. Lumber recovery from dead ponderosa pine in the Colorado Front Range. Studies on dead white pine (Pinus monticola Dougl. ex D. Don) in Idaho (Snellgrove and Cahill 1980) and on tussock moth-killed grand fir {Abies grandis (Dougl. ex D. Don) Lindl.) in Oregon (Snellgrove and Fahey 1977) show similar results with regard to classes. Cubic recovery percentâThe CR% of mill-length logs for surfaced-dry lumber, rough-green lumber, sawdust, and chips for the combined classes sums to 100 per- cent (fig. 2). The difference between surfaced-dry lumber and rough-green lumber is shrinkage and planer shav
. Lumber recovery from dead ponderosa pine in the Colorado Front Range. Studies on dead white pine (Pinus monticola Dougl. ex D. Don) in Idaho (Snellgrove and Cahill 1980) and on tussock moth-killed grand fir {Abies grandis (Dougl. ex D. Don) Lindl.) in Oregon (Snellgrove and Fahey 1977) show similar results with regard to classes. Cubic recovery percentâThe CR% of mill-length logs for surfaced-dry lumber, rough-green lumber, sawdust, and chips for the combined classes sums to 100 per- cent (fig. 2). The difference between surfaced-dry lumber and rough-green lumber is shrinkage and planer shavings. Chippable percentage is 100 minus rough-green lum ber and sawdust. The CR% curve shows the expected pattern of low recovery for small logs, which increases sharply for intermediate size logs and levels off for large logs. Mills are generally less efficient at converting small logs to lumber; therefore, a higher percentage of the log volume ends up as chips or hog fuel. Although there was no difference in the CR% among the classes, there was an in- crease in the percentage of narrow boards. The percentage of boards 6 inches and narrower was 46 percent for class I logs and 58 percent for class III logs. This in- crease can probably be attributed to drying checks in trees, which cause splits in lumber. These splits can result in narrower or lower graded boards. Similar results were shown for dead western white pine (Snellgrove and Cahill 1980). 100 -i â â 1 90 -. 10 0 4 8 12 16 20 24 Diameter (inches) Figure 2âRelation of cubic volume recovery to small-end diameter for all logs combined. Cubic recovery percent of surfaced-dry lumber increases as log size increases, while shrinkage and planer shavings and sawdust remain constant over diameter. Equations and statistics are given in table Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not pe
Size: 2290px × 1091px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
