Tension Vs Compression Where Is The Strength

Описание: IN 2004 I wrote an article for TCIA magazine about the tapered hinge, which is used to help fight the side lean in falling trees. The concept is that by leaving more wood on the tension side of the hinge the hinge will have greater strength to fight side lean because tension wood is stronger than compression wood.

The reaction to that article was quite varied. One of my favorite comments was "my Dad showed my that the first time he took me into the woods when I was 12. You might as well write an article about where to put the gas and oil in a saw." On the other hand, Ken Palmer, of Arbormaster Trainings, told me to my face that the tapered hinge doesn't work. That his scientists buddies in Germany had proved that it doesn't work and so the entire premise of the article is wrong.

Tim Ard, another well-repspected industry trainer also claims that the taered hinge doens't work and that the best way to handle side leaners is by using the adjusted gun technique. That is if the tree has x feet of side lean, you need to aim the notch and back cut 1.5x in the other direction. So a tree with 10 feet of side lean to the left should be aimed 15 feet to the right of the lay. There are all kinds of problems with that teaching, but I won't get into any of those criticisms here.

Suffice it to say that I hold by the belief that tension wood has a lot more strength to fight side lean and therefore the tapered hinge is a valuable technique and reliable enough to be accepted industry wide. It's more reliable than the adjusted gun technique IMO. MUCH MORE.

Add a little sizwheel to the tapered hinge, and adjust the direction of the pull line to compensate for side lean and I AM feeling 100% confident that my cuts are better, that is more reliable not to fail, and more accurate in hitting the lay, than anyone using the adjusted gun.

Who would have thought that this article would create such a controversy?

In this video, I use a simple illustration to show that in long horizontal limbs the tension wood at the top of the limb is far stronger than the compression wood on the bottom of the limb in supporting the limb's weight.

To some, this might seem as simple a concept as where to put the gas and oil in a saw, but apparently people like Tim Ard and Ken Palmer need to know these things. Please let us know your thoughts and experiences in the comments