Feet/hour is the rate for building a skidding road. It appears as hours/feet in the 

 progran^ equation, 



Forbes! provided the following data on the performance of a typical roadbuilder using 

 crawler tractors: 



Performance Slope 



(Linear feet/hour) (Degrees) (Percent) 



400 10 17.6 



190 20 36.4 



110 30 57.7 



Using this data, we developed the following quadratic formula for estimating linear feet/ 

 hour of road bladed as a function of slope: 



F = 0.185 - 21.155 S + 715.045 



where : . F = linear feet per hour of road bladed 



S = percent slope. 



The regression equation of feet /hour as a function of slope is found at the end of Line 2, 

 statement 35, in the computer program. 



•^Forbes, Reginald D. Forestry handbook, section 18, page 20, table 12. 1,143 pp., 

 illus. New York: The Ronald Press Co. 1961. 



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