I had a bad one tuesday, I mean I lost a poplar and stripped all the side of a nice horse chestnut.
It was pretty big, for me, around 32" and, overall, a hard sideleaner, like the stump was almost at the drip line of the crown (not a lombardi poplar but a full spread one). Where it was, the best way was to fell it. I knew it would be very heavy, and I can't see how the hinge could hold that during the fall. So, I put nearly halfway up a 5/8 guy line with a redirect on a stump and a comealong + 2:1 MA on an other stump. I preloaded the bullrope at about 3500 lbs, maxing out the comealong. Not enough to compensate the unbalance, but I trusted the rope to catch the weight (16000lbs breaking strength). HO said that the tree started to lift back. Good.
90° to the guy line and toward the intended lay, I put an other bull rope and the Maasdam on a 2/1 MA, as there was some back lean too and a serious back weight from a major limb. I loaded it and went cutting.
Nice notch, deep to get a full wide hinge. I started the backcut, set a bunch of wedges to help the Maasdam. I keep cutting, slowly to keep an eye to an eventual pinching. OK so far. I left a fat hinge, 8" on the high side and 4" on the low side. Murphy would be proud of me ! But it's really really hard to bend such an hinge. I putt all my energy to bang on the wedges. Tough in the heat.
A vertical split appeared in the stump behind the hinge. A lot of tension there. Eventually, the back weight/lean has been taken care off and the tree started to move seriously. Nice.
The trajectory started as intended, but then, I heard the hinge breaking and saw in disbelief the tree changing its path and go sprawling on the horse chestnut, all the way from the top to the ground. What a mess !
It seemed that my bullrope wasn't even there. It didn't broke but was stretched like a rubber band. I can't believe it. Same with the sling of the redirect, made with 1" tenex tec. I 'd like to know the final tensile, it was like a violin chord.
I made two mistakes (at least). One, I grossly underestimated the load and the stretch of the bull rope. I was way too light on my rigging. Two, I didn't took in account a clue given by the trunk : the wedge on the low side became crushed harder and harder to the point it wouldn't move at all while the one on the high side started to go in more easily (5 wedges total). Afterward, it was clear that my bull rope didn't do its job and the tree was held mainly by the hinge. When this one started to let go, the rope just followed the move under the increasing load.
Rooky time.