My understanding is that the benefit of using a snatch block pulley (SBP) during winching is that it allows you to double the winch line, creating a 2:1 system and doubling the pull force of the winch.

For instance, a recovery strap, wrapped around a tree or another fixed object, is used to anchor the SBP, and the winch cable is threaded though the SBP, and attached back to the truck. If the winch is rated for 10K, and the recovery strap and SBP are both rated for 20K, this lets you max out the system without over-stressing anything.

Now for the question: what is used to attach the recovery strap loops to the SBP? Most shackles are rated for 9.5K or less, but you would need a 20K rated attachment to maintain the integrity of the system. Any ideas would be appreciated. Links to products would be great! Thanks.

 

Wabfab sells shackles.

Keep in mind when using a snatch block: double the pull, half the speed. Also, you only get twice the pull when the far end of the cable is back by the winch. Oh and its called a tree saver....technically.

 

the shackles can be rated to 10k cause you got two of them.
Edit: so the only things that need to be rated to 20k are the tree saver and the snatch block.

 

A D-ring shackle. http://www.quadratec.com/products/92144_310X_PG.htm

 

Thanks for the replies - the problem with just using a D ring shackle is that they are only rated to 10K, and if the 20K recovery strap is connected to a 20K snatch block pulley by a 10K shackle, the system is only rated to the weakest link, which is the 10K shackle. Are there any shackle type products that are rated to 20K?

Also, snatch blocks only have one attachment point, so I don't think that the shackles can be doubled up. For instance:
http://www.quadratec.com/products/92144_3001.htm

 

I know what your saying. But I've never had a problem using a D-ring, just a suggestion.

 

5 ton is the working rating NOT the ultimate strength which is probably way beyond anything you'll need...

 

http://www.usariggingsupply.com/product/M654P

Used to have one from a overhead hoist we used for lifting boats off trailers...dang thing is heavy as though...

 

Treesaver? lmao no need to get technical guys


ever seen that Dirty Jobs episode where they use some rope( i think...?) and a BUNCH of snatch blocks, to pull out a stuck humvee BY HAND..lmao it was pretty great.

 

Tree straps work wonders...I don't even have my winch set but this is part of the recovery gear that goes with me every time:

 

i think they only use two..
theres some math behind it..
like every single snatch block increases your pulling power by like 5 because of mechanical advantage.

 

i need to snatch a couple of the straps from my summer pipeline job, rated at around 40,000lbs and are anywhere from 3ft long to about 25ft or longer, a think a good 10ft one would be nice lol maybe a couple of the shackles rated for 40K

 

i thought they used about 6? maybe 4? or 5? lol

 

Okay it was 7 lol.
I guess i didnt pay too much attention

 

aha! i knew i was close lmao

it was still pretty amazing to watch manpower pull out a stuck vehicle.

 

Every snatch block you add increases the force by 2 and cuts your line-speed in half. Your correct on the shackle, but this stuff usually has a safety factor of 5, meaning that its rated at 1/5 of its breaking strength. Their are many good reasons for this safety factor and you should never purposely over-load your equipment.

 

Yes you can get shackles rated up to 25,000 pounds for only $45.00 each

For a lot of recovery gear check out www.awdirect.com toll free # 1-800-243-3194

I have bought a few things I have no complaints .

Once you upgrade all your goodies then you start pulling trees out of the ground!

 

http://www.awdirect.com/high-capacit...nd-connectors/
is this what your looking for?

 

Where are you going to find a 20k load? You did say self recovery and the toyota won't give 20k resistance buried to the cab in mud.

 

K I'm gonna go nerdy here lol:

Is the load on the snatch block/shackle actually doubled? I've always had trouble trying to think it through... But the way I try to see it, it's like pulling yourself towards a tree with one arm, it's hard, but then use a snatch block and tie the rope to your other arm. You have to use half the force because the pulling with your one arm is also pulling your other arm.

So that leads me to believe that it's not doubling the load, it's cutting the force required in half. So we should be safe with good ol' 3/4" shackles i think...

So it doubles the winching capacity in a given situation by reducing the force required by half... But no matter what, your winch will never magically pull more than it's rated for.