Snatch Block Recomendation

[jgoodhart]

To gain pulling power you need a double and single block. Anchor to tree go to (Double) block back to a single block also anchored to the tree then back to the double block then to the pulling forse. It works just like a crane were you have a single line pull to the top of the crane then a bunch of loops down to the hook.

 

[brnchbrkr]

Not cheap but I'm gonna get one this spring to go with my logging winch.

http://www.labonville.com/shop/pc/viewPrd.asp?idcategory=121&idproduct=380

Nice. Labonville has a nice video with it in action.
http://www.labonville.com/Videos/v7.htm

 

[stihl sawing]

That Nissan getting pulled through that muck brings back some unwanted memories.lol Now Amber's video brings back..uh...................never mind.

 

[maplemeister]

To gain pulling power you need a double and single block. Anchor to tree go to (Double) block back to a single block also anchored to the tree then back to the double block then to the pulling forse. It works just like a crane were you have a single line pull to the top of the crane then a bunch of loops down to the hook.

If you were using a 6000# pulling force, and used a snatch block to double you pulling power, does this mean you now need a cable and block rated for at least 12000 lbs?

Maple:

 

[turnkey4099]

To gain pulling power you need a double and single block. Anchor to tree go to (Double) block back to a single block also anchored to the tree then back to the double block then to the pulling forse. It works just like a crane were you have a single line pull to the top of the crane then a bunch of loops down to the hook.

No you don't. Winch-snatch block (attached to load)-anchor. Doubles the pull with one pulley.

winch-snatch block - tail of snatch block (attached to load) - anchor. 4x the pull.

Drawback of course is that on the 2x pull you need to pull 20 ft of cable to move load 10 ft. On 4x you need to pull 40 ft cable to move load 10 ft.

(edit) oops - thought that looked wrong.

You need cable from anchor to snatch block (on load) with the cable end attached to another snatchblock. That one has the cable from winch through it to anchor. Maybe someone who can do drawings could illustrate that.

Wench - snatch block (tail attached to cable) - anchor. \


I use my F150 as the pulling power and rigging for 4x pull is a PIA as I have to keep shifting the cable every 12 ft. All my cables are about 50 ft long.

Harry K

 

[WidowMaker]

No you don't. Winch-snatch block (attached to load)-anchor. Doubles the pull with one pulley.

winch-snatch block - tail of snatch block (attached to load) - anchor. 4x the pull.

Drawback of course is that on the 2x pull you need to pull 20 ft of cable to move load 10 ft. On 4x you need to pull 40 ft cable to move load 10 ft.

(edit) oops - thought that looked wrong.

You need cable from anchor to snatch block (on load) with the cable end attached to another snatchblock. That one has the cable from winch through it to anchor. Maybe someone who can do drawings could illustrate that.

Wench - snatch block (tail attached to cable) - anchor. \


I use my F150 as the pulling power and rigging for 4x pull is a PIA as I have to keep shifting the cable every 12 ft. All my cables are about 50 ft long.

Harry K

====


Here ya go...

 

[brnchbrkr]

Good Question

If you were using a 6000# pulling force, and used a snatch block to double you pulling power, does this mean you now need a cable and block rated for at least 12000 lbs?

Maple:

Found this snatch block rig calculator on line.

http://www.thecrosbygroup.com/productcatalog/calculators/calculators/snatchblockrigcalc.htm

Plugged in 10M lbs. In one of the configurations, 15m was the load on one of the blocks.....

 

[Lloyd H]

block advantage

Simple way to caculate mechanical advantage is count the lines going to load block, ie 3 lines = 3 to 1 advantage.

 

[Mike Van]

Never saw those flat steel plate ones before? These are the ones I use - 6" block that takes 1" cable or rope. One side drops to SNATCH up the cable.....

 

[maplemeister]

Never saw those flat steel plate ones before? These are the ones I use - 6" block that takes 1" cable or rope. One side drops to SNATCH up the cable.....

