Rigging down logs stance

[Treetopflyer]

Look at the video posted by the OP... https://www.facebook.com/reel/378961651407319

Is there any way in any world that anyone can hang such a log on the hinge and then go back to cut the hinge fibers to release the piece? ANSWER ...... NFW..no way... no how...

Is there any way to use the hinge to significantly alter the force and momentum of such a log after the hinge breaks? again NFW....

If we are talking about a log as per the video: Tom is spouting complete nonsense...

it doesn't matter if it's a log or a top being negatively rigged.. the forces on the tree or the rigging on anything even close to that kind of mass cannot be significantly altered with the hinge....

I didnt see the video until you pointed it out
That was a long log at a small enough diameter to give a ride regardless and a top would have been similar. A fat hinge will slow a fell though let’s all agree on that
To what point the variables are too many to discuss individually
I’ve no energy for that shit
Wait I just re read your last line about the hinge
Aren’t you like a hinge scientist or some shit
Now this ?

“t doesn't matter if it's a log or a top being negatively rigged.. the forces on the tree or the rigging on anything even close to that kind of mass cannot be significantly altered with the hinge....”

 

[DSMc]

As seems normal, everyone would like a single answer that will cover everything. Not going to happen with tree work. The best you will get is what will work most of the time with the type of trees 'you' do and 'your' climbing style. When someone asks for an opinion on what I would do that is the answer they get. It is not a recommendation for everyone or all situations.

The thump the climber in the video experienced was a non issue as far as rides go and totally predictable. He looked prepared and unfussed by it. It was his choice in that situation and we can't know what his motives were for doing it that way. Given his apparent competency, it would only be fair to give him the nod that he had his reasons.

 

[Daniel]

A fat hinge will slow a fell though let’s all agree on that

Aren’t you like a hinge scientist or some shit
Now this ?

“it doesn't matter if it's a log or a top being negatively rigged.. the forces on the tree or the rigging on anything even close to that kind of mass cannot be significantly altered with the hinge....”

There is no "it all depends" in this situation. We're talking about what kind of ride the climber takes after negative rigging a large top or spar. There are several strategies that can be used to his favor. The main topic of this thread, body position after the cut, is one. Evo mentioned the best type of notch, which is a narrow Humboldt according to the consensus of west coast climbers. Stretch in the lowering line is another important factor. And having a ground man that allows the piece to run can be huge.

Using a fat hinge to slow the fall is NEVER EVER going to be an effective strategy. There are no factors to consider in this matter. Here's why:

First, we have to understand what causes the ride... there are several factors to consider. Unless you're in tall skinny trees, the way the piece pushes back on the stem and then loads the rigging isn't going to rattle the stem much. In the vast majority of our east coast backyard trees, the real concern is the violent shake that happens when the piece slams back into the stem. The video in the OP is a perfect example of that. Big top come off and nothing much happens to the ride until the piece slams back into the trunk. Note: There was a local climber that almost died here in Philly a couple decades ago, when the top he took slammed back into a hollow trunk causing the top to come down with him in it. It was the impact that caused the trunk to fail, not the way the rigging was loaded.

No matter how the much hinge you leave, it's only going to slow the top down very early in the fall... There is simply not enough effect to slow the speed at impact down significantly, 180 degrees later. As with many aspects of tree work, this is somewhat counter-intuitive. As many of you know, I have been promoting fat hinges in falling for well over 10 years. I love a fat hinge for holding against side lean in falling cuts. After studying countless videos, they don't appear to effect the speed of ground impact. That's at 90 degrees. By the time you get to 180 degrees there's no possibility of the hinge making a difference of speed at impact. Anyone that wants to argue the point, just show us a video.

The fat hinges I use in falling cuts, can't be tripped when pulling by hand. You need a truck or loader to break my fat hinges. As mentioned, even those hinges don't effect the ground impact speed 90 degrees later. You're not going to want to be pulling on a spar with a truck when a climber is in the tree. And in the rare cases that you might need to do that, you're going to try to minimize the amount of pull needed by using a thin hinge. You don't want to load that pull line up any more than necessary, when there is a man in the tree and all that leverage yanking on the stem and root system. The kind of pull needed to move a fat hinge isn't going to help the climber. Once the piece starts moving, the loaded stem is going to have to rebound.

