Dumb Recovery Strap Question

[flintknapper]

The Black one pictured is slightly smaller than the one I witnessed being straightened it was a 1" used by the military for their large 8 wheel drive trucks PLS system, and in a lot of situations should have been fine.

But what happens is when the strap has slack in it the end loop can move to appox. where the fingers are in the picture, and since rarely can you pull directly straight, the shackle becomes side loaded effectively shearing the hitch pin used to keep the pin from falling out.

I'd rather keep my head and use screw type clevises.

Just as I thought. Misuse of the clevis.

NO clevis (pinned or screw type) is designed to give full strength when side loaded. In fact they are not to be side loaded at all.

Your example would be like me saying it is unwise to use synthetic winch line because I once saw a person wrap one around the sharp edge of a bumper..and it failed.

It is incumbent upon the person using the equipment to know the limitations and to exercise common sense with respect to its use.

The ONLY way the clevis I have shown could be "launched" would be for the pin to shear....or for someone to "rig" it incorrectly and side pull it from the wrong direction.

For arguments sake...lets say some nitwit side-pulled it from the same side as the "lug" on the cross pin. Yes, it is possible (with enough) pressure to spread the clevis and shear the latch pin on the other side.

OTOH....if rigged correctly, you only allow for any side pulling to be done from the side OPPOSITE the "lug" so that even if you manage to spread the clevis enough to shear the latch pin...the clevis is still retained in the anchor point by the cross pin (you lose your strap only).

Same thing holds true for the "screw type". It is possible to pull the threads through a clevis as well, so..... if you absolutely have to "side load"...then arrange your clevis so that the direction of pull is away from the lug end of the bolt.

If a person is not willing to learn how to use recovery equipment correctly/safely....then I can just about guarantee you...they will hurt/kill someone given half a chance.

As much as equipment manufacturers try to make things "monkey proof", it seems it is all in vain...because they just keep making "better monkeys".


I do appreciate you bringing up the subject however...because there are lots of folks that don't know their ass from page 8 about safe recovery practices. And if you have enlightened even one of these people....then your point was well made.

Thanks,

Flint.


Edit:
In the interest of making my own equipment a bit safer, I drilled out my cross pin and replaced the old 1/8” clip with a new 7/16” latch pin.

I am always happy to add a measure of safety to recovery gear, especially when its easy to do.

 

[Blue77FJ40]

Tractor Supply is another place to get reasonably priced shackles. May see some China stickers there, though.

 

[Niner]

Just as I thought. Misuse of the clevis.

NO clevis (pinned or screw type) is designed to give full strength when side loaded. In fact they are not to be side loaded at all.

Your example would be like me saying it is unwise to use synthetic winch line because I once saw a person wrap one around the sharp edge of a bumper..and it failed.

It is incumbent upon the person using the equipment to know the limitations and to exercise common sense with respect to its use.

The ONLY way the clevis I have shown could be "launched" would be for the pin to shear....or for someone to "rig" it incorrectly and side pull it from the wrong direction.

For arguments sake...lets say some nitwit side-pulled it from the same side as the "lug" on the cross pin. Yes, it is possible (with enough) pressure to spread the clevis and shear the latch pin on the other side.

OTOH....if rigged correctly, you only allow for any side pulling to be done from the side OPPOSITE the "lug" so that even if you manage to spread the clevis enough to shear the latch pin...the clevis is still retained in the anchor point by the cross pin (you lose your strap only).

Same thing holds true for the "screw type". It is possible to pull the threads through a clevis as well, so..... if you absolutely have to "side load"...then arrange your clevis so that the direction of pull is away from the lug end of the bolt.

If a person is not willing to learn how to use recovery equipment correctly/safely....then I can just about guarantee you...they will hurt/kill someone given half a chance.

As much as equipment manufacturers try to make things "monkey proof", it seems it is all in vain...because they just keep making "better monkeys".


I do appreciate you bringing up the subject however...because there are lots of folks that don't know their ass from page 8 about safe recovery practices. And if you have enlightened even one of these people....then your point was well made.

Thanks,

Flint.


Edit:
In the interest of making my own equipment a bit safer, I drilled out my cross pin and replaced the old 1/8” clip with a new 7/16” latch pin.

I am always happy to add a measure of safety to recovery gear, especially when its easy to do.

Side load is consideably more on a screw type even if the pin is modified for a thicker pin.


What I stated was that originally the product was used properly, but while making a recovey of a vehicle and backing about 10' away from the buried vehicle on the 3rd or 4th attempt on a 30' strap and even Vegas would lay odds that thing is coming off.

I'm Passionate about this because this happened at an event where the loss of life could have been very real since there where at least 4000 spectators.

WHY CHANCE IT?

