by Gene Clark
UW Sea Grant, Superior
Fact sheet, 6 pages, color photos
Many Great Lakes coastal communities, ports and harbors are protected from damaging storms, waves and ice by offshore and coastal structures. Early harbor entrance breakwaters were often constructed with an underwater timber crib base filled with rock. On top of the structure, a cap of stone or concrete was added above the water surface. When Great Lakes timber structures remain underwater, the timber can last indefinitely. However, when exposed to air, the timber will begin to rot.
This fact sheet describes some timber structures that are failing and some possible preservation solutions.
Publication #: WISCU-G-13-003