Predicted Cubic-foot Yields of Lumber, Sawdust, and Sawmill Residue from the Sawtimber Portions of Hardwood Trees by Leland FmHanks FOREST SERVlCE RESEARCH PAPER ME-380 11977 FOREST SEFSVlCE, U.S. DEPARTMENT OF AGRICULTURE NORTHEASTERN FOREST EXPERIMENT STAPiOM 6816 MARKEnSS-REEI, UPPER DARBY, PA, 19082 The Author LELAXD Ti", HANKS received his B.S. degree in forest management and his M,S*degree in forest mensuration from Iowa State University. During the summer sf 1961,he worked for the Forest Service in Washington, D.C., and accepted a position with the Central States Forest Experiment Station in 1962. He is now a. research fores"r,products tecfnnologist with the Kortheastern Forest Experiment Station" project on quality and grade of hard~roodLimber at Delaware, Ohio. MANUSCRIPT RECEIVED FOR Ptr BLXGATlbOK 24 C)@TBBER 3975 ABSTRACT Ve have presented prediction equations and tabfes for estimating the gross cubic-food volume of sawtimber for hardwood trees, and cubic-foot yields of lumber, sawdust, and sawmill residue that are produced during the sawing process. Yields are presented for northern red oak, black; oak, white oak, chestnut oak, red maple, sugar maple, yeHolv-poplar, yelloiv birch, paper birch, and basswood, Predicted Cubic-foot Yields of Lumber, Sawdust, and Sawmill Residue from the Sawtimber Portions of Hardwood Trees SINCE THE TURN of the century, much has SAMPLE been written about the board foot versus the cubic foot as the standard measure for tree vol- The trees used for this steady were selected in ume. Now, after many years, the cubic-foot groups of about 50 at 45 locations in 16 states measure is being viewed more favorably. (figs. 4-10), We measured the diameter at breast The board-foot measure has been used for height (dbh) on standing trees, and measured trees that are sawed into lumber, and this prac- the merchantable height after the trees were tice will continue for some time. But, if lumber felled. The merchantable height included all logs volume is measured in board feet, why not use that qualified as local use or better.' Inside bark the same unit for measuring log and tree diameter at each end of a log was measured to volumes? On the surface this may appear the nearest 0.1 inch, and length was measured to reasonable, but utilization practices have the nearest 0.1 foot. Log lengths ranged from 8 changed; the multiproduct tree is now on the to 16 feet, and averaged about 12 feet. The logs scene. Veneer, chips, sawdust, and, of course, were sawed, and nominal green board widths, lumber, are all being marketed from the same lengths, and thicknesses were recorded for all tree. And each of these products requires a lumber that was produced from the sawing. separate unit of measure. Ninety-five percent of the lumber volume was Initially we have to account for the total wood sawed in thicknesses of 4/4,5/4,6/4, and 8/4 in- content of a tree; this requires a unit of measure ch. We numbered the logs and boards so that all that can be used without regard for the product boards from a tree could be identified. that is marketed from that tree. The cubic foot For each of the 10 species that we studied, is such a measure, and cubic-foot tree volume data were separated by trees that were sawed at can be related meaningfully to any end product. band mills and those sawed at circular mills. The cubic-foot volumes of end products in this Because we required a minimum sample of 100 paper represent the output of several sawmills. trees for inclusion in the analysis, our investiga- The trees that were processed through the mills tion at circular mills was limited to red maple, varied in size, straightness, and interior defect; yellow-poplar, yellow birch, and paper birch. the mills' cutting schedules also varied. A total of 1,802 trees from all species were Therefore we are not presenting case histories sawed at band mills; 790 trees were sawed at cir- for specific sawmills and the surrounding timber, but species averages that will be useful A local-use class log must scale at least 8 inches in diameter inside bark (dib) by 8 feet long, and it must be one- to timber sellers and buyers. third sound. Figures I-10.-Location of general areas where sample trees for each species were cut. cular mills. Because of the 100-tree minimum, This equation produces the volume for a con- 242 of the trees that were sawed at circular mills oid, and has been. wed extensively for es- were available only for calculating the gross tree timating the cubic-foot volume for logs. Because volumes and the sawmill residue volumes (table of butt-flare, the first log was divided at breast 1). height, and volumes were determined for each section. DEPENDENT VARIABLES We used the equation to compute the cubic- foot volume of sawlogs for five groups of trees. Gross Tree Volume We compared these volumes with those that were computed from measurements obtained Gross tree volume is the volume inside bark with a Barr and Stroud dendrometer, a very ac- from the top of the stump to the top of the last curate measuring de~ice.