Which cut to rig down a spar?

[Keeth]

I learned to rig down a spar on itself in a conventional fashion using a block or some other friction saving device. Traditionally I've used a standard notch with an appropriate back cut that leaves enough holding wood for the hinge to work properly. Lately though I've skipped using a notch and instead have been using matched cuts instead.

In place of the notch I make a standard perpendicular cut with the top of the bar just over half way through the diameter leaving sawdust in the kerf. After tying the piece off I cut from behind and let the piece settle on my bar. At this point the piece is free to fall in any direction within 180 degrees (as it is still tied). Now I kill the saw and push forward on the wood enough to free the saw so that I can saddle it. Now I push the piece off as slowly as I want to and in any direction the rope will allow.

I've experimented with this technique on various species and diameters, but mostly with chunks between 10-28 inches and at most six feet in length (smaller diameter means less stability.)

So what do you think? Of course you have to be very careful with letting a piece rest unattached to the top of a wiggly spar, but I usually wait until I'm a ways down with about 60% of the original height left before employing this method. It much easier for both cutting and positioning while minimizing the initial speed of the wood on the way down.

I've watched plenty of rigging videos, but have only seen a couple of instances where someone didn't use a notch.

Do any of you use something similar?

 

[TreeLogic]

You need a notch on the larger stuff. I actually prefer a deeper one when negative rigging. You don't want an option of different directions of fall as that decision should be made prior to the initial cut. Larger pieces could be so heavy your pinched saw might not come out. Always make logs coming down on block and rigging so that they want to fall toward your block. What you're describing sounds like a snap cut and I'd only use that on smaller logs I'm just going to toss, or maybe crane picks.

 

[Treetopflyer]

Humboldt notch usually for me and everything in paragraph two sounds either unstable and slow or a bit of both.

 

[Leroy]

A tag-line on top of the piece is a good idea when you are using that method.

 

[Keeth]

I'm not questioning the traditional methods. I still understand and use them all the time.

Not cutting a notch means less cutting overall. The context I'm presenting is where rigging is a must. No cranes, no nearby lowering points, no chunking down by hand... everything must be lowered.

 

[SRTsteve860]

if you are rigging down a piece its because you are protecting something in the drop zone, be it a garden, sidewalk, or just preventing dents in a yard, so while protecting something why then take the shortcut and cut a piece that might not go exactly where you push it. if the trunk has any lean, set the block on the low side so gravity and a notch will take the wood over, and if its straight up and down, either a deep notch (>50% diameter) wedges, a push, or pull line to send it over, and as the piece begins to move, there will be a small dissipation of energy as the hinge fibers break, where as if you just push off a free standing chunk the only resistance to the woods acceleration would be the rigging line.

-Steven

 

[TreeLogic]

I'm not questioning the traditional methods. I still understand and use them all the time.

Not cutting a notch means less cutting overall. The context I'm presenting is where rigging is a must. No cranes, no nearby lowering points, no chunking down by hand... everything must be lowered.

Yes, it takes more time but the notch is greatly increasing your chance of success and your safety. The tagline mentioned above is always a good idea (even with the notch) but with the method you described the chance of the log coming back towards you, the climber, is much greater. Not trying to be contrary but I think it's a bad habit to get into for heavy rigging. Sometimes, without a notch, the log will start going the direction you want but then change direction when tipping, and could cross the block in a side load manner. With a proper back cut it will always fall towards the notch though.

 

[Keeth]

No offense taken.

I'm not really taking about log lengths. Think 20 inch diameter and 4 ft long with little to no lean.

My interest is to see what other non-traditional methods are being used.

 

[TreeLogic]

Usually, if I can comfortably lift the piece standing on spikes then I might use that method. Anything beyond that I'll probably notch it.

 

[ROYCE]

No offense taken.

I'm not really taking about log lengths. Think 20 inch diameter and 4 ft long with little to no lean.

My interest is to see what other non-traditional methods are being used.

If your worried about speeding up your process, I would not skip the notch, I would rig bigger pieces. A 20" 4 foot piece can be thrown to the ground onto a piece of plywood. Not always the case, but the joy of rigging is you can take larger pieces much more controlled. I would be using a notch, and be rigging out 8-10 foot sections. Once you get close to the ground and clearance is an issue, either move the porta-wrap up to where you hang the block, or just cut and chuck the pieces to the ground

 

[TreeLogic]

The faster the job can be turned into ground work (without collateral damage) the better off you'll be. Rule to live by in tree work.

 

[Keeth]

Again, nothing can be thrown down, everything has to be lowered with no impact to the ground.

I should have provided a little more background too. I've been climbing and rigging for over 20 years. I know the mechanics of hinging and can explain the stress and strain tensors used to predict pull and compression of the hinge fibers using the Bulk Modulus and Young's Modulus. That is not what this thread is about.

This method has the advantage that your saw is saddled and you get to control when and how fast the piece comes off. There is no lifting. The sawdust in the kerf acts as a lubricant, allowing you to push a pretty hefty chunk of wood without much effort. Whoever is manning the lowering device has a little more time to react as well. I also understand the uncertainty that comes with having a piece simply resting on the spar and the subsequent risks involved.

Time is not my biggest concern either. There is a balance of risk, safety and time that we all (should) measure out.

If you are a "no school like the old school" type of person, good for you. However I am interested in opening a dialogue about different approaches to lowering chunks from a spar here...

