Noise and crosstalk in open wire telephone lines are reduced through
the use of a transposition.
The average deviation per transmission
section should not exceed
Occasionally, pole setting and guying conditions at river or railway
crossings are such that new pole locations must be selected.
changes in the original plans must be approved by the
layout crew chief.
Approved surveying methods include slighting with range rods or with a
It is important that accurate readings are taken and
recorded and that
this accuracy depends on the newness of the equipment.
two range rods are sufficient to sight along the line.
the pilot does the work or directly supervises the recordings.
range rods are used to maintain more accurate pole alignment.
Pacing and the use of field wire are two methods of measuring span
lengths. For accuracy in measuring spans, the field wire must be
50 feet long and marked off in 5-foot lengths.
150 feet long and marked off on each end for at least 50 feet.
180 feet long and marked off on one end for at least 50 feet.
180 feet long and marked off on each end for at least 50 feet.