A Collection of Log Rules U.S.D.A
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A COLLECTION OF LOG RULES U.S.D.A. FOREST SERVICE GENERAL TECHNICAL REPORT FPL U. S. DEPARTMENT OF AGRICULTURE FOREST SERVICE FOREST PRODUCTS LABORATORY MADISON, WIS. CONTENTS Introduction 1 Symbology 3 A graphic comparison of log rules 4 Section I. Log Rules of United States and 9 Canada Section II. Some Volume Formulae, Lumber 41 Measures, and Foreign Log Rules Tables showing the board foot volume of 16- 50 foot logs according to various log rules Bibliography 56 A COLLECTION OF LOG RULES By FRANK FREESE, Statistician Forest Products Laboratory Forest Service U.S. Department of Agriculture INTRODUCTION A log rule may be defined as a table or formula names. In addition, there are numerous local showing the estimated net yield for logs of a given variations in the application of any given rule. diameter and length. Ordinarily the yield is ex- Basically, there are three methods of develop- pressed in terms of board feet of finished lumber, ing a new log rule. The most obvious is to record though a few rules give the cubic volume of the the volume of lumber produced from straight, log or some fraction of it. Built into each log rule defect-free logs of given diameters and lengths are allowances for losses due to such things as and accumulate such data until all sizes of logs slabs, saw kerf, edgings, and shrinkage. have been covered. These “mill scale” or “mill At first glance, it would seem to be a relative- tally” rules have the virtue of requiring no as- ly simple matter to devise such a rule and having sumptions and of being perfectly adapted to all the done so that should be the end of the problem. But conditions prevailing when the data were obtained. it would seem so only to those who are unfamiliar Their disadvantage, aside from the amount of with the great variations in the dimensions of lum- record keeping required, is that they may have ber which may be produced from a log, with varia- been produced in such a restricted set of condi- tions in the equipment used in producing this lum- tions that the values are not applicable anywhere ber and the skills of various operators, and finally, else. with the variations in the logs. All of these have an The second method is to prescribe all of the effect on the portion of the total log volume that pertinent conditions, e.g., allowance for saw kerf ends up as usable lumber and the portion that be- and shrinkage, thickness and minimum width and comes milling residue. length of boards, taper assumptions, etc., and then Historically the lumber industry has consisted to draw diagrams in circles of various sizes, rep- of a number of independent marketing areas or resenting the sawing pattern on the small end of even of separate companies. Since no industrial a log. These “diagram rules,” of which the organization or government agency had control Scribner is an example, will be good or bad, de- over the measurement of logs, each district or pending on how well the sawmilling situation fits even individual buyers could devise a rule to fit the assumptions used in producing the diagrams. a particular set of operating conditions. The re- The third basic procedure is to start with the sult is that in the United States and Canada there formula for some assumed geometric solid and are over 95 recognized rules bearing about 185 then make adjustments to allow for losses in saw Maintained at Madison, Wis., in cooperation with the University of Wisconsin. 1 kerf, slabs, edgings, and so forth. These are re- course of answering inquiries about the various ferred to as “formula rules” and as is the case rules. Most of the information was obtained from for any type of rule, their applicability will de- over 200 references listed in the Appendix, with pend on how well the facts fit all of the assump- the bulk of it attributable to the writings of H. C. tions. Belyea, Austin Cary, H. H. Chapman, H.S. Graves, The development of a rule may involve more H.E. McKenzie, and J. M. Robinson. Although log than one of these procedures. Thus, the step-like rules are no longer as big an issue as they once progression of values in a mill-tally or diagram were, they are an important element in the history rule may be smoothed out by fitting a regression of forestry and the lumbering industry and it equation. Or the allowance to be used for slabs seemed desirable to bring together under one and edgings in a formula rule may be estimated cover, all of the material that had been accumu- from mill-tally data. lated. Finally, there