Skip to Main Content
Recovery from simulated sawn logs with sweep.Author(s): Robert A. Monserud; Dean L. Parry; Christine L. Todoroki
Source: New Zealand Journal of Forestry Science. 34(2): 190-205
Publication Series: Scientific Journal (JRNL)
PDF: View PDF (1.0 MB)
DescriptionA sawing simulator, AUTOSAW, was used to examine the effect of increasing sweep on lumber recovery. Sample material consisted of 51 logs from 22 western hemlock (Tsuga heterophylla (Raf.) Sarg. ) trees in western Oregon, United States. All knots on the 4.9-m logs were measured, mapped, and converted into 3-dimensional digital formats. The digital logs were then increasingly bent, in 25.4-mm (1-inch) increments, with the bend occurring at the mid-point for one set of logs and at quarterway from the log small-end for another, and sawn into primarily structural grade dimension lumber. On average, conversion decreased at a rate of 10% for each 100-mm increase in sweep, equivalent to a decrease of 5-7% for each 0.1 unit increase in sweep-to-diameter (s/d) ratio. Conversion losses were represented by an exponential decay function. There was no significant difference in conversions between the two sets of logs; however, the rate of loss of Select Structural and 1 Common lumber was greater for logs bent at the mid-point when sweep was within 51 to 152 mm (2 to 6 inches).
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationMonserud, Robert A.; Parry, Dean L.; Todoroki, Christine L. 2004. Recovery from simulated sawn logs with sweep. New Zealand Journal of Forestry Science. 34(2): 190-205
KeywordsAUTOSAW, sweep, conversion, grade recovery, value, modelling, Tsuga heterophylla
- Moisture distributions in western hemlock lumber from trees harvested near Sitka, Alaska.
- Sitka spruce and western hemlock beach logs in southeast Alaska: suitability for lumber, pulp, and energy.
- Product Recovery From Hemlock "Pulpwood" From Alaska.
XML: View XML