CONTENTS 



FICURES— Continued 



Page 



119 Predicted performance of tethered-f loat breakwater with low density, 5-f oot-diameter 



spherical floats which provide 50-percent wave height reduction of the modified 

 Pierson-Moskowitz spectrum 173 



120 Estimated number of rows of 5-f oot-diameter spheres of tethered-f loat breakwater 



required to reduce wave heights of Pierson-Moskowitz spectrum to sea-statr 3 175 



121 Prototype tests of tethered-f loat breakwater, using 12-inch-diameter spherical floats 



designed for 2- to 4-second wave periods with heights up to 5 feet 176 



122 Concept of floating concrete articulated-frame ballast tethered-f loat breakwater 178 



123 Shallow-water, bottom-resting, steel frame ballast tethered-f loat breakwater concept 



using scrap tires 179 



124 Porous-walled breakwater model under test conditions 185 



125 Definitive sketch of porous-walled breakwater 185 



126 Effect of breakwater width, b, and dlmensionless wave frequency, o 2 h/g, on 



coefficient of reflection, C r , for the porous-walled floating breakwater 188 



127 Effect of incident wave steepness, Hj/L, and dimensionless wave frequency, o 2 h/g, 



on coefficient of reflection, C r , for the porous-walled floating breakwater 188 



128 Effect of bottom removal, incident wave steepness, H./L, and dimensionless wave 



frequency, o 2 h/g, on coefficient of reflection, C r , for the porous-walled floating 

 breakwater , 189 



129 Comparison of seaward mooring line forces for porous-walled versus solid-walled floating 



breakwater. 190 



130 Experimental arrangement for evaluating effectiveness of open-tube floating breakwater 



concept 192 



131 Effect of relative breakwater width, L^/Lj, and number of tubes 



on reflection coefficient, C r , for open-tube floating breakwater 193 



132 Effect of incident wave steepness, H^/Up and relative breakwater width, Lj/Lj, on 



reflection coefficient, C r , for open-tube floating breakwater 193 



133 Effect of relative breakwater width, Ly/L,, and number of tubes on transmission 



coefficient, C t , for open-tube floating breakwater 195 



134 Effect of incident wave steepness, H^/L^, and relative breakwater width, L T /L lt 



on transmission coefficient, C c> for open-tube floating breakwater 195 



135 Effect of incident wave steepness, K^/h^, and relative breakwater width, l^/L^, 



on power loss, P n , for open-tube floating breakwater 196 



136 Conceptual model of operation, pneumatic and hydraulic breakwater systems 197 



137 Qualitative description of current patterns produced by pneumatic breakwater 199 



138 Two sizes of small-scale laboratory flumes used to investigate pneumatic breakwater 



effectiveness 200 



139 Effect of unit air discharge, q, and relative depth of submergence, y/d, on maximum 



surface current velocity, U 201 



11 



