should be noted that the Goodyear design curve in Figure 44 is independent of 

 B/D, having been tested over a broad range of B/D during experiments at 

 the Canada Centre for Inland Waters (CCIW) (Harms, 1979a, 1979b). A similar 

 series of experiments for the PT-Breakwater was scheduled at CCIW in September 

 1980 (see Harms, Bishop, and Westerink, 1981 for results). 



2 . Mooring-Force Data. 



a. PT-1 Breakwater. This breakwater was tested most extensively in 

 the MS-1 mooring configuration (i.e., with a six-tire mooring-force damper 

 installed) . It was also tested with the MS-2 and MS-3 mooring systems at the 

 deepest water depth of 4.7 meters. As is explained in Section III, the MS-2 

 mooring configuration is the "stiffest" system tested and the MS-1 is the most 

 elastic or "softest" system tested with the elastic properties of the MS-3 

 system lying somewhere between them. 



The peak mooring force is plotted in Figures 45 and 46 as a function of 

 wave height for the case of MS-1 and two water levels, D/d = 0.51 and 0.22. 

 An exponential relationship between the mooring force and the wave height can 

 be detected in the data, even though this information is masked at times by 

 the relatively large scatter of data (even at fixed L/B) that is common in 

 this type of measurement. The best "by eye" fit has been drawn and indicates 

 that at both water levels F is proportional to H 3/2 . For a given wave 

 height and wavelength, the peak mooring forces are clearly higher at the lower 

 water level. This is shown in Table 4 where the value of the force coeffi- 

 cient K is listed and defined. The influence of L/B is difficult to quan- 

 tify from the data: an increase of F with L/B appears to be indicated, 

 particularly at D/d = 0.51, but additional tests would have to be made to 

 define this relationship. 



F 



PT- I 

 MS- I 



a • a / 



a o ° 



a /*a 



° / A 4+ 



a it 



/. : 



L EGEND 



L/B 



2.5 lo 3.3 



1.7 to 2.5 



L3 to 1.6 



1.0 to |.2 



.75 1.00 1.25 1.50 



Incident Wove Height H (m) 



1.75 2.00 



Figure 45. PT-1 peak mooring-force data (MS-1, d = 2.0 m) . 



45 



