Angled Back Cut

From: John R.

Sent: Monday, March 15, 2010 9:21 AM
To: Info@forestapps.com
Subject: Angled back cut

Tim, I live in an area of the country where a good deal of the populace like to employ the sloping back cut when felling trees.  Getting them out of the habit is a little like trying to explain why "mulch volcanoes" around landscape plantings is not a good idea.  People hear it, but don't "buy" it. Any additional comments from you would be appreciated.  Thanks.

John R.

 

Hi John,

Sloping back cuts from a safety standpoint probably do not have an issue. You can present the following line items as somewhat limitations.

1. If the tree begins to move, as the sloping back cut is at a high level above the notch apex, the fiber pulls apart splitting vertically instead of breaking from the back of the hinge to the front at an even rate. So if lifting with a wedge or pulling with a rope this separation can possibly cause “barber-chair” in the trunk.

2. Wedging the angled back cut pushes against fiber and separates vertically where as a level back cut lifts and breaks the fiber from back of the hinge to the front.

3. As the tree’s weight transfers forward with the back cut high and angled above the notch cut, the entire weight of the tree can collapse the fiber. Support is lost for side weight or lean. The tree can twist because of the crushing fiber. When the back cut is level, and at the level of the face notch, there is only movement the width of the saw kerf behind the hinge. Limits some of the chance of twist.

4. The back cut level to the notch apex, instead of angled down, can better insure the fiber planned in the hinge width. If the back cut is high and angled and the fiber at an angle in the hinge area, there is a good chance that the hinge is completely cut when you have anticipated and planned a given hinge width.

Some quick thoughts…. Better explained with a hands on class to demonstrate.

Good Sawing,

Tim Ard