sgbotsford
ArboristSite Member
I have a bunch of tall poplar that are nearing end of life, and are leaning the wrong way to fell normally without putting house, barn, or shed at risk.
Check my calculations:
A 2 foot diameter poplar with have a stump area about 3 square feet. 80 feet tall. Let's assume that the branches make up for the trunk taper and for weight purposes it is a cylinder. 240 cubic feet.
Wet poplar at 40 lbs/cuft gives me a mass of 9600 pounds -- about 5 tons
If it leans 15 degrees, (over estimate) then there is about 25% of that load is in the horizontal direction. 2400 lbs.
I have 150' 3/4" nylon solid braid) rope with a rated breaking strength of 20,000 pounds in new condition, with an eye splice on either end.
My thought is put a messenger line into the crown, draw the rope up and over, bring the eye down, and pass thorugh. Attach the other end to my tractor (Deuzt 55 hp -- weighs about 3 tons)
Coefficient of friction on a tractor tire on firm soil is aobut .5 So maximum force tractor can put on rope is about 3000 lbs.
So use the tractor to tension the rope until wheels start to skid, OR it stretches 8% (Estimate of elastic stretch. I have an inquiry with the rope maker for this number)
My plan was to make the wedge cut first, then tension the rope, then make the back cut.
Is this a reasonable approach?
Check my calculations:
A 2 foot diameter poplar with have a stump area about 3 square feet. 80 feet tall. Let's assume that the branches make up for the trunk taper and for weight purposes it is a cylinder. 240 cubic feet.
Wet poplar at 40 lbs/cuft gives me a mass of 9600 pounds -- about 5 tons
If it leans 15 degrees, (over estimate) then there is about 25% of that load is in the horizontal direction. 2400 lbs.
I have 150' 3/4" nylon solid braid) rope with a rated breaking strength of 20,000 pounds in new condition, with an eye splice on either end.
My thought is put a messenger line into the crown, draw the rope up and over, bring the eye down, and pass thorugh. Attach the other end to my tractor (Deuzt 55 hp -- weighs about 3 tons)
Coefficient of friction on a tractor tire on firm soil is aobut .5 So maximum force tractor can put on rope is about 3000 lbs.
So use the tractor to tension the rope until wheels start to skid, OR it stretches 8% (Estimate of elastic stretch. I have an inquiry with the rope maker for this number)
My plan was to make the wedge cut first, then tension the rope, then make the back cut.
Is this a reasonable approach?