July 1, 2023

Choosing the Right Anchor Point

Many of us can vividly remember when we began in this industry. We looked up into trees to watch what that experienced person was doing and likely felt as if there was some bit of magic happening. The ropes, the climbing, the equipment and the drop zones. Oh, the drop zones. I can still see the first job I was on that seemed to have no space to land anything of size, but the climber, utilizing ropes and pulleys, created something that allowed us to bring branches and wood down in a controlled manner. It was awesome!


I had so many questions for that climber, about what we were using, how we were using it and how they knew it would all work. What was consistently communicated, though, was the concept of choosing the right anchor points. My mind has been occupied by this very topic ever since. You see, our industry is unique in many ways, but one thing that stands alone is that we don’t have rated points in the tree like other climbing and rigging disciplines.


Another way to think about it is that we don’t know when things will break. We could do a break test on a tree, but it would be a one and done, as it’s not easily repeatable. We rely heavily on training and experience to know when something will be strong enough to hold the weights we require of it in order to conduct our work. This ability, in my opinion, is awesome, but it takes time and practice to know when the weight is too much.

Looking up at a tree with ropes and pulleys
On my first job, the climber, utilizing ropes and pulleys, created something that allowed us to bring branches and wood down in a controlled manner. It was awesome! What was consistently communicated, though, was the concept of choosing the right anchor points. Photos courtesy of the author.

What do you look for when choosing anchor points?


With that in mind, what are some things you look out for when choosing anchor points, whether it be for climbing or rigging? The reality is, the process should be the same for both climbing and rigging. The only thing that really changes is the weight we are loading into the system. Climbing is pretty much only going to see the climber’s weight, or potentially more than that based on the system the climber deploys.


But with rigging, the goal often is to take the largest piece we can fit into our drop zone. Most of the time that weight is going to be much heavier than, say, the weight of the climber in the tree. So here are a few things I look for when setting up my anchor points in a tree.

Looking down from a roof at workers in red shirts and ropes on a broken tree branch.
We don’t know when things will break. We rely heavily on training and experience to know when something will be strong enough to hold the weights we require of it.


Species


What we are working with is huge when it comes to our decision-making. Sure, we have a green-log weight chart that tells us how heavy a certain species is, but not necessarily where its strength is.


The difference between, say, a pine tree and an oak is quite significant, both in overall growth habit (excurrent vs. decurrent) and also the fact that branches break at different loads. Typically, in a very vague and general sense, an oak is stronger and can usually handle being subjected to heavier loads than a pine.

A broken tree branch with ropes and pulleys near utility wires
Anchor points that are higher in the tree allow for improved rope angles, but caution should be taken to consider the weight of what’s being removed.


What that does for me, as the person working with each species, is help me immediately narrow down my options on how to tie what and when. I also try to get my anchor points as high into the tree as possible. Many folks think a larger-diameter anchor point is “safer,” but that often leads to being anchored lower in the tree and causes flatter rope angles and steeper drops.


With climbing, I tend to access the tree on a branch about two-thirds of the way up the tree, as it’s a bit more stout and easier to hit with a throwline. But after access, I’ll climb up as high as possible to maximize movement potential and mitigate exposure and risk by having gentle rope angles. This, of course, will change and be adapted to each situation, but having this as a standard way of operating saves me time, energy and stress every day.

Aerial view looking down at a metal roof with a tree banch and a worker in a white bucket truck
With rigging, it may make sense to incorporate more friction to reduce the strain on the tree and maximize the strength of its structure.


Growth habit and drop zone


Once we know the species, identifying how the tree is occupying its space is the next important factor. Recognizing how a tree and its branches are growing also gives you information about how said tree and its branches are attached. Why is that so important, you may be wondering? Well, if we have a tree that’s grown tall and straight with no inclusion, it’s likely the root system is stable, the branches are attached well and we can essentially build whatever system we want. Basically – it’s strong.

A dead tree with green metal hardware and orange and green rope.
How a tree grows and fills its space can greatly inform the arborist as to its strength and how to best work with it.


However, if the tree is highly phototropic (leaning) and has included unions, and we can’t just drop everything into the yard, we have to get a bit more creative. This is when I teach that we should make rainbows in trees with our ropes. Essentially, that means designing a system that has a gentle arc from the friction device below, through the blocks/rings/unions, back to the ground. This avoids sharp bends and steep angles, which have the potential to increase the force and/or torque on the tree and its parts. That increased force and/or torque can be a recipe for disaster, so whenever we can reduce that risk, the better off we will be.


Equipment


The great and terrible thing about being an arborist in this day and age is that there are countless options available for either climbing or rigging. Knowing when to deploy a piece of kit takes as much training and experience as it does to learn about the trees themselves. Friction can be our worst enemy or our best friend.


With that in mind, when climbing, consider using friction-reduction tools for your anchor point, as doing so is far easier on the body. With rigging, though, it may make sense to incorporate more friction to reduce the strain on the tree and maximize the strength of its structure.


Just because one has something that is pretty and shiny and has curved edges doesn’t make an arborist competent. It’s imperative to know how to use, or not use, equipment for the task at hand.

Close up of purple pulley and green rope anchored into a tree with a house in the background.
The right anchor point has direct impact on the safe operation, quality of work and overall efficiency of a project.


Selecting a system


The system chosen is the last part in this process for me. If I’m climbing a tall tree, I’ll want to deploy, say, a stationary rope system (SRS) to access the tree and maximize efficiency. How I choose to anchor that rope will depend on the tree itself. But knowing that a basal-anchor system will have a level of force multiplication, as opposed to a canopy anchor that is mainly being loaded with just the weight of the climber, is vital information to think through.


Rigging is much like a basal-anchored climbing system, as we have a friction device at the base that enables us to control the load coming down. So there is a force multiplier that is applied with our rigging that needs to be accounted for with the weight of tree parts we release into the system. I’ll reference rainbows again in that, depending on the load – whether it be climbing or rigging – a sharp angle can cause some serious damage quickly.


We could get heavily into more of a physics discussion here, but we intuitively apply these concepts daily. Many times, the sharper the bend, the harder the hit on the tree. Try new things low and slow, where they will have little to no consequence. That way, when it’s critical, we’ve previously practiced and have more familiarity with how everything works together.

Aerial view of a roof with wood debris and a yellow house. A tree with orange rope is to the right of the roof being lowered.
The right anchor point has direct impact on the safe operation, quality of work and overall efficiency of a project.


Tying it all together


We don’t know what these trees are consistently rated for or when/how they will break. We heavily rely on our experience and training, but also on collaboration with the team we are working with. Anchor points and the selection of them, in my experience, are the make-or-break factors for how a tree project flows. The safe operation, quality of work and overall efficiency of said project depends so much on these anchor points.


Continue to learn, ask questions and pay attention to the trees. Climb high, cut small and go home safe. That’s my motto, and I’m sticking to it!


Jeff Inman Jr., CTSP, is an ISA Certified Arborist, is ISA Tree Risk Assessment Qualified and is an ISA Tree Worker Climber Specialist. He is risk manager with Truetimber Arborists Inc., an accredited, 19-year TCIA member company based in Richmond, Virginia, and Truetimber Academy director.


This article is based on a presentation he made in the TCIA Trainer’s Lab at TCI EXPO ’22 in Charlotte, North Carolina.

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