# Best knot or device for attaching block and tackle to lowering line



## Ax-man (Jul 3, 2004)

I recently bought one of those fancy block and tackle for raising limbs and pulling trees over. I finally got a chance to play with it this week raising a small lead straight up, I used the typical six coil prussik to attach the traveling block to the lowering line. It slipped the first time and I had to fool with to get it to bite.

Basically I'm looking for a first time, every time, type of attachment, that is basically idiot proof, if someone else has to set up this kind of rigging.

We have needed a tool like this for a long time to go along with the Porta Wrap and I'm going to make some alterations to my homemade Bollard friction brake to accomidate my new toy. So we have something like a GRC to work with, which will probaly be next to buy.

If there is anyone who has used this tool extensively and can pass along some tid bits I'd appreciate it. I've done a search all over the sites on the net, and I know it has been talked about before, I just can't find it and am tired of looking .

Larry


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## Joe (Jul 3, 2004)

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## rbtree (Jul 3, 2004)

Ax-Man,

Use a very long Vt, say with 5-7 wraps and 3-5 braids.....That will be the easiest hitch to break loose, and will not slip!


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## Stumper (Jul 3, 2004)

Rb, You are the man who would know. Thanks for the tip. I had assumed that the VT would slip at about 1000lbs but hadn't considered adding a bunch of wraps.


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## John Stewart (Jul 4, 2004)

Hey
Dont think it has a name and it sounds silly but it works trust me
It is the only attachment knot I use on my 5:1
Take a long piece of rope maybe 30 inches long braid a eye in each end
Hold one end with about 6 inches of tail hanging to the tag line
Take the other end and wrap it around the tag going up towards the tree about 7 times
Now bring that eye right back down to meet the other eye
Secure with a Biner and you are good to go
You dont have to do anything fancy just the 7 wraps hold it in place
John


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## rbtree (Jul 4, 2004)

John,

That becomes a Vt when you dress and set it.


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## wiley_p (Jul 4, 2004)

I use a VT and it hasnt slipped yet I'm sure if you used a truck on it it would slip or some type of failure would occur, I,ve also used a steel Gibbs it moves easily and is strong enough for what you can lift with a fiddle block.


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## John Paul Sanborn (Jul 4, 2004)

I've used both VT and klem hitches on fiddleblocks to good effect.

It may be a rope wear and compatability issue, what is your prussick cord and your rigging line? How old are they?


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## Frans (Jul 4, 2004)

Why not use a Gibbs?
We always used one and it worked great.
Just push it up the load line with a pole pruner
Frans


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## MasterBlaster (Jul 4, 2004)

What is the SWL of the Gibbs? It isn't stated in the Sherrill catalog.


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## MasterBlaster (Jul 4, 2004)

So that's lower than most climbing lines, and all bullropes. That would definitely be the weak link.


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## rumination (Jul 4, 2004)

The Gibbs will slip or shred the rope before it reaches its SWL, or so I have been told. I think a VT is your best bet.


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## Ax-man (Jul 5, 2004)

Hope everyone is enjoying the holiday, for me it is just another work day, not out on a job but around the house trying to shorten the honey dew list.

Appreciate the info it saves me time trying out different applications and some money. A vt seems to be the knot of choice, I've got plenty of cords and webbing I can use for this.

JP, I'm glad you brought up the age issue, we were working in a non critical type situation, I wasn't using our good ropes that were in the boom truck because there was no need for the truck on this job. This was just sort of a practice run, I was using an older 1/2 in. Arbor Plex with a 3 strand prussic loop spliced spliced onto a rope snap, I robbed it off a 2 in 1 lanyard I never liked.

I've got a variety of ropes that are in excellent shape like Tru-Blu, Stable Braid and a few others, also have cords of different material and diameters. What would be some of the better combinations to mate to each other ??

I thought about using one those camming devices so I wouldn't have to try teaching someone how to tie a knot. How realistic is this scenario to damage a rope in some way using one of these devices.

I always used manpower with a pulley to lift pieces of wood or snap back limbs. But with this new toy I can easily see it can double or even triple what one or two men can do.

Larry


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## Kneejerk Bombas (Jul 5, 2004)

For the type of pulling one does with a 1/2" rope, the Gibbs acsender is a good choice for a tool to connect a come-along or block and tackle. 
I've done distructive tests with a winch and gibbs on a half inch climbing rope. The rope broke, not at the gibbs, but at the bowline at the other end of the rope.
Perhaps some of the testing where the Gibbs damaged rope was done with kernmantle ropes, with thin sheaths. In a couple years of hard pulling on the Gibbs I have yet to see damage at the rope or any slipping.
Another possiblity is the Gibbs damaged the ropes during dynamic loading. I would not use it for situations where I would encounter dynamic loads.
If you are planning on putting the Gibbs to the test with big loads, do a google search. I recall seeing a couple different tests on the internet.


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## TheTreeSpyder (Jul 5, 2004)

i beleive a gibbs is supposed to cut through 1/2" rope at 2000#, so 1000# load is deemed safe; i have to respect MM experiments; but always look to rescue/mountaineering as being ~50 years ahead in a lot of theories, gear etc. The rope cam devices are from their field, and i believe that loads over 1 rescuer and possibly a rescuee are not acceptable. 

The good thing about the force is it is not so much dynamic; but still i believe it is shunned practice and could make possible, long term, internal rope damage; i don't think this is designed use or range of loading use either.


