newbie hi lift questions

[emmodg]

The "main answer": The Extreme has the following over the base HiLift - powder coating, zinc-plated fasteners, and "Extreme Top Clamp". Capacities are the same.

Please don't disseminate information such as - "...chain or strap, doesn't really matter which...". It does matter...quite a bit!

 

[garrett]

Yeh I believe that chain stores just a BIT more energy than a strap. Or that a strap will give you a little warning when it is about to break.

Two very different pieces of equipment that will have two very different outcomes.

You want the strap or winch extension to be the weakest link in any case.

 

[matt s]

The "main answer": The Extreme has the following over the base HiLift - powder coating, zinc-plated fasteners, and "Extreme Top Clamp". Capacities are the same.

Please don't disseminate information such as - "...chain or strap, doesn't really matter which...". It does matter...quite a bit!

I think you misunderstood. Both of them are dangerous when they fail. I was respoding to the posts where people seemed to think a strap would not hurt them. Sorry but I have seen both fail and it's ugly either way.

 

[alexrex20]

The "main answer": The Extreme has the following over the base HiLift - powder coating, zinc-plated fasteners, and "Extreme Top Clamp". Capacities are the same.

Please don't disseminate information such as - "...chain or strap, doesn't really matter which...". It does matter...quite a bit!

you're right, it does matter.

chain does not store energy, a strap does. when a chain fails, it falls to the ground. when a strap fails, it whiplashes and takes out anything in its way.

 

[Bennyhana]

I'm pretty sure the shear pin in the hi-lift climbing mech. will break before a chain will. If you are using a hi lift to winch and putting that much strain on the chain you are using the wrong tool. The hi lift should be the weak link in your come along set up any way....if you can pull on the handle of the jack hard enough to break a chain why not just lift the truck out youself with your bare hands?

 

[neverestablished]

If the chain does not stretch it does not store energy, correct? So what grade and thickness of chain should it be? If its rated higher than the shear pin it really shouldn't be a problem.

Also if using a strap, which strength? 20 or 30k, the 30 would stretch less i assume, so if it breaks, will not fly as far. Or will it since there is the same amount of energy?

Is there a way to tie off a strap or do you have to use the whole length every time?

 

[garrett]

you're right, it does matter.

chain does not store energy, a strap does. when a chain fails, it falls to the ground. when a strap fails, it whiplashes and takes out anything in its way.

So would you say that one reason steel winch line is more dangerous is because it stretches? I believe a steel line stretches just under 2%. Or is it because it weighs more than synthetic line? So a synthetic line has more of a tendancy to drop to the ground than steel because it stretches less. Correct? Hmmmmm. Please explain if you will.

 

[alexrex20]

So would you say that one reason steel winch line is more dangerous is because it stretches? I believe a steel line stretches just under 2%. Or is it because it weighs more than synthetic line? So a synthetic line has more of a tendancy to drop to the ground than steel because it stretches less. Correct? Hmmmmm. Please explain if you will.

steel cable does stretch, but not nearly as much as nylon strap. i think the main reason people switch to synthetic winch line is the safety issue - synthetic does not store energy at all. the light weight and gloves-free usage are just added bonuses.

 

[garrett]

steel cable does stretch, but not nearly as much as nylon strap. i think the main reason people switch to synthetic winch line is the safety issue - synthetic does not store energy at all. the light weight and gloves-free usage are just added bonuses.

I'm still confused. Not trying to nit pick, but synthetic line DOES store energy, but just not as much as steel. Reason being is because it weighs less. But because it still has some weight to it, it will store energy. Most new synthetic lines have less stretch than steel line.

Synthetic line under most heavy loads will not just simply drop to the ground. That is mostly a myth. To imply that you don't use gloves with synthetic is another myth and bad advice.

We can also dust off the brain and use this equation. E = MV(squared) Energy (weight/mass) = Mass times Velocity (squared)

Now we have two types of "pulls". Dynamic and static. How does a chain act under a dynamic pull? It doesn't stretch right? What happens when it breaks? Just fall to the ground?

