finding timber hight

[labmission]

i'm having a tough time doing a survey of my timber for harvest
i want to use the old "a squared plus b squared equals c squared"
and might end up using a plumb bob on a upside down protractor
by sighting to the top of my prospective log along the straight edge
and subtracting 90 degrees from that i should get my 2nd angle
*on level ground* and do the math
but my trees are on slopes so what do i do now?
some how i know there is a cheap plastic Clinometer/ distance laser out there that would do me better service
anyone ever done this?
i dont want to waste my trees or labor....

 

[Grace Tree]

Go to Home Depot and get a cheap 45 degree angle square and a cheap short level. Hold the square level with the ground and at eye level and look up the 45 and see where it falls on the tree. Back up until your sighting to the top of the tree at a 45 degree angle to the ground. The distance to the tree from where you're standing (plus the 4 or 5 ft. at which you're holding the 45 degree and level) is the height of the tree. You said the trees aren't on level ground but there must be one side where the tree is perpendicular to the ground. If you're shooting up or down hill it can throw off the measurement. If you're not in a hurry you can sometimes find a Suunto clinometer on ebay fairly cheap. I put a little tube on a string and hold it on the clinometer, sight a 45 and measure the distance to the tree. 'Never let me down yet.
Phil

 

[Treecutr]

Native Americans used to walk away from the tree at the same ground level, and bend over and look between your legs back at the tree, when you can see the top, the distance from you to base of tree is height of tree. Looks and sounds funny, but I did see a video on it somewhere, and it works.

 

[Grace Tree]

That's funny. At my age I'd be lucky to see the tops of my arborvitae using that method
Phil

 

[labmission]

im cross posting to another forum

check the help i've gotten there

http://www.homesteadingtoday.com/showthread.php?p=4198093&posted=1#post4198093

(you may have to cut and paste as i cant insert a hyper link here)

and see my replys to see what im getting so far

failing that
know im on rough ground in the Ozarks here

 

[S Mc]

The least expensive way I know was a method we used during an Arbor Day demonstration to a group of school kids.

We cut out a right angle out of cardboard. Holding one side level with the ground, which puts the right angle parallel to the tree. Hold this up to your eye and site up the angle to the top of the tree. Move your body until this lines up. Then pace off or measure from where you are standing to the base of the tree. This plus your height is the height of the tree.

However, that is going to be really time consuming.

I would go buy a range finder that shows degrees of inclination....which is what we have.

Sylvia

 

[slinger]

Buy this one use it and sell it when you are done. Or not.
http://cgi.ebay.com/Suunto-PM-5-Clinometer_W0QQitemZ280445453437QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item414bda047d#ht_500wt_1128

 

[BC_Logger]

this will hopefully will explain the math involved http://www.tiem.utk.edu/bioed/bealsmodules/triangle.html



tools needed

30 meter tape
calculator
clino ( such as the one on the ebay post above )

 

[gwiley]

stick trick

From Jepson's book:

1. get a stick that is a little longer than your outstretched arm
2. Stand at a distance from the tree about where you think the top of the tree will land
3. extend your arm so that it is horizontal and hold the stick vertical (plumb)
4. sight the tree by matching the bottom of the stick with place you will notch on the trunk and the top of the stick with the top of the tree
5. move forward/backward until the stick and tree are the same height

You will now be standing about where the tree will land.

If the ground is sloped or you or the tree are not level then you will need to adjust the position accordingly.

 

[aldo]

I have used gwileys method mentioned above and it works a treat. I read it on this site a few months back and used it since. Try it against a known height, say a tele pole, to test your accuracy and you will find it's a goodun.

 

[rarefish383]

I'm with Gwilly on this one too. Take a stick and in your hand with your arm stretched out straight in front of you. Bend your wrist back and adjust the stick to touch your shoulder. Straighten your wrist up till the stick is perpendicular to the ground, this should make the length of the stick and the lenghth of your arm the same, creating a 90* angle, looking at the tip of the stick move forward or back till the tip of the stick is even with the top of the tree. Then extend that line back till it touches the ground behind you, shouldn't be more than a yard or so. Then measure that point to the base of the tree and the #'s will be close enough for goverment work, Joe.

 

[SINGLE-JACK]

Here's the way it's been done around here for generations:

Stand almost anywhere along a line 90º from where you want the tree to fall.

1. Hold any stick upright, at arms length with your hand lined up with the base.

2. Adjust the stick to sight its tip in line with the top.

3. Keeping your hand aligned with the base, rotate your arm 'til the tip of the stick 'touches' the ground.

That's where the top will be if you fall it right.

