94 BULLETIN 711^ U. S. DEPABTMENT OF AGRICULTURE. 



CASE 3. 



Equipment. Cost. 



12 by 14 inch standard compound-geared yarding engine $5, 000 



Repair parts and materials for yarding engine 220 



Yarding engine sled 450 



Fair-leaders 150 



Extended fire box 250 



JSti-aw driuu 150 



Electric signal 100 



Fuel-oil equipment and water tank 450 



Blocks and extra parts 675 



Yarding rollers 150 



Ground yarding lines: 1,000 feet of IJ-inch main line; 2,500 feet of |- 



incli trip line; and 2,500 feet of |-inch straw line 1,161 



Butt chains, butt hooks, and clevises 70 



Chokers and choker hooks 185 



Miscellaneous equipment 275 



Total cost 9, 286 



Note. — Statement includes equipment in use and in stock. 



COST. 



Output. — Taking it straight through by camps, good and bad 

 country, the ground yarding output, naturally the basic element in a 

 cost computation, ranges between 40,000 and 80,000 feet per yarding 

 engine per yarding day of 10 hours. A few camps average a little 

 less than 40,000 feet, others average more than 80,000. For a short 

 period the output may be considerably lower or higher. The largest 

 volume of timber ever yarded in a day of 10 hours in this region 

 amounted to 432,000 feet. The crew, on its mettle, was working in 

 ideal natural conditions and with first-class equipment. A crew 

 working in a particularly hard chance may get as little as 100,000 

 feet in one week ; in a particularly good chance, as much as 1,000,000 

 feet in the same time. 



The estimating of the average output in a given chance or set of 

 conditions is extremely difficult and liable to error. It has been esti- 

 mated that a yarding engine carrying 900 feet of line should average 

 45 logs, or from G7,500 to 90,000 feet per day in timber Avhere the logs 

 average from 1,500 to 2,000 feet to the log; 50 logs, or from 50,000 to 

 75,000 feet per day in timber where the logs average from 1,000 to 

 1,500 feet: 55 logs, or from 27,500 to 55,000 feet per day in timber 

 where the logs average from 500 to 1,000 feet; and 65 logs, or about 

 30,000 feet per day in timber where the logs average less than 500 

 feet. These estimates were based on time records. One hour eacli 

 day was allowed for moving yarding engines ; four for the placing of 

 chokers, unfastening of logs by the chaser, removing unmerchant- 

 able timber from the roads, hauling wood logs, changing lines, etc.; 