 

[emmodg]

you're right, it does matter.

chain does not store energy, a strap does. when a chain fails, it falls to the ground. when a strap fails, it whiplashes and takes out anything in its way.

That is so far from the truth it's downright dangerous!

Have you seen a chain break? Believe me, it DOES NOT just fall to the ground!

I've seen a 60,000lb recovery strap snap at the loop by an 1151 HMVEE - it made quite a noise, recoiled a few feet and fell to the ground. This is NOT the case with a chain. Chains do not like to be subjected to dynamic recovery forces. Bad things happen.

Straps, steel, and feathers for that matter ALL have potential energy in a given position. They all store energy. That's what potential energy is: stored energy of position . Remember the old physics example, (well, one of them anyway..), of a drawn bow? When the bow is drawn that cord has a given amount of potential energy due to it's position. (Conversely, a bow that is not drawn shows no potential energy in the cord's "rest" position, or, there is no stored energy in the bow at this position.)

Put simply - it is the mass of the material that "hurts". I could throw a strap at you at 100mph or I could throw a steel chain at you at 100mph - which would you rather be hit by?

Chains "stretch", they do store energy,(potential energy), when in a given position, ie stretched between a truck and dead man/anchor. Everything has potential energy. Some things do; however, have more mass.

All of the talk so far in this thread is merely cocktail-party physics. Suffice it to say: In a recovery situation straps hurt when they break at your face, chains hurt more when they break at your face; and stretch a grade-8 chain to it's breaking point? It does not fall to the ground!

 

[emmodg]

Wow! Wasn't this originally a question about which HiLift to buy? :Wow1:

 

[alexrex20]

by all means, use nylon strap for winching and chain for dynamic pulls. just don't do it anywhere near me.

 

[emmodg]

by all means, use nylon strap for winching and chain for dynamic pulls. just don't do it anywhere near me.

Who's using chains for dynamic recovery work? And didn't you say previously that a chain just falls to the ground?

 

[neverestablished]

Wow! Wasn't this originally a question about which HiLift to buy? :Wow1:

Thanks.

Static and dynamic?

With a winch i assume a chain is better and a stretchy strap is better for pulling with another truck (dynamic?) so the stretch helps.

Anyways, is an extreme worth the extra $30 and is the all cast worth the extra $10? And if Im using it to winch occasionaly, should i get the 60" over the 48"? I really do appreciate the chain vs strap discussion but I need to figure out which hi-lift to get to get in the first place.

 

[garrett]

Just to clear up any confusion.

Never use a chain for any kind of dynamic recovery/situation. Meaning any time inertia it put into a recovery operation. I was using the term as a example to prove a point that chain (though it may not stretch much at all) still has the ability to store energy and do a lot of damage.

It's best not to have to use a chain for ANYTHING. A chain will give you no indication that it is about to fail. A strap might not always either, but when it does it's far less dangerous. So no, never use a chain with a winch unless your ONLY option is to use a chain to anchor the winching vehicle (because it is sliding). But preferably you want to use a strap once again (if going to a tree). Same goes for rigging snatch blocks, etc. Always straps (aka tree savers).

You're right about a vehicle to vehicle recovery though. Using a kinetic rope is ideal as it does have around 30+% stretch. Using that kinetic energy to recover a stuck vehicle. Straps can be used safely too. Just make sure they don't have sewn in hooks, are the right strength, etc.

Someone earlier noted that the "weak" part of the come-a-long setup with the Hi-Lift is the shear pin. This is correct. This is not to say something else won't or can't break though.

A good reference book to have is Jim Allens, Four-Wheeler's Bible. Get a copy of this and keep it around for reference.

As for Hi Lifts. If you have the space just go ahead and get the 60". It's nice if you start fitting after market suspensions and need the extra height to get wheels, etc off the ground. If you don't see yourself using the Hi Lift all that much, I'd just stick to the standard model. If $30 isn't a big deal just get the Extreme though.

Sorry for all the chatting, but I'm not a fan of misinformation. Especially when it comes to potentially dangerous applications and situations.