TESTS OF ROCKY MOUNTAIN WOODS FOR TELEPHONE POLES. 



15 



POLES. 



Table 1 gives the test data for individual poles. 



Table 2 gives the maximum load of each pole in terms of both the 

 equivalent pull at the top and the actual load obtained in the testing 

 machine at the ground line. This table is of value chiefly in com- 

 parmg the results of these tests with those from other methods of 

 applying the load, as all may be reduced to the reaction at the top 

 support for poles of the same size. 



Table 3 gives a summary and comparison of the average results 

 obtained in the tests on the four classes of poles, based on the western 

 red cedar as 100. On a basis of fiber stress developed it will be 

 seen that — 



1. Air-seasoned lodgepole pine is superior to western red cedar in 

 all the mechanical properties determined. 



2. Fire-killed lodgepole pine is only 80 per cent as strong as western 

 red cedar at maximum load. In elastic values, however — that is, the 

 fiber stress at elastic limit and the work absorbed up to this point — 

 they are practically equal. In stiffness the fire-killed lodgepole pine 

 is quite comparable to the cedar, although the latter proved to be a 

 more flexible wood. 



3. Fire-killed Engelmann spruce was inferior in all mechanical 

 properties to the cedar and pine. 



Table 2. — Top and ground-line loads required to break poles. 





Western red cedar, 

 cut green and air 

 seasoned. 



Lodgepole pine, 

 cut green and air 

 seasoned. 



Lodgepole pine fire 

 killed 10 years. 



Engelmann spruce 

 fire killed 10 

 years. 



Pole No. 



Top reac- 

 tion at 

 maxi- 

 mum, 

 load. 



Maxi- 

 mum 

 load at ■ 

 ground 

 line. 



Top reac- 

 tion at 

 maxi- 

 mum 

 load. 



Maxi- 

 mum 

 load at 

 ground 

 line. 



Top reac- 

 tion at 

 maxi- 

 mum 

 load. 



Maxi- 

 mum 

 load at 

 ground 

 line. 



Top reac- 

 tion at 

 maxi- 

 mum 

 load. 



Maxi- 

 mum 

 load at 

 ground 

 line. 



1 



Pounds. 

 2,020 

 1,705 

 2,238 

 2,075 

 1,745 

 2,070 

 2,090 

 1,782 

 1,762 

 2,320 

 1,473 

 2,948 

 2,360 

 1,768 

 2,175 

 1,854 

 2,244 

 2,005 

 1,935 

 2,440 



Pounds. 

 11,600 



9,800 

 12,870 

 11,920 

 10,030 

 11,900 

 12,000 

 10,250 

 10, 130 

 13,320 



8,470 

 16,940 

 13,580 

 10, 170 

 12, 500 

 10,650 

 12,900 

 11,530 

 11, 120 

 14,030 



Pounds. 

 2,185 

 1,770 

 1,866 

 2,740 

 1,913 

 2,182 

 1,975 

 2,828 

 2,219 

 1,938 

 2,226 

 2,463 

 2,638 

 1,928 

 2,116 

 3,050 

 1,854 

 2,635 

 2,395 

 2,445 

 2,148 

 1,991 



Pounds. 

 12, 580 

 10, 190 

 10, 720 

 15,730 

 11,000 

 12, 540 

 11,350 

 16,240 

 12, 750 

 11,130 

 12,800 

 14, 180 

 15, 150 

 11,080 

 12, 170 

 17, 520 

 10, 650 

 15, 130 

 13,770 

 14,050 

 12,340 

 11,450 



Pounds. 



714 



Pounds. 

 4,110 



Pounds. 

 1,811 

 1,980 

 1,431 

 1,262 

 1,094 

 2,053 

 2,105 

 2,652 

 1,205 

 1,963 

 1,900 

 2,270 

 1,810 

 1,515 

 2,640 

 1,449 

 1,726 

 731 

 2,058 

 1,850 



Pounds. 

 10, 410 

 11 390 



2 



3 



1,094 

 1,980 

 2,000 

 1,852 

 2,370 

 1,762 

 1,854 

 1,873 

 2,118 

 2,840 

 2,270 

 2,526 

 1,267 

 2,220 

 1,377 

 1,412 

 1,369 

 1,822 



6,290 

 11,380 

 11,500 

 10,650 

 13,620 

 10, 130 

 10,650 

 10,780 

 12, 180 

 16,320 

 13,070 

 14,520 

 7,280 

 12,780 

 7,910 

 8,120 

 7,870 

 10,480 



8 230 



4 



7,260 

 6,290 

 11 800 



5 



6 



7 



12 100 



8 



15,250 

 6,930 

 11 290 



9 



10 



11 



10;920 

 13 050 



12 . 



13 



10,400 

 8,710 

 15 190 



14 



15 



16 



8,330 

 9,920 

 4 210 



17. 



18 



19 



1 1 820 



20 



10 620 



21 





22 





























Average 



Maximum 



Minimum 



2,050 



2,948 

 1,473 



11,785 

 16,940 

 8.470 



2,250 

 3,050 

 1,770 



12,930 

 17,520 

 10, 190 



1,830 



2,840 



714 



10,510 

 16,320 

 4,110 



1,775 



2,652 



731 



10,210 

 15,250 

 4,210 



