Wave Generafors 
Figure 3. Photo of test basin setup. 
1. Basin Layout. 
A diagram of the basin setup is shown in Figure 2. The basin is 45.72 
meters long, 30.48 meters wide, and 1.22 meters deep. The alongshore and the 
shore-normal directions of the sand beach were 7.62 and 11.45 meters, respec 
tively. The backbeach was 3.05 meters in the shore-normal direction, but it 
was not part of the test beach. 
Immediately downdrift of the beach was the sand trap, 0.91 meter wide and 
12.7 centimeters deep (Fige 4), used to catch the longshore transporte 
Concrete aprons, 4.57 meters in the alongshore direction, were located on 
the downdrift side of the sand trap and on the updrift side of the beach. The 
updrift apron provided enough distance for the longshore current to develop 
between the updrift training wall and the beach. This phenomenon is discussed 
in Galvin and Eagleson (1965). The downdrift apron served two purposes-——one 
as a platform for depositing the longshore transport that escaped the trap, 
the other as a surface on which the waves traveled to diminish diffraction 
effects since no downdrift training walls were used. 
The major limitation in the experimental planning was the size of the 
SPTB, which permitted three wave generators, each 6.10 meters long, to be 
linked together and leave enough room to be rotated through various angles to 
the beach. The other limitation was the decision not to use downdrift train- 
ing walls due to the wave reflection problem. When downdrift training walls 
are used, the wave energy, which is reflected off the beach at an angle in the 
downdrift direction, strikes the downdrift wall and is reflected back toward 
the updrift direction. The energy is then reflected by the updrift wall and 
the process repeats. The reflected wave energy is being trapped within the 
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