COMPARISON, VIA THE SEESAW SIMULATOR, OF THREE SAWING SYSTEMS FOR PRUNED LOGS

Data from 89 real pruned Pinus radiata D. Don logs, representing most of the pruned log types currently being traded in New Zealand, were used in a com-parison of sawing systems. Each log was "sawn " three times in the SEESAW simulator to provide results from No Taper Cant, Half-taper Cant, and Half-taper Live sawing. Total conversion to sawn timber and volumes of clearwood recovered were very similar under all systems but the form in which this timber was produced differed markedly. Half-taper Cant sawing proved the best system for most purposes because it produced the fewest pieces and the most desirable distribu-tion of widths. No Taper Cant sawing gave the second best result and is recommended as a good system for mills which do not have a half-taper sawing capacity. Half-taper Live sawing gave the poorest result with a 43 % increase in the number of pieces produced and 47 % of clears grades recovered in narrows less than 100 mm wide