LOGGING IN THE DOUGLAS FIR REGION". 



181 



ber of cars, unloaded and loaded, that can be hauled at a trip is 

 illustrated in Table 30. 



Table 30.^ — Effect of grade on number of cars that can be hauled at a trip. 



TRAFFIC DOWN HILL. 



Rate of 

 grade 

 (per 

 cent). 



Resist- 

 ance in 

 pounds 

 per ton. 



Weight 

 of loco- 

 motive 

 (tons). 



Number 

 of empty 

 cars per 



train 

 (uphill). 



Capacity 

 of train 

 in feet 

 board 



measure 

 of logs 

 (down- 

 hill). 



Capacity 

 of each 



car 



in feet 



board 



measure 



of logs. 



Weight 



of empty 



cars 



(tons). 



1 

 2 

 3 

 4 

 5 



30 

 50 

 70 

 90 

 110 



60 

 60 

 60 

 60 

 60 



62 

 36 

 25 

 19 

 15 



310, 000 

 180, 000 

 125, 000 

 95, 000 

 75, 000 



5,000 

 5,000 

 5,000 

 5,000 

 5,000 



10 

 10 

 10 

 10 

 10 



TRAFFIC UPHILL. 



Rate of 

 grade 

 (per 

 cent). 



Resist- 

 ance in 

 pounds 

 per ton. 



Weight 

 of loco- 

 motive 

 (tons). 



Number 

 of loaded 

 cars per 



train 

 (uphill). 



Capacity 



of train 

 in feet 

 board 



measure 

 of logs 



(uphill). 



Capacity 

 of each 



car 



in feet 



board 



measure 



of logs. 



Weight 



of loaded 



cars 



(tons). 



1' 

 2 

 3 

 4 

 5 



26 

 46 



■ 66 

 86 



106 



60 

 60 

 60 

 60 

 60 



19 

 14 

 9 

 7 

 5 



95, 000 

 70, 000 

 45, 000 

 35,000 

 25, 000 



5, 000 

 5,000 

 5,000 

 5,000 

 5,000 



27 

 27 

 27 

 27 

 27 



1 From The Timberman. 



Except when topographic conditions forbid, long main-line log- 

 ging railroads are usually constructed to permit the use of rod 

 engines. When such engines are used, the grades should not exceed 

 3 or 4 per cent where empty cars are moved up grade and 1 per cent 

 in the case of loaded cars ; and the sharpest curves should not exceed 

 16 degrees. In the more mountainous region, the main lines can not 

 be constructed for the use of rod engines except at a prohibitive cost, 

 so that geared engines must be used. In such cases, the maximum 

 grades do not ordinarily exceed 5 per cent when empty cars are to 

 be hauled up them and 2 per cent in the case of loaded cars. The 

 maximum curves used with a geared locomotive, as a rule, do not 

 exceed 20 degrees. 



Logging spurs are usually constructed for the use of geared 

 engines, since the grades and curves on these lines must be heavier 

 than those required on the main lines. Ordinarily, the maximum 

 grade for empty cars is 7 or 8 per cent ; for loaded cars, 3 or 4 per 

 cent. Most operators try to keep the maximum curvature of the 

 spurs down to 20 degrees, although in extreme cases the curvature 

 may run as high as 50 degrees. 



