Tauchwände als Wellenbrecher

Scum boards as breakwaters - experiences and latest developments

Scum boards are a usual method to skim floating objects (e.g. debris) of the water surface e.g. to protect power plant intakes or water treatment plants. The application as a breakwater for coastal protection or port constructions is quite seldom. Thus the design of scum boards as breakwaters (baffle breakwater) is mostly not included in standard design manuals. Nevertheless as a total blockage of waves and currents is not needed for many breakwater constructions baffle breakwaters can be a cost efficient alternative as less material is required especially for large water depths. The up to a certain degree protected area is still connected to the surrounding water body which may be required e.g. for ecological reasons (water circulation and quality). In addition the bed load sediment transport will not be interrupted which will reduce the morphological impact of the breakwater (lee erosion). The difficulties in the application of baffle breakwaters are the assessment of the hydraulic function and loads especially due to wave attack. The present article describes experiences from recent projects and gives an overview about the existing design rules for baffle breakwaters.