Curve sawing is a primary log breakdown process that incorporates gang-saw technology to allow two-sided cants from logs with sweep to be cut parallel to the log surface or log axis. Since curve-sawn logs with sweep are cut along the grain, the potential for producing high quality straight-grain lumber and cants increases, and strength, stiffness, and dimensional stability are maximized. Presently, curve sawing methods are widely incorporated in high production softwood lumber manufacturing facilities. However, with a few exceptions, the practice of curve sawing is virtually nonexistent in hardwood sawmills. A previous study indicated that approximately one-third of hardwood sawlogs contain measurable sweep. The purpose of this study was to investigate the impact of sawing pattern (straight vs. curve sawing) on lumber, cant, and pallet part yield from small-diameter hardwood logs with varying degrees of sweep. The results of this study indicate that cant and pallet part yields are not affected by sweep since cants are cut from the center of a log. Although curve-sawn pallet cants did not straighten out completely when stacked, they did not cause handling problems during the pallet part manufacturing process. The yield of lumber from the outside ofcurved logs increases significantly when curve sawn. The results indicate that lumber yield can be as much as 10 to 12 percent higher when curve sawing hardwood logs with an average sweep of 3.3 inches and greater (12-ft basis). Since approximately one-third of hardwood logs are not considered straight, significant lumber yield improvements can occur when curve sawing lumber and cants from these logs.
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