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## Frans (Jul 5, 2004)

Dynamic loading?
SWL?
Why talk about this?
A fiddle block is designed to lift loads right?
So you set it up on a bull rope, attach a port-a-crap below it, and raise a limb. Then take out the slack, hold the load line with your port-a-crap and take off the fiddle block. Then you lower the load.
where are the huge loads?
Are you raising massive limbs over a thousand pounds? I read your posts and you said you were not so I dont understand the answers you received regarding all this "SWL" & "dynamic loading" Just confusing the issue and majoring in minutiae in my mind. There is no dynamic loading in this application. To bring it (dynamic loading) up is not relevent to your question.
The Gibbs is an excellent choice for this application. It is easy to set up and requires little or no thinking to attach the Gibbs. As for harming the rope, well if you over load it and it rips down the rope then you have a problem. Just stay awake and if this does happen notice it and replace the rope. No big deal. If you break the Gibbs then you have a serious issue of not being aware of the loads you are dealing with and you need to deal with that basic understanding first.
Frans


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## TheTreeSpyder (Jul 5, 2004)

i was saying that the dynamic part in lifting/compressing line didn't matter as minimal dynamic force multipliers on the cam device in question/no real dynamic part as you say. But i think that SWL would apply.

i've used gibbs like this (line tensioner-5/1 etc.) many times, Tom and reading has convinced me different, just offering that side in the conversation.

Also, if i am blocking and catching 400# on same spar; i wouldn't mind inital line tension of 800#+ to take out some of the drop & give control of line catch or run could take over sooner; also i think it could help pull hinge over a little stronger for more buffered hinging like that. That has been my major need for leveraged pulling on line that needed an adjustable slider.

Or soemthing like that
:alien:


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## Joe (Jul 5, 2004)

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## Frans (Jul 5, 2004)

> _Originally posted by TheTreeSpyder _
> 
> 
> 
> ...


TreeSpyder,
Then is not the fiddle block and gibbs a great combo for this application? Why discourage a person asking about this set-up? Why not just say this is a good way to go?
I believe this web site has a lot of great thinngs to offer but I see such confilicting/bad /confusing advice sometimes that I feel I have to say something.

I was wrong about the technical definition of "dynamic". My point is, the original poster was not trying to dump loads into the fiddle block. just to tension a load line, so what is the big deal? I think I made myself understood. I just dont think the talk about dynamic loading etc was really directly relevent to the original question.
Frans


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## TheTreeSpyder (Jul 6, 2004)

Once again i've seen enough warnings about using a cam in such a position, as to pass it on. Irrespective of block/tackle choice; i thought that the type of rope grab that the compression tackle grabs the rigging line line was the question.

Sorry i used the D word; but i was ruling out that type of loading, as to focus on the rest


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## wiley_p (Jul 6, 2004)

on 1/2" linee the Gibbs is just fine, moves easier for more purchase, also how many yahoos do you think it takes to lift much more than 1/2 ton anyway witha fiddleblock? Have not had a gibbs fail in the feild yet. Not to mention our arborist ropes don't really crush/pinch like rock climbing ropes.


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## TheTreeSpyder (Jul 6, 2004)

Most of our 12 strand 1/2" is hollow.


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## wiley_p (Jul 6, 2004)

Never liked the durability or feel of twelve strand line. 16-strand for lifeline only or doublebraid for rigging.


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## John Stewart (Jul 7, 2004)

Hey
RB
Don't you have to criss cross the tails on a VT
I could be wrong but I will look for a Pic
John


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## John Stewart (Jul 7, 2004)

Hey RB,
The knot I'm talking about is not a VT. 
As you would know you criss-cross the two eyes behind your tag line to create the VT. 
Giving you the benefit of the doubt I double checked on the VT and found the knot I was describing was called the Machard. 
John


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## Ax-man (Jul 7, 2004)

Really appreciate the input guys,

I'll stick with the knots for now, as that was the main reason I started this thread looking for the the best rope to rope attachment. But on the other hand I'll more than likely get a Gibbs if I question the other persons knot tying abilities. I have a hard enough time teaching some of the basic knots, let alone something like a vt. 

I raised the question on the Gibbs only because I've never used one in a rigging scenario, only on a lanyard. I got some good common sense answers to using the Gibbs, for this type of application.

John,

The VT and the Machard are the same knots, variations of the French Prusik.

The only difference is the cords, VT is a single cord which has two seperate eyes, the Machard is one continious loop, usually spliced, confusing isn't it   

Larry


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## Tom Dunlap (Jul 8, 2004)

Frans,

I'm not going to be able to quote chapter and verse to support my point but I firmly believe that a Gibbs is the wrong tool to use in a rigging situation. In every bit of reading that I've done it always sets limits for the loads. When using a jigger or compression tackle we can get a pretty high load, quickly.

MM seems to have done some colloquial testing with good results...for him. MM is concentious and careful, except when clipping corners off houses  but as a piece of general advice I don't agree.

The characteristics of the VT make it far superior. I like the slip-grab possibilities for reducing loads. 

I take the stance that anyone who is working the lowering line needs to know how to operate every piece the use. There have been times when the groundie just runs the compression tackle after I rig it. They don't need to know the knots but they do need to know how to compress and reset the rig.

Besides, a Gibbs costs over $60 right? A hitch is much less. That means more money in my pocket to buy cool tools.

Tom


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