Another important factor to consider is what happens when the face closes... The longer the hinge holds at that point, the worse it's going to be for the climber. When the face closes, the force from the momentum of the top starts yanking on the stem, and continues yanking until the hinge breaks. The longer it takes to break the hinge, the more the stem gets loaded. If the stem gets loaded by using a fat hinge, when the hinge breaks, the stem is going to rebound violently. This is the reason the narrow Humboldt is the preferred method for taking tops by those whose lives depend on it. With the narrow face, the top doesn't have enough time to build speed and momentum. And when the face closes and the hinge starts transferring force to the stem, the top isn't leaning so far out, so the leaning top has far less leverage because it's still fairly straight, rather than leaning 45 degrees or more. Racing through the hinge helps too. Once the piece starts moving, you keep cutting to reduce the holding ability of the hinge. That's just the opposite of using a fat hinge....

I'm pretty sure Rico knows all this. The forces he deals with when topping those 150-200' west coast conifers are far more complex than almost anything I've ever had to contend with on the east coast. What do you think @rico ?

And it's worth repeating, that the most important factor in reducing the climber's ride on the trees I deal with is going to be the way the top impacts the stem. IMO the reason letting the piece run is the most important variable, has more to do with the fact that letting the piece run results in the piece hitting lower on the trunk, and not so much with the gradual deceleration, though both work together in the climber’s favor.

 

[evo]

I agree with many of your points, and what we westcoasters do.
Your hinge thickness theory is a bit off though. Thicker hinges and wider faces DO play a role on the force and impact. When felling the thicker the hinge and wider the face slows the acceleration forces until the hinge breaks.
Taking a top is no different, yet the thicker the hinge and wider the face the more it pulls the spar forward (and pushes back). It also influences the initial speed of rotational force which influences how the piece lands. When facing wood this matters a little less (other than rotation).

Now tie a rope to it, a savvy groundie with a device that can pull slack (half trunk wrap, GRCS, Hobbs) can take up slack as the top or log rotates on a wide face/thicker hinge. Often this is a split second opportunity but it ‘lays’ the rigged piece into the line with less acceleration and slam back. That initial rotation plays a part in how far the rigged piece swing out and away before the deceleration from the friction occurs. This too can be timed as you mentioned, and a well oiled groundie can time this to land on the ground before the rigged piece slams into the trunk.

Lots of dance steps that don’t always coordinate along with variables.

Point is there are nearly endless factors at play, but a fat hinge DOES slow the rotational force of the rigged top/log but here on the west coast that translates into more whiplash. When we take tops here we start slow and tend to finish fast if we aren’t worried about the weight orientation or hanging the saw.

Acceleration - Wikipedia

en.m.wikipedia.org

 

[Daniel]

Thicker hinges and wider faces DO play a role on the force and impact. When felling the thicker the hinge and wider the face slows the acceleration forces until the hinge breaks.

I gather from your last post that you are saying that though hinge thickness does effect the speed of rotation, you would still never recommend a thick hinge for rigging tops due to other factors.

Then we are in agreement, that the idea of using a thick hinge in negative rigging is nonsense. After that the argument is just academic... Since you're never going to use it, how exactly it effects the falling speed is a non-issue. That's one for the good guys..

Note: my belief that thick hinges do not significantly effect force of imapact is based on close observation of hundreds of falling videos and many attempts to try to preserve the lawn with falling techniques... Your suggestion that fat hinges slowing acceleration until the hinge breaks does not necessarily significantly reduce force at impact... With rare exception, trees pretty much all hit the ground with the same speed. I have stopped a tree on the hinge and left it hovering over the ground, but only on trees with extreme holding strength.

 

[evo]

I gather from your last post that you are saying that though hinge thickness does effect the speed of rotation, you would still never recommend a thick hinge for rigging tops due to other factors.

