Double-Block Rigging a Hanging Pine
Tree workers all along the Eastern Seaboard for years to come will remember the October 2019 nor’easter. Dubbed a “bomb cyclone,” it set records as the strongest October storm ever in the Boston area, and plunged hundreds of thousands of people into the dark, toppling trees and wreaking havoc across New England. This storm hadn’t even finished churning its way up the states before the phones started ringing with calls of trees down on houses, across driveways and hung up in other trees.
Contrary to what most people think, professional tree workers do not always look forward to storm work (at least the ones I know). We know that storm work brings some of the most hazardous conditions to work in due to the wreckage that is left behind and what is involved in the clean-up process.
I received a phone call from one of our long-time customers who lives near us in the Lakes Region of New Hampshire. His chalet-style house sits at the base of Gunstock Mountain, a heavily wooded ski resort area that regularly sees high winds, even when you don’t have a nor’easter pounding the slopes overhead.
A codominant eastern white pine, Pinus strobus, 26-inch DBH (diameter at breast height), had partially sheared off about 25 feet up the stem and had lodged itself in an adjacent red oak, Quercus rubra, and a sugar maple, Acer saccharum, (Photo 1). It was still precariously attached – at about a 45-degree angle – without a lot of fibrous, structural strength holding it. My first thought was, “Boy, I don’t want to have to climb and rig this tree out from itself.” There were power, cable and telephone lines running perpendicular and parallel to the tree, so there was no way to just fell it into the woods, and I knew from past experience that the utility services in this area were not going to give us a line drop to do the work.
So we started looking around to see if we could get a crane into the site. The problem was, the tree was located down a very steep, wooded slope with numerous, large, second-growth white pines surrounding it and the only access in was from a side road, which was not really wide enough for a crane to pass through. Also, the distance from the tree to where a crane would have to set up would have necessitated getting such a large crane that it just wouldn’t have been practical.
I decided our best course of action was going to be to mitigate the hazards as much as possible and come up with a viable work/rigging plan to safely get the hung-up portion of the tree down. I didn’t want to just hope the tree could be climbed safely, because hope alone is always a very poor tree-risk-abatement tool. So I began by doing a full evaluation of the tree using TCIA’s Best Practices for Rigging in Arboriculture manual. Then, after walking around the site completely and getting a good idea about the site conditions such as targets and hazards, I went back to the shop to start taking inventory of our climbing and rigging gear and coming up with a viable job plan/work order.
The job was scheduled for the following week, and the weather promised to be fair and sunny. My crew was assembled and my plan was sound and reliable (or so I hoped). On highly technical jobs like this, I don’t always get a good night’s sleep the night before “the action.” This is not because I am nervous about having a catastrophic accident, but more about wondering if I have left out a crucial piece of gear or a part of the job plan that will affect us being able to do the work safely. I usually end up taking the tree down at least a dozen times in my head before, and as, I fall asleep, going over each step of the work plan. At least by doing this, I know I have thought through everything to be as prepared as possible for what we may encounter.
The next day arrived with beautiful fall weather as forecast, and everyone had their “game face” on for the work ahead. We arrived on site and began by laying out two blue polyester tarps and organizing all the planned rigging gear (Photo 2). Knowing this was going to be one of our more rigging-intensive jobs, we brought nearly every piece of gear we owned, plus some new stuff we knew was going to be required. Then I held a job safety meeting to go over the JSA (job safety analysis) plan and what was expected of everyone. I can’t begin to stress how important a JSA is on jobs like this, as everyone has to know what each other person’s responsibility is going to be before, during and after each step of the job. After that, we were ready to begin work.
My first step was to climb up to the split, codominant pine (co-dom) and secure the fractured area with my trusty 2-inch, heavy-duty, ratchet tie-down straps with double J hooks and a 10,000-pound breaking strength. Unfortunately, I didn’t like the looks of any of the trees adjacent to the damaged one, so I wasn’t able to set a backup line into any of them. I also was apprehensive about climbing up directly underneath the hanging section, knowing it could rip out, so I climbed off the back section of the tree, gingerly flipping my steel-core lanyard up every few steps and watching and listening to the “feel” of the tree. I also had one of my ground workers watching for any movement in the hung-up section, ready to notify me if something moved.
