Typical Communication Line Construction
 

For a communication line carrying from approximately 6 to 20 conductorsin a Light Loading area, the following specifications adequately meet all intents and requirements of this order:

Poles

Round, wood, butt–treated, 25 feet in length, minimum top circumference of 15 inches, and set to a depth of 4.5 feet in firm soil.

Crossarms

3–1/4 x 4–1/4 x 10’. Attached by means of through bolts and washers, with a 15 inches center line of pole clearance to nearest conductors. Standard 30 inches quarter braces installed on the face of the crossarm with 3/8 inch bolts and 1/2 inch drive screw at the pole.

Pins

1–1/4'' x 8'' wood pins.

Insulators

Pin type insulators to be of design that will engage the thread of the pin for not less than two and one–half turns.

Conductors

Size and material dependent upon the class of circuit involved.  The average span length is 150 feet.

Guys

For guying at angles or dead ends, it is recommended that a “Lead over Height” (ratio of the horizontal distance from the face of the pole to the point of entrance of anchor rod in the ground to the vertical height above the ground of the attachment of said guy wire to the pole) of 1 be used. At angles in the line where the pull of the line exceeds 4 feet, i.e., the angle of departure exceeds 5 degrees, a guy strand having a strength of 1900 lbs (1/4 inch or greater) shall be used with the necessary pole shims, hook bolts, etc. (see Appendix G, Figure 86 ).

Hardware

All line hardware to be galvanized or of other corrosion resisting material.