Then we are in agreement, that the idea of using a thick hinge in negative rigging is nonsense. After that the argument is just academic... Since you're never going to use it, how exactly it effects the falling speed is a non-issue. That's one for the good guys..

Note: my belief that thick hinges do not significantly effect force of imapact is based on close observation of hundreds of falling videos and many attempts to try to preserve the lawn with falling techniques... Your suggestion that fat hinges slowing acceleration until the hinge breaks does not necessarily significantly reduce force at impact... With rare exception, trees pretty much all hit the ground with the same speed. I have stopped a tree on the hinge and left it hovering over the ground, but only on trees with extreme holding strength.

No, there is a time and place for it. See the rest of my post on how this can be adapted into a rigging situation. It’s all relative to the situation. Yes in some cases one can expect more wobble.

 

[evo]

Note: my belief that thick hinges do not significantly effect force of imapact is based on close observation of hundreds of falling videos and many attempts to try to preserve the lawn with falling techniques... Your suggestion that fat hinges slowing acceleration until the hinge breaks does not necessarily significantly reduce force at impact... With rare exception, trees pretty much all hit the ground with the same speed. I have stopped a tree on the hinge and left it hovering over the ground, but only on trees with extreme holding strength

This isn’t correct, ask any feller on ways to avoid breaking a log. Someone with experience in felling for power poles would yield the most experienced answers. That and someone who logs redwoods.
Often when cutting sawlogs from a spar in a redwood, the goal is to get them to land nearly end on, they frequently shatter if landed flat.
Hence the blocked out face (maximizing hinge) and a Humboldt snipe, gently sliding the butt off the stump.

But this isn’t the subject on this thread. We aren’t talking lawn damage, but rigging and spar wobble.

 

[Daniel]

This isn’t correct, ask any feller on ways to avoid breaking a log. Someone with experience in felling for power poles would yield the most experienced answers. That and someone who logs redwoods.
Often when cutting sawlogs from a spar in a redwood, the goal is to get them to land nearly end on, they frequently shatter if landed flat.
Hence the blocked out face (maximizing hinge) and a Humboldt snipe, gently sliding the butt off the stump.

But this isn’t the subject on this thread. We aren’t talking lawn damage, but rigging and spar wobble.

ya.. but you don't get the last word here... Using the humboldt to reduce log breakage isn't about the hinge holding longer to slow the fall down. It's about getting the but to slide off the stump and hit the ground first, well before the tips hit. This disipates the energy at impact in a way that preserves the log. The loggers are looking for early separation, not hinges that slow the fall.

And I finally came up with the explanation for why fat hinges don't slow the fall down, so I appreciate this mental jousting becasue it stimulates my thinking process.

Here it is... ALL TREES no matter how they are cut start the fall very slowly. No matter how you cut the hinge, the tree is going to have get a good ways into the fall before it picks up any appreciable speed. By the time the it gets far enough into the fall to start picking up speed, the hinge (fat or thin) has very little resstance to slow the fall. Even if a fat hinge is better at holding against side lean, the amount of control needed once a tree is already moving in the right direction and picking up speed is negligable. That extra hold against side lean isn't going to slow the forward motion.

An experiment can be set up very easily to check and put this puppy to bed once and for all. Just take two very similar trees in height and width, on flat open ground: cut one with a fat hinge and the other with a skinny hinge and same notch, and video tape the fall to check for time. Measure the time from when the tree is half way through the fall to until it hits the ground.

 

[evo]

ya.. but you don't get the last word here... Using the humboldt to reduce log breakage isn't about the hinge holding longer to slow the fall down. It's about getting the but to slide off the stump and hit the ground first, well before the tips hit. This disipates the energy at impact in a way that preserves the log. The loggers are looking for early separation, not hinges that slow the fall.

And I finally came up with the explanation for why fat hinges don't slow the fall down, so I appreciate this mental jousting becasue it stimulates my thinking process.

