system was programmed to sample selected transducers for 1 min on an hourly 

 basis. When either wind speed, current speed, anchor force, or significant 

 wave height exceeded a preset threshold value, an 8-min record of all trans- 

 ducers was made at a sampling rate of 4 Hz. The microprocessor was capable of 

 a limited amount of data processing, including calculations of maximum, mini- 

 mum, mean, and standard deviation of selected channels of transducer data. 

 After each data tape was retrieved from the breakwater, it was processed at 

 the University. Selected statistics and data plots were analyzed to determine 

 whether all critical components of the data acquisition system were operating 

 properly. When problems were detected, repairs were made as soon as the 

 breakwater was safely accessible. Keeping this complicated and extensive sys- 

 tem operational in such a hostile environment proved to be a challenging enter- 

 prise. Salt water flooded instrumentation, waves and tidal currents broke 

 transducers and tore out electrical leads, and logs, fish nets, and other de- 

 bris caused damage continuously. Despite these difficulties in the 16 months 

 of data collection, 130 data tapes were recorded, representing approximately 

 one-quarter billion measurements. After initial processing at the University, 

 the data were transferred to CERC for detailed analysis. 



DATA ANALYSIS 



Analysis of the data has been initiated, with the major effort being di- 

 rected toward the transmission characteristics and anchor forces of the break- 

 waters. These two parameters are being looked at initially because they ap- 

 pear to be key factors in the effort to optimize the cost effectiveness of 

 floating breakwater design. Other parameters, i.e., the internal concrete 

 strains and wave pressures, have been checked to ensure the reliability of the 

 data; but detailed analysis has not been initiated. 



Figures 1 and 2 are wave transmission characteristics and mooring forces, 

 respectively, for the concrete breakwater. The data plotted in Figures 1 and 

 2 constitute a partial data set for the 150-ft pontoon with clump weights on 

 the anchor lines, one of the configurations tested for the concrete breakwater. 

 In Figure 1 the prototype data are plotted versus a laboratory curve of a 

 model of a 16-ft-wide pontoon (Carver, 1979). From Figure 1 the prototype 

 wave transmission data seem to follow the laboratory trend. The mooring line 

 loads shown in Figure 2 are much lower than calculated using simple wave force 



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