~ sawlog. To calculate the actual gross tree volume, we added the cubic-foot volumes for all bucked sections, using this equation: Sectional cubic-foo t volume = .001818 (D2+Dd+d2)L D =inside bark diameter of large The use of trade, firm, or corporation names in this end publication is for the information and convenience of the d =inside bark diameter of small reader. Such use does not constitute endorsement or ap- proval by the Forest Service or the U.S. Department of end Agriculture of any product or service to the exclusion of L =log length others that rnay be suitable. Species Dendrome fur Equation Percen 1: of trees differe~ce - - .. - - - - - St" - - - - - - - Black oak 43 2,752 2,755 4"O.l White oak 88 4,382 4,350 -0.7 Yellow-poplar 66 4,278 4,313 +0,8 Yel low-poplar 53 3,749 3,"713 - 1.0 Bass wood 45 1,988 1,965 -1.2 The closeness of the sawlog volumes for each 514 1.40 tree group indicates that our equation provides 6/4 1.65 a good base from which to work. 714 1.95 814 2.20 Lumber Volume 914 2.50 1014 2.70 Lumber volume is the cubic-foot volume of 3- 1O3 nominal green lumber that is produced during the saw- ing of all sawlogs from a tree. We did not Therefore, the cubic-foot volume of each measure the actual dimensions of the lumber board that is sawed from the study trees is the sawed from study trees; instead, we recorded product of nominal width, nominal length plus 2 nominal sizes and adjusted them to industry inches, and average thickness, averages. These averages were then used to es- timate cubic-foot volume. To determine the in- dustry averages, we visited several mills and Sawdust Volume measured actual sizes of green lumber; other Sawdust volume is the cubic-foot volume of l%search groups provided similar data. As ex- solid wood that was to sawdust dur- ~ected,the actual width of rough hardwood ing the sawing of all sawlogs from a tree. The boards is random; this means that the industry sawdust volume equals the kerf multiplied by average width of boards in the 7-inch class is 7.0 the sum of the area that is included in both inches. We found that the industry practice for edges and one surface of each board. we used trimming hardwood lumber is to leave 2 inches kerfs of and 10164 for lumber sawed at of trim beyond the nominal length. Therefore and band mills, respectively. we added 2 inches to the nominal length of every board. It was more difficult to determine the in- Sawmill Residue Volume dustry average thickness for each thickness Sawmill residue Volume is the cubic-foot class because the thickness for each class varied volume of a tree-including rot and voids-that within and between The average reaches the mill and is not converted to lumber thicknesses that we used for the or sawdust. We calculated this volume for each thicknesses of lumber were: tree by subtracting the cubic-foot volumes of lumber and sawdust from the gross cubic-foot volume of sawlog material. Nwni%clE tkicfiaiess Ave~aget hick~zess (inc hesf (inches) A. small amount of timber and sound square-edge material was sawed in these sizes: when sawed properly, this material was sized to nominal thickness. " 22 ;v?z '3 m. y 9 H M=>-d't? W rim H hn m ri Go? %?c: zqoc: 2 a33 mmc- COmiCcw C3 Me9 MMrn mmMM .a -..?Go 'j'iqcioi w LC3 33 w m00m d rid ,+rid riN3Jd w mri WdCO rn=>rie $ Q?si Fa?" oisiclr-. 2 Z? -..zz $??Z 0 mri Wri0 Nf-C-CV 33 TFm wmm m dd ddN mmmmOTI'-;flO W W GI cli PI CL N 8% 2 232% 22 mwdm 2 2 8S8 fi SS88 a 8 88 990 4 0990 W 1 r3 ffi rn;r, h am mm0 d WM COmm NNrnrnmriw* 03 CDO MrnLC3 LOC-rim " 9.1 99" e999 C- coo Cnri-e CVm33m m rim meow dedwd m MCO hC3LC3W W';rC-hhl mm C-oOm g ?3 @2$$ GM3G9999 CD Me- C-Cr3M 33-d'ulioO ri Wri mmm wdm* C- ma COm-d' CnCnOoLC3 " c'3" OtjL?L? qO?o* mm Id* I I I I 71 y A - m V) e, 8 3 &G s --i 2 .yc cz 2 s* a'""-"$&2 % gm3 &z F "%= .C;a r= 2,s 2 E *$gz 2 p.5 23.6 $ 353: mcli n m $233 C MW MMM W'MOCM m om C-W~ C- WNCJ a NO mcom MOC-W di m05 t-rn03 d-tCclOC- CJ mm mmw 4CJ=cn Woo MC-C- mmmti .+ti~~w 61 dim caw weC-m r;;: 3% $2323 MtiOd dm OOd 9 99 9=* 9999 3 90 99s RESULTS between species are meaningful, he may com- bine two or more species and create a composite Prediction Equations table for gross cubic-foot t~olume.