The same beach slope was used for all 15 tests and was determined as shown in 
Figure 21. A value of &€ was calculated for each test using the average 
H for the entire test. These values are listed in Table 5. 
-0.4 
-0.3 
-0.2 
_-0.1 
= (2.65 ,0.000) SWL 
a] (0) ase he ee 5 SS SS SSI Se 
a SS. Slope Used in Surf Similarity Parameter 
0.1 S 0.253- 0.000 | 
é Si tan B: 658-265 = 0.0644 
mo 0.2 \ 
e (6.58, 0.253) 
= 0.3 
2 
S 0.4 
Backbeach Test Beach 
0.5 
0.6 
0.7 
-3 -2 -l 0 | 2 3. 4 5 6 7 #8 Qs 107 alee We 
Station (m) 
Figure 21. Determination of beach slope used to calculate 
the surf similarity parameter. 
4. Special Tests. 
Three tests were performed under special circumstances. Test 2 was a 
repeat of test 1; test 8 was a repeat of test 7, except the sand feeder was 
moved shoreward; and test 11 was done with a generator angle of Zero. 
Tests 1 and 2 were both run with a period of 2.35 seconds, a generator 
angle of 10°, and a generator eccentricity of 5.9/7 centimeters. Test 1 ran 
for 25 hours, test 2 for 50 hours. A twofold comparison of the two tests was 
originally planned. The first 25 hours of test 2 data was to be compared to 
the test 1 data, and then, both sets of data were to be compared to the last 
25 hours of test 2. Unfortunately, due to an experimental error, only the 
first 30 hours of the test 2 longshore transport data was collected accu- 
rately. Therefore, the only comparison made was test 1 to the first 30 hours 
of test 2. Reference to test 2 in the remainder of the report refers to the 
first 30 hours only. Appendix A contains all 50 hours of test 2 data. 
Table 6 compares the results of the two tests. The differences listed 
give an indication of the repeatability of the data collection. The longshore 
transport rate changed by 12.6 percent, which is a significant variation. This 
is an inherent problem of longshore transport tests, indicating that some 
important unknown factors are at work. 
3ii/ 
