Come-along vs. Rope mechanical advantage system

[Groundman One]

Thanks Groundman. That was an old drawing I had on my hard drive.

I see now that you are talking about guying a tree that the climber is in. I like to use two guy lines if at all possible. If a limb or piece of trunk were to hit a guy line it can put a large load on the tree being guyed.

I hear ya. But it happens sometimes that only one line to secure the tree is possible. Sometimes we're lucky to have one solid tree at 180 degree to the leaner to tie off to at all. That being the case, I want to put a good amount of tension on the line. That's where I'm wondering if a small "undersized" M/A setup would suffice. A 3:1 setup from some small pulleys might be enough to tighten that securing line enough so that there is minimum play in the leaner as my climber is either removing the top so we can lower the trunk, or is cutting the top to free it from another tree it is stuck in.

 

[imagineero]

http://www.arboristsite.com/community/threads/light-rigging.212035/

I put a post with a link about half way down the first page. I've made a few posts on the same topic in other threads but this is probably the most comprehensive one I've made

 

[Groundman One]

I see now that you are talking about guying a tree that the climber is in. I like to use two guy lines if at all possible. If a limb or piece of trunk were to hit a guy line it can put a large load on the tree being guyed.

In case my explanation wasn't bad enough, I offer you even worse artwork.

My climber is in the leaner/uprooted tree, and he either has to remove the top which is over something we can't damage, or it's stuck in another tree. I want to tension that line really well to secure the tree and minimize play. Once he's removed the top or cut it free from the tree it is in, we either lower it with the porta-wrap, or drop it as it won't damage anything.

This is where I would want a small M/A right at the porta-wrap to maximize the tension, but not to actually lift the tree.

 

[BC WetCoast]

In that situation, I would use a prussic around your pull line above the portawrap. You could either use a puller (come-a-long, tirfor or pulleys) to put as much pull into the situation as you want, then secure it with the portawrap. Then lowering with the portawrap is easy. The other way is to anchor the portawrap with the puller, however, you may run out of pull rope and then have to muck around to capture your rope.

 

[imagineero]

Kind of depends on the size and lean of the tree, but from my experience 3:1 is nowhere near enough to put tension on anything but a small tree. I've guyed some huge leaners this way, but average size trees need somewhere in the 10:1 range. I usually have the boys start tensioning while I'm standing off to the side perpendicular to the direction of pull. As soon as the top moves even an inch that's enough, they've taken the strain. I don't see any benefit in adding a porty to the mix in that scenario, so I usually just tie it off.

In the case of buying a tree to climb you also want to keep an eye on the system to watch for slack. If the rope starts getting slack the tree is standing up. It's sometimes too subtle to notice it as you're going along, but if it has a bf uprooted root ball then that's a lot of counterweight. I've guyed them on the down hill side also to remove danger of the tree standing back up while I'm in it and when the crown has been taken out. Storm work can bring out some real head scratchers with multiple large trees uprooted and heavily leaning.

The same setup occasionally gets used as a side guy for a tree where the hinge would otherwise side snap when falling. You sometimes need a lot more MA for countering the weight of a heavy side leaner so you can fall it perpendicular to the natural lay. Some times it will be bothe a side leaner and a back leaner, needing two sets of ropes to manage. In the case of severely brittle/rotten back/side leaners I've also sometimes added a ground tie off to prevent the butt of the tree kicking in the event that it just collapses while making the back cut. It's a long slow process to set all that up, but sometimes it's the only safe way of taking a tree out.

 

[Nish]

I often use the Maasdam rope puller plus extra MA. I used tenex prussics to link the three-strand to the bull rope until I started melting the prussics and glazing the double braid. Anyone one else had this problem? Now I use a bowline or BOAB with rigging carabiners or shackles.

Has anyone ever had a Maasdam rope puller fail under load? What exactly happened?. I'm wondering when it's worth the trouble to back up these devices.

 

[Groundman One]

In that situation, I would use a prussic around your pull line above the portawrap. You could either use a puller (come-a-long, tirfor or pulleys) to put as much pull into the situation as you want, then secure it with the portawrap. Then lowering with the portawrap is easy.

That's what we've been doing. Works really well. Just wondered is a small rope MA had an advantage for speed and portability.

 

[Groundman One]

Kind of depends on the size and lean of the tree, but from my experience 3:1 is nowhere near enough to put tension on anything but a small tree. I've guyed some huge leaners this way, but average size trees need somewhere in the 10:1 range. I usually have the boys start tensioning while I'm standing off to the side perpendicular to the direction of pull. As soon as the top moves even an inch that's enough, they've taken the strain. I don't see any benefit in adding a porty to the mix in that scenario, so I usually just tie it off.

In the case of buying a tree to climb you also want to keep an eye on the system to watch for slack. If the rope starts getting slack the tree is standing up. It's sometimes too subtle to notice it as you're going along, but if it has a bf uprooted root ball then that's a lot of counterweight. I've guyed them on the down hill side also to remove danger of the tree standing back up while I'm in it and when the crown has been taken out. Storm work can bring out some real head scratchers with multiple large trees uprooted and heavily leaning.

The same setup occasionally gets used as a side guy for a tree where the hinge would otherwise side snap when falling. You sometimes need a lot more MA for countering the weight of a heavy side leaner so you can fall it perpendicular to the natural lay. Some times it will be bothe a side leaner and a back leaner, needing two sets of ropes to manage. In the case of severely brittle/rotten back/side leaners I've also sometimes added a ground tie off to prevent the butt of the tree kicking in the event that it just collapses while making the back cut. It's a long slow process to set all that up, but sometimes it's the only safe way of taking a tree out.

