19 June 2001
TR-12: REPLACING DAMAGED DOLPHIN PILE
Problem: One or more timber piles are broken or damaged by marine borers
and the dolphin can no longer fully serve its purpose.
Description of Repair: Before replacing any piles, the fastenings should be
removed only as far as is necessary to release the damaged piles. Take care to
drive new piles at an angle so that they will not have to be pulled too far to fit
them in place. Carefully note the size of piles to be replaced, particularly at the
head or intermediate point where they are fitted together with other piles. Trouble
cutting and fitting replacement piles can be avoided by selecting piles with the
proper size head. Replace and drive all piles before any are brought together.
After all the piles are driven, the center cluster should be brought together first,
fitted, chocked, bolted, and pinned; when all rows have been properly fitted, etc.,
wrap with wire rope. All cuts in piles for fittings, bolts, and wrappings should be
thoroughly field-treated with creosote. Avoid these cuts as much as possible
because field treatment with creosote gives only marginal protection against
marine borer attack.
Wrapping the dolphin with PVC may provide protection. See repair technique TR-
Application: This method is routinely used.
Future Application Requirements: Remaining piles should receive special