Rubble-Mound Breakwater Design for Refuge Harbor

An investigation for a small-boat refuge harbor project at Kelleys Island (western end of Lake Erie) was made and breakwaters designed by use of statistical data and analysis from existing data and soundings made in the field. Wave diffraction and reflection theories were used together with rubble-mound stability data from tests conducted previously. The recommended plan consisted of two separate, overlapping breakwaters: One approximately 350 ft in length, and the other approximately 850 ft in length. For analysis and design purposes, the breakwaters were broken into six separate reaches, and stability analyses made for each reach. Design wave height, minimum weight of cover-layer stone, cover-layer thickness, crown elevation, and crown width, as determined by applying the Waterways Experiment Station (WES) formula for design of cover layers for rubble-mound breakwaters, are tabulated and given for each reach. A typical section of breakwater is shown.