Yesterday I stopped by a friends mill to see how he was doing on my way back from delivering some lumber and noticed that he had a nice load of walnut that he had bought ,he siad he scaled his walnut on the doyle scale ,most every one in this area uses the international scale for saw logs tie logs ect. But he siad that most places north of where we are that buy big grade logs use the doyle scale Im not familar w/the doyle scale since I dont ever use it could anyone clear this up a little for me .
Hillbilly
Back a bunch of years ago, I had the Corley mill and bought logs by Doyle. I think it's a regional thing. That's what was used in the area.
I was told that the Sawmill makes out on Doyle scale, up to a 24" dia. log, then the logger makes out. Doyle won't show near the footage in a smaller log compared to Intl. I always gave 1" on the log scale, for QUALITY logs. Try to get something past me, and I would take back the inch for a spell. ::)
It was explained to me that the Doyle scale was meant to "punish" loggers for cutting small logs, or perhaps entice them to cut only large logs, but it doesn't seem to work. :D The difference is also supposed to make up for the extra time spent processing smaller logs for diminished yeild.
As FDH said, the crossover point is about 24". The smaller the diameter, the worse the logger gets spanked on volume with Doyle.
i.e.
10"x10' log Doyle = 23bdft, Int = 35bdft
20"x10' log Doyle = 160bdft, Int = 175bdft
30"x10' log Doyle = 423 bdft, Int = 410 bdft
Doyle is indeed the most common scale around here.
At least where Im at I think that every one uses the International scale I knew that the two scales didnt strat to match up until you got past a certian size Igeuss we just have smaller logs here ;D But was wondering why you would use the doyle to scale out walnut and higher grade oak ,Igeuss its for keeping out the smaller tie and pallet size logs :-\does any one else use the doyle ?
HILLBILLY
You can use one of the Forum calcs for an easy comparison, Crossover on 8 ft logs is around 30 inches
https://forestryforum.com/calcs/sawlogbf.htm
What are Log Rules?
Since the first sawmill was built in the United States, over 100 log rules have been developed, using a variety of methods. Some were based upon the lumber tallies of individual mills, others were developed by diagramming the cross-section of boards in the ends of logs, while still others were developed using mathematical formulas. In general, log rules must account for the taper that exists in all logs, saw kerf (or the loss of wood as sawdust), and a fixed procedure for removing wood on the outside of the logs for slabs. The Doyle, Scribner, and International log rules are probably the most widely used rules in the eastern United States.
Doyle Log Rule
The Doyle Log Rule, developed around 1825, is based on a mathematical formula and is widely used throughout the southern United States. This rule allows for a saw kerf of 5/16 inch and a slabbing allowance of 4 inches, which is about twice the normal amount. Because of this, the Doyle Rule is somewhat inconsistent; it underestimates small logs and overestimates large logs. As a seller of timber, you must be aware that for smaller logs the Doyle Rule will underestimate the actual volume of wood that you have in your trees.
Scribner Log Rule
The Scribner Log Rule, developed around 1846, is a good example of a diagram rule. It was created by drawing the cross-sections of 1-inch boards within circles representing the end view of logs. A space of 1/4 inch was left between the boards to account for saw kerf. The Scribner Rule does not have an allowance for log taper and typically underestimates logs, particularly if the log length is long. The Scribner Decimal C is a different form of the Scribner Rule; it rounds the volumes to the nearest 10 board feet. For example, 392 board feet on the Scribner is equivalent to 390 board feet on the Scribner Decimal C scale.
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.
Price makes all things relative. If a tree scales a higher footage, then the $/Mbf is lower. Doyle is always higher in price than Scribner or Int.
Doyle is used in our area since that is how veneer is bought. That way they're not jumpig all over the place with different scales or prices.
Here in Southwest PA Doyle is used almost exclusively. As long as both parties are familiar with the scales then all is good and well. Like Ron said price makes all things relative. I am concerned with how much money I can make out of a log, not what some stick says.
Thank you Jeff for the well explained differences between the scales. For a beginner like me it helps a lot. From what I hear in Minnesota, the Scribner is used the most. But again that may be a regional thing. At least now I can visualize the difference.
Here in Maine, International is what seems to be the scale of choice for selling. Buying is done with the Scribner.
Jeff, as you said, Its always sold up here on the international scale. although in my particular area, there is what's call the "Bangor Scale." I have never seen one, but that is what most of the log yards are using. If you go to the actual logging site as I do, I bring all three.
I think from what I have heard, the dif between Bangor and International is something to do with 1/4" factor. Not quite sure thou ???
Hardwoods are done with the Doyle here in northern Arkansas but we do cedar by a cedar scale and pine by the ton or 1/4 Int. We just change the price per bdft so we end up making the same coin.
A 10" 8' log will scale Int 30 and on Doyle it will go 18. You can get a 6x8 tie which will have 32 bdft in it. You will also get two boards for about 8 more bdft. In the same about of time you could have sawn a 14 inch log and made twice the lumber. Also if the log is not real straight then you may lose the tie. Doyle was in fact set up to discurage bringing in little logs. Before long we will be glad to get 10" logs.