Alternative, If you can't stand 90º away:
Stand anywhere, do the same maneuver and pace off the height of the tree.

 

[clearance]

Find one that is average to all the others, fall it. Measure it and then you will know about how tall they all are.

 

[oscar4883]

Here's the way it's been done around here for generations:

Stand almost anywhere along a line 90º from where you want the tree to fall.

1. Hold any stick upright, at arms length with your hand lined up with the base.

2. Adjust the stick to sight its tip in line with the top.

3. Keeping your hand aligned with the base, rotate your arm 'til the tip of the stick 'touches' the ground.

That's where the top will be if you fall it right.

Alternative, If you can't stand 90º away:
Stand anywhere, do the same maneuver and pace off the height of the tree.

x2 Works quite well.

 

[NCTREE]

Try a biltmore stick you can measure diameter and height with it. Its accurate enough if you are just measuring merchantile timber height. It looks like a yard stick, you can buy one or make one. It's been a while since I used one but I think you stand about 30' away on ground level with the stump to get height. When measuring dbh you hold the stick at chest level in front of you about 25" away. If you look it up online you can find instructions on the proper way to use it. It's quick and easy, does take a little nack to get good with it though. Here's a link on how to make one:

http://www.indianriverlagoonenvirothon.com/forestry/11 Appendix A-How To Make A Biltmore Stick.pdf

 

[BC WetCoast]

The official BC Government Timber cruising method.

Measure out from the tree in a direction that will give a clear view of the top. With the clinometer measure the slope to the top to the nearest %. Measure the slope to a height of 1.5 m above the base of the tree. With the tape measure, measure from your eye to a point plumb under the top of the tree. Using a slope correction table, correct the slope distance (what was measured) to horizontal distance.

Now add the upper shot (in %) to the lower shot (in %), mulitply by the horizontal distance and add 1.5m. Done correctly, you will have an error factor of 1%.

 

[2FatGuys]

You guys are making this MUCH more difficult than necessary! Any First Class Boy Scout can do this with only a pencil (or other stick) and a helper (or object of known height). I am not at home where I could scan the directions and images fron the BSA Handbook. But, the process involves holding a pencil at arms length. Have a helper (or other object of known height - let's use something 5'-0" for example) stand next to the tree. Stand about 25 yards from the base of the tree. Sight along your arm, aligning the top of the pencil with the top of the known height. Place your thumb on the pencil aligned with the bottom of the known height. Now, maintainging your thumb position on the pencil, just start at the base of the tree with your thumb aligned with the base of the tree. Note where the top of the pencil aligns. Move your arm up to align your thumb with the position noted. and again note the position of the top of the pencil. Keep doing this until you reach the top of the tree. Each "jump" is equal to the height of the measured object. There is some "human error" involved, but it has worked for me since I was 12. We use this method to quickly estimate heights and make measurements daily.

 

[NCTREE]

You guys are making this MUCH more difficult than necessary! Any First Class Boy Scout can do this with only a pencil (or other stick) and a helper (or object of known height). I am not at home where I could scan the directions and images fron the BSA Handbook. But, the process involves holding a pencil at arms length. Have a helper (or other object of known height - let's use something 5'-0" for example) stand next to the tree. Stand about 25 yards from the base of the tree. Sight along your arm, aligning the top of the pencil with the top of the known height. Place your thumb on the pencil aligned with the bottom of the known height. Now, maintainging your thumb position on the pencil, just start at the base of the tree with your thumb aligned with the base of the tree. Note where the top of the pencil aligns. Move your arm up to align your thumb with the position noted. and again note the position of the top of the pencil. Keep doing this until you reach the top of the tree. Each "jump" is equal to the height of the measured object. There is some "human error" involved, but it has worked for me since I was 12. We use this method to quickly estimate heights and make measurements daily.

Sounds like the same process as a biltmore stick which is gonna be more accurate in figuring out merchantile log height. Logs are measured in 1/2 logs(8') or full logs(16') when measuring standing timber. You can find a log chart that has bd.ft. volume in scribner, doyle, or internation log rules. Lumber companies use one of these three to figure out volume. The log chart makes it easy to figure volume by taking the dbh and the height an identifying it in the log chart which will give you bd.ft. volume.

Heres a link to estimating timber with a biltmore stick:

http://www.ces.ncsu.edu/forestry/pdf/WON/won05.pdf

Heres a link to a pocket size table for estimating standing timber volume:

http://www.forestry-suppliers.com/product_pages/View_Catalog_Page.asp?mi=1349