 

[flintknapper]

Side load is consideably more on a screw type even if the pin is modified for a thicker pin.


What I stated was that originally the product was used properly, but while making a recovey of a vehicle and backing about 10' away from the buried vehicle on the 3rd or 4th attempt on a 30' strap and even Vegas would lay odds that thing is coming off.

I'm Passionate about this because this happened at an event where the loss of life could have been very real since there where at least 4000 spectators.

WHY CHANCE IT?

The answer is: I am NOT "chancing it". The way I use my equipment..there is zero "chance" I am going to side load one or "launch" it.

And you are missing my point completely:

An "idiot" misusing a product will manage to endanger himself and others just about every time. We can't "idiot proof" everything....and there is no cure for stupid (except that person gets killed). That doesn't make all products unsuitable for use.

The clevis I have posted is perfectly safe.

If you want to contribute something useful here....tell us about the event that led up to the failure of the clevis...and why the hell someone was using a 30 foot "snatch strap" and getting a 10 foot run at it. This is exactly the idiotic kind of thing I am talking about.

No one had a winch?
The "pull" couldn't be made from a safe angle?
Was there another vehicle available that could assist in a controlled pull?

I think we'll find the "real" problem when you tell us the facts surrounding this circumstance.

What happened?

 

[Niner]

Flint Knapper,

I did explain the circimstances, I think you have blown this out of proportion. Obviously I have offended you by having a opinion that doesn't agree with yours.

 

[flintknapper]

Flint Knapper,
I did explain the circimstances,

Marginally. I am asking for details..because there is no way in hell that clevis was straightened unless it was a piece of junk or was pulled at such an angle (perpendicular to intended design) that any fool should have known better.

I think you have blown this out of proportion.

And I think you witnessed idiots misusing a clevis and now have the opinion that it is unsuitable for use of any manner. Doesn't make sense to me, that is why I have labored the point.

Obviously I have offended you by having a opinion that doesn't agree with yours

Not at all. I don't "offend" that easily. Hope you don't either.

 

[timmer]

Chains are expressly forbidden in our SAR group. They offer no give and generally break whatever they are tied to. Plus they are heavy.

we use snatch type recovery straps. They stretch and have give to them.

IMO chains are dangerous and of no use to me.

Please remember there is a BIG difference between static recovery gear and kinetic recovery gear.

chains, winch line i.e. steel rope or dacron kevlar dyneema, spansets etc. are used for straight on tension pulling , lifting and anchoring.

Snatch straps and ropes such as Nylon double braid and notable others load and unload like a super duper rubber band or gorrilla bungie cord. these are used to jerk stuckies out of their holes usually with another rig. OR in extreme cases jacking a boulder or log off a very short cliff.

remember when tension pulling (like with a hi lift jack) any rig out of a hole on an otherwise downhill grade by yourself anchor the ass end off to a big unmovable object with a measured bit of strong rope. also place the Jack nearier the object being pulled upon rather than the 4x4.

a aquaintance of mine spent a miserable night trapped under his newly loosened truggy when it pulled free and ran him down.another solution might be pulling over a slightly set parking break. OR jumping out of the way and letting the heap go over a cliff or into an arroyo, coolie, canyon or river.

proper rigging is a dying art these days. and wheelers would do well to encourage a resurgance.

taking a rigging class at a crain or equipment rental place would be a really good place to start. also a pretty damed good place to get rigging gear.

Las Vegas Rigging - Desert Specialty Rigging Supply, Las Vegas, NV - Training Agendas

timmer

 

[ohrly?]

buy a winch

ek=1/2mv^2
lots of energy if ur taking a 10 foot run... thats fxxxing stupid,
and think of the inertia.

 

[flintknapper]

buy a winch

ek=1/2mv^2
lots of energy if ur taking a 10 foot run... thats fxxxing stupid,

Pretty much my take on it too.

 

[Dusty 66]

Having worked as a crane rigger for years, for pulling out stuck rigs Rated Nylon slings and matching WLL shackles for me Only !

IMHO Chains Kill !

Some People can screw up anything...

 

[flintknapper]

Having worked as a crane rigger for years, for pulling out stuck rigs Rated Nylon slings and matching WLL shackles for me Only !

IMHO Chains Kill !

Some People can screw up anything...

Man, thats the honest truth!

 

[Bogo]

another solution might be pulling over a slightly set parking break. OR jumping out of the way and letting the heap go over a cliff or into an arroyo, coolie, canyon or river.

Instructional video:

YouTube - How not to upright a car after an accident

 

[WES1977]

Instructional video:

YouTube - How not to upright a car after an accident

I thought it was going to be worse than it was. In the beginning the guy is right under where the vehicle was going to land.

 

[MDH33]

Instructional video:

YouTube - How not to upright a car after an accident

It's a 55, that will buff right out.