Forest Industry Safety & Training Alliance, Inc.

Ben Parsons, FISTA Training CoordinatorDecember 2013

Looking for H.H.E.L.P. (Part 2)

Have you ever had to make a plan B?  How many times have we had to make a plan B after discovering plan A isn’t going the way we thought?  My guess is that when plan B is an impromptu plan, it tends to begin with at least one expletive.  Some plans, especially C and D are rarely effective without incorporating several expletives.  Why is it, then, that once plan “O.S.” fails a prayer is incorporated in the next step; if anything, to take back all the expletives in the previous failed plans?  It’s a great idea to have backup plans, but by establishing control over the situation and developing a solid Plan A, we avoid utilizing our preceding plans, as well as expletives.

Continuing on with our “Felling Five” steps, we are now on the second “H” of the process and a very important step in establishing our control: Hinge.  Calculating an adequate hinge for the tree we are felling is a very simple, but extremely necessary.  The function of a hinge on our tree is very much like that of a hinge on a door. 

Think about how a door will swing open or closed, but won’t lift out of, or fall from the jamb.  This is because of the strong and properly installed hinges in the door.  The hinge on our tree will allow it to fall in the direction of our notch, or to sit back if we’ve misjudged a back lean.  When established correctly, the hinge provides directional control by not allowing the tree to spin, twist or kick off the stump, as well as fall to either side, just like hinges for a door keep it in place, yet allow proper function.

Basic calculation of the hinge is simple.  We have an 80% length, 10% thickness of the DBH general rule.  For example, a tree that is 10 inches in DBH should have a hinge that is 8 inches long and 1 inch thick to be a safe, adequate hinge.  Just because we base our calculation at DBH does not mean that we plan on leaving a high stump, obviously.  This is simply where we figure out what we need.  Going low on the stump provide so many more advantages.

In regards to the hinge, I’ve always been told that “the strength is in the length”.  From a safety aspect, when we look to the base of the tree, we gain much more room to work and room for error.  We also provide the ability to make our hinge longer than 80% of the DBH.  From a value aspect, this gives us volume to our butt log.  Since going low on the stump gives us a longer, stronger hinge, we now have the liberty to thin the hinge up a bit without compromising control.  A thinner hinge helps us to avoid deductions for stump pull, yet by going lower and longer on the hinge, we also avoid compromising our safety or control.

Any acceptable tweaking that we can make with the hinge tends to come with substantial risk.  There are three ways we can compromise our hinge.  Number 1 is the most obvious; we can unintentionally cut it.  Number 2, we can go too thin on the hinge, regardless of length, where the hinge cannot support the weight of the tree, thereby sitting down and crushing it.  In this case, the hinge may look like it’s still intact, but the fibers have broken and no longer possess structural integrity.  If we believe that we may have set the hinge too thin, we can sometimes catch it before the crushing process by gently snugging a felling wedge directly behind the hinge.  Only do this with extreme caution, or we may end up with the third way of compromising the hinge; Number 3, lifting too close behind the hinge with wedges or other felling devices and separating the fibers. 

If we take a moment to calculate the hinge our tree needs, set it carefully and properly and protect the structural integrity of it, we have gained a great deal of control as well as opening several other options for a back-up plan; no expletives needed.


Ben Parsons, FISTA Training Coordinator, is originally from West “By God”, Virginia as they say in that part of the Appalachian Mountains. His family’s deeply rooted philosophy of living off the land was monumental in deciding to earn a degree in Forest Management from West Virginia University.  Throughout his career, Ben has had the opportunity to tackle a wide variety of assignments.  He measured Forest Inventory and Analysis research plots in Virginia and Georgia, been involved with urban and utility forestry operations throughout the Appalachian region, procured lowland hardwood timber in the swamps of South Georgia, managed logging contracts and harvest operations in Arkansas and specialized in water quality and harvest planning as well as fighting forest fires in Virginia. As FISTA Training Coordinator, helping to meet your safety and educational needs is the number one priority here at FISTA.  For more information, contact Ben at 800-551-2656 or ben.parsons@fistausa.org