reflection caused a standing wave to form to windward of the breakwater; the 

 average height of the standing wave was about 150 percent of the incident wave 

 height. The reflected wave appeared more pronounced when the wavelength was 

 approximately equal to or slightly greater than the breakwater width. The 

 wave damping efficiency of the breakwater was judged on the basis of the 

 reduced wave recorded in the 100-foot-wide by 80-foot-long area in the lee of 

 the breakwater. The data from these investigations are in the form of contour 

 maps of wave height amplification for the area downstream of the breakwater at 

 various width structures and various incident wave characteristics. An 

 example of the data is shown in Figure 107. 



Idge of 



Figure 107. 



lee pontoon- 







40 



50 



63 



100 



60 





=105 ".84 °54 "46 °41 "18 "31 °41 "31 "67 c 97 



"95 "87 "79 ".62 ".56 °.51 "38 "45 "45 ".57 "1.10 



"1.08 "79 "59 °54 °33 ".51 °.46 "54 "56 "79 "89 



°105 °.64 "56 ".41 "59 '-.41 "55 »43 ".79 -79 ".64 



"85 "82 ".77 "49 ".64 :55 "82 "49 ".57 "69 ".59 



»82 ".87 °67 °69 "49 '74 "77 °31 -72 ".77 ".67 



".74 "77 "74 ".74 "35 ^.87 "87 "49 "64 ^82 ".59 



"77 ".69 ?74 =51 °59 ,82 "56 -59 °,41 ".82 ".69 



20 t 20 



D stance in Feet 



40 



Total wave amplification downstream of A-frame, pontoon-type 

 floating breakwater — 1:23.4 scale model, breakwater width = 35 

 feet, incident wave height = 4 feet, incident wavelength = 30 

 feet (after Western Canada Hydraulic Laboratories Ltd., 1966a); 

 numbers indicate total wave height amplification, including 

 transmission and diffraction. 



158 



