Production comparisons between the standard and study 

 units were made on an hourly basis, thinning on a per-acre 

 basis, and log production on the number of pieces handled or 

 volume produced per hour. Comparisons of production time 

 per acre and per hour are shown in table 8. Unit III required 

 the greatest number of hours per acre, probably because a trac- 

 tor was underutilized. The other unit systems were very similar 

 in hours per acre required. Unit IV had no landing time be- 

 cause logs were cut at the stumps and only decked at the landing. 



Table 8.— Production comparisons of man-machine hours per piece and per acre 



Systems 



Operation 



1 



II 



III 



IV 



Felling trees/h 



88 



38 



69 



40 



hours/acre 



1.52 



3.53 



1.94 



3.35 



Limb and buck trees/h 



M6.0 



'55.7 



30.4 



46.3 



hours/acre 



'2.91 



'2.41 



4.41 



2.89 



posts/h 



68 



71 







hours/acre 



2.03 



2.45 







Skid pieces/h 



31.8 



20.3 



21.9 



20.4 



hours/acre 



4.21 



6.60 



6.12 



6.57 



Landing pieces/h 



34.7 



95.2 



11.9 



NA 



hours/acre 



3.86 



1.41 



11.26 



NA 



Total hours/acre 



'12.50 



'13.95 



23.73 



12.81 



'Does not include post-making operation. 



Table 9.— Stand and treatment volumes on a per-acre basis for each of the study units 



Product recovery. — Sanitation-salvage cutting removed 60 

 percent of the volume on unit III, 75 percent on unit I, and 77 

 percent of the volume on unit II (table 9). The commercial 

 thinning, unit IV, removed 71.6 percent of the stand. All 

 insect-infested trees were removed from unit I, only commercial 

 sized trees were taken from unit III, and units II and IV were 

 thinned to 1 10 ft^ basal area. Logging residue was the cubic 

 volume of material left on the area after the trees or logs had 

 been skidded to the landing. 



Unit 



Item I II III IV 





FP 



Percent 



FP 



Percent 



Ft' 



Percent 



Ft' 



Percent 



Initial volume 



3,378 



100.0 



3,272 



100.0 



2,779 



100.0 



3,703 



100.0 



Removed 



2,540 



75.2 



2,519 



77.0 



1,668 



60.0 



2,650 



71.6 



Residual volume 



672 



19.9 



384 



11.7 



985 



35.5 



703 



19.0 



Logging residue' 



167 



4.9 



369 



11.3 



126 



4.5 



350 



9.4 



'Logging residues 1 inch (2.5 cm) or larger in diameter. 



7 



