**Original General Order
95**

**Appendix
C**

**Conductor Sags**

**(a) Basis of Sag Curves for Supply Conductors**

Data are presented in Appendix
C
in the form of curves in Charts numbers
1
to 9
inclusive, showing conductor sags which produce tensions that do not exceed
either 35% of ultimate strength of the conductor at 60° F. and no wind,
or 50% of ultimate strength (safety factor of 2) of the conductor under the
maximum loading conditions specified for Light or Heavy Loadings in
Rule 43
. These sags are considered particularly applicable to the stringing of new
wire (i.e., they should be considered initial sags for conductors which have
not been prestressed) and are not recommended in the case of used or so–called
prestressed wire.

The curves of the sag charts were drawn from computations made under the following conditions:

**1.
**Sag curves in the Light Loading charts are based on 35% of
conductor ultimate tensions at 60° F. and no wind.

**2.
**Sag curves in the Heavy Loading charts show sags which will
obtain at 60° F. and no wind, in conductors which are so strung that
under heavy loading conditions the conductor tension will be one–half of
the ultimate tension.

**3.
**The sag curves for weatherproof wire are for conductors having
a triple–braid–weatherproof covering.

**4.
**Conductor dimensions, weights and loadings were taken from
the tables in Appendix B.

**5.
** Modulus of Elasticity–lbs. per square inch

Copper |
17,000,000 |

Steel and iron, solid |
29.000,000 |

Steel, stranded |
21,000,000 |

Copper–covered steel, solid |
24,000,000 |

Copper–covered steel, stranded |
23,000,000 |

**6.
**Coefficient of Linear Thermal Expansion – per degree F.

Copper |
0.0000094 |

Steel and iron |
0.0000065 |

Copper–covered steel |
0.0000072 |