**Original
General Order
95**

**Section
IV**

**Strength Requirements for All Classes of
Lines**

**48.2****
****Structural
Steel**

Steel structures, steel structural members and their connections, shall be designed and constructed so that the structures and parts thereof will not fail or be seriously distorted at any load less than the maximum working loads developed under the construction arrangement with loadings as specified in Rule 43) multiplied by the safety factors specified in Rule 44.

The safety factors specified in Rule 44 shall be applied as follows to structural steel:

**Tensions and Bending:** The yield point, 33,000
pounds per square inch, shall be divided by the safety factor to determine the
maximum allowable working stress.

**Compression:** The maximum allowable working stress
shall be calculated by the following formula:

where S_{max}
= maximum allowable working stress, lbs per sq in.

f_{s} = safety factor specified in Rule 44

YP = yield point of the steel, 33,000 lbs per sq in.

l = unsupported length of member, inches

r = radius of gyration of member, inches

**Shear:** The ultimate tensile strength, 60,000 pounds
per square inch, shall be multiplied by 2/3 and divided by the safety factor
specified in Rule 44 to determine the maximum allowable working stress.

Where the figures given are used, structural steel shall conform to Standards Specifications A7-39 of American Society for Testing Materials for carbon steel of structural quality. Other values may be used for steel of other strength provided the yield point and ultimate tensile strength are determined by test.