analysis. This was definitely shown in the design of the anchor force load 

 cells, which for the concrete breakwater were designed for a maximum load of 

 50,000 lb (approximately 1,670 lb/ft of breakwater) which is more than forty 

 times larger than the loads experienced by the breakwater. 



Figures 3 and 4 show the wave transmission characteristics and the moor- 

 ing line loads, respectively, for the pipe-tire breakwater. In Figure 3, the 

 prototype wave attenuation does not appear to be as effective as the model 

 data predicted (Harms and Westerink, 1980). There are several possible 

 explanations for this discrepancy between the prototype and the model data 

 such as relative depth effects, long period wave energy, background noise, and 

 diffraction around the breakwater. Figure 4 presents a plot of the mooring 

 loads versus wave height for the pipe-tire breakwater. The prototype data 

 show that the mooring loads are less than predicted. The laboratory data show 

 mooring loads increasing with wave heights; whereas the prototype data are 

 nearly constant for any given wave height. The model data used in Figures 3 

 and 4, the best available for comparison, are based on two-dimensional labora- 

 tory studies conducted using prototype materials (Harms and Westerink, 1980). 

 When mooring loads experienced by the tire breakwater and the concrete break- 

 water are compared on a per linear foot of breakwater basis, the tire break- 

 water has on the average larger loads for wave heights 2 ft or smaller. 



These are only preliminary results for the prototype breakwaters, and a 

 detailed analysis of the data is currently under way. 



Future projects utilizing floating breakwaters (Section 107 studies for 

 Oak Harbor, Washington, and Juneau and Saxman, Alaska, are presently under way) 

 will benefit greatly from the test data, and even more cost-effective and lower 

 maintenance designs are anticipated. 



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