[ChainPoint] Understanding Directional Felling

[ChainPoint Connections]

Hi ChainPoint¹s

I hope you had a great Labor Day Weekend? It was a good time around our
place this year. Being home and having time with family and friends is
always great.

The article this week (below) is taken from the Forest Applications
Training, Inc. eBook. If you don¹t have a copy, it¹s a great tool to have
for review of just about everything regarding chain saws. It is available
from our eStore as a download, CD or even a printed binder version. You can
also download from Barnes and Noble Booksellers. The links are up on the
main page of our website if you would like your copy...

The Fall is going to be busy, our schedule is full. We are looking forward
to seeing many of you at programs near you. Check out our calendar under
events on the website. Laura is booking our calendar for January and
February now. If you or your organization are considering training after the
first of the year you can contact her at the office number or email
Laura at ForestApps.com

Cooler weather is moving in again... I am ready for it I think... We¹ve seen
some hot weather for training this summer. A good article to review is
http://www.forestapps.com/chainpoint/woolpower/woolpower.html  Woolpower
offers some awesome products for year round use but especially as weather
gets chilly.

Follow Tim on Twitter   @ForestApps
Face Book ­ see our link on the Website.
Tim¹s Blog ­ http://www.ForestApps.Blogspot.com

Have your friends subscribe to ChainPoint -
http://mail.forestapps.com/mailman/listinfo/chainpoint_forestapps.com

We are headed to South Carolina for the rest of this week and next... See ya
there! 

Good Sawing,
Tim Ard
Forest Applications Training, Inc.

O 770.222.2511


http://www.forestapps.com


Understanding Directional Felling ­ Chapter 9 ³The Complete Guide to Chain
Saw Safety and Directional Felling²
Written by Tim Ard and Mike Bolin

There are many ways to fell a tree and no two people probably accomplish the
task exactly the same way.  Depending on what part of the country you live
in, who you work for, or who you learned your tree felling skills from will
influence how you fell a tree.  Each method has its merits and I will
discuss a number of these, but I will concentrate my detailed discussion on
the Œopen-face technique¹ of directional felling which I promote and teach
in my training programs. Importance should be placed on the plan that
selects the technique ­ every tree is different.

Directional felling is placing the tree in a desired location, not
necessarily where it wants to go.  Employing directional felling techniques
simplifies the felling process in that you can control where and to a
certain extent how the tree falls.  Directional felling techniques allow you
to move away from the falling tree and observe its descent from a safe
distance rather than standing right beside the tree using Œtrial by fire¹
techniques.  With proper planning and the use of directional felling
techniques, you can help maximize efficiency in skidding the logs from the
woods.

Directional felling is also good for the residual stand (the trees left
standing after harvesting is over) in that it minimizes damage to the
standing timber.  As a tree falls, its limbs brush against the limbs of
neighboring trees and can break them leaving unsightly widow-makers hanging
in these trees and open wounds that attract insect and disease vectors.  If
the tree is allowed to fall where it wants, it¹s likely you will have damage
to many residual trees in the woods instead of just a few.  Similarly, there
may be areas with young tree regeneration that you do not want to damage by
dropping a tree into the area.  Directional felling allows you to steer the
tree away from these areas. Directional felling is a win-win situation, both
for you and for the environment.

Felling Techniques ­ The Match Cut.
Match cutting is an illegal felling technique used by many loggers to
harvest high value timber species or large trees with valuable veneer logs.
It is also a technique used by inexperienced chain saw operators who do not
recognize the merits of a notch and hinge.  A match cut involves cutting the
tree off flush without using a hinge.  The tree falls in the direction of
its weighted side lean or in the direction the wind is blowing.  This may or
may not be the direction the operator wants it to go.  I feel this is an
unsafe technique and should not be used because you have to stand right next
to the tree until it is completely severed from the stump and you have
virtually no control of the tree.

OSHA requires that a directional notch and hinge be used in any manual
felling process.  Occasionally, I hear loggers say their employer or a
timber buyer purchasing logs from them requires them to use a match cut
because they want a clean, flush cut on the base of the butt log.  I cannot
refute what an employer or buyer requires, but I can say that they are
likely misinformed about the merits of using a notch and hinge, particularly
the open-face technique and they are not placing much regard for the
operator¹s safety.

Felling Techniques ­ Anchor or Spur Cuttings
A variation of the match cut is a technique using anchor spurs of wood on
two to four corners of the stump to help control the direction of fall.
Many times spur roots are use as anchors.  This technique is often used by
loggers to Œswing¹ a tree in a desired direction, but again it is a
dangerous technique in that you have to stand next to the tree to
systematically cut off the wood spurs to get the tree to land where you want
it.  This technique does not meet OSHA requirements generally because of
little or no notch and usually inconsistent hinges. I suggest we move on
from this technique, I don¹t recommend it either.

Felling Techniques ­ The Common Notch.
Most operators employing the use of a notch and hinge use the common notch.
In this technique, the common rule is that the notch is cut back into the
trunk at least one-third of its diameter.  The opening of the notch is
normally 30-45 degrees.  The back cut is made one or two inches above the
back point of the notch to form a ledge that helps keep the butt from
rebounding behind the stump.

 Use of the common notch affords more control than the match cut during the
felling process, but only to a certain point.  Let¹s see why this is true.

