an inferior product. It is more to do with the construction and quality of materials that can store the kinetic energy required.
Having said that I do have the green Opposite Lock strap and it is a quality strap.

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Originally Posted by wovenrovings

So heres what i have been wondering. If you have an 8000kg snatch strap and you want to get some shackles how do you decide what size to get?

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Please dont take this wrong but I cant beleive there are SOOOO MANY posts about shackles and snatch straps; Shackles?? Thats what hooks are for! Why would you add another place for possible failure? IMO

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Originally Posted by Blknight.aus

huh?

the total force required to debog any given vehicle in any given situation will always be the same...

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Surely that cant be right? So a landy with two wheels spinning in sand will require the same force to recover as one bogged to the bonnet in mud; or did I miss understand ?

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Originally Posted by Slunnie

When 4WDAction had testing done on straps, there were quite a few that failed before their rating also. I'm pretty sure the Supercheap one failed a exceptionally early.

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Check out the findings to this, seems cheap is not always rubbish, look at the Super Cheap Auto 8000kg strap.

As said cheap is not always worst and dearest is not always best.
There are some issues to bear in mind, while apparently the Super Cheap strap in the test faired well this time, same tests a couple of years ago it failed badly. I think this has a lot to do with what Chinese company and what batch they buy as their gear is quite often just bought in batches and labelled as their product. Just something to be wary about. Can happen with any supplier I suppose. But most suppliers like O/L, ARB etc would demand consistency (at least I would hope they would) where as a discount store will generally buy a bulk lot of whatever is available at a price.
As for the comment on shackles. Shackles if attached correctly are always better than hooks as there is no chance of the strap slipping off. I have seen several straps come off of recovery hooks, even with the retainer clip on them. Not saying they are not usefull, but my preference is a shackle securely attached. We are not just talking about attaching a shackle anywhere. The area a shackle should not be used is for joining straps or on an unsuitable recovery point. The pin of a shackle is a hell of a lot stronger than a recovery hook or a tow hitch receiver pin, so it is highly unlikely it would fail. It is the attachment location that would fail.
Since getting a dedicated recovery tow hitch pin I have hardley used shackles, but do with the truck on rated eye recovery points. Jate Rings are also another good example of where shackles can be used. If a recovery hook breaks that will still become a lethal weapon.
But I must emphasise a shckle should be used in its correct application, not just hooked on to anything.

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Originally Posted by CraigE

As for the comment on shackles. Shackles if attached correctly are always better than hooks as there is no chance of the strap slipping off.

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My mistake I suppose for posting late at night, what I was trying to say was that if a shackle is used there is potential for it to become a missile in the event something goes wrong, no shackle no missile.