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Properly installed cross-arms require little maintenance. Crossarms can decay; aging can cause separations such as checks or shakes; lightning can splinter crossarms; or they may twist or bend by overload. These occurrences may necessitate replacement. All crossarm attach-

ments should be kept tight. If preservative treatment is applied to the pole, the crossarms should also be treated. Crossarms should be inspected visually from the ground whenever a pole is inspected. If the pole inspection indicates the pole may be climbed, a closer inspection should be made. a. Decay. Crossarm decay usually starts at pin-holes and can best be detected with a probe, if warranted by visual inspection. Probe the arm enough to determine the extent of the decay.

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T M 5-684/NAVFAC MO-200/AFJMAN 32-1082

C * SHAPED STEEL TRUSS

BAND

TREATING HOLE

DECAY

-GROUND LINE

Figure 4-8. Steel reinforcing for a wood pole

b. Weathering. Crossarms may lose their strength because of cracks caused by weather separations. If cracks are near through-bolts or dead-end bolts, replace the arm because the crack may allow the bolt to pull through.

c. Twisting. Twisted arms may be caused by an unbalanced strain or insufficient guying. Where twisted arms impair the safety of the line, or create an unsightly appearance, the condition should be corrected.

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