. Lumber recovery from old-growth coast Douglas-fir. Douglas fir; Lumber. o o S 30 20 o DC LU Q 10 Sawn-length defect percent = + (diameter) standard error estimate = Woods-length defect percent = + (diameter) standard error estimate = Woods-length logs. Sawn-length logs 1 10 20 30 40 50 SCALING DIAMETER (Inches) 60 70 80 Figure 6.—Relationship of scale defect to scaling diameter. The total gross scale of the woods- length logs was 2, 362,010 board feet, and the total net scale was 2, 019, 870 board feet. The average deduction was 14 percent of the gross scal
. Lumber recovery from old-growth coast Douglas-fir. Douglas fir; Lumber. o o S 30 20 o DC LU Q 10 Sawn-length defect percent = + (diameter) standard error estimate = Woods-length defect percent = + (diameter) standard error estimate = Woods-length logs. Sawn-length logs 1 10 20 30 40 50 SCALING DIAMETER (Inches) 60 70 80 Figure 6.—Relationship of scale defect to scaling diameter. The total gross scale of the woods- length logs was 2, 362,010 board feet, and the total net scale was 2, 019, 870 board feet. The average deduction was 14 percent of the gross scale. The defect deductions of the two scaling systems are almost identical as shown in figure 6. The gross and net scale values for the woods-length logs average about 16 percent lower than those of the sawn-length logs due to the differ- ence in scaling practices. LUMBER TALLY RATIOS (OVERRUN) The ratios of lumber tally to net scale (overrun values) are related to log size and defect. The ratios tend to decrease with increasing log diameter. The reader may observe a different trend in recovery ratios for each log grade, but this is due in part to the diameter distribution of the logs in the grades. If the differences due to diameter distribution are considered, the differences in recovery ratios are not too marked. The relationship is shown in figure 7. Due to the different scale basis, the woods-length ratios are consistently higher. CUBIC RATIOS The relationship of the lumber cubic volume recovery ratio to scaling diameter is shown in figure 8. This ratio has an opposite trend to that of the lumber tally ratio. The cubic ratio tends to increase as diameter increases. On the average, about 63 to 64 percent of the cubic content of the log was manu- factured into rough green lumber. Ap- proximately 25 percent of the rough green lumber volume was lost as planer shavings and shrinkage. Thus, about percent of the cubic log content was shipped as lumber. The relationship of lu
Size: 2628px × 951px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookco, booksubjectdouglasfir, booksubjectlumber
