Offroad-Express

PR wrote:OK so do we all agree that when it comes to snatching 4wds use rated snatch straps and if you have climbing ropes they would be better used for towing.

Sorry to cause a shit fight but I am just trying to get people educated

i dont think its a question of causing a shitfight. An idea has baan touted and we are looking at different aspects of that idea. No shitfight necessary i wouldnt have thought (or maybe i didnt thought and thats the problem )

And no, i wouldnt use one for towing either.

i love a good shitfight

Having done a lot of both climbing and abseiling,
2 different types of rope by the way
Climbing = Dynamic = 9-10% stretch = $300 for 50m
Abseiling, rescue, work at height = static = 2-45 stretch = $200 for 50m

Most snatch straps = 20-245 stretch = $60 for 20m

Though I think that a worn out climbing rope may stretch more they do not retract quickly ... even new they do not otherwise when you fall you would end up being a yoyo on the end of the rope.

Personally I would stick with a strap for a snatch but I would not trust my life on one...

I think that climbing rope would work ok as a back up but for the space and price I would just buy another snatch strap

My 10c worth .... or is that too much

xj wrote: And no, i wouldnt use one for towing either.

Fair enough I wouldnt either but I am just trying to get people away from the idea of using them as snatch straps

xj wrote:
Do they not???? If something has a SWL stamped on it, or an equivalent rating, there is generally a factor of safety that is a superior number that the SWL is worked backwards from.

For example, a wooden plank over a 2.4 mtr span is "rated to" or has a SWL of 225kg, which means, it has been tested to maximum flex and destruction, and the factor worked back. Same for fibre/synthetic ropes, steel wire ropes, Acrow Props, Scizzor platforms and the list could continue........ where does a "Load Rating" of 2500kg come from then, there must be a measurement it comes from.

yes you are absolutly right mate...but is there a SWL on your snatch strap ?

ive just been for a look on the ones i have here and it clearly states

COOKS SNATCHMASTER RECOVERY STRAP HIGH ELONGATION 8000KG BREAKING LOAD.....

no SWL

fair enough too.... i had a chap offer to "snatch" with a chain should i need it........ ermmmmmmm.... no ta

Then there's the debate on what straps are better...................

When side by side the Cookes ones seem like they are a different weave to the Bush Ranger and others i have seen. The Cookes ones are quite fluffy and have an open feeling weave when they come out of the washing machine. They are quick to soak up the shit and need washing regularly in the washing machine.

The Bush Ranger ones have a more closed weave appearence. Seem to do the trick though??

At the end of the day, if it snaps during a recovery, count it as a blessing. It means that you are too stuck for a snatch recovery to be sucessfull, so look for another way. If you had a stronger rope, it may have straightened your hooks or pulled them off the chassis or worse.

wopass wrote:
yes you are absolutly right mate...but is there a SWL on your snatch strap ?

ive just been for a look on the ones i have here and it clearly states

COOKS SNATCHMASTER RECOVERY STRAP HIGH ELONGATION 8000KG BREAKING LOAD.....

no SWL

aha.... but mine has a "rating"... where did that figure come from. Your "breaking load" may divide back to a "rating" of ohhhh.... 2500kgh (ono - 2666kg with a safety factor of 3 - seems a bit close to be coincidence doesnt it?)

xj wrote:

wopass wrote:
yes you are absolutly right mate...but is there a SWL on your snatch strap ?

ive just been for a look on the ones i have here and it clearly states

COOKS SNATCHMASTER RECOVERY STRAP HIGH ELONGATION 8000KG BREAKING LOAD.....

no SWL

aha.... but mine has a "rating"... where did that figure come from. Your "breaking load" may divide back to a "rating" of ohhhh.... 2500kgh (ono - 2666kg with a safety factor of 3 - seems a bit close to be coincidence doesnt it?)

So what your saying is that seeing as we know the breaking load of the strap (8000lbs) and using what ever equation is used to calclulate a SWL rating, you can work out the SWL for the strap.

Makes sense to me. So how do you work out the SWL exactly??

On the other hand, does knowing the SWL of the strap matter??

Your stuck, snatch or winch??? Usually snatch, if that doen't work, out comes the winch. Who's going to stand there and estimate the amount of force required to extract the stuck vehicle and calculate if its going to be within the SWL of the strap??

Tongue in cheek I know, sorry

because a snatch strap is expected to break at its rating which should be lower than the recovery point or tow hook I wouldnt expect it to have a SWL?

DieselBoy wrote:

xj wrote:

wopass wrote:
yes you are absolutly right mate...but is there a SWL on your snatch strap ?

ive just been for a look on the ones i have here and it clearly states

COOKS SNATCHMASTER RECOVERY STRAP HIGH ELONGATION 8000KG BREAKING LOAD.....

no SWL

aha.... but mine has a "rating"... where did that figure come from. Your "breaking load" may divide back to a "rating" of ohhhh.... 2500kgh (ono - 2666kg with a safety factor of 3 - seems a bit close to be coincidence doesnt it?)

So what your saying is that seeing as we know the breaking load of the strap (8000lbs) and using what ever equation is used to calclulate a SWL rating, you can work out the SWL for the strap.

Makes sense to me. So how do you work out the SWL exactly??

Sorry, thought i'd covered that. break it, measure the kg needed to break it, divide it by 3. or whatever it is your testing to its pre designated safety factor.

back to the plank scenario....... impact force break it, measure that force. weight break it, measure that weight.... etc etc. im not a physics expert..... so idont know HOW they come to these formulaes, just that they do. Ill have to go back to my reference material to see what wire rope is tested to ( i think 9mm, 7 strand is 6), but for instance and acrow prop has weight loaded on it until it collapses, norm is around ten ton. Hence a max load rating of 3300kg = safety factor of 3 also. It will take more, but thats what the safety factor is for.

