How to Know the Height and Where the Top will wind up?

[UrbanHunter]

Is there a formula to determine where the top of a tree will hit the ground at when you are logging or clearing?:rockn:

 

[tawilson]

There's a few threads around here on it. I haven't seen one in a while and I forgot what it's called, but you use a stick with your arm straight out and touch it to your chin. Then put the stick straight up and look at the top, and move till you see the top of the tree, and that will be close to spot the top will hit. It's based on the isoceles triangle, two sides being equal. I'm sure someone will come along and explain it entilligently, I'm just bumping the thread.

 

[tree_beard]

ekka shows the stick trick in one of his excellent videos;

http://www.arboristsite.com/showthread.php?t=35362

asset to the community that man

 

[Ianab]

Yup.. the stick trick works pretty well.

Now if you feel confident, push the stick into the ground, use it as an aiming point for your scarf cut, and see how close you can get the top of the tree to your stick

It will impress the onlookers if you can hit it exactly opcorn:

Cheers

Ian

 

[Beweller]

Sight on the base of the tree with your clinometer. Algebraically add one half of the angle to 45 degrees. If the top of the tree coincides with that sight line, the top of the tree will pass through your eye when felled. If not, move to a new position and repeat. If you are not far off, the angle to the base of the tree will not change much and you can home in rapidly.

This method works up slope, down slope and cross slope, where many other methods fail.

 

[Sprig]

And, since I looked this up for another thread here ya go >
http://www.arboristsite.com/showthread.php?p=597203#post597203



Serge

 

[Beweller]

The attachment describes a method of measuring tree heights that I find convenient

 

[slowp]

Use a clinometer. Figure out which side of the scale is the % side. If it is a short tree,measure out a distance of 50'from the edge of the tree. If you are on steep ground and don't want to correct for slope, go out sidehill, at the same level as the tree base. Take a sighting on the base of the tree. Then take a measurement on the top of the tree. If the bottom is 0 or a minus reading, add it to the reading of the top of the tree.
Divide by 2 and you have the height.

If the tree is too tall to get a reading at 50', go out 100' and repeat. Add the two readings together and that is the total height.

Example at 50' distance

stump reading is -5
top reading is 135
added together =
140 Half of 140 is 70' which is pretty close to the height of the tree. The stick method works on flat ground, or so I here, but I've always used a clinometer.

 

[Beweller]

Revised attachment

Sorry, the attachment to my post above was not complete. Please see the revised attachment here.

 

[ray benson]

Beweller, I read your proposed document. It has been over 30 years( pre-calculator) since I have used the trig. functions.I should probably stay with the stick method. Or I stand back from the tree and visualize the tree from bottom to top broke up in 10' increments.

 

[Beweller]

Math?

Ray,

It's nothing but high school trig--at least it was high school trig 65 years ago. I'm not sure about today.

But no problem. Program it--or get someone to program it--on a spread sheet and you don't have to know what the trig functions stand for.