I'd like to hear from someone that buys hardwood logs....
How they determine grade... 1,2,3, etc.?
How to deduct for defects such as sweep, twist, forked hearts, hollows/bad centers, damage from lightning, fence, stump shot, insect damage, cat faces, etc. ?
Had a part-time logger bring in about 50 logs a couple of weeks ago and tried to pass them off as red oak when they were in fact, new growth black oak – insect damaged and filled with small knots. When Mary pointed out the numerous obvious knots, he came back that they were only "surface knots and won't show in the lumber". He was expecting grade red oak prices and went looking for another buyer. He came back a week later and took the check and didn't say another word.
Bibbyman
Hard to imagine a surface knot with clear lumber underneath. Trees just don't grow that way. Good for Mary, to not buy into that story.
But I have heard a lot of stories of what some will say about tree or log quality, to either convince of higher quality (if selling) or convince of poorer quality (if buying). An uncle of mine told of a walnut buyer running his walnut trees down and claiming that they were not worth much, because they were not male trees. Seems all the walnuts had dropped off of them, or it was a year without any, and the buyer was trying to capitalize on that. :)
There are scaling handbooks that could give some pointers on scale deductions for the things you mention. Usually, if I remember right, the volume of unusable wood for sound lumber or missing wood is estimated and deducted from the gross scale. Sweep, crook, butt flutes, decay, forked stems, etc have 'rules' or formulas to use. Likely some of the foresters cruising timber take into account some of these same deductions.
AH ,Mary smelled a rat ,way to go mary Bibby Im after the same sort of Info that you are ,I'm also after any info on buying walnut logs Ive scaled alot of oak logs that where my own or ones that we have cut and skid for some one eles but never did any buying from someone hauling them in.
I can see where the doyle would be hard on the smale log scale Im sure that is why we dont use it here for hardwoods I think ceder is bought buy the cord and alot of pine is being bought by the ton ,but maybe Im just slow ::)
BIBBY you andMARY buy some walnut do scale it doyle or int and if so then why?
HILLBILLY
I used to scale and grade logs for a large mill and a few small mills. Grade is usually set up by the mill to meet their specs. Some guys do mill studies to figure out the best price structure, most set it up and see if they can buy logs that way. They usually change their specs as the market changes.
The best log scalers are sawyers. They are also the best to judge tree quality. They should have a good knowledge of lumber grades and what defects to look for. Some defects do saw out, some don't. Epicormic branches will saw out, depending on species. Some bud clusters won't saw into a defect, depending on your market. You have to know the timber in your locale to make a really good decision on them.
I have used the Forest Service grades and most loggers just don't understand them. The bucking process determines the grade of every board that comes from the log. This grading method is determined from 3rd best face instead of the best face. The FS has lots of yield data on their grades and you can develop prices. But, sometimes you have to add a premium or select grade to attract those really good logs.
For volume defects, a lot depends on the log. For sweep, I would take either a percentage or knock it back by a few inches or a lenght class. Too much sweep will also drop the log down a grade. You start cutting into the heart too soon, and that justifies it.
For butt rot, I would box it out and make the necessary deduction or drop a length class. You're only losing pallet wood. Shake drops both grade and volume. Depending on severity, I'd either box it out if it was a lot, or do a volume deduction. Again, seeing these logs go through a mill is a major benefit. For surface rot, depends if it can be cut out. Logs from dead trees get measured inside the heartwood. Splits also have to be factored in. Shattered logs give no lumber.
There are 2 ways to buy logs. The first one seeks a way to establish a fair price between the buyer and the seller on the merits of the log. The second way is to see who can screw the other guy the most. I try to use the first method, but have reverted to the second method at times.
I had one logger who brought in a log that was covered in mud. I thought it looked like a defect, but the mud was too thick to fool around with. He assured me that there was none. I saw the log go through the mill, and he tried to pull a fast one. That trick cost him a lot of money. I never trusted him after that, and still don't. You know which loggers to trust and which ones not to.
I found that most loggers care more about the volume than they do about the grade. Volume they understand. They think if they take their logs to the mill giving them the most volume that they will make out the best. It don't work that way. I can be easy on scale but hard on grade or the other way around. Its hard to buy logs if you're tough on both and you'll be out of business if you're too easy on both.
Mary has taken a class put on buy the Hardwood Association on log grading and has the rules – someplace. And she has seen the inside of countless thousands of logs (so she knows "Beauty may be skin deep – but ugly is to the bone"). She does all the buying, grading and scaling. She has her methods. I was just trying to get input from others.
Walnut logs.... We scale them the same as we do any other – Doyle. Although we're sawing quite a bit of walnut, we're not involve in the buying process as a log broker goes around and buys them and has them shipped in. All we got to do is put them into nice neat bundles of 6/4 lumber.