If bennys snatch has a breaking load of 8000kg, and if the safety factor is 3 (three, and multiples of, are a recurring theme for some reason) it divides down to a "RATING" of 2666, or quite possible down rated further to 2500kg. SWL's relate to anything which has a downward weight placed on it, so to be 100% technical about it, a snatch strap wont have a SWL per se.

just wanted to mention this..

after being an avid climber back in my trophy days, i know that a major thing to look after was ya rope.. a biggy was to keep any sort of dirt/silt out of the fibres and especially the core as over a time it would act like a cutting type of grit and thus when the time came to require the "snatching" effect, oopsy doodle splat goes the nibby.. seeing as 4wdin is suceptible to a little filth (not meaning rex and his zuk either), my veiw is rated snatch straps..

my opinion..

FOS on wore rope is: When hoisting normal loads – 5:1

FOS on web slings is: Synthetic (nylon) fibre – 6:1

FOS on chains is: 4:1

all these rules apply to LIFTING (hoisting) loads, not horizontal applications which have a much lesser saftey margin.

ie: to rate a hoist (winch) for lifting,your warn 8724 would only rate at around 500kg as opposed to its 2000kg in horizontal use (pulling).

PR wrote:Sorry to cause a shit fight

you asked for it dude, shame on you for bagging someone for having an idea ! without even looking into it first... Tsk Tsk.

are we not Kiwi's here ?

the most ingenuitive people on the planet ?

do we not see something and think "fark that would make a mean ....."

or "maybe if i put this and that together i would be able to ....."



and yea, good topic for discussion

PR wrote:Sorry to cause a shit fight but I am just trying to get people educated Rolling Eyes

I like it. People like me need to learn these things becasue

DieselBoy wrote:If you had a stronger rope, it may have straightened your hooks or pulled them off the chassis or worse.

Back when the dickhead Safanagri got his first lux we went out with a friend in his late model surf. The surf got bellied in soft clay and we went through 30m of some shitty Russian sailors rope before having to use a 3m crane strop. It had no stretch what-so-ever and we ended up pulling half the chassis together under the tray. It was a mess.

Shit it was scary when we saw what had happened.
Damn lucky nothing gave way.
made memories that day...

Question about climbing ropes; Wouldn't climbing ropes be designed to have little recoil so when you fall they stretch to take your weight but don't recoil like a bungy rope? Thats a bit of a rhetorical question because the ones I have seen and used were like that. So if that is the case then they wouldn't be that good for snatching, you would just get lots of stretch but there would be no energy in the recoil, does that make any sense?

Bubba wrote: does that make any sense?

bubba dude, thats about the only thing of yours i've ever read that made sense!!

niblik wrote:

Bubba wrote: does that make any sense?

bubba dude, thats about the only thing of yours i've ever read that made sense!!

Not sure how i should take that :scratch:

Bubba wrote:Question about climbing ropes; Wouldn't climbing ropes be designed to have little recoil so when you fall they stretch to take your weight but don't recoil like a bungy rope? Thats a bit of a rhetorical question because the ones I have seen and used were like that. So if that is the case then they wouldn't be that good for snatching, you would just get lots of stretch but there would be no energy in the recoil, does that make any sense?

Makes all the sense in the world.

That is the point I was trying to make too

wopass wrote:FOS on wore rope is: When hoisting normal loads – 5:1

FOS on web slings is: Synthetic (nylon) fibre – 6:1

FOS on chains is: 4:1

all these rules apply to LIFTING (hoisting) loads, not horizontal applications which have a much lesser saftey margin.

ie: to rate a hoist (winch) for lifting,your warn 8724 would only rate at around 500kg as opposed to its 2000kg in horizontal use (pulling).

And this is a point i tried to make ages back when dudes were talking about using a tirfor (or other puller) to LIFT. Horizontal and vertical loads are worlds apart.

Different ratings for different applications.

So wire when "hoisting" a load is 5:1, what is winch ropes FOS then...???

Good info Ben, i've been flat out all day and havent had the chance.

not sure but i think the breaking strain of my 13mm wire rope on the winch is 11,000kg ? cant find my PCA manual at the moment so dont have the formulas for working it all out
divide that by 5 and you have your SWL of 2200kg


but in that situation regarding wire rop its not the rope that has a different rating, its the means by which the load is moved ie:winch (horizontal) or hoist (vertical)

looking for manual still

ok found my load lifting and rigging PCA manual and all it has in it is lifting info really..... but i did find some info on wire rope

"Rope diameter and SWL are based on minimum breaking loads of New Zealand made Rope BS 302 "180" tensile fibre core 6x39 construction load factor six. "

steel core rope is much stronger but still has the same SWL as the lesser strength same size rope.

another thing is that ANYTHING used in a LIFTING manner WILL HAVE a SWL.

says nothing about pulling or horizontal movement gear..... so im no use really

Bubba your logic is a bit short... if it has no recoil it would mean it works only once trust me after repeatedly falling at the same piont on some climbs I can tell you it does work repeatedly
dynamic climbing line has elastisity and with it recoil (it will be stated as %stretch or elastisity in the rating) the reason the climber dosn't get launched back up on a fall is just that the stretch in the rope takes the kinetic (falling) energy out of the climber, bringing the loaded weight way under its SWL (and if they fall right they are in an arc'ing motion, better to jump out than chease gratter yourself down the cliff face ).... a truck being recovered or towed applies alot more force, building up more kinetic energy (recoil)
One good thing tho is all climbing line is rated at breaking strain over a 10mm bar (simulate being used over a carabina) so if your using it around tow hooks it is stronger so long as your knot's are good

Sorry about all the science talk, I'm not very good at simplifing things :scratch:

Cheers Reece