Wednesday, January 5, 2011

Know Your 800 Pound Gorilla

We are going to tackle practical limits of lean and weight when you are dropping trees with a short series of posts.  These items are not understood very well by most weekend wood cutters, and even loggers get in trouble with lean and weight if they become complacent.  Reviewing your basic falling plan steps is recommended if you don't know them, and lean and weight evaluation will be added to your skills to improve your falling plans.  The first step in determining lean and weight of the tree you wish to cut is to look at the tree from the spot you want to drop it on.  The red maple in the above photo has a stem that is pretty well vertical, but you can see the crown is heavy on the left side.  As you look at your tree, extend your hands in front of you, and surround the crown with your index fingers and thumbs.  Mentally draw a vertical line down from your fingers and thumbs to the ground.  You will see that this tree is balanced about three feet to the left of the stem.  That is side lean from where you stand, and it is probably a safe amount that you can handle on this tree if you make a good hinge.

Now, look at the tree from a spot that is 90 degrees around the tree from your first spot, and determine if the tree is leaning, or heavy to your right or left.  You have now established quadrants for the tree, and you can safely say which quadrant the tree would fall into if the stem was severed with no hinge, and no wedges to guide it.  You also know now if you will need to use wedges to tip the tree in the direction you want it to fall.  Some will say this takes too much time, but these easy steps make each tree fall where you want it, and they save you from smashing saws, skidders, and other valuable items, such as houses.

In the YouTube video below, you can easily see a wedge cut out on one side of the stem.  Many people think that a tree will magically fall toward this cut, but the opening is actually made to allow a tree to rotate downward on the hinge you should have built right behind it.   There is nothing magical about this cut.  As you watch the video you will see the cutter severs all the wood holding the tree up, and it falls the way the lean and weight are directed.  At least no-one was hurt.

Balanced stems are rather special, and they MUST be pushed or pulled in the right direction, with a good hinge set up to guide them.  Simply cutting them loose turns them into unguided missiles, as this smokestack drop demonstrates.  After watching the video a few times, it appears to me that the explosives knocked out all the support except in one spot, and the stack fell away from that point.  Since I am a forester and not an engineer, I won't give my opinion on how this stack should have been set up to fall, but I do think that the guys who did this ought to spend some time in the woods with a good logger before they do another.

Parts Two and Three: 
  • Put It Where You Want It: Part Two
  • Put It Where You Want It: Part Three

    KurtP said...

    I'm not a logger, but I saw in that first video that there was no way that I'd be cutting into that tree without help.

    At the very least, I'd have a rope or chain pulling it away from the house- if not taking it down from the top.

    Even I saw that it was overbalanced the wrong way without you saying anything... common sense.

    David aka True Blue Sam said...

    My rule for trees around improvements such as houses, and powerlines, is that I will not cut a tree there. I don't want to deal with the liability. Out in the woods I can just go nuts checking my limits, and pounding wedges. The guys who have bucket trucks, winches, and etc., deserve the business anyway, for the investment they have made in equipment, training, and insurance costs.

    JimmyDean at IFRC said...

    What a great instructional video. How many "you never want to do this...) items does the vid contain? 1. Not wearing PPE, 2. No chain brake use, and the best of all, 3. Sawyer watches while standing right next to the tree as tree goes the wrong way and squashes the house! Loved it, lets hope that he was not the best qualified arborist in the neighborhood or the willing but non-qualified neighbor. Lets hope that the cutter was the homeowner and the unlucky husband of the videographer!