Physics is Used to Take Down a Tree

Today we took down the second big oak of the week.  This one was larger than yesterday's and caused us a little trouble.  One of the principle difficulties felling large oaks in a forest is getting them to fall where you want.  Any logger can tell you the general technique for felling a tree: You cut a notch on the side of the tree towards where you want it to fall.  Then you back cut the tree, sometimes driving a wedge behind your saw blade on a large tree to help tip it in the right direction.  Ideally the tree falls towards the notched side.  This works nicely on straight vertical pine trees where the center of mass of the tree is located directly above the center of the diameter of the tree.  On forest oaks this is almost never the case.  The center of mass may be as much as a meter or more away from the center of the base.  No mere notch is going to help make that tree fall anywhere except towards its center of mass.   We have had to put physics to work in order to reliably fell an oak where we want.  Our technique is to provide a force in the direction we want the tree to fall in order to compensate for the off balance force of gravity due to the lean of the tree.  For most trees the force needed is not too difficult to achieve.  We tie a rope around the tree as high as we can, typically 20 to 25 feet (6 - 7.5 m) up is adequate.  We then set up a come-along on the rope attached to any convenient anchor point, usually another tree trunk.  We cut the usual notch in the tree in the direction of the rope and we tighten up the come-along.  It doesn't take as much force as you might think.  For example, a 3000 lb. tree leaning at 5 degrees is only producing a torque of 261 lbs x the vertical distance to the center of mass of the tree.  So if we attach our rope anywhere near the center of mass of the tree we only have to pull with about that much force to pull it over.  Of course this is more than you could pull by hand but the come-along can pull with many times this force limited more by the strength of the rope employed than the come-along.  In the case of today's tree this technique was essential.  The tree looked fairly vertical but when we started to back cut it the tree started to lean in the wrong direction.  We actually had to increase the initial force we had with the come-along to get it to fall in the right direction but physics worked again and the tree fell right where we wanted.  Archimedes would have approved.

The tree of the day with the rigging rope attached.

The trunk of the tree was fairly vertical
but the branches were concentrated on one side .

For this big tree we had to put the 20 inch blade on our Stihl chainsaw.

A close up of the rigging in the tree.

The come-along being set up to pull on the tree.

The notch cut is made. 

With a bit of a pull the tree comes down where we wanted it to.

The behemoth on the ground.

This trunk will make excellent timber.

We got four sections of trunk from this tree which pretty much filled our new log crib.

Spring Comes Early - Work Resumes

The sun is shining, the air is warm, breathe deep that 293 ppm carbon dioxide.  Sometimes ya gotta love this whole climate change thing.  I wasn't expecting to get too much done this early in the season but I can't ignore fine weather like this.  We have a lot of digging to do but first we have got to get a couple of big trees out of the way.

Nick is standing in front of the two trees we plan to take down this week.
They are fairly large and we plan to save the trunks for future lumber.

Cutting the first tree.

It falls neatly into our level dig site.
This type of oak does not grow very straight but the wood has a beautiful dark color.

This was a fairly good size tree so the logs are going to be rather heavy.

We got three 13 ft lengths of wood out of this tree.
This is the last, and heaviest, section.

The three logs loaded onto our new wood crib for long term storage.
We still have to seal the ends.

Storing Tree Trunks (part 2)

I built this wood crib to hold some of the larger trunks we anticipate taking down once the spring build season gets into full swing.  Behind the crib you can see one of the many stacks of firewood we have been accumulating up until now.

Can you hear me now?

When we are on our land in West Virginia we are very cut off from the rest of the world.  There is no nearby cell phone tower so coverage is spotty at best.  Also, since there are no utility poles running to our land there is no electricity, no land line telephone, and definitely no internet.  It's even hard to get the news.  The local gas station only carries the local county paper which is a weekly publication containing little information beyond the latest high school sports schedule.  I am pretty sure that if WWIII started while I was out here the first I would know about it would be the green glow of the radioactive fallout.  Some day we will bring a bit of the 21st century to our spot of wilderness.  We are talking to the power company about getting poles put in but it is a complicated process involving getting permission from other land owners to have power lines traverse their land as well as a significant amount of money.  In the meantime we are trying to work with what we have.  There is a cell phone tower about 30 miles away beyond a couple of mountain ridges.  A wee little bit of electromagnetic energy from that tower will diffract its way to our location but it is too weak to be detected by a regular cell phone.  We are trying to utilize this weak signal by boosting it with an auxiliary RF amplifier and an external antenna.  We put the antenna on a pole on top of our trailer and hooked everything up.  The result was mixed.  On some days we can get a clear signal and once again talk to the rest of the world.  On other days we get nothing.  I think the antenna needs to be higher up.

