General Order 64-A
Section IV
Strength Requirements For All Classes Of Lines
Table 4
Minimum Safety Factors*
Element of Line |
Grade of Construction |
|||
Grade “A” |
Grade “B” |
Grade “C” |
Grade “F” |
|
Conductors, splices and conductor fastenings (other than tie wires) |
2 |
2 |
2 |
1 |
Pins |
2 |
2 |
2 |
1 |
Pole line hardware |
2 |
2 |
2 |
2 |
Line insulators (mechanical) |
3 |
2 |
2 |
2 |
Guy Insulators (mechanical) |
|
|
|
|
Interlocking |
2 |
2 |
2 |
2 |
Noninterlocking |
3 |
3 |
3 |
-------- |
Guys, except in light loading districts |
2 |
2 |
2 |
1 ½ |
Guys, in light loading rural districts |
2 |
1 ½ |
1 ½ |
1 ½ |
Messengers and span wires |
2 |
2 |
2 |
2 |
Wood poles |
4 |
3 |
2 |
1 |
Structural or tubular steel poles, towers, crossarms and steel members of foundations |
1 ½ |
1 ¼ |
1 ¼ |
-------- |
Foundations against uplift |
1 ½ |
1 ½ |
1 ½ |
-------- |
Foundations against depression |
3 |
2 |
2 |
-------- |
Reinforced concrete poles |
4 |
3 |
3 |
-------- |
Crossarms (wood) |
2 |
2 |
2 |
1 |
*All tables covering detail specifications considered as meeting the safety factors prescribed herein.