HOW TO USE TABLES 



Four variables must be known or estimated before entering the cost tables. These are: 



1. Area density in MBF/acre, which is presented for a range of from 5 to 15 MBF/acre 

 in steps of five on all of the tables . 



2. Skidding distances in feet. In tables 1-7, these are presented in 100-foot steps rang- 

 ing from 200 to 600 feet. In table 8, the distances range from 100 to 400 feet in 100-foot steps, 

 while in table 9 they range from 25 to 125, in 25-foot steps. 



3. Slope in percent, which ranges from 5 to 40 percent in steps of 5 percent on all tables. 



4. Number of logs/MBF, or tree size, which ranges from 4 to 16 logs/MBF in steps of 

 two logs on all tables. 



Example 1. 



Suppose the stand density in an operating area is about 10 MBF/acre, the average skidding 

 distance is 400 feet, the average slope is around 30 percent, and the number of logs/MBF cor- 

 responding to the stand density is 14. 



Enter table 1. The data under 10 MBF/acre would provide the desired values for the 

 operating conditions given. Look to the left column under "DISTANCE" and stop at the 400 

 group in the middle of the sheet, then choose the 30-percent slope to the right of the 400 group. 

 You are now on the correct row. Move across the row to the right and stop in the column 

 labeled 14 logs/MBF. The cost estimate is $7.65/MBF. 



Next turn to table 2. Proceed as you did in table 1 and you'll get $6.72/MBF. Continuing 

 in this manner using the remaining seven tables, you would derive the following: 





Cost 





($/MBF) 



Crawler tractor, 25-40 DBHP 



7.65 



Crawler tractor, 41-60 DBHP 



6.72 



Crawler tractor, 61-80 DBHP 



4.32 



Crawler tractor, 110-130 DBHP 



7.87 



Rubber -tired vehicle, 55-80 BHP 



4.04 



Rubber -tired vehicle, 81-117 BHP 



5.63 



High-lead, portable tower 



9.02 



Idaho jammer 



8.71 



Shovel (w/tongs) 



Not practical 



In this example, no extrapolated values were taken; hence, eight of the values may be 

 compared directly. Shovel skidding was not considered because 400 feet is outside its skidding 

 range. We immediately see that the smaller rubber-tired skidder is the most economical, as 

 could be expected because of the low stand density and small logs involved. 



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