We used a couple of 10 ft sections of PVC plumbing pipe to make our pole.   We erected the pole on top of our trailer.  The trailer height of about 10 ft plus the pole gives the antenna height about 30 ft.  Unfortunately it is not enough for a consistently good signal.

A close up of the antenna atop our pole.

Broken Oak

I was hiking up the hill to an area of our land where I hadn't been for a while when I came upon a large oak tree that had recently fallen over.  I don't know exactly when it happened.  It could have been during the heavy wet snow we had back in October or it could have happened more recently during one of the windy winter rain storms.  In any case it must have been at a time when no one was around, otherwise we surely would have heard it.  It was a large but weak tree - the base was rotted hollow from insects and fungi.  We have a number of such damaged trees on our land.  Our long term plans for managing the forest is to remove the worst of the infested trees and try to halt the decay of the others.

There wasn't much of a base to the tree and what there was split in a spectacular way.

As can be seen, it did not fall all the way to the ground but rather hung itself up in a neighboring tree.
I don't know how I will safely clean this up.  However, since it is not near any of the current activities on the land, I will probably leave it be for now.

Storing Tree Trunks

Since last summer we have been cutting down trees on our land to make a clearing for our building project.  The fact that we are not done with this process this many months later is a good indication of the extent to which we underestimated the magnitude of this task.  Perhaps all this exposure to fresh country air has made us a little crazier than we were when we started, but we recently decided that we should make this task even more challenging.  Up until now, when we fell a tree we have been cutting it up into short sections suitable for firewood.  We got a great collection of firewood by now.  It's mostly oak with a little bit of maple and poplar.  Actually at this point we have years of firewood stored up; we really don't need any more.  Also, most of the wood we have been cutting up into firewood has been really nice timber, worthy of fine wood working.  So we decided that rather than cutting it up into little pieces, we would try to save it in long lengths which we could later mill into planks for woodworking projects.  We don't want to mill the wood immediately since we have as yet nowhere to store milled lumber out of the elements.  Logs can be stored for future milling if you are careful how you handle them.  They have to be kept off the ground and the ends have to be sealed so that they dry more uniformly so as to reduce cracking.  We decided to cut all future good trunks into 11-13 ft sections.  This will be tricky.  Some of our larger trees have trunks  12 to 15 inches in diameter.  Such a log can weigh as much as 900 pounds.  This is near the upper limit of what our equipment can handle.  It is interesting to think that people used to handle such logs before there were diesel engines.

This is a maple log being prepped for storage.  We started with some of the smaller trees to get the hang of it - this one is only about 6-7 inches in diameter.

We cut the ends square and remove a stripe of bark along its length to promote uniform drying.  We put it on some cribbing to keep it off the ground.

A small oak log being prepped for storage.
These smaller logs are relatively easy to handle.   The tractor pulls them easily.

The last step is to paint the ends of the logs with a sealant. 

We sealed the ends of the three oak logs immediately.  We will seal the ends of the maple log in a couple of days once it has stopped dripping sap.

Winter

O, wind, if winter comes,
can spring be far behind?
        Percy Bysshe Shelley




Of winter's lifeless world each tree
Now seems a perfect part;
Yet each one holds summer's secret
Deep down in its heart.
        Charles G. Slater




I prefer winter and fall, when you feel the bone structure of the landscape.  Something waits beneath it; the whole story doesn't show.
        Andrew Wyeth




Now is the winter of our discontent.
        William Shakespeare

Some of our equipment at the partially excavated build site during a snowstorm.

It's either cold and frozen or thawed and muddy this time of year.
Either way, progress is made at a reduced rate.

We call this road the "West Boulevard".
Completed this Autumn, it is now the main access to our build site.