block/ pulley

[chewbacca]

How 'bout this?

 

[sherwood7]

I would say no. Blocks r for rigging and pulleys r for, well... Pulling stuff. Those r fine for little stuff. But any time u are actually rigging and removing a lead or a tree grab a loopie and an actuall block. Get those carabiners out of the system. The little bit extra weight buys u a lot more piece of mind.

 

[chewbacca]

According to the previous definition, neither of those two require a connecting link, therefore they are both blocks.

 

[TreeLogic]

So is this a block?View attachment 27772

Nope, it's a heck of a special pulley though. Pretty much the only pulley I know of where that's possible and definitely new to the game. But point taken.

 

[TreeLogic]

And the revolver, not really a block or pulley so kinda hard to compare that one.

 

[chewbacca]

I think it qualifies as a pulley.

 

[TreeLogic]

The revolver? I thought it was a carabiner I have discomfort calling it a pulley. Doesnt look like one.

 

[wyoclimber]

Thank you, exactly what I was trying to point out earlier.

 

[KevinS]

As well if I biner my omni 'block' on that would make it a pulley but if I spliced it into a loopie it would be a block.

And anything can take a dynamic load or shock load as long as you stay with in the swl.

If I use a biner or an xring as a 'redirect' by some definitions that would make them a pulley. They are changing the direction/ angle of the line.

 

[monkeylove]

Blocks are Yellow, Pulleys are Purple and Biners are Grey, it is really that simple, ha ha.

 

[KevinS]

Blocks are Yellow, Pulleys are Purple and Biners are Grey, it is really that simple, ha ha.

That sucks if I'm colour blind lol.

 

[John_KAYS]

Guys, I looked it up on google images. Here's the answer.



Block




Pulley


Pretty obvious, actually, which is which.

 

[TreeLogic]

So blocks are wood, pulleys are metal. Got it!

I'm starting to think that there's no easy answer on this one, though for all intents and purposes I like my way of explaining it. C'mon guys, it's how I've trained employees for years. I can't back out now.

And, what about the article I linked? If it's in writing in a published article it has to be true doesn't it??? Kidding. But the author, Michael Tain won't be happy.

I'm enjoying the debate.

 

[wyoclimber]

I think we're in an exciting time to be involved in tree work. Equipment and techniques are evolving rapidly. It is important off our industry to have generally accepted terms for things. Items like the Pinto and the Omni, techniques like SRT (or SRWP) are really a paradigm shift in our industry. Finally we are having things designed solely with tree work in mind, rather than cannibalizing equipment from other disciplines. I love the buzz because it helps me keep up, something that can be tough in this arboricultural dead zone I call home.

 

[chewbacca]

As well if I biner my omni 'block' on that would make it a pulley but if I spliced it into a loopie it would be a block.

And anything can take a dynamic load or shock load as long as you stay with in the swl.

If I use a biner or an xring as a 'redirect' by some definitions that would make them a pulley. They are changing the direction/ angle of the line.

A couple of good points you have here. Perhaps the words "rotating sheave" should be included in both definitions. Also, perhaps a quantification is in order for the shock loading portion of the "block" definition. Although, I have no idea what that might amount to. Any suggestions? Perhaps that quantification already exists in the proper definition of the term "shock-loading". I'm sure we could go on and on with this.

 

[KevinS]

According to the ISA's glossary of Arboricultural terms (1) a block is a heavy duty pulley used in rigging. Designed for dynamic loading. (2) casing enclosing one or more parallel pulleys.

What is heavy duty? At work we run a 5/8" cmi 'block' on a tenex eye sling. But if I drove down to do a euc I'd be less than prepared. That's all right tool right job, cycles to failure, swl, etc.
But ISA says a block is a pulley, paraphrasing of course I'll have to see if I dig deep into enough dictionaries to hammer out something better

 

[KevinS]

http://www.treeservicesmagazine.com/article-585.aspx

Per the above article, "The obvious and most important difference between pulleys and blocks for arborist rigging applications is that a pulley lacks a bushing for sling attachment."

Tree Logic, I finally got a chance to read through that whole article, it makes sense thanks for clearing up this question for us.

 

[KevinS]

So is this a block?View attachment 27772

The pinto does attach straight to the sling but not around a bushing so I suppose it's still a pulley

 

[Boomslang]

In my experiences a block has two integrated sheaves whereas a pulley has only one. They are both capable of performing the same functions.