Table 1. — 1971 data — balloon logging 







(B) 





(C)2 







(P)3 



Unit 



Volume 



Piece size 



Yarding cost 



Turns per 



Pieces per 



Percent 



# 



M bd. ft. /acre 



bd . ft . /piece 



$/M bd.ft. 



productive 



productive 



productive 





(mVha) 



(m^/piecc) 



($/m3) 



hour 



hour 



hours 



1 



11.0 



350 



38 



.97 



5. 02 



1 1 . 34 



76.9 





(125) 



(1.58) 



(8 



.61) 









2 



6.5 



236 



59 



.73 



4. 14 



11 .42 



63. 7 





(70) 



(1.07) 



(13 



.20) ■ 









3 



5.0 



259 



65 



.77 



4.59 



11,35 



59.7 





(56) 



(1.17) 



(14 



.54) 









14 



7.3 



192 



63 



.70 



k 



k 



h 





(81.6) 



(0.87) 



(14 



.08) 









13 



11.9 



216 



49 



.62 



5.89 



16.33 



72. 3 





(133) 



(0.98) 



(10 



.97) 









16 



13.0 



293 



37 



.10 



6.35 



19.22 



69.5 





(145) 



(1.33) 



(S 



.20) 









Average volume harvested on the unit in thousand board feet per acre. 

 ^ The cost in dollars per thousand board feet for moving the logs from the stump to the 

 landing (this includes balloon yarding, changing cable roads, landing costs, as well as 

 costs for yarder downtime) . 



3 Total yarding hours divided by total hours logged by yarder times 100. 

 ^ Data, were not collected as tliis was the first unit logged on the sale. 



Equation (1) shows that costs decrease as average piece size increases with this 

 single variable explaining approximately one-half of the cost variation. Average piece 

 size is used by many logging companies as one criterion on which to estimate costs of 

 logging. From a physical standpoint, it also is reasonable to expect that costs would 

 be lower when fewer pieces liad to be handled per M bd.ft. of production. 



In equation (2) , volume per acre explained 83 percent of the variation in cost per 

 M bd.ft. This relationship shows that volume per acre is the most important factor for 

 predicting the cost of balloon yarding. At first glance, volume per acre seems to 

 explain more of the cost variation than would be expected. Further analysis yielded a 

 relationship between percent productive hours (P) and volume per acre 



P = 53.50 + 1.5SV or in metric terms > (4) 



3 



P = 53.50 + 0.1413(^) 

 ha 



with an - 0.6795. This equation shows that the percent productive hours increases as 

 the volume per acre increases. Rased on field experience, it is reasonable to expect 



14 



