History Short: Locks made of stacked stone
The Fox Locks pre-date the Civil War, so there is a large body of historical information on the system. We are lucky to have an amateur historian on staff, and these are excerpts from Scott Thompson’s greater research into the system.
Stacked Stone construction was the earliest method of building the Fox River Locks and was used until the Army Corps of Engineers took over management in the 1880s. At that time, locks were rebuilt with quarried limestone blocks and concrete. Fortunately for us, Kaukauna Lock 5’s original construction somehow avoided the limestone block upgrade and retains the original stacked stone construction style. It is the only operating lock in the system with this style.
The walls of this lock are 6’wide at the top and 12 ‘ wide at the bottom which is anchored into the bedrock. In the photo refurbishing is about to start on this lock with the construction of an earthen coffer dam on the downstream side.The ragged looking debris on the stone walls is the remnants of a system of support timbers, tie rods and planking. The timbers and tie rods help keep the stone in place, while the planking helped protect the boat hulls during a lockage. Mostly wooden boat hulls in the old days!
It sounds like the big challenge with this construction style was the freeze/thaw cycle that took place early and late in the season. Water loves to find its way into the small cracks and crevices and doesn’t completely drain out. Freezing temps would create ice and damaging expansion forces. But again, somehow this lock survived and was eventually restored true to its original construction.
Blog – Fox Locks
https://foxlocks.org/blog/history-short-locks-made-of-stacked-stone/