a. Shifting pole sites from stated locations. If rock formation or other conditions prohibit
location of the pole at a designated location, shift the pole location as much as 10 feet either direction in
the line of lead. However, inform the project engineer whenever the location of an open-wire
transposition pole is shifted. If more than three transposition poles in a transposition section are to be
shifted, the project engineer must be consulted before changes are made.
b. Use of existing pole. If it is necessary to use existing lines in which pole spacings are
unsuited to the required new transposition patterns, the movement of poles at times can be avoided
through the use of the standard midspan transposition bracket.
2.
Diameter and depth of holes.
a. Diameter of pole holes. The center of the pole hole is located at the stake site. Make sure the
diameter of each pole is the same from top to bottom and is large enough to leave 4 inches of free space
around the pole. This space is used for the backfill and tamping.
b. Depth of pole holes. When practical, dig pole holes deep enough to provide for planned
change in grade.
c. Average depth in firm ground or solid rock at ground level. The standard depth for pole
holes in average firm ground or in solid rock s listed in Table 1-3. If the diameter of a pole hole in solid
rock is 2 feet or more, dig the pole hole the same depth as a hole in average firm ground.
Table 1-3. Standard pole hole depth.
SS0439
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