Earlier I mentioned the purpose of the notch is to allow the hinge to work.
If the notch opening is 30-45 degrees, how far will the top of the tree move
before it encounters internal resistance?  If you answered 30-45 degrees,
you are correct.  In this situation, visualize where the top would be when
the notch closes.  If you envision the top of the tree at a 45-60 degree
angle from the ground, again you are correct.  If you use the common notch
technique, the top will never be anywhere close to the ground‹unless you are
falling a tree uphill‹when the notch closes. And what happens when the notch
closes?  The hinge is stressed, wood fibers break and the hinge fails.  At
this point, the tree is free to go where it wantsŠnot a good situation.
Frequently the butt log splits, commonly called a Œbarber chair¹.  Part of
the butt log remains attached to the stump and the remainder sails violently
backward.  Barber chairs have injured and killed many operators.

Felling Techniques ­ The Humboldt Notch.

The Humboldt notch is a variation of the common notch technique and was
developed in the Pacific Northwest for felling large trees in mountainous
terrain.  Basically, it is a common notch that is inverted on the stump.  If
you can envision tree¹s 10-12 feet in diameter, you can also imagine how
heavy and cumbersome the notch wood is to remove from the cut.  With the
Humboldt notch the wood slides easily from the notch since the bottom cut is
made at a 45 degree angle rather than flat as in the common notch technique.
In addition, the Humboldt notch helps to better lock the tree on the stump
during the tree¹s fall.  However, a higher back cut is still required to
prevent butt rebound.  Similarly, the butt log of the tree is always flat so
there is no perceived board-foot volume deduction for the notch when the
butt log is scaled.

Felling Techniques ­ The Open-Face Technique.
The technique I prefer to use and teach is called the open-face or deep ŒV¹
technique.  This technique has been around a long time and is commonly used
in Scandinavian countries, but is gaining popularity in the United States as
more loggers and landowners learn of its merits.

The open-face technique uses a notch with an opening of at least 70 degrees.
Recognizing that the hinge will continue to function as long as the notch
opening remains open, the open-face technique allows the top of the tree to
completely reach the ground, or is at least parallel to it, before the notch
closes.  Thus, you have complete control of the tree¹s fall provided you set
up the proper size hinge and execute the back cut correctly.  And, an
opening of 70-90 degrees allows the notch to be set up so that it often does
not penetrate the log cylinder when it is squared up at the sawmill. This
saves wood fiber and allows more usable product to be cut from the log.
With a notch of 70 degrees or more, the back cut may be level with the back
point of the face notch.  This is often important in trees with diagonal
wood grain low on the stump. This situation is described in further detail
under the ŒHinge¹.

The notch is started by making the top cut first.  The operator positions
himself/herself to the side of the tree looking directly down the intended
Œline of fall¹.

A cut is made in a downward and slightly inward direction until the length
of the notch, corner to corner, is approximately 80 percent of the diameter
of the tree.

 This sets up the length of the front side of the hinge.  The operator then
removes the saw and finishes the notch by making the second cut in a
slightly upward direction.  The advantage of making the top cut first is the
operator can easily look into the top cut and see when the second cut meets
the first. With practice, the operator should be able to make both cuts meet
exactly on the first try.

If the top and bottom cut do not meet, a by-pass (or Dutchman) is created.
If a by-pass of more than 3/8 inch exists, the by-pass can cause serious
problems for the hinge and hinge failure can result.  When the by-pass cut
closes, the hinge is stressed with very little forward movement of the tree.
The hinge will break or the tree will barber chair and control will be lost.
Avoid making by-pass cuts and clean up any by-pass in the open-face notch
before completing the hinge and back cut.

 Here¹s a tip on making the two notch cuts meet every time.  Did you know
the front handle on your saw is designed to make these two cuts easy for
you? As long as you do not move around and change your stance after making
the first cut, you simply withdraw the saw from the first cut and rotate the
saw to its side cutting position by sliding your left hand along the front
handle.  Put the bar of the saw at the bottom of the first cut, accelerate
the saw, and let it feed itself into the tree.  Maintaining your position,
you should be able to look down into the top cut and see the chain teeth
emerge into the kerf (space) of the first cut.  The notch wood should slide
out on its own or with very little assistance.

Positioning the Notch Determines the Direction of Fall.
If you have determined where you want the tree to land, you must position
the open-face notch correctly to accomplish this.  Remember‹the corner of
the notch is the front side of the hinge and the hinge needs to be roughly
perpendicular to the intended Œdirection of fall¹ line.  Corrections for
weighted side lean may be necessary and this will be discussed in more
detail in Chapter 12 of the Forest Applications Training, Inc. eBook.

How do you know if the notch is pointing directly at the intended Œline of
fall¹?  Did you know that all saws have felling sights on the them?  They
are either raised lines molded into the top and side of the power head or
they may be decal lettering on the saw.  The felling sight works just like
the sight on a gun or rifle and is perpendicular to the movement of the
chain in the guide bar.  If you position yourself and the saw correctly
before making the first notch cut, the resulting notch will point directly
toward the Œline of fall¹ you planned.

See this information with illustrations and pictures in your copy of the
ForestApps eBook.

© Copyright Forest Applications Training, Inc. 
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