sequences of the records. Since gages 1 and 4 are the farthest apart they 

 show the greatest differences. The data from gages 1 and 4 are tabulated in 

 Appendixes A, B, and C. 



Some additional monochromatic wave data over a horizontal bottom were 

 collected in CERC's 0. 9-meter-high by 0.9-meter-wide by 45.7-meter-long wave 

 tank. This tank has a 1 on 30 hogs hair absorber beach to keep reflected wave 

 energy to very low levels. Three parallel wire resistance-type wave gages were 

 used to record the wave conditions. A profile view of the test setup is shown 

 in Figure 5; the data are tabulated in Appendix A. 



© 



Wove Goges 



© © 



._JZ_ 



I on 30 Hogs Hair Slope 



15m to 

 Wove Generator 



Gages Spoced One -Fourth 

 of a Wovelengtti 



Profile View 



Figure 5. Experimental setup in CERC's 0.9-meter-wide tank. 



Wave data were also collected in CERC's 0. 9-meter-high by 0.4-meter-wide 

 by 45.7-meter-long wave tank. The setup in this tank was designed to obtain 

 data on the shoaling and breaking of irregular waves. Ten parallel wire wave 

 gages were used: three gages over the horizontal tank bottom and seven over a 

 1 on 3 concrete slope. Figure 6 shows a profile view of the test setup and 

 gage locations; the data are tabulated in Appendix D. 



Table 1 provides a summary of the wave conditions, data and test setups 

 used in the laboratory tests. 



b. Procedures and Analysis . All the waves were generated using hydrauli- 

 cally actuated piston-type wave makers. The monochromatic waves studied 

 included waves with sinusoidal blade motion with Ursell numbers less than 25 

 and cnoidal waves with Ursell numbers greater than 25. The Ursell number, Uj^, 

 is defined 



Ut, = 



HL 



(1) 



where H is the average wave height over the flat bottom part of the wave 

 tank and L^ the local wavelength, calculated using linear theory and defined 

 by 