If I get a chance today, I'll take the camera around the lot and put up some examples of logs and see how people would adjust scale/grade.
frickman, most of the guys I deal with here in Allegheny/Beaver counties use International (about 6-8 guys)
Up Mercer County way where our farm is it's Doyle
Does anyone have the actual formulas for Doyle and International?
post them for me
You could use our calculators. Hit the "Forum Extras" link at the top, then go over to the toolbox. There is a volume calculator for logs. Download it to your computer, then you won't have to mess with the formulas.
Doyle forumla = (D-4)^2 * L/16
Int. 1/4 formula = (0.796*D^2-1.375*D-1.23) * L/16
D=diameter inside bark L=Length
Ron, do you have the formula or tables for the International 1/8th scale?
I have run across it somewhere in my travels. I have to dig it up. You want to add that to the calculator?
is the 1/8th scale assuming 1/8" kerf?
Quote from: Ron Wenrich on May 11, 2005, 05:57:32 AM
I have run across it somewhere in my travels. I have to dig it up. You want to add that to the calculator?
I was thinking we could, the other reason I need a table for it is for perhaps another reason I cant divulge. :D
thanks Ron
Doyle forumla = (D-4)^2 * L/16
Int. 1/4 formula = (0.796*D^2-1.375*D-1.23) * L/16
What does ^ stand for?
^2 means to square the number (raise to whatever power)
"" A rule of thumb sometimes used for logs of any length is,
Int. 1/8 formula = (0.66*D^2 - 2.12*D) * L/12 ""
From "A Collection of Log Rules" by Frank Freese, 1973
Jeff, did you forget to type something?
Actually, I dont know what happened there. Must of got click happy.
I've found one that is (0.22*D^2-.71D)*.904762 per 4' section. Then it figures a 1/2" taper per 4' section. It also said to add about 10.5% to get the 1/8 scale. Source: Forestry Handbook
ok, now I'm really corn-fused
let's figure the bf in a log 10 foot long, 12 inches dia
the Forestry Forum calculator gives these totals
International 61
Doyle 40
Scribner 54
My pocket Wood-Mizer Log Rule and Lumber Scale gives these
International 55
Doyle 40
Scribner 50
why the difference in International and Scribner?
various log dimensions are all different
For starters, the calculators use formulas that were developed by the USDA. We developed the log calculators first, which later developed into the tree volume calculator. In order to get figures that are consistent with tree volume charts, you have to use those formulas for the logs.
There are several different formulas for International scale. Here's another one. 0.049762*L*D^2+0.006220*L^2*D-.185476*L*D+0.000259*L^3-0.011592*L^2+0.042222*L That forumla gives you 55 bf.
I used the one that is accepted by the industry as a standard, and it was easier to program. Wood-mizer may be using the 1/8 scale. Usually you will see it listed as Int 1/4 or Int 1/8.
For Scribner, there are 2 ways of comupting that. Here in the east, we use the Scribner as it computes. But, there is a Scribner Decimal C. It is used mostly on the West Coast. It basically rounds the Scribner computation to the closest 10, then they drop the last 0. It must fit on the scale sticks better. :D You just have to multiply the Scribner Decimal C scale by 10 to get to a rounded version of of Scribner. Are all of there Scribner figures ending in "0"?
In the end, it really doesn't matter what scale you use. A log is worth so much money. Whatever scale you use, you should come up with a dollar value that is pretty close. The $/Mbf changes with each scale.
Here's a calculator we have on the Timberbuyers.net site. It compares the difference in log values under different scales. I don't see it on this site.
http://www.timberbuyer.net/logvalue.htm
Its here, I must have over looked it.
https://forestryforum.com/calcs/logvalue.htm
I have added it to the tool box
https://forestryforum.com/board/index.php?action=toolbox
Quote from: Ron Wenrich on May 12, 2005, 07:01:21 PM
I've found one that is (0.22*D^2-.71D)*.904762 per 4' section. Then it figures a 1/2" taper per 4' section. It also said to add about 10.5% to get the 1/8 scale. Source: Forestry Handbook
Ron
I found that formula also in the Freese publication "A Collection of Log Rules" under the 1/4" Int'l rule.
It is attributed to Judson Clark in 1917 to appease the band mills that couldn't quite get the yields predicted by the 1/8" Int'l rule (which was also set up for 1/2" taper and for 4' log sections).
Log rules are good for just giving one an estimate of what is in a log. When deciding what to pay for a log, or what to sell a log for, having a general idea of the bf in the log (or tree) helps one to make the decision. Getting the estimated bf from the log depends on many things, of which the accuracy of the rule used is but one of them.
Ron
Good response on the log calculators and explanation of the rules. At least the surface of what all has been involved and revolved over the years has been scratched. For those interested in what the mathematicians and forest mensurationists and statisticians have struggled with over the last 100 years, the Collection of Log Rules is a pretty good summary, IMO.
Thanks Ron
just a habit to question everything
BTW, WoodMizer uses International 1/4