are the “combination” rules such The existing data on log rules is scattered, as the Doyle-Scribner which uses values from the incomplete, and often contradictory, hence, there Doyle Rule for small logs and from the Scribner are undoubtedly numerous errors and omissions Rule for large logs. The aim, of course, is to take in this work. The author would greatly appreciate advantage of either the best or the worst features receiving corrections or additions from readers. of the different rules. Particularly needed are complete tables of values This publication lists and describes all of the for the various mill-scale and diagram rules. log rules that the author has encountered in the 2 SYMBOLOGY Unless otherwise indicated, The diameter in inches, inside bark, at the small end of the log. The diameter in inches, inside bark, at the middle of the log. The length of the log in feet. Volume in board feet. Volume in cubic feet. 3 SECTION I LOG RULES OF UNITED STATES AND CANADA In this section the log rules used in United end. The volume of any log then would be, States and Canada are listed and described in alphabetic order. For a number of rules, refer- “Adirondack Standards” ence is made to the formula given by McKenzie. The three general types of formula which H. E. The volume of the Adirondack Standard (ignor- McKenzie used to approximate the values of many ing taper) is 25.6 cubic feet or roughly one-third rules are discussed in detail under the” McKenzie of a cord. It was usually regarded as equalling Rule” (page 26) and it is suggested that the 200 board feet though Defebaugh says that reader go over this section before examining the the Hudson River Boom Association allowed 186 other rules. board feet per standard. The second section starting on page 41 describes The Adirondack Standard was also called the some of the lumber measures that are sometimes Adirondack Market , Dimick Standard , Glens Falls confused with log rules, some general log volume Standard , and Nineteen-Inch Standard . Cary ( 44 ) formulae, and a few of the log rules used outside referred to it as the New York Standard but there of North America. were two other standard rules (Twenty-Two-Inch Standard and Twenty-Four-Inch Standard) that carried this name. Adirondack Market --See Adirondack Standard, The Adirondack Standard was one of a number of “standard” rules. In 1863, Maxfield Sheppard pub- lished his “Tables for Sawlogs” ( 179 ) in which the Adirondack Standard (and other volumes of logs of various dimensions were shown rules based on “Standards”) in terms of “standard” logs 12 feet long with small-end diameters of 15, 16, 19, 20, 21, and 22 In a number of early rules, the volume of a inches plus one for a standard 13 feet long and given log or group of loge was expressed in terms 19 inches in diameter. In Canada, Crown Timber of the number of “standard” logs of equivalent Regulation lf, 1866, applicable to “Upper” and cubic volume. Thus, if the standard was defined “Lower” Canada assessed dues on the basis of a to be a log d inches in diameter and feet in standard sawlog 13-1/2 feet long and 20 inches in length, then for a given log D inches in diameter least diameter ( 162 ). Roy ( 169 ) states that among and L feet in length the volume in number of the units of measurement used in Quebec between standards would be, 1865 and 1890 was a “standard” log 17 inches in diameter and 16 feet long which was later con- sidered the equivalent of 200 board feet. The Saranac Standard , used along the Saranac River of northern New York, was based on a log One of the better known and more persistent of of 22 inches in diameter and 12 feet long, which these rules was the Adirondack Standard which is was equivalent to 250 board feet. It was also called generally attributed to Norman Fox who lumbered the Twenty-Two-Inch Standard or the New York in the Sacandaga and upper Hudson watershed of Twenty-Two-Inch Standard and was apparently the northern New York from 1814 to 1821. same as the Canadian Twenty-Two-Inch Standard . The Adirondack Standard was defined as a log The Quebec Standard was a log 20 inches in 13 feet long and 19 inches in diameter at the small diameter and 12 feet long and five standards were Underlined numbers in parentheses refer to literature cited at the end of this report. 9 assumed to be equivalent to 1,000 board feet. This Rule but it is often called the Alberta Rule because rule is ascribed to Norman Fox (author of the it was made the official rule of that province in 1957 Adirondack Standard) who moved to Canada some- (by Order-in-Council 263/57).