PART B - INSPECTION OF POLES
1.
Inspection of poles above ground. Inspect the condition of poles above ground as indicated in
Part A.
2.
Tools. In addition to the tools normally required (framing chisel and hatchet), the following
special tools are necessary:
a. Increment borer. The increment borer is used to determine the condition of the interior of the
pole. It consists of a handle, a bit, and an extractor.
b. Measuring scale. The steel scale is used to make accurate measurements of the decayed and
sound wood in the borings. It is also used to measure the width and depth of decay pockets.
c. Pole prod. A standard screwdriver is used as a probe to check the amount of decay.
3.
Boring procedure. To prevent injury to the cutting edge of the borer, remove dirt and grime from
the surface of the pole at the point selected for boring. Be sure the decayed wood is not compressed by
forcing the bit too rapidly.
a. Bore at right angles of the pole surface. Bore to the center of the pole. Use the extractor to
remove the core from the pole. Do not remove the core from the extractor until the examination of the
core is complete.
b. Whenever a hole is bored in a pole and it is determined that replacement of this pole is not to
be recommended, carefully plug each hole by driving a creosoted dowel into it.
4.
Inspection of poles below ground line. Remove the earth from around the pole to permit easy
inspection of the butt from below the ground line. In addition, dig a hole in the ground at the face to
permit use of the increment borer.
5.
Restoration after inspection. When the inspection is completed, replace the earth and make a
mound of dirt around the butt of the pole. If there is not enough dirt to form a mound, obtain additional
earth and use it for this purpose.
6.
Inspection of pole decays. After completing the visual inspection, measure the good wood
remaining in decayed poles. The rate of ordinary decay is approximately 1/2 inch (1.27 cm) of
circumference per year in untreated poles. Poles which are infested with ants or termites will deteriorate
more rapidly.
a. Preparation for measurement. Remove all completely decayed wood. Avoid damage to the
treated portion of the poles and sound wood. Partial decay is a change in the composition of the wood
that reduces the strength of fibers, but still provides a substantial portion of the original strength. Do not
chop away good wood to expose a decayed pocket. Explore it with the borer.
SS0439
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