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 material should not be accepted as an alternate in bids. Whenever pos-
sible, specifications should state that poles should be pre-cut, pre-
drilled, or otherwise mechanically altered, prior to preservative
treatment.
7.3 Enhanced Preservative Treatments.
Additional fortification (preservative loading) of the original pressure
preservative treatment is one of several techniques used to improve ser-
vice life performance when environmental conditions are considered
harsh and contribute significantly to the early failure of wood poles.
This procedure will increase both preservative penetration and retention
which in turn will effectively protect poles against extremely hostile en-
vironments to which they are sometimes subjected.
Preservative treatments for new wood products are specified in accord-
ance with the American Wood Preservers Association (AWPA) treat-
ment standards. AWPA standard C-4 (POLES) specifies preservative
retention levels in accord with geographical location and associated
decay hazards. As conditions worsen, higher retention levels are
specified. At many sites world-wide, poles are subjected to extremely
hostile environments and even the highest retention level prescribed by
AWPA treatment standard C-4 may not be sufficient to attain satisfac-
tory performance. Increasing preservative loading to an acceptable level
therefore requires that pole treatments be specified in accordance with
AWPA treatment standard C-3 (PILES), a treatment standard which ac-
commodates higher loading level requirements. High preservative reten-
tion poles to be ordered under this standard are, by AWPA treatment
standards definition, piles and should be described (for specifying treat-
ment in accordance with AWPA Standards) as piles.
NOTE:
Appendix (B) is a pole treatment
specification which has been tailored in
concert with the above guidelines.
8.0 POLE PERFORMANCE EVALUATION (IN-SERVICE). Wood in-
spection surveys conducted at several sites around the world deter-
mined that many poles are performing extremely well, even in the most
hostile environments. Preservative assays were conducted at these sites.
Surprisingly, retention assays for these poles (all creosote preservative
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