Good stuff. Some of that we're already doing.

Sometimes we add the porta-wrap to secure the leaner just for the option of a slow descent. Some of those leaners, stuck or uprooted, are as you say puzzles, and sometimes we have to figure them out as we go. We porta-lowered an uprooted skinny (8") maple right over a woman's immaculate garden a few years back. Stopped the trunk a foot over the petunias or whatever the hell they were, and then bucked it up right over the garden and damaged not a flower. I thought she was going to have sex with the whole crew she was so impressed.

You might be right on the 3:1 being insufficient on anything but a small tree for tensioning the line, but I'm still wondering if it might be handy sometimes just for that little extra "oomph!". Then again, the rope puller seems to beat the rope MA in just about every way.

 

[DR. P. Proteus]

Sometimes a ratcheting puller offers to slow of a pull rate and is the slowest out of these three:

1. Ratcheting puller = very slow
2. Z rig= slow
3. Electric winch = a little faster than slow

Also a ratcheting puller is not a steady pull.

 

[old CB]

I use a come-along to pull trees. Never have set up a M.A. pulley system, as the come-along is so simple. Don't have a Massdam rope puller, just the common come-along w/ steel rope. Set a log chain around the anchor tree, hook the come-along to the chain, girth hitch the rope to come-along hook, and go from there. Only thing you've got to watch is to make sure you've got enough length of pull on the come-along to get the tree over. Sometimes when tensioning we have to bust out small branches caught in the system and then re-tension. You don't want to get the tree almost pulled and run out of pull. For the size of trees we deal with here a one-ton come-along is sufficient.

As far as rate of pull, I like that it goes slow. I can monitor the progress. I'm usually at the base of the tree being pulled--having just done my back-cut--and my groundie is operating the come-along. "Gently" is usually my advice to him--I don't want to horse the thing and put undue strain on the hinge.

 

[BC WetCoast]

I use a come-along to pull trees. Never have set up a M.A. pulley system, as the come-along is so simple. Don't have a Massdam rope puller, just the common come-along w/ steel rope. Set a log chain around the anchor tree, hook the come-along to the chain, girth hitch the rope to come-along hook, and go from there. Only thing you've got to watch is to make sure you've got enough length of pull on the come-along to get the tree over. Sometimes when tensioning we have to bust out small branches caught in the system and then re-tension. You don't want to get the tree almost pulled and run out of pull. For the size of trees we deal with here a one-ton come-along is sufficient.

As far as rate of pull, I like that it goes slow. I can monitor the progress. I'm usually at the base of the tree being pulled--having just done my back-cut--and my groundie is operating the come-along. "Gently" is usually my advice to him--I don't want to horse the thing and put undue strain on the hinge.

Get a prussic loop and connect your pull line to the come-along hook at to the prussic. That way, when you run out of pull, you can tie the pull rope to capture what you've pulled and just slide the prussic up the pull rope.

 

[TheJollyLogger]

And a strap or a whoopie for the anchor tree, save some bark.

 

[imagineero]

Most guys could do better just by rethinking their work method a little. A common one I see is guys not thinking about line angles. If you're trying to pull over/lift with a rope, as the angle of the rope moves away from 90 degrees, the amount of side pull/lift you can exert diminishes. Beyond 45* you're pulling down more than you're pulling sideways. Beyond 20* you're pretty much wasting your time. A lot of groundies don't seem to get it. If we're pulling over and I keep telling them to move further away from the tree, they say something like "we're far enough away, there's no chance to get hit", not realising that 1 man further up hill can put more meaningful effort than 3-4 of them being close to the tree. The other issue is that with a steep rope angle you can't put anywhere near as much pull on it as you can with a flat rope. Finally, only 1 man can exert any meaningful pull on a rope with a steep angle - the others are doing very little.

The solution for pullovers is get far away, and try to head up hill. If you're doing big trees in a residential setting, you can't get far enough away and still be in the same yard. Go into the neighbours yard. You need to be at least as far away as the tree is tall to get 45*. The second option is to use a redirect off the base of another tree. With the redirect, the rope is now flat, and as many men as you have can exert meaningful pull on it. That can be better than MA because they can pull fast. With an initial angle of 45* and a redirect, 4 men can exert a side pull of 400-500lbs if they have good traction. Those same men at 20* with no redirect are lucky to exert even 100lbs.

Redirects are useful for manual lifting too, and you can just redirect from the base of the tree you're working on. In this way, a few guys can put quite a lot of lift, and it's easy to control the speed/distance for dynamic situations. You can also set MA from another tree back to the redirect which is practical. A lot of the time without a redirect you can only set the MA attachment not very far because the rope angle is too steep you can't reach. Having the rope redirected lets you make good use of the full length of it. I've got a light rigging setup which i often use for tight residential work, it's some 1/2" rope, a ratchetting one way pulley that lets the person hold 5x their grip, another pulley for redirect at base, and some slings. I'll take some pics of it if anyone is interested. I think I posted about it before.

 

[Nish]

I've got a light rigging setup which i often use for tight residential work, it's some 1/2" rope, a ratchetting one way pulley that lets the person hold 5x their grip, another pulley for redirect at base, and some slings.

This sounds useful. What's the one-way pulley that you use?

 

[imagineero]

Have a read of this thread if you havent done so

http://www.arboristsite.com/community/threads/fiddle-block-ratio.283445/