KOCKY MOUNTAIN MINE TIMBERS. 7 
Table 4. — Summary of bending tests on round beams, 16 feet long (span, 15 feet; third- 
point loading). 
GREEN (WATER SOAKED). 
Species, size, number of 
Moisture. 
Rings 
per 
inch. 
Diameter. 
Modulus 
of 
rupture. 
Fiber 
stress at 
elastic 
limit. 
Stiffness 
factor 
Cu) 
Work 
to maxi- 
tests. 
Top. 
Butt. 
mum 
load. 
Lodgepole pine, cut 'from 
live timber: 
8-inch butt, 10 tests- 
Average 
Per cent. 
77.3 
99.4 
62.1 
90.2 
118.2 
73.4 
91.8 
99.6 
78.3 
38.1 
45.2 
35.0 
40.1 
47.7 
29.8 
37.2 
41.7 
27.8 
32 
37 
28 
27 
32 
21 
23 
24 
18 
44 
52 
34 
40 
48 
35 
28 
34 
24 
Inches. 
6.77 
7.32 
6.29 
8.26 
9.23 
7.24 
9.82 
10.82 
9.23 
7.00 
7.08 
6.92 
8.21 
9.23 
7.56 
10.00 
10.98 
9.31 
Inches. 
8.20 
8.75 
7.76 
9.97 
10.74 
9.39 
11.62 
12.41 
10.98 
8.50 
9.06 
7.80 
10.24 
11.14 
9.71 
12.47 
12.97 
11.77 
Lbs. per 
sq. in. 
5,348 
6,210 
4,860 
5,233 
6,230 
4,510 
5,095 
6,2 7 
4,230 
5,448 
6,580 
3,570 
4,940 
6,500 
3,870 
4,430 
5,680 
3,820 
Lbs. per 
sq. in. 
3,120 
4,200 
2,425 
3,008 
3,905 
2,038 
2,987 
3,780 
2,298 
2,905 
3,690 
2,210 
2,950 
4,180 
1,592 
2,320 
2,960 
1,828 
10.99 
13.42 
9.26 
10.32 
11.73 
7.48 
10.23 
13.70 
8.16 
10.38 
13.25 
8.00 
8.84 
10.97 
7.09 
7.71 
9.71 
5.18 
Inch lbs. 
per cu. in. 
4.7 
Maximum 
Minimum 
6.6 
2.6 
10-inch butt, 10 tests- 
5.5 
Maximum 
7.8 
Minimum 
3.2 
12-inch butt, 10 tests- 
Average 
5.2 
Maximum 
7.0 
Minimum 
2.0 
Lodgepole pine, cut from 
timber after standing 
dead for 30 years: 
8-inch butt, 5 tests- 
Average 
5.3 
7.6 
Minimum 
2.3 
10-inch butt, 5 tests- 
3.4 
Maximum 
5.4 
Minimum 
1.6 
12-inch butt, 5 tests- 
Average 
4.3 
8.2 
Minimum 
2.0 
AIR SEASONED. 
Lodgepole pine, cut from 
live timber: 
8-inch butt, 5 tests- 
Average 
Maximum 
Minimum 
10-inch butt, 5 tests- 
Average 
Maximum 
Minimum 
12-inch butt, 5 tests- 
Average 
Maximum 
Minimum 
Lodgepole pine, cut from 
timber after standing 
dead for 30 years: 
8-inch butt, 9 tests- 
Average 
Maximum 
Minimum 
10-inch butt, 10 tests- 
Average 
Maximum 
Minimum 
12-inch butt, 11 tests- 
Average 
Maximum 
Minimum 
16.8 
19.9 
15.2 
32 
34 
29 
6.99 
7.64 
6.37 
8.04 
8.36 
7.64 
7,748 
9,310 
7,160 
5,018 
5,290 
4,640 
14.05 
16.80 
12.43 
17.1 
18.3 
14.6 
25 
27 
23 
8.09 
8.59 
7.08 
9.77 
10.03 
9.55 
6,948 
9,060 
4,480 
4,816 
5,940 
3,190 
13.33 
18.75 
10.31 
19.3 
21.8 
17.7 
22 
23 
21 
9.73 
9.95 
9.55 
11.51 
11.81 
11.14 
5,409 
6,350 
3,745 
3,741 
4,340 
2,875 
9.57 
11.62 
6.85 
13.7 
14.6 
11.5 
40 
51 
34 
6.98 
7.64 
6.45 
8.39 
8.91 
7.48 
5,625 
7,780 
3,843 
4,649 
6,720 
3,195 
10.92 
12.51 
9.58 
12.9 
14.4 
12.1 
34 
42 
24 
8.27 
8.91 
7.64 
10.11 
10.66 
9.31 
5,166 
8,970 
2,690 
4,489 
6,400 
2,585 
10.54 
13.53 
8.06 
13.8 
16.6 
12.0 
31 
37 
24 
9.16 
11.14 
9.07 
12.15 
12.49 
11.46 
4,720 
7,310 
2,060 
3,925 
5,960 
1,343 
9.84 
12.29 
8.12 
3.8 
4.9 
2.7 
3.1 
4.0 
1.5 
2.3 
3.0 
1.2 
2.1 
5.6 
2.3 
4.2 
.5 
1.7 
3.8 
.4 
The average results do not show a consistent difference in the 
relative strength of the various species tested. Figures 1 and 2 show 
that, with the exception of the green props and caps of Douglas fir 
and the dry props of lodgepole pine (Shipment B), there is not a 
very large difference in the strength of the various shipments. It 