 

[Treetopflyer]

I also understand the uncertainty that comes with having a piece simply resting on the spar and the subsequent risks involved.

That's another reason I'd not use the cut(s) your talking about. Pretension the rigging line and I'm thinking about how the piece would have to move up and over without the notch taken out as it comes off which is not a huge concern just seems like more energy, and if the rigging line isn't that tight where you can move the log by pushing or pulling or gravity pulls in any way other than towards the anchor point does not seem very safe. Seems like its more energy than making one more cut when your already right there in position with a saw by turning the bar a few degrees and the results are more repeatable with a notch forming the hinge. From what I gather from your initial post of the way you'd do it.

 

[TreeLogic]

Keeth, you sound like you know your stuff. If it works for you then have at it brother. My main concern is the potential for lack of directional control on larger stuff, and that someone not as experienced as you on this forum may misunderstand or hurt themselves.

 

[Treetopflyer]

Once you get close to the ground and clearance is an issue, either move the porta-wrap up to where you hang the block

I've never moved porty up where I hang the block what am I missing out on Royce? I've put it in the tree and worked it myself on certain occasions if I really had to ,but not for spar rigging that I can recall , are you just dumping wood right on porty by the sounds of it?.

 

[ROYCE]

I've never moved porty up where I hang the block what am I missing out on Royce? I've put it in the tree and worked it myself on certain occasions if I really had to ,but not for spar rigging that I can recall , are you just dumping wood right on porty by the sounds of it?.

Yeah, I do it for two reasons. One, I don't want a lot of rope in the system because I am worried about stretch. Maybe because of a fence right below the tree or something.
The second would be if I want to change the load on the tree. If the porta is in the tree, at the location of the block, then you are not getting double the force or more on the tree. Works good if your worried about structural integrity

 

[ROYCE]

Yes, I am dumping wood right into the porty. Some will disagree, but I find good reasons to do it upon occasion

 

[Keeth]

Yes, I am dumping wood right into the porty. Some will disagree, but I find good reasons to do it upon occasion

This is what I mean. Of course people will argue with you over the potential of improper loading and damage to the porty too, but you have found this useful and have a legitimate reason to do so. I will occasionally use a stainless rescue 8 in the same way, but not with anything much over 300 lbs. Now that tree specific rigging rings are finally showing up in the industry, I think we'll start to see several changes in the way rigging is performed. This forum is full of Xring stories that would have received even more skepticism just a few years ago.

My main concern is the potential for lack of directional control on larger stuff, and that someone not as experienced as you on this forum may misunderstand or hurt themselves.

I understand that it is one of those "you'll have to try it" methods to see how it works. I too have tried new techniques that I've seen on forums and in Journals or magazines. If one is still doing tree work the same way they were 5, 10, or 20 years ago, they probably won't be apt to try any of this anyway. As a disclaimer, I recommend that anyone who does not understand rigging not attempt to use this method. If however, you have a few years under your belt and are looking for a way to reduce fatigue and increase communication with the ground, it might be worth a try in the right situation. Most of the time I never even pull the saw out of the kerf, but transition to a plunge cut. I guess that's another can of worms all together.

 

[Treetopflyer]

Yes, I am dumping wood right into the porty. Some will disagree, but I find good reasons to do it upon occasion

Ive never tried that.

Yeah, I do it for two reasons. One, I don't want a lot of rope in the system because I am worried about stretch. Maybe because of a fence right below the tree or something.
The second would be if I want to change the load on the tree. If the porta is in the tree, at the location of the block, then you are not getting double the force or more on the tree. Works good if your worried about structural integrity

That's interesting to me .. Your wrapping the porty and ground help controls rigging line or how is that oriented ,not to go off on another subject to far?I understand less rope in system theory and that your close to ground and targets for the purpose. Shorter pieces as the diameter increases and targets get closer. I can Invision it mostly ,but if your successful with it , I like more tools in the box ..

 

[Treetopflyer]

This is what I mean. Of course people will argue with you over the potential of improper loading and damage to the porty too, but you have found this useful and have a legitimate reason to do so. I will occasionally use a stainless rescue 8 in the same way, but not with anything much over 300 lbs. Now that tree specific rigging rings are finally showing up in the industry, I think we'll start to see several changes in the way rigging is performed. This forum is full of Xring stories that would have received even more skepticism just a few years ago.



I understand that it is one of those "you'll have to try it" methods to see how it works. I too have tried new techniques that I've seen on forums and in Journals or magazines. If one is still doing tree work the same way they were 5, 10, or 20 years ago, they probably won't be apt to try any of this anyway. As a disclaimer, I recommend that anyone who does not understand rigging not attempt to use this method. If however, you have a few years under your belt and are looking for a way to reduce fatigue and increase communication with the ground, it might be worth a try in the right situation. Most of the time I never even pull the saw out of the kerf, but transition to a plunge cut. I guess that's another can of worms all together.

So your making front kerf in direction logs to fall half way through diameter then leaving thin strap and plunging in ,coming in completely even with front cut going out the back ? And just having ground help with tag line pop them off or you pop them off pushing yourself ? Either way is your saw is on harness? I like trying to figure out other styles if you can't tell and like to have a real good understanding, to see the advantages and limitations of different ways to approach certain scenarios . I feel many have there time and place . Just figuring out what and when makes for monotony breaker I like trying new things as long as its for the right reasons like safety of course and productivity/ fatigue reduction. Which leads back to safety I think !