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International 1/4" Rule  Question?

Started by Sawyerfortyish, September 17, 2004, 10:53:29 AM

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Sawyerfortyish

Just got an invitation to bid on timber. It was tallied International 1/4 Rule form class 80.  My biltmore stick says it's form class 78. Whats the differance? Dont tell me 2 either ::). 2 What?

Jeff

Form class can vary by region. Certain trees grow to a different form class depending on where they grow. There is a tool in the  Forum Toolbox to estimate form class by region and species. Use the tree value calc, and look for the link on it that says "Click Here for Form Class guide for region and species"

International 1/4-Inch Log Rule

This rule was developed in 1906 and is based on a reasonably accurate mathematical formula. The rule allows for a 1/4-inch saw kerf and a fixed taper allowance of 1/2 inch per 4 feet of log length. Deductions are also allowed for shrinkage of boards and a slab thickness that varies with the log diameter. Overall, the International 1/4-Inch Log Rule is the most consistent and is often used as a basis of comparison for log rules.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Jeff

You may need to enable pop ups for this site, as that link pops up over the calc. OR in its unformated version, here is a direct link.

Form Class by Region
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

beenthere

Pls. explain to us a bit about what you do understand about form class. The comment that you are 'using' a biltmore stick that gives you a tree form class of 78 implies that you understand what form class is, but the rest of your question implies that you don't.  ???  Are you looking for a formula for form class?
Seems someone has cruised the timber assumming the form class is 80, but you find in your cruise that it is 78. I'd think you would adjust your bid down to adjust for less volume  expected from the listed volume. Maybe I am missing something here, but maybe you could fill in some of the blanks. Hope to be of some help.

P.S. see the following message from JeffB with reference to a very good site that should be helpful to the question.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Jeff

Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Sawyerfortyish

Thanks Jeff now I understand what form class means. My area for oaks is 78. The forester in this case is from western PA and used form class 80 stick. But what really blows my mind he has marked 340,000 ft of sawlogs on 44 acres!. He also numbered every tenth tree and recorded it on paper so his tally can be checked by whoever looks at the job. You can bet im going to look. This sounds more like a clear cut than anything. About a year ago I finished a 40 acre clear cut for the state and there was only 134000 ft timber on that. So 340,000 on 44 acres??? Something just don't sound right.On top of that I just got the bid today and the closing date for bids is the end of next week not very much time to look.
 Beenthere as of this morning I thought International was International had no idea there was differant variations of it. It makes sense a mile away from me you can drive up a mountain and the trees get shorter. I kind of got the idea that theres going to be a lot of adjustments on the bid for this job. Will see i'm going to look on sunday and i'm taking my stick to check the foresters tally on some of the numbered trees.

Ron Scott

That does appear to be a heavy cut @ 7.70MBF/acre.
~Ron

Ron Wenrich

What is the avg DBH of the stand?  I would put a higher form class on trees that had a higher DBH.  Bigger trees usually have less taper.  

I think there is a 2% difference for each form class.  I'd also be suspect on how many logs this guy is giving to the trees.  I've seen guys overscale too many times, since they've never cut any trees themselves.  Some guys will even count limbwood as logs.  

I could throw a cruise on that job in 1 day.  Point sample the stand and see what your cruise comes up with.  I would take 1 plot per acre, or 44 plots.  Unless its rugged terrain, that can be done.  Or if you want a 5% cruise, you can do it with 22 plots.

International will over scale small trees.  I've seen stands of oak that had 10 Mbf/acre and tulip poplar with 20 Mbf/acre.  But, they were fully stocked stands with some pretty nice trees.  

Chances are, its a diameter limit cut.  It does sound high for a "thinning".  
Never under estimate the power of stupid people in large groups.

Sawyerfortyish

Ron I looked at the job today. The terrain is good one side hill not that steep and the rest of the job gentle slope and level ground. As for the scale he numbered every tenth tree so one could judge his tally. He was right on for diameter but his height went way up into the limbs. I think his scale is way off.  I'm going to have to give this some thought. I have always bought on Doyle scale and I don't like International scale.  
   There is a lot of small to medium trees mostly ash and some oak. I can use the ash but it's not really valued at much. He's got an additional 600 and some pulpwood trees marked as well as some cull trees that must be removed from the job. So there aint going to be much left standing. I talked to the owner and I don't think anyone else has even looked at this job. The owner going to sell this farm in the near future and get out of N.J.so I don't think he really cares about what things look like after the cut. I don't like cutting trees this way I prefer a select cut. Leave something for the future.

RMay

Form class is D.B.H at 4 1/2 ft. divided by  D.N.B. at 17 1/2 ft.form class will be the same on all log rules ;D
RMay in Okolona Arkansas  Sawing since 2001 with a 2012 Wood-Miser LT40HDSD35-RA  with Command Control and Accuset .

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