When I reached the co-dom split, I quickly threw my climb line (which consisted of my Zag-Wrench and 11mm Yale Kernmaster line) above the critical section and then did the same with my lanyard and ascended to slightly above it, where I then had a comfortable work position. Just being above that split felt a whole lot better! I secured three load-binder straps, again watching for any movement in the stems (Photo 3).
I then began to climb higher to a spot where I installed the first DWT (double-whip tackle). Using a medium and a large Hobbs block (still the industry gold standard for arborist blocks, in my opinion) along with a 5/8-inch Samson double-braid rigging line (Photo 4), I ran the line down to an X-Rigging Ring redirect at the base of the tree and over to our first lowering device, which was our GRCS (Good Rigging Control System). The reason for the redirects at the base of the tree was that I did not want to have any of my ground workers have to be in close proximity to the base of the tree, knowing there was a whale-sized piece of wood hanging above their heads.
At this point, my objective was to secure and stabilize the tree to a point where it was safe enough that we could then begin the real work, which was to rig out the hanging co-dom. Moving up approximately another 20 feet, I installed the second DWT to the stems, using another large Hobbs block and a mammoth DMM Impact Block. Using a ¾-inch Samson double-braid rigging line, I again ran this down to a redirect at the base of the tree, and the ground crew ran it over to our second lowering device, which was my modified Hobbs H2 lowering device (Photo 5). We proceeded to tighten up both DWT systems, watching the tree carefully. My goal was not to lift the tree out of the other trees, as I knew the weight and strain would snap the pine we were using as our gin pole, but again to secure and stabilize the tree as needed.
As we were tightening, I noticed the stem of our gin pole start to flex and move, so I immediately had the crew ease off on the tension. I decided right there to install a back guy at the second DWT to reinforce the point where the strain from the bending moment was at its greatest. Calling up for a ½-inch double-braid rigging line, I secured it to the stem and ran it to the base of a large pine directly behind the tree I was working in. The ground crew tightened the line using a Maasdam ¾-ton rope puller. Once again taking up on the DWTs, I saw we now were keeping the gin pole steady.
One thing I would like to mention is, when using many different pieces of rigging gear and lines on a tree job such as this one, be sure your pieces of equipment are compatible with each other. Many years ago, in a wonderful TCIA (NAA at the time) publication called Rigging for Removal, my friend and mentor Don Blair wrote about “the ABCs of rigging” and a systems approach to designing your work plan. In it, he describes how a systems approach to rigging means thinking of every component as part of an overall system. Blair further states that your rigging system, just like a chain, is only as good as its weakest link. I highly recommend this book to anyone who would like to learn more about designing rigging systems.
The last thing I needed to fully stabilize the tree was to install two side-
tension lines on the hung-up stem at the upper DWT. I had visions of removing the last contact point from the pine in the adjacent trees and having the stem take a violent swing either left or right, taking out power lines, the side of the house or, worst-case scenario, my ground crew! To prevent this, I secured two ½-inch, double-braid rigging lines and had the ground workers use two Port-A-Wraps set up on adjacent side trees (Photo 6). They tensioned the side guy lines using a Sterling Pocket Hauler kit. This mini fiddle-block setup is a mechanical-advantage system that allows workers to increase their pulling strength to 5:1, and it really is great when extra power is needed.
At this point, we finally were ready to begin the actual removal portion of the job. So far, everything was going smoothly and according to plan. There wasn’t any rushing around, for as the mantra in SAR (search and rescue) goes, “You have to go slow in order to go fast.” I descended out of the pine and prepared to climb the maple to set up rigging and begin cutting. I ascended the maple using another climbing system, which consisted of the Petzl Zigzag and Chicane combo along with an 11.7-mm Yale Blue Moon climbing line. I really like this setup, as it allows me to quickly move from an SRT/SRS (single-rope technique/system) climbing system to a DdRT/MRS (doubled-rope technique/multi-rope system) as needed.
