Original
General Order
95
Section
IV
Strength Requirements for All Classes of
Lines
Table 5
Wood strengths
Species |
Modulus of rupture in bending |
|
Sawed rectangular poles, crossarm, etc. (a) |
Round Poles |
|
Cedar, western red |
4,700 lbs. Per sq in |
5,600 lbs. Per sq in |
Douglas fir, dense |
6,300 lbs. Per sq in |
6,800 (b) lbs. Per sq in |
Douglas fir, not dense |
5,800 lbs. Per sq in |
6,800 (b) lbs. Per sq in |
Fir, white or red, local |
4,700 lbs. Per sq in |
5,600 lbs. Per sq in |
Pine, southern yellow, dense |
6,300 lbs. Per sq in |
6,800 (b) lbs. Per sq in |
Pine, southern yellow, not dense |
5,800 lbs. Per sq in |
6,800 (b) lbs. Per sq in |
Redwood, virgin |
5,300 lbs. Per sq in |
6,200 lbs. Per sq in |
Redwood, second growth |
3,900 lbs. Per sq in |
4,600 lbs. Per sq in |
(a)
Figures given are for select structural
grade of material under short time loading with the neutral plane parallel
to a side. Multiply the values shown by 1.4 where the neutral plane
is on the diagonal of a square. Multiply the given values by 0.55 where
the loading being considered is a long time loading (continuous load for
one year or more).
(b) Where poles meet specifications of American Standards Association, 05.6-1941 for Douglas Fir Poles (creosoted) and 05.4-1941 for southern Pine Poles (creosoted), this value may be increased to not more than 7,400 lbs. Per square inch.