Has anyone ever used a shackle pulley for rigging?

[petes_sakes]

I was checking out this shackle pulley from CMI (8,000lb rated) and was thinking about doing some light rigging with it (WLL in the 300lb range). I thought it would be nice with a webbing sling, a lightweight option to a block. I figured I'd try here before arboristsite, it's friendlier here So, anyone ever shock-loaded a shackle pulley?

http://www.karstsports.com/cmirpshp...gclid=CJyEzMHBr8MCFYQ5aQodWj0AtQ#.VMUSsY85BMs

 

[Montanalocal]

Do a search for a snatch block and get one with a hook. You will find it much easier to use.

 

[Sleeper-6]

That's a tiny shiv, It's going to be hard in the rope and eat up a lot of energy making that drastic a change in direction.

 

[ironpony]

being on a sports website, I see it more as a safety to protect your rope while climbing/repelling. I would not use that for any sort of lifting. Like the snatch block with a hook idea above.

 

[petes_sakes]

Yea, I have a block, it is just heavy, and this has good strength for the price, I found it on wesspur for $40. I was gonna pair it with a little webbing sling, but I might just get one of those Omni-block 1.5's, they look pretty tough, and with a swivel and easy rope loading, its worth paying more..... I guess-

 

[TMonter]

I have a 7-ton A6 block by Skookum I bought on craigslist for $40 about 9 years ago that I really like. Built like a tank and works great.

 

[CountryBoy19]

Yea, I have a block, it is just heavy, and this has good strength for the price, I found it on wesspur for $40. I was gonna pair it with a little webbing sling, but I might just get one of those Omni-block 1.5's, they look pretty tough, and with a swivel and easy rope loading, its worth paying more..... I guess-

I have some small, easy-load pulleys with about 1.5" dia shive at home. I don't know the load cap. but it's definitely more than 300 lbs. They are super simple, I can't imagine them costing more than $15. I'll take a look at them to see if I can find a make/model so they can be looked up or priced...

 

[Jon1270]

If you want cheap and able to handle up to 1000#, this is serviceable.

 

[petes_sakes]

Those are some good options. I always learned that if you are doing any operations that will cause a 'shock load' (the object being caught or stopped by the rigging), you should use something rated for at least 10x the weight of the object. A lot of physics in it to complex for me to understand, but that 10x rule has served me well so far-

 

[petes_sakes]

I have a 7-ton A6 block by Skookum I bought on craigslist for $40 about 9 years ago that I really like. Built like a tank and works great.

Those skookum blocks look solid, I have a 3/4 cmi that I like for the big stuff, I was looking for something that would be nice and light for the climb up-

 

[TMonter]

Those skookum blocks look solid, I have a 3/4 cmi that I like for the big stuff, I was looking for something that would be nice and light for the climb up-

Would make sense for light climbing tackle. I was thinking more along the lines of what I use for firewood gathering and getting logs down onto the road.

 

[CountryBoy19]

Those are some good options. I always learned that if you are doing any operations that will cause a 'shock load' (the object being caught or stopped by the rigging), you should use something rated for at least 10x the weight of the object. A lot of physics in it to complex for me to understand, but that 10x rule has served me well so far-

Probably not a bad rule to live by for absolute certainty but there is a LOT that goes into account of figuring such a thing. If you're using steel cable the shock load will be MUCH higher than if you're using a braided rope and/or strap. Generally anything that has some "give" to it will reduce shock-loading.

What exactly are you doing with it that you expect a 300 lb load to be a shock load on the line? If it's anything that could cause severe damage to property, or bodily injury don't skimp.

 

[petes_sakes]

I am an 'aspiring' arborist. That's how I got into wood stoves (lots of free fuel!) I've been at it for a couple years and I have used my large CMI 3/4 for all my negative blocking and lowering needs, but it is heavy and clumsy at times. The sling for it is also bulky. Eventually, i'd like a small, medium, and large option, but for now, I think I'll go with this as my small and everything bigger with the CMI-

(broken link removed to http://www.bartlettman.com/OMNI-BLOCK-15-PULLEY_p_890.html)

 

[Mr4btTahoe]

So what exactly will be hanging from this block? What you are lifting will play a HUGE part in how cheap/light you can go on your rigging.

Are you planning on using rope or the synthetic strap through the sheave? If rope, what type?

What kind of lifting are you wanting to do?

When it comes to blocks, I'm a big fan of McKissick, however they are built heavy and are on the pricey side unless you can find one used.

Keep in mind, a 300# shock load can be substantial. I work for a rig shop and anything we make for use as lifelines or fall protection has a WLL of 5000lbs with a 5:1 design factor.. just for an idea. That is taking into consideration the use of a harness, lanyard, etc.. which is all designed to decrease the shock load.

 

[Studdlygoof]

Keep in mind, a 300# shock load can be substantial. I work for a rig shop and anything we make for use as lifelines or fall protection has a WLL of 5000lbs with a 5:1 design factor.. just for an idea. That is taking into consideration the use of a harness, lanyard, etc.. which is all designed to decrease the shock load.

I work in the rigging industry myself and the term "shock loading" makes me cringe. I think instead a trying to rig for shock, I would try to rig to avoid it. Like Mr Tahoe talked about with the safety harnesses they do have deceleration devices you could possibly install maybe?