When I reached the top of the tree, I immediately realized I had an unforeseen problem ahead of me. My initial work plan called for me to stay tied into the maple that the pine was lodged in and safely work out of it. But upon further inspection, I saw that the pine shot up and out another 20 to 25 feet beyond the top of the maple. This had not been discernible from the ground, and it meant that initially I was going to have to be tied into the suspended pine stem (Photo 7), at least until I was able to rig it down to the contact points, at which time I would be able to transfer safely back into the friendly arms of the maple.
Realizing I did not have any other options, I transferred to the pine stem. Before doing that, though, I set an ISC Rigging Block and ½-inch lowering line in the maple to use as a redirect down to the base of the tree, where we had our fifth and final lowering device set up, which in this case was a large Port-A-Wrap. We would be negative rigging everything down until we were clear of the power lines and maple tree, at which point we could slowly lower the stem down using the GRCS and H2 off of the DWTs.
Back on the pine stem, I looked around at the “attitude of the work” to decide what I was going to need for rigging gear. I first heard the term “attitude of the work” from another one of my mentors, Jerry Beranek, back in 1996 in his classic book, The Fundamentals of General Tree Work. This is “The Book” on tree work and is a must read for both beginner and experienced climbers alike. The work attitude refers to the angle at which the piece of wood being removed is orientated (vertical, horizontal or leaning). From this, you can decide what gear and technique you will need to make the wood behave the way you want in order to safely accomplish the work.
In the case of the pine stem I was working on, I needed to use the fishing-pole technique, loading the stem into compression to get it down to the contact points in the maple. This was accomplished using a couple of my original X-Ring slings, which I received from the X Man himself, David Driver, years ago to test out. Since the first time I used them, they have been my go-to gear for redirects. These slings really have opened up a lot of rigging options for our industry, and we owe David a debt of gratitude for introducing them to us.
The top of the pine was stuck fast up in the maple, and I knew that pieces of wood and brush were going to get hung up as well as we lowered them. So we used a tag line on each piece to yard them through the maple after I cut them. Removing the top and brush down to the remaining contact points was straightforward and went as planned, without any movement on the pine stem. When I had the tree brushed out down to the last three contact points, I transferred back into the maple to cut the rest of the branch stubs holding the approximately 5,000-pound pine stem. As I cut the first two points – which popped like Fourth of July fireworks – I noticed the stem shudder a little bit each time and knew we were still supporting a lot of weight in the rigging lines.
I had the ground crew tighten up one last time on the DWTs and then proceeded to “trip” the last contact point. The instant I put the chain saw into the underside of the pine stub, it popped with another bang, and I watched as the pine dropped down further into the rigging about a foot or so and then settled completely. Breathing a sigh of relief, I realized we now had the broken pine stem completely in control and supported 100% by our rigging. We still had a few more pieces to rig down, but soon we had the tree down to our highest DWT, and I could descend out of the maple and help the ground crew lower the remaining portion of the stem to the ground (Photo 8).
I went up one more time into the pine and removed the load-binder straps, as they were going to get in the way of us being able to lower out the pine stem. Then, with each one of the crew on the four separate lowering devices, I guided them as we gently eased off the rigging lines and lowered the piece smoothly to the ground, watching it tear out as we were lowering but still in complete control. By this time it was 3 p.m., and we had just enough time to buck up the stem on the ground, clean up the rigging and call it a day. We would be back another day to remove our gin-pole tree, which, though still compromised from the co-dom tearout, I did not consider an immediate concern.
All in all, the job went smoothly and according to the JSA, with minor changes as the job progressed. My ground crew, as usual, did an incredible job and made my day a whole lot easier. I really enjoy jobs like this because I look at them as a chance to expand my knowledge. I try to remember that if I find I have a lack of knowledge in a particular area, it is not a hindrance, it’s an opportunity to learn more, and I try to use that opportunity to become a safer and more efficient arborist. So, for now, we’ll just have to wait and see what Mother Nature next throws our way – and, if I know New England weather, we probably won’t have to wait long!