Here it is... ALL TREES no matter how they are cut start the fall very slowly. No matter how you cut the hinge, the tree is going to have get a good ways into the fall before it picks up any appreciable speed. By the time the it gets far enough into the fall to start picking up speed, the hinge (fat or thin) has very little resstance to slow the fall. Even if a fat hinge is better at holding against side lean, the amount of control needed once a tree is already moving in the right direction and picking up speed is negligable. That extra hold against side lean isn't going to slow the forward motion.

An experiment can be set up very easily to check and put this puppy to bed once and for all. Just take two very similar trees in height and width, on flat open ground: cut one with a fat hinge and the other with a skinny hinge and same notch, and video tape the fall to check for time. Measure the time from when the tree is half way through the fall to until it hits the ground.

Maybe get a treefund grant and set up that experiment. Wait… do it on your own dime.
Nothing to argue about with the blocked out face?

 

[chiselbit]

This one went pretty slowhttps://www.youtube.com/watch?v=-eZ66dJDbSU&pp=ygUkQ2Fyc3RlbiB0cmVlIHNlcnZpY2Ugc3F1YXJlIHVuZGVyY3V0

 

[chiselbit]

 

[Treetopflyer]

There is no "it all depends" in this situation. We're talking about what kind of ride the climber takes after negative rigging a large top or spar. There are several strategies that can be used to his favor. The main topic of this thread, body position after the cut, is one. Evo mentioned the best type of notch, which is a narrow Humboldt according to the consensus of west coast climbers. Stretch in the lowering line is another important factor. And having a ground man that allows the piece to run can be huge.

Using a fat hinge to slow the fall is NEVER EVER going to be an effective strategy. There are no factors to consider in this matter. Here's why:

First, we have to understand what causes the ride... there are several factors to consider. Unless you're in tall skinny trees, the way the piece pushes back on the stem and then loads the rigging isn't going to rattle the stem much. In the vast majority of our east coast backyard trees, the real concern is the violent shake that happens when the piece slams back into the stem. The video in the OP is a perfect example of that. Big top come off and nothing much happens to the ride until the piece slams back into the trunk. Note: There was a local climber that almost died here in Philly a couple decades ago, when the top he took slammed back into a hollow trunk causing the top to come down with him in it. It was the impact that caused the trunk to fail, not the way the rigging was loaded.

No matter how the much hinge you leave, it's only going to slow the top down very early in the fall... There is simply not enough effect to slow the speed at impact down significantly, 180 degrees later. As with many aspects of tree work, this is somewhat counter-intuitive. As many of you know, I have been promoting fat hinges in falling for well over 10 years. I love a fat hinge for holding against side lean in falling cuts. After studying countless videos, they don't appear to effect the speed of ground impact. That's at 90 degrees. By the time you get to 180 degrees there's no possibility of the hinge making a difference of speed at impact. Anyone that wants to argue the point, just show us a video.

The fat hinges I use in falling cuts, can't be tripped when pulling by hand. You need a truck or loader to break my fat hinges. As mentioned, even those hinges don't effect the ground impact speed 90 degrees later. You're not going to want to be pulling on a spar with a truck when a climber is in the tree. And in the rare cases that you might need to do that, you're going to try to minimize the amount of pull needed by using a thin hinge. You don't want to load that pull line up any more than necessary, when there is a man in the tree and all that leverage yanking on the stem and root system. The kind of pull needed to move a fat hinge isn't going to help the climber. Once the piece starts moving, the loaded stem is going to have to rebound.

Another important factor to consider is what happens when the face closes... The longer the hinge holds at that point, the worse it's going to be for the climber. When the face closes, the force from the momentum of the top starts yanking on the stem, and continues yanking until the hinge breaks. The longer it takes to break the hinge, the more the stem gets loaded. If the stem gets loaded by using a fat hinge, when the hinge breaks, the stem is going to rebound violently. This is the reason the narrow Humboldt is the preferred method for taking tops by those whose lives depend on it. With the narrow face, the top doesn't have enough time to build speed and momentum. And when the face closes and the hinge starts transferring force to the stem, the top isn't leaning so far out, so the leaning top has far less leverage because it's still fairly straight, rather than leaning 45 degrees or more. Racing through the hinge helps too. Once the piece starts moving, you keep cutting to reduce the holding ability of the hinge. That's just the opposite of using a fat hinge....

