Softwood Sawmill Improvement Program

The relationship between annual softwood sawmill production and lumber processing variables was examined using data from Sawmill Improvement Program (SIP) studies of 650 softwood mills. The variables were lumber recovery factor (LRF); headrig and resaw kerf width; total sawing variation, rough green size, and oversizing-undersizing for 4/4 and 8/4 lumber; planer allowance; and average log diameter and length. All variables except planer allowance and average log diameter were significantly influenced by annual sawmill production. The conversion efficiency of the mills in terms of most of these variables increased as sawmill size increased but decreased at annual production levels approaching or exceeding 100 million board feet. Study sawmills were grouped by geographic region and annual production class. Weighted values of LRF, sawing, and resource variables were calculated for each region by weighting by the percentage of mills of that production class in each category. Weighted and mean values are presented for each annual production class by region.

The relationship between annual softwood sawmill production and lumber processing variables was examined using data from Sawmill Improvement Program (SIP) studies of 650 softwood mills. The variables were lumber recovery factor (LRF); headrig and resaw kerf width; total sawing variation, rough green size, and oversizing-undersizing for 4/4 and 8/4 lumber; planer allowance; and average log diameter and length. All variables except planer allowance and average log diameter were significantly influenced by annual sawmill production. The conversion efficiency of the mills in terms of most of these variables increased as sawmill size increased but decreased at annual production levels approaching or exceeding 100 million board feet. Study sawmills were grouped by geographic region and annual production class. Weighted values of LRF, sawing, and resource variables were calculated for each region by weighting by the percentage of mills of that production class in each category. Weighted and mean values are presented for each annual production class by region.