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 7.4 CROSSTIES.
7.4.1 Problems To Be Found. Crossties often are produced from small diameter, lower
grade logs and, thus, contain a pith center. As a result, deep checking and end splitting can be a
problem. "S" irons, dowels, and end plates (anti-splitting devices), driven into the ends of ties, are
frequently used to prevent splitting. Tie plates to hold the rails are placed on the top side of the tie.
A combination of metallic degradation of wood by these plates and heavy loadings can wear or
crush the wood to the point where the preservative shell of the tie is broken or the structural in-
tegrity of the tie itself is destroyed.
7.4.2 Inspection Procedures. Inspection of ties in place is done by an experienced in-
dividual. The presence of excessive plate wear, loosened spikes or "spike kill", deep checking, split-
ting, plant growth in ties, soft wood, etc., are indications that decay may be present. On heavily
loaded tracks, the first signs of deterioration occur near the tie plate. On less heavily loaded lines,
decay in the untreated portions of the tie may be more of a problem.
7.4.3 Remedial Treatment. Treatment to arrest existing decay may range from a simple
surface application of creosote, pentachlorophenol or other preservative to pulling spikes, inserting
a preservative into the hole and then redriving the spikes. Application of preservative into the spike
hole is intended to reduce wood metal interactions, thereby reducing the loosening of spikes. Small
rods comprised of boric acid can also be inserted into holes drilled at angles under tie plates. This
procedure is particularly effective in arresting decay in the vicinity of the tie plate.
Caution: Preservatives are toxic pesticides. The status of preservatives changes constantly because
of regulatory actions. Therefore, installations should consult with the cognizant PMC to determine
the most appropriate material for use in remedial treatments. Further, the label directions on pre-
servative containers must be understood and adhered to, for the protection of humans and the en-
vironment.
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