LOGGING IN THE DOUGLAS FIE EEGION. 
181 
ber of cars, unloaded and loaded, that can be hauled at a trip is 
illustrated in Table 30. 
Table 30. 1 — Effect of grade on number of cars thai can be hauled at a trip. 
TRAFFIC DOWNHILL. 
Rate of 
grade 
(per 
cent). 
Resist- 
ance in 
pounds 
per ton. 
Weight 
of loco- 
motive 
(rons). 
Number 
of empty 
cars per 
train 
(uphill). 
Capacity 
of train 
in feet 
board 
measure 
of logs 
(down- 
hill). 
Capacity 
of each 
ear 
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 
i so; ono 
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). 
N umber 
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 
5 
95, 000 
70; 000 
4 "',000 
35, 000 
25, 000 
5,000 
5,000 
5, 000 
5,000 
5,000 
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 -1 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, 
