Lifting slings for large timber?!?!

[TKO]

Iv recently moved firms and today had the new boss tell me to use a large ,3t polyester lifting, sling to snatch heavy timber. I asked about it and he said its stronger and because the line won't take that much weight with that harsh a bend in it.

 

I am tying, and always have tied, a timber hitch/running bowline followed by a half hitch. This is because I figure that the half hitch eases the Bend ratios in the line and the multiple hitches allow for some energy absorption as they constrict on the piece. Also your rigging system is only as strong as the weakest link.

 

i did question this at the time but didn't force it. My thinking is that if you tie a bowline and put a steel carabiner and sling on you are not only loading a bowline fully (potentially reducing the strength of the line by 30%) but you are also subjecting the rope to a harsh bend around the steel carabiner.

 

I suppose my question is, am I right in thinking that it would be safer to continue using my current method simply the line)? or is what the boss saying true and am I missing the bigger picture?

 

Any help or insight would be much appreciated!

 

Cheers in advance guys

[Johny Walker]

Iv recently moved firms and today had the new boss tell me to use a large ,3t polyester lifting, sling to snatch heavy timber. I asked about it and he said its stronger and because the line won't take that much weight with that harsh a bend in it.

 

I am tying, and always have tied, a timber hitch/running bowline followed by a half hitch. This is because I figure that the half hitch eases the Bend ratios in the line and the multiple hitches allow for some energy absorption as they constrict on the piece. Also your rigging system is only as strong as the weakest link.

 

i did question this at the time but didn't force it. My thinking is that if you tie a bowline and put a steel carabiner and sling on you are not only loading a bowline fully (potentially reducing the strength of the line by 30%) but you are also subjecting the rope to a harsh bend around the steel carabiner.

 

I suppose my question is, am I right in thinking that it would be safer to continue using my current method simply the line)? or is what the boss saying true and am I missing the bigger picture?

 

Any help or insight would be much appreciated!

 

Cheers in advance guys

 

 

do as he says ,then if it goes tits up the blames on him , if you do it your way ,you get the sack, ^& you could always try to educate him to yr way of thinking

[Joe Newton]

I'd say you're spot on there.

 

You seem to have a decent understanding on the forces applied to rigging gear, and should stick to what you know/have experience in.

 

In my opinion the more links you introduce to a system the more complex it becomes in terms of understanding the dynamics, and the more there is to go wrong.

 

Using a steel crab (no matter how high it's rated) with a bowline will put way more stress on the line than a half hitch/timber hitch combination. The 3t sling may be stronger than the rope, but just because the sling won't fail, that doesn't mean it's safe.

 

An anchor hitch would be a better termination from the rigging line to the crab, but why complicate things.

[edwood]

Sling to catch the timber or a sling for the lowering Pully? Either way it's a bad idea

[Stephen Blair]

slings all the way, forget all your bend radius theories, its a time thing , they are quick and simple to use and slings are a lot tougher and last longer, they can take a good amount of abuse aswell.

[edwood]

slings all the way, forget all your bend radius theories, its a time thing , they are quick and simple to use and slings are a lot tougher and last longer, they can take a good amount of abuse aswell.

 

 

For snatching timber though? I've always used them for the crown but to snatch heavy timber with them seems like a disaster waiting to happen

[Peter]

The bend radius is the same is the same whichever you do.

 

Using a karabiner in a dynamic loading situation with heavy sections will almost certainly overload it. A shackle would be a better choice.

 

Other than that is doesn't make much difference which method you use.

[Pete Mctree]

If the rope has a knot in it, then that will be the week point - splice Is the way to improve strength.

Without a sling, your half hitch will probably reduce rope strength by up to 40%

[Stephen Blair]

For snatching timber though? I've always used them for the crown but to snatch heavy timber with them seems like a disaster waiting to happen

 

as long as its tight you are good to go, ive never lost a bit.

personally if its not big enough to warrant a sling, i cut n chuck it onto a brash mat or dumpy bag full of stuff.

When it comes down to it, you are incharge of what you cut off the tree as a climber, if you are not happy with what is provided then discuss with the boss and take it from there.

If you have never done it with slings then you need to try it so you have a valid arguement.

[edwood]

as long as its tight you are good to go, ive never lost a bit.

 

personally if its not big enough to warrant a sling, i cut n chuck it onto a brash mat or dumpy bag full of stuff.

 

When it comes down to it, you are incharge of what you cut off the tree as a climber, if you are not happy with what is provided then discuss with the boss and take it from there.

 

If you have never done it with slings then you need to try it so you have a valid arguement.

 

 

Does it not increase shock loading though? Buy tying a half hitch right close to the gob then a timber hitch further up you reduce the distance the timber has to fall before the rope catches it? With a sling surely it would have to be choked high up on the stem to take all the slack out of the system which would then cause it to fall further?

 

I'm not sure I like the sound of it but I've got a big pop to come down soon I'll try it out on, if it tickles my fancy in practice it would certainly make my life allot easier. Half hitch and timber hitch can be a bit of a drag on a massive stem with a big saw swinging about!