Recovery strap/hook dilemma

[HnM]

I received two 10,000lb recovery hooks from Ashley @ Coastal 4X4 & Outdoors to be used on the rear of my truck and was planning on using rated eye-bolts on the front because there was no real space for hooks apart from the std weak recovery points which the previous owner had stripped.

However once I had the new hooks to play with it seemed that with the bodylift they sit quite nicely on top of the chassis and allow more aproach angle compared to the std position. So I drill through the chassis and place it in there (havent got the bolts yet) and it looks good and functional until I chuch the snatch strap in.

The strap will fit in there but I wouldn't want to have to fit it under mud or with the vehicle sitting on two wheels and in a rush.

I don't wanna have to use shackles if I can avoid it so what sort of strap can be made up that will fit in my small gap and between the two hooks like an equalising strap??

http://www.4wdlinks.com.au/albums/highnmighty/ads.sized.jpg

[taziiy]

You could do that but i think that defeats the porpuse ;D

[Bundy]

Just put it on when you start 4bying then all you have to do is attach the strap to the recovery vehicle

[BLU-125]

If you must use an equaliser strap, a Tree Trunk Protector is often used,...............don't agree with their use, however.

[HnM]

Why not chris?

[2 BRUTAL]

we use an equalizer strap all the itme, at least you centralize the pull, never caused us any grief and we've had a few nasty recoveries with it this way,

[BLU-125]

H&M, every time you use it you chafe it. At what point do you reduce its S.W.L?

Straps are designed to be used in extension, which is why the ends a reinforced, not the middle.

"We do it all the time and have never had a problem" is the reason O.H & S. is a nightmare for employers.

[2 BRUTAL]

the equalizer strap we use has a heavy sleeve over the strap to allow it to slide thru and not damage the strap when the tow strap or snatch is tensioned, is yours still getting damaged even with the protective sleeve blu.

[haycait]

I am a little confused here :-\

I thought that hilux's didn't get stuck. ::) Surely if you are putting recovery hooks on for towing out other trucks you would put them on the rear to avoid CV damage. :o :) ;) :D ;D 8)

[BLU-125]

2Brutal, its never a bad day when you learn something. I was not aware anyone made a purpose built strap with a sleeve. This would, of course, minimise the problem that occurs when you use a tree protector (as I said).

Will investigate suppliers.

By the way, how do the rate a strap used like this. Determining the S.W.L. when the load can be applied at different angles would surely be a problem.

[cuttin loose]

Say if a tree trunk protector's SWL is 10,000lbs.

when you use it around a tree do you think the amount of area of the strap that has contact with the tree increases or decreases the straps load rate??

i think you'll find that the load rate of the strap is the same whether or not the area covered on the strap is 1metre or 10cms. The only thing that will change is obviously the amount of force on that area.. so if you're pulling 5,000lbs on a 10,000lbs strap i don't think you'd have any dramas unless you exceed that 10,000lbs... in lifting equipment - a strap must have a certain percentage of safety factor built in too.... so you might find that a 10,000lbs strap is actually good for 12,000lbs... it doesn't hurt the strap to occaisionally go over the SWL provided it's only by a small amount and that you don't do it all the time..

but don't forget that our recovery equipment isn't really set to any standards so anything could happen...

chafing of the strap could occur from a tree aswell couldn't it?

[BLU-125]

Lachie, the reason for my question is that the diameter of the tree which determines the angle at which the strap meets effects the load on the strap. (I'm sure I read that in 4WD Monthly)

As its been many years since Physics related courses for me, I thought one of you might know about vectors(?) or whatever it is that relates force to applicable angle.

Any help gratefully accepted.

[2 BRUTAL]

2Brutal, its never a bad day when you learn something. I was not aware anyone made a purpose built strap with a sleeve. This would, of course, minimise the problem that occurs when you use a tree protector (as I said).

Will investigate suppliers.

By the way, how do the rate a strap used like this. Determining the S.W.L. when the load can be applied at different angles would surely be a problem.

Blu. we sell Just Straps equaliziers, they are 3m 65mm webbing and rated at 8000kg. the sock is about 18" long and it helps the attached snatch strap or winch strap to centre itself with out binding on the main strap. :)
You could also double it up as another TTP or short winch extension if needed 8)

[Humpy]

When the 3 straps are at equal angles (120°), the tension in each will be the same, since winch & tree straps are rated at around 10000kg and snatch straps are only 10000lb (4540kg) you wont break the equaliser first, unless its worn.

What is more likely at that angle is bending the hook over sideways because 87% of the tension is working sideways

If you had a 3m strap and your hooks are 0.8m apart, the angle between the equalizer straps would be 31° and the force in each would be 52% of the snatch strap, the side load would be only 14%

[HnM]

So a longer strap would be better for loads then??? I was thinking just a very short one that can stay their whilst wheeling?

[Humpy]

Yes

The first example is a pretty extreme angle, but provided your anchor points are up to it, its possible

I wouldnt go more than 90° between the equalizer straps, thats about a 1.1m strap at 0.8m attachments. That would give 70% tension in the strap and 50% sideways. I would still be concerned about the hooks, they arent designed to be loaded sideways

If you went for a 1.6m strap the angle would go to 60° and the loads reduce to 58% in the strap and 29% sideways. while still not ideal for the hooks, its probably OK

Disclaimer: I dont really know what hooks are designed for so dont blame me if they break

[HnM]

ok Paul. I gues I need to try and bracket it forward or panel beat the body around it (wich is preferrable)...

[Humpy]

Another option would be to mount the hook on the outside of the chassis facing outwards, so the strap would be pulling back into the base of the hook. You would need some compression tubes for the bolts but it should work pretty well