I'm pretty sure Rico knows all this. The forces he deals with when topping those 150-200' west coast conifers are far more complex than almost anything I've ever had to contend with on the east coast. What do you think @rico ?

And it's worth repeating, that the most important factor in reducing the climber's ride on the trees I deal with is going to be the way the top impacts the stem. IMO the reason letting the piece run is the most important variable, has more to do with the fact that letting the piece run results in the piece hitting lower on the trunk, and not so much with the gradual deceleration, though both work together in the climber’s favor.

Lots to read in this post …. I’ve been using various forms of all sorts of cuts for various situations I’ve encountered in my life. I highly doubt anything I would say in regards would bring value to this thread to you..
I will however look for a video of me getting my ass beaten on a tree taking a log off

 

[Keeth]

Thank you all, for your replies. The truth is you need to PLAN the reactive forces for a given scenario. The worker in my OP is very skilled, as well as the groundie. I bet this is the exception, not the norm. Hinge opening, thickness, and back-cut are all part of the planning process. The key is communication and skill!

 

[rico]

If your groundie doesn’t let it run you are gonna take a beating, and your choice of undercut and hinge thickness are a gonna do very little to change that.

 

[Daniel]

Thank you all, for your replies. The truth is you need to PLAN the reactive forces for a given scenario. The worker in my OP is very skilled, as well as the groundie. I bet this is the exception, not the norm. Hinge opening, thickness, and back-cut are all part of the planning process. The key is communication and skill!

I thought that was well played... for that size piece and length/diamter of stem therre was ver little ride

 

[Treetopflyer]

I like when they let it run like this if possible!
All we had to do here was avoid hitting the newer asphalt driveway just out of picture home owner took this and I’m looking for one my cousin took too many wraps on a double whipped log truly negative rigged log I’m sure he didn’t even attempt to let run..
This isn’t really that as we had high anchor point on the right high side that redirected down the stem I’m working no double whip either
View attachment 16620534_822959494508447_3458777604880859136_n (1).mov

 

[Treetopflyer]

2015 contract climber days
This wasn’t the worst , I’ve ever had as I didn’t take a very large piece, but here is what I’ll call snubbed off oak log. I’m not sure who’s making all that noise grunting and yellin lol all I say is coffee break
the rope man clearly having a conversation not giving a fuck right before the action and this show he doesn’t even have a clue wtf goin on shoulda left a thicker hinge lol hit me with your best shot
View attachment 16462000_213966975734809_6643792838968475648_n.mov

 

[Daniel]

2015 contract climber days
This wasn’t the worst , I’ve ever had as I didn’t take a very large piece, but here is what I’ll call snubbed off oak log. I’m not sure who’s making all that noise grunting and yellin lol all I say is coffee break
the rope man clearly having a conversation not giving a fuck right before the action and this show he doesn’t even have a clue wtf goin on shoulda left a thicker hinge lol hit me with your best shot
View attachment 92960

how many wraps?.. that seems to be the issue... you can see that when he let slack in the line, it just sagged.. rope man may suck, but climber has to call the wraps.. And to me, that's not a bad ride... I always like to see how many wraps he takes off when he gets to the tree, but the video ended short before it showed that...

 

[Mick Dempsey]

Yeah, not a bad ride.
Difficult for the climber to always call the wraps, I have never used the bollard, it’s always been me up the tree!

The temptation for the groundy is to always over-wrap, as the consequences of the climber getting a shake are less than an expensive asset getting crushed underneath.

If we’re talking about very large pieces then it is a different story.

’letting stuff run’ is an imprecise science, lot of guesswork.

 

[Treetopflyer]

how many wraps?.. that seems to be the issue... you can see that when he let slack in the line, it just sagged.. rope man may suck, but climber has to call the wraps.. And to me, that's not a bad ride... I always like to see how many wraps he takes off when he gets to the tree, but the video ended short before it showed that...

One too many in that one