~P\I3.P : t ffLCT Of RESAW ON OUTPUT Of SINGLE BAND MILLS IN SOUTHERN HARDWOODS May 1933 1 3 IR DA UNITED STATES DEPARTMENT OF AGRICULTURE FOREST SERVICE FOREST PRODUCTS LABORATORY Madison, Wisconsin In Cooperation with the University of Wisconsin Digitized by the Internet Archive in 2013 http://archive.org/details/effectOOunit EEEECT 0E RESAW ON OUTPUT 0? SIITC-LE BAiiD MILLS IK" SOUTHERN HARDWOODS* By R. D. GARVER, Senior Forester, and R. E. IIILLER, Associate Engineer Over one-third of a million "board feet of southern oak logs was recently timed and tallied "by the United States Forest Service through S sawmills located in Louisiana, Tennessee, and Arkansas. Half of these mills were equipped with a "band and resaw, and half had only a single hand saw. No quarter sawing was done during the test, so that the output from each group of mills should be comparable, except as influenced 'oy the use of a resaw. The table gives the milling time per thousand board feet for each group of mills, the relative output per hour, and the labor cost for logs varying in size from 10 inches to Uo inches. Overrun is shown for all mills together, because there was no appreciable difference for the two groups of mills. Eor comparative purposes, the 22-inch diameter class may be taken as an average for both groups of mills. The time required to saw a thousand board feet of lumber from 22-inch logs for single band mills was 1^.3 minutes, whereas in the band and resaw mills only S.U- minutes was necessary. Based on these time factors, the output for the first group would be ^,196 board feet an hour and, for the second group, J ,lhj, board feet. According to these figures, the output of a single band mill may be increased about 70 percent by the addition of a resaw. The time figures are for actual operation; no delay time is included. To operate the single band mills, an average of 21 men were required at a cost under present wage scales, of 6.33 cents a minute and, for the band and resaw mills, 29 men at a cost of 8 cents a minute. Based on these costs and time figures, the single band mills produced lumber at a mill labor cost of 91 cents per thousand board feet, and the band and resaw mills at 67 cents per thousand board feet. Summing up, the addition of a resaw to a single band mill increases the output 70 percent, and results in a decreased mill labor cost of 26 percent, also a substantial reduction of overhead costs. ♦Published in American Lumberman, May 27, 1933 R12^5 Out-put of single band and single "band and resaw mills whe n c utting southern oak± logs of different sizes Diameter [Overrun^ for .Milling time per I-i . Output per hour ? tally)z Mill labor cost inside all mills . (lumber tally)! : (lumbe; -oer M ( lumb er bark (net log t • illy) : scale basis) Single : Single Single Band and Single Single band : band and : resaw ' band resav; band band and resaw Inches Percent 50.8 Mi] lutes Boarc 1,9^3 1 feet 2,353 $1.95 10 30. : 25.5 S2.04 12 m.c 21.7 : 17.0 2,765 3,529 1.37 1.36 lk 31.5 17.9 : 12.3 • 3,352 M73 1.13 .98 16 21.0 lo.l : 9.9 3,727 6,06l 1.02 •73 18 12.5 15.3 : 8.7 3,922 6,897 •97 .70 20 5.5 1^.7 : 8.5 4,082 7,059 •93 .68 22 2.0 1^.3 : S.U M96 7,1^3 .91 ' .67 2k 1.0 13.9 8.3 4,317 7,229 .SS : . 66 26 .0 13.5 : 8.2 4,444 7,317 .85 : .66 28 : - .5 13.5 : S.l 4,444 7,^07 .85 .65 30 -1.0 13.5 : 8.0 4,444 7,500 .85 .64 32 : -1.5 : 13. 8 7.9 ! 4,348 7,595 .87 : .63 3^ -1.5 1U.5 : 8.0 4,138 7,500 : .92 : .64 36 : -2.0 15.3 : 8.1+ 3,922 7,1*3 - • 7 .67 38 : -2.0 lb.2 : 9.2 : 3,70U 6,522 1.03 : .7^ ho -2.5 17.2 10.2 3,488 5,SS2 1.09 .82 —Includes the following oaks: overcup, cherrybark, willow, lowland black, nut tall, and pin. 2 —Based on Scribner Decimal C Log Rule and green lumber tally. ^Actual running time. —Green lumber tally. RI2U5 -2- ■2!L V .£S3Z£ ? F foRiDA 3 1262 08866 4619