Homeowner's Piling-Dock Repair...
 

As member Blyblvrd pointed out elsewhere, wood docks will suffer hidden damage from wakes. Cross-members are especially affected, but surprisingly, wood pilings can be "nudged" back under the dock. (Just as ice had "nudged" them out from under the dock).

Owing to a limited number of dock-repair barges (and their expense :eek:) several "desperate repairs" have been made here over the past 35 years. Those repairs can be searched here with the words "farm jack". (Of which, I now have three). :cool: Since first writing about farm jacks, their price has doubled. :(
https://www.winnipesaukee.com/forums...ight=farm+jack

https://www.winnipesaukee.com/forums...34&postcount=9

https://www.winnipesaukee.com/forums...ad.php?t=23287


Picture one (below) shows both ice damage and rot. In replacing that cross-member, I was surprised that the piling had been under stress, and sprang back into its original position after the dock's weight had been lifted. :eek2: Heavy chains were added 20 years ago to prevent the ice from pushing the pilings out from under the dock.

Picture two shows the dock planks removed for access ("digging-bar" pry-tool pictured at left), and support/lifting tool. (Farm jack). The horizontal steel bar with the five chains attached is a discarded traffic signpost. At $3, it was the least expensive tool used in this operation—available from a metals scrap yard. Tractor Supply stores provided the standard 5/16" bolts, which are sold by the pound.

Using two ½-inch bolts, the farm jack was bolted to a 2x4 to extend its length to reach the bottom—six feet below. (Remove the jack's base—just one metric bolt).

Picture two also shows (at the top) the cross-member from which the newly-replaced 5-foot cross-member was sawed. (About 12-feet long, it was recovered floating in the middle of Winter Harbor last spring).

It took longer to put all that hardware in one place than to make the repair but anyway, good luck. :)