Cutting down a black locust tree in our back yard that was dying / dead
We had a black locust tree that a couple years ago was late to have leaves, and then as the years went by only had leaves in one area of the tree. A couple years go my good friend Nick and I did some work removing some of the branches, and it was a bit terrifying how heavy they were. The tree appeared to show some new life after that, but the new life unfortunately just looks like the branches that sprout from a dead tree. We made another attempt at removing it, this time got it down! Full disclosure, there was a not of terror and caution using this kind of equipment (full, diesel powered lift; chainsaws, winches, etc.)
This picture completely fails to capture how thoroughly coated in sawdust we were. We're wearing safety harnesses, which got surprisingly heavy as the day wore on. I think they are only 5-10 lbs. so I can't imagine how people would wear 30-50 pounds of armor in medieval and ancient combat. Or how modern soldiers pack a third of the body weight on a day's march!
The tree before starting any work. The right branch is completely bare
Scratch work estimating the size of the tree - I used a tape measure to get 50 feet from the base of the tree, then used the CamSextant app to measure the angle to the top of the tree (~44 degrees). I was slightly up hill from the bottom of the tree, so I measured the angle to the base of the tree (~6 degrees). I then did some geometry to determine the tree was ~53.2 feet tall. I should have measured it before cutting it! Science FAIL. But this led me to rent a lift with a height of 66 feet, which when I went up to the maximum height, I was looking down at the top of the tree below me, so that worked.
The lift we used - it was massive, a tank. I was terrified when they delivered it. It weighs 25,341 pounds, exerting a pressure of 85 psi on the ground. The tires, although they are rubber, are so strong that when combined with that weight they dug into the asphalt and left their imprint in it.
Here is very quick video looking at the lift:
Here is a time-lapse video of some of the work:
Using the lift we removed everything down to the fork. We then decided to look into dropping the rest of the tree with a cut at the base. At that point the height of tree was ~26 feet, and the distance to the house was more than that. We tied ropes around fork, and attached them to a come-along winch whose other end was attached to a rope attached to the base of another tree, and then tightened the winch - this was intended to guide the fall direction of the tree.
Nick did almost all of the cutting, at that point I was exhausted and for whatever reason when I used the saw it tended to overheat. After making the hinge cut, he made the back cut, and I manned the winch to keep tightening it if the tree started to lean forward. Eventually Nick was most of the way through the tree and kept looking at me expectantly, I gave him the thumbs up to keep going.
When the tree actually fell, it was somehow both slower and faster than I'd expect. I noticed the tension go out of the rope and winch and started waving frantically at Nick to get away from the tree. Of course then as it tipped out of its vertical position it started accelerating rapidly! It ended up putting a nice dent in the asphalt driveway, and bouncing a foot to the side.
One thing that always amazes me is how little it takes to hold up the tree. Here is a picture of the stump afterwards - notice the jagged section next to the tape measure. That is the part that broke when tree well - it is about 4 inches by 1/2 inch.
Before Nick cut it down to that size, the tree was unmoving, was still stable. I've seen similar things before cutting down approximately the same size trees. It gives a sense of how strong the wood is to hold that massive weight in place with so little material.
Moonrise over the stump
The next day I cut the tree into smaller sections to move it, and discovered the rot in the center. We noticed tons of ants on the tree especially when we made new cuts - they had apparently thoroughly colonized it. Sorry ants for damaging your home, I hope you can still live in it now that it is horizontal.
View of the downed tree now cut into 3 pieces (2 quarters, left, 1 half, right). The sawdust circle in the middle is sawdust filling in the hole the tree made when it fell. Sawdust circles above that are holes the lift made just by resting on the ground!
I was unable to cut through the other half of the downed tree, despite numerous sharpenings of the chainsaw, and I could only do some limited rolling by myself. In desperation I nudged it with the lift, and the lift moved it like it was nothing! So I was able to slowly push it to the back of the driveway.
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