Table 1 . --Relationship of system variables to cost 



Symbol 



Variable description 



Units 





^2 



s 



^4 





^6 



s 





A 



Total logging area 



acres 



X 



X 









X 







Dc 



Construction method cost 



$/hr. 







X 



X 



X 









Dm 



Layout method cost 



$/hr. 





X 















US 



Skidding method cost 



3>/hr. 















X 



X 



r 



Productivity (construction) 



yd . /nr. 







X 



X 



X 









rm 



Productivity (layout) 



C*. /I . 



rt . /hr . 





X 















HI 



nx 



Excavat ion/ 1 and ing 



yd . / 1 anding 











X 









nx 



nxcdVciL ion/ r L • or roau 



yu . / Tz . -ra . 







X 















Lidnaing lengun 



ree L 











X 









T V 



Ml im o T* IrtfTC /irr^lii TTl a 

 INUJUUCX lU^O/ vUlUlllU 



of timber 



logs/MBF 

















X 



Mx 



Maximum road grade 



decimal % 







X 











X 



Nc , 



Move-in cost (construction) 



$/move 



X 

















Ns 



Move-in cost (skidding) 



$/move 







- 







X 







Pc 



Productivity coef. (const.) 



none 







X 



X 



X 









Pm 



Productivity coef. (layout) 



none 





X 















Ps 



Productivity coef. (skid) 



none 

















X 



Ro 



Percent rock in excavation 



decimal % 







X 



X 



X 









S 



Slope of sidehill 



/ 



decimal % 







X 



X 



X 









Sp 



Time/setup (skidding) 



hr. /setup 















X 





V 



Timber volume/horiz . area 



MB F/ acre 



X 



X 



X 



X 



X 



X 



X 



X 



Vc 



Volume/skidding cycle 



MBF/cycle 

















X 



w 



Road width 



feet 







X 



X 











Wl 



Landing width 



feet 











X 









X 



Road spacing 



feet 





X 



X 



X 



X 





X 



X 



Y 



Landing spacing 



feet 











X 







X 



Zb 



Level road/switchback 



feet 









X 











Zs 



Distance between setups 



feet 















X 





dav. 



Average skidding distance 



feet 

















X 



^1,2,3,4 



Regression coefficients 



none 

















X 



7 