That looks like a pretty heavy duty beast Mike. Are those available to the general public?


Maple:

 

[turnkey4099]

====


Here ya go...

Thanks. The one I diagrammed gets you 4x1 with just 2 single pulleys (snatch blocks).

More confusing to rig though.

Harry K

 

[Mike Van]

This link http://www.e-rigging.com/store_Categories.cfm?Cat_ID=49&Menu_Choice=Catalog will find them in all shapes & sizes.

 

[maplemeister]

This link http://www.e-rigging.com/store_Categories.cfm?Cat_ID=49&Menu_Choice=Catalog will find them in all shapes & sizes.

Mike:

Thanks for the link, but I was asking specifically about the one you showed in your post. Is that a Military surplus job?

Maple:

 

[GRAYSTONE]

Snatch Blocks and Tree Straps

The attached picture shows a 3 to 1 set up using 3/8" cable to a 12500 lb winch. Total pulling power on the first wrap of cable on the winch drum would be 37500 lbs less friction.

The snatch blocks are rated for 16000 lbs which is above the 12500 lb winch rating. the hooks on the snatch blocks are rated for SWL of 4000 lbs but I have never broken a hook yet. The tree straps are rated for 15000 lbs.

Note this picture is shown at the very end of the pull. If it had gone 1 inch further the blocks would have contacted each other resulting in some kind of damage.

Snatch Blocks shown are from Princess Auto Part 3800046 cost $24.99

 

[maplemeister]

The attached picture shows a 3 to 1 set up using 3/8" cable to a 12500 lb winch. Total pulling power on the first wrap of cable on the winch drum would be 37500 lbs less friction.

The snatch blocks are rated for 16000 lbs which is above the 12500 lb winch rating. the hooks on the snatch blocks are rated for SWL of 4000 lbs but I have never broken a hook yet. The tree straps are rated for 15000 lbs.

Note this picture is shown at the very end of the pull. If it had gone 1 inch further the blocks would have contacted each other resulting in some kind of damage.

Snatch Blocks shown are from Princess Auto Part 3800046 cost $24.99

Graystone:

Thanks for providing pictures of your setup. These things are a lot easier to understand when looking at a picture rather than trying to interpet someone's
verbal description. I do have one question however. Why do the hooks only have a rating of 4000 pounds if they are sitting on a 16000 lbs block? Is that the hook that came with the block originally or some you added after initial purchase?

Maple:

 

[GRAYSTONE]

More Snatch Block

Graystone:

Thanks for providing pictures of your setup. These things are a lot easier to understand when looking at a picture rather than trying to interpet someone's
verbal description. I do have one question however. Why do the hooks only have a rating of 4000 pounds if they are sitting on a 16000 lbs block? Is that the hook that came with the block originally or some you added after initial purchase?

Maple:

The hooks with clip are something I have added to the snatch block. I replaced the original hook which was much smaller. I think it has to do with the difference between SWL Safe Working Load and Ultimate breaking strength. Hook is rated at 4000 lbs SWL but has a ultimate strength of 16000 lbs which is the same as the other snatch block components.

The main thing to remember is than by adding snatch blocks, to a winch pull, greatly reduces the chance of any 1 part breaking. I also reduces the speed at which the log is moving so you can keep you eye on it better. Pulleys also greatly reduce amperage draw on your battery ( Assuming an electric 12 Volt winch) which helps the battery last much longer.

I never winch to a point where the winch stalls. I always shift the log if it is caught or which in a different direction. Be sure to stay well away from the direction of the pull as well. Place a spare tree strap or blanket or coat over the winch wire if you are pulling near the max so the cable or pulley if it breaks can't fly and hit you or break your wind shield.

Picture here shows a 2 to 1 purchase at the end of a pull. The big pulley is one I got at a farm auction but since I can hardly lift it I don't use it to much.

 

[maplemeister]

Now it makes more sense. Thanks for clearing that up.


Maple: