Raymond
Addicted to ArboristSite
:agree2: If you have to hold on with one hand you're not using your rope and buckstrap at it's full potential.
Lay back, relax and whistle while you work.:hmm3grin2orange:
Knotless rigging (caribeaners)?
- Thread starter Nailsbeats
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Lay back, relax and whistle while you work.:hmm3grin2orange:
if you leave your saddle on the groundWhy would you ever only have one hand free?
Raymond
Addicted to ArboristSite
That's when I tie a rope to something above my head, (you can even leave it up in your roping crotch, with just a simple loop knot) throw the other end of the rope though a fork (don't have to be a big one) have a groundman pull the rope tight as I cut and it'll fold the limb, sliding it down right to him.
The closer I am to a roof or over the top of another smaller tree, etc. the more I use it.
The closer I am to a roof or over the top of another smaller tree, etc. the more I use it.
Raymond
Addicted to ArboristSite
LOL sounds like someone went around the block to many times that morning.if you leave your saddle on the ground
VA-Sawyer
Addicted to ArboristSite
Let me try this again. Maybe side loading isn't the proper term here. Here is how I was taught about biner loads....
"Proper loading" is pull applied along the long axis. Think of it as trying to stretch the biner out even longer than it started.
"Cross loading" is pull 90 degrees to proper loading and tries to turn the oval into a circle.
"Side loading" tries to bend a biner so it looks like a pringle potato chip. To demo a side load, clamp a biner upright in a vise so about 3/4 of the biner is sticking out above the jaws. Now try to fold the biner over by pushing or pulling on the top.
The same "side load" is applied to the biner when it lays "flat" against a chunk of round wood. The wood makes contact in the center, but the ends of the biner are suspended in the air and not touching the wood. The smaller the diameter of the wood, then the more the ends are suspended above the wood. The rope is tied to one end of the biner , goes around the wood and passes through the other end of the biner. When tension is applied to the rope, it tries to bend the ends of the biner down towards the wood, while the wood is pushing up against the center of the biner. If the area of the wood where the biner is laying is fairly flat these bending loads are lower. However, if the biner is laying across a ridge, then the bending loads can be considerable. Maybe even enough to bend or break the biner. I haven't seen any "side loading" rating info for biners.
Note: The number of turns around the wood will increase the grip on the log, but it doesn't change the bending loads on the biner. If you don't belive me, rig it over your wrist with one turn and give it a good tug, then try 3 turns around the wrist. The biner will dig into your wrist about the same in both cases.
Dang! I wish I could do a few drawings to show what I'm trying to explain. It would be so much easier.
Rick
"Proper loading" is pull applied along the long axis. Think of it as trying to stretch the biner out even longer than it started.
"Cross loading" is pull 90 degrees to proper loading and tries to turn the oval into a circle.
"Side loading" tries to bend a biner so it looks like a pringle potato chip. To demo a side load, clamp a biner upright in a vise so about 3/4 of the biner is sticking out above the jaws. Now try to fold the biner over by pushing or pulling on the top.
The same "side load" is applied to the biner when it lays "flat" against a chunk of round wood. The wood makes contact in the center, but the ends of the biner are suspended in the air and not touching the wood. The smaller the diameter of the wood, then the more the ends are suspended above the wood. The rope is tied to one end of the biner , goes around the wood and passes through the other end of the biner. When tension is applied to the rope, it tries to bend the ends of the biner down towards the wood, while the wood is pushing up against the center of the biner. If the area of the wood where the biner is laying is fairly flat these bending loads are lower. However, if the biner is laying across a ridge, then the bending loads can be considerable. Maybe even enough to bend or break the biner. I haven't seen any "side loading" rating info for biners.
Note: The number of turns around the wood will increase the grip on the log, but it doesn't change the bending loads on the biner. If you don't belive me, rig it over your wrist with one turn and give it a good tug, then try 3 turns around the wrist. The biner will dig into your wrist about the same in both cases.
Dang! I wish I could do a few drawings to show what I'm trying to explain. It would be so much easier.
Rick
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logantree
ArboristSite Lurker
I've never used a biner to rig, I always just use a running bowline and a half hitch, or two if needed. I'm going to teach any of my groundies how to untie a bowline before I leave the ground if they don't already know. I don't know how much quicker a biner would be, I can tie a running bowline with my eyes shut almost. I've done a lot of pretty heavy rigging over houses and plenty of other valuables, and never had a failure. Not saying biners are bad really, just don't know that I would want to use one over a house. opcorn:
opcorn:
Doesn't anybody use a timber hitch anymore ?
All this talk about running bowlines. Sure, they work fine, but they don't cinch down to the branch as securely, and they can become difficult to untie when loaded.
I have almost completely abandoned bowlines, using the timber hitch instead, and I teach all my climbers to do the same. Put a full hitch in front of the timber hitch if it's going to be a heavy pull. Once they learn how to use it, all the people I have taught continue to prefer the timber hitch over the running bowline.
1. It's faster to tie than almost any other knot, even with the full hitch, although it does require "dressing" to hold properly. Just a yank, take out the slack, then cut!
2. It cannot be made to bind up, no matter how great the load.
3. Groundies can always figure it out, and it gets the rope back up the tree quicker.
4. Technically, it's a stronger knot, less likely to break.
5. If you are really into getting the job done fast, a timber hitch can be tied like a slip knot with reversing twists that come undone when the tail is yanked. I don't trust that too much, so I don't use it.
Nails (& Ekka): You guys started (and added to) this thread, so I ought to put in my two cents worth.
I don't quite see the advantage of slings & 'biners the way you do. Unless we are speed-lining the wood away from the drop zone, I think much more time is spent handling all the slings and 'biners by groundies and climber than they would if they just tied onto the branch. Maybe we just aren't good enough to use that sophisticated stuff.
I have no problem putting a hitch on the branch then closing with a 'biner instead of using the timber hitch, at least on lighter stuff. Real light wood, just the 'biner to clip onto the branch is good for me, so at least I am not a purist about knots either. In fact, I started climbing using a 'biner on a splice at the end of my rope, and I dropped that in favor of using the timber hitch.
The earlier remark about using clevises sounds like insanity: they are strong, to be sure. But who wants to risk dropping the pin from 40' up. Clevises take both hands to screw together, too, unless you don't mind dropping pins.
This topic, as with so many other things at AS, has many widely different opinions on what works best. I like to hear everyone's ideas, so I put mine up for abuse too!
All this talk about running bowlines. Sure, they work fine, but they don't cinch down to the branch as securely, and they can become difficult to untie when loaded.
I have almost completely abandoned bowlines, using the timber hitch instead, and I teach all my climbers to do the same. Put a full hitch in front of the timber hitch if it's going to be a heavy pull. Once they learn how to use it, all the people I have taught continue to prefer the timber hitch over the running bowline.
1. It's faster to tie than almost any other knot, even with the full hitch, although it does require "dressing" to hold properly. Just a yank, take out the slack, then cut!
2. It cannot be made to bind up, no matter how great the load.
3. Groundies can always figure it out, and it gets the rope back up the tree quicker.
4. Technically, it's a stronger knot, less likely to break.
5. If you are really into getting the job done fast, a timber hitch can be tied like a slip knot with reversing twists that come undone when the tail is yanked. I don't trust that too much, so I don't use it.
Nails (& Ekka): You guys started (and added to) this thread, so I ought to put in my two cents worth.
I don't quite see the advantage of slings & 'biners the way you do. Unless we are speed-lining the wood away from the drop zone, I think much more time is spent handling all the slings and 'biners by groundies and climber than they would if they just tied onto the branch. Maybe we just aren't good enough to use that sophisticated stuff.
I have no problem putting a hitch on the branch then closing with a 'biner instead of using the timber hitch, at least on lighter stuff. Real light wood, just the 'biner to clip onto the branch is good for me, so at least I am not a purist about knots either. In fact, I started climbing using a 'biner on a splice at the end of my rope, and I dropped that in favor of using the timber hitch.
The earlier remark about using clevises sounds like insanity: they are strong, to be sure. But who wants to risk dropping the pin from 40' up. Clevises take both hands to screw together, too, unless you don't mind dropping pins.
This topic, as with so many other things at AS, has many widely different opinions on what works best. I like to hear everyone's ideas, so I put mine up for abuse too!
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TreeTopKid
ArboristSite Guru
TreeTopKid
ArboristSite Guru
I do like web slings too.
Ekka
Addicted to ArboristSite
However, there's more than one way to skin a cat.
And this configuration takes a lot of heat off the biner, do you not agree?
And this configuration takes a lot of heat off the biner, do you not agree?
logantree
ArboristSite Lurker
I don't have any problem with a timber hitch, but I have to say I've rigged a lot of pretty heavy stuff, and never had the bowline cinch up. I know I've done some static loading on my bull line that was at least 800-900 lbs., and like I said I've never had any trouble getting the bowline loose.
I've never used a timber hitch to secure the load. I do use a timber hitch to secure my block though. Looks like a timber hitch for the load would take a bit longer to tie then the bowline. But hey, whatever works.
outofmytree
Addicted to ArboristSite
Whoa, way to misinterpret! I was simply comparing ease of use, not stating my method of climbing. I climb and teach my own climbers that if you MUST use 1 hand to rig you havent climbed up or out far enough.
outofmytree
Addicted to ArboristSite
Thanks for the diagram TreeCo. It seems you are talking about blocks based on what you drew. I said previously it is not my habit to rope down blocks.
Ekka
Addicted to ArboristSite
outofmytree
Addicted to ArboristSite
Well explained mate. This is possibly an issue for krabs used on branches whose diameter is less than "length" of the krab, however for branches that small I cannot see how the shock generated could have any adverse affect on a steel biner. Even if such a small diameter branch weighed 100kg it would need to fall roughly 10 metres to generate 1000kg of force which is still only 6.5% of the krabs lowest rated capacity.
I started off in life in the metal industry and so have a decent grasp of the tensile strength of steel and aluminium. So far, I have not seen any reliable scientific data to support the elimination of krabs from rigging other than "its traditional". I am not saying knots are bad or that krabs are the "true way" but rather there is room for both in a well rounded arborists bag of tricks.
As a side note. It is interesting that after this thread started I asked a few local arborists and not one of them rigs on knots alone. It seems as though Australians favour krabs and Americans favour knots.
TDunk
Addicted to ArboristSite
What i prefer to do is have a rope "choker" with a bowline on each end. Wrap around the limb once and then through the one end of the choker. I just use the biners to connect the lowering line to the choker. Keeps the biners from smashing into other trees, there's no side loading, and i can clip the lowering line to my harness until i'm ready for it (while i set the choker) instead of having it in my mouth.
outofmytree
Addicted to ArboristSite
However, there's more than one way to skin a cat.
And this configuration takes a lot of heat off the biner, do you not agree?
Whilst we are all doing pretty pictures, this is how I lock off branches of all sizes.
Nice and simple. Once around and once again then lock off and set.
tying the bowilne is just as fast, and you dont load the same knot load after loadWhilst we are all doing pretty pictures, this is how I lock off branches of all sizes.
Nice and simple. Once around and once again then lock off and set.
its also more safe to support the bowline with a marl or half hitch(what-ever its called) on the heavy stuff.
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tying the bowilne is just as fast, and you dont load the same knot load after load
YES! Well...almost. A timber hitch is faster than a bowline. But I still agree.
I haven't tracked down the reference yet, but what we are both referring to is best called "a hitch" or "a full hitch", even though it is structurally about the same thing as a 1/2 hitch.
The full wrap around the log (as drawn above) reduces the load on the carabiner by a little bit, but the full hitch will reduce the load by way more than 50%. A wild guess on my part would be that the hitch takes at least 75% of the load, and it is the single strongest structure that can hold a load with a rope except a straight line winding onto a windlass.
From a nautical manual: "MARLING is winding any line round a rope, and securing every turn by a hitch, so that they may be independent of each other..."
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I found a reference to the Marl or single hitch
Just tie one of these on the loaded side of your carabiner, bowline, timber hitch, whatever. Then dare it to break your rope or shake loose.
http://www.realknots.com/knots/hitches.htm#marlsteek
Here is a great picture of rigging a spar with several hitches to protect the carabiner that secures the bitter end. (I personally think he over-did the rigging on that little chunk)
Just tie one of these on the loaded side of your carabiner, bowline, timber hitch, whatever. Then dare it to break your rope or shake loose.
http://www.realknots.com/knots/hitches.htm#marlsteek
Here is a great picture of rigging a spar with several hitches to protect the carabiner that secures the bitter end. (I personally think he over-did the rigging on that little chunk)
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