Free Fall (almost)
04/09/09 09:00 AM
Our small parcel includes many thriving plants and
trees and is home to a wide range of wildlife. In
future posts I plan to display our favorite flora and
fauna, but this update is about a tree that was not
well. This 50' Walnut is a split-trunk tree. The
smaller trunk was storm-damaged some time ago with the
top half broken into a hinge and supported by a
neighboring tree. The larger trunk shows significant
rot and has more dead limbs than live ones. I decided
to remove it for safety and to make room for new
plantings.
First, I climbed the main trunk using 2 loop lines to anchor against falling. At about 35 feet I established a top-rope in a four-way crotch. Using the top rope I self-belayed and removed the limbs on the East face (opposite the intended fall-line) with a bow saw. The two largest limbs provided surprises on the way down and reiterated in my mind why tree work is considered so dangerous; The variables are numerous and the forces are severe. I spent a lot of time just sitting and watching the tree, considering each step, and visualizing where problems might arise. The biggest challenge was working around the lines and safety equipment and keeping the lower lines free from impact as the limbs fell. If I did the job over I would: (1). Leave all the tools on the ground until the cutting position is reached, then haul them up with a line. Repeat for each move. (2). Haul up all lines to the cutting position so no lines dangle below the level of the limb to be dropped. (3). Triple-check for all neighboring limbs (all trees) within reach of the cutting limb and carefully consider how those may affect trajectory. (4). Approach each limb with a 1/5 front-cut before felling with a back-cut for a more predictable break-line
To fell and buck the tree I rented a powerful, Stihl chainsaw from the helpful folks at Art Pancakes' Rent All. The main trunk was worked first and fell within a few degrees of the intended path.
The main trunk's final move was made with wood wedges hammered into the back-cut channel.
The main-tunk notch and back-cut...
The second, spit trunk notched and back-cut to plan but wouldn't fall on account of the supported top, propped and wedged into a neighboring tree (the photo below was taken prior to the cuts but shows the broken, supported top).
After several stressful moments of uncertainty (mostly relating to how the hinged top half of the trunk might react in various scenarios), I borrowed a plan from the worst of the "tree-felling-gone-wrong" videos available on U-Tube http://www.youtube.com/watch?v=8xQ74YQyksY (1:15 for the coup de main). I did however, adjust according to better sense. Using several, webbed tow-straps I cradled and led the trunk in the direction of the intended fall. I secured the lead to the AWD Subaru hitch, triple-checked that the lead was considerably longer than the trunk was tall, and slowly muscled forward. The resistance was surprising considering the tiny amount of wood left on hinge, but within 20 seconds several thousand pounds of water-logged walnut came smashing down (unfortunately, no photos of this action, but the scene was intense and my spotter was, thankfully, focused on the job at hand).
The salvaged rounds from both trunks stacked to season, and a profile-view of both cuts.
First, I climbed the main trunk using 2 loop lines to anchor against falling. At about 35 feet I established a top-rope in a four-way crotch. Using the top rope I self-belayed and removed the limbs on the East face (opposite the intended fall-line) with a bow saw. The two largest limbs provided surprises on the way down and reiterated in my mind why tree work is considered so dangerous; The variables are numerous and the forces are severe. I spent a lot of time just sitting and watching the tree, considering each step, and visualizing where problems might arise. The biggest challenge was working around the lines and safety equipment and keeping the lower lines free from impact as the limbs fell. If I did the job over I would: (1). Leave all the tools on the ground until the cutting position is reached, then haul them up with a line. Repeat for each move. (2). Haul up all lines to the cutting position so no lines dangle below the level of the limb to be dropped. (3). Triple-check for all neighboring limbs (all trees) within reach of the cutting limb and carefully consider how those may affect trajectory. (4). Approach each limb with a 1/5 front-cut before felling with a back-cut for a more predictable break-line
To fell and buck the tree I rented a powerful, Stihl chainsaw from the helpful folks at Art Pancakes' Rent All. The main trunk was worked first and fell within a few degrees of the intended path.
The main trunk's final move was made with wood wedges hammered into the back-cut channel.
The main-tunk notch and back-cut...
The second, spit trunk notched and back-cut to plan but wouldn't fall on account of the supported top, propped and wedged into a neighboring tree (the photo below was taken prior to the cuts but shows the broken, supported top).
After several stressful moments of uncertainty (mostly relating to how the hinged top half of the trunk might react in various scenarios), I borrowed a plan from the worst of the "tree-felling-gone-wrong" videos available on U-Tube http://www.youtube.com/watch?v=8xQ74YQyksY (1:15 for the coup de main). I did however, adjust according to better sense. Using several, webbed tow-straps I cradled and led the trunk in the direction of the intended fall. I secured the lead to the AWD Subaru hitch, triple-checked that the lead was considerably longer than the trunk was tall, and slowly muscled forward. The resistance was surprising considering the tiny amount of wood left on hinge, but within 20 seconds several thousand pounds of water-logged walnut came smashing down (unfortunately, no photos of this action, but the scene was intense and my spotter was, thankfully, focused on the job at hand).
The salvaged rounds from both trunks stacked to season, and a profile-view of both cuts.