FOR IDAHO JAMMER OPERATIONS. 



(See figure 3 on facing page for typical area configuration.) 



1. Average setup time = 0.416 hour (mean from 12 jammer operations). 



2. Area for setup = 40,000 sq.ft. or 0.918 acre. 



3. ComiDining steps 1 and 2 get 0.453 hour /acre. 



4. Average skidding distance = 466 feet (slightly beyond center because of diagonal 

 skidding) . 



5o Multiplying results from 3 and 4 get 211, thus y = 211/x (see explanation in step 5 

 under "FOR HIGH -LEAD, PORTABLE TOWER OPERATIONS"). 



FOR SHOVEL SKIDDER OPERATIONS. 



(See figure 4 on facing page for typical area configuration.) 



1. Average setup time = 0.099 hour (mean from 16 shovel skidding operations). 



2. Area for setup = 15,000 sq.ft. or 0.344 acre. 



3. Combining steps 1 and 2 get 0.29 hour /acre. 



4. Average skidding distance = 76 feet. 



5. Multipl\T.ng results from 3 and 4 get 22, thus y = 22/x (see explanation in step 5 

 under "FOR HIGH- LEAD, PORTABLE TOWER OPERATIONS"). 



Ideally, since the maximum skidding distance for shovel skidding is 150 feet, it would 

 seem that each setup covered a semicircular area enclosing 35,350 sq.ft. instead of 15,000 

 sq.ft. However, in practice figure 4 as sketched shows the typical operating procedure . 



FOR ROLLING STOCK SKIDD ERS. 



Setup times were not considered for rolling stock skidding operations, which includes 

 such equipment as tracklaying and wheeled skidders. This equipment is used in other opera- 

 tions of the production cycle; namely, traveling unloaded, clearing trails, hooking chokers, 

 freeing chokers , traveling loaded, unhooking chokers , and decking logs . However, "hook 

 chokers" were not included in the production cycle for rolling stock. 



$/hOUr denotes the hourly owning and operating costs normally experienced from 

 equipment service, which includes such items as depreciation (initial cost less salvage value), 

 interest, insurance, taxes, fuel and lubricants, repairs, tires, workmen's compensation, and 

 operator's wages. It is called "COST" in the program. The average hourly owning and 

 operating costs for the skidding operations observed follow: 



Roadbuilding costs are made up of the three inputs showTi in figure 1 and now described 

 separately. 



$/hour 



Crawler tractor, 25-40 DBHP 

 Crawler tractor, 41-60 DBHP 

 Crawler tractor, 61-80 DBHP 

 Crawler tractor, 110-130 DBHP 

 Rubber-tired vehicle, 55-80 BHP 

 Rubber-tired vehicle, 81-117 BHP 

 High -lead, portable tower 

 Idaho jammer 

 Shovel (w/tongs) 



6.86 

 8.21 

 9.97 

 12.00 

 6.78 

 9.85 

 18.87 

 16.00 

 8.36 



10 



