T MS-2 

 A 



|=000000=-»-T MS- 1 



^f*—A70 cm ►] ► X 



1 



20 40 60 



DEFLECTION X (cm) 



80 



Figure 27. Load elongation curves for mooring-line inserts. 



A stress-strain diagram for the conveyor belt with a five-hole bolted connec- 

 tion is shown in Figure 28. The strain values are influenced by the connec- 

 tion itself (i.e., elongation of the boltholes is being measured along with 

 any stretching of the belt). The belt failed at a load of 2270 kilograms, not 

 at the five-hole bolted connection but at the transition, where the belt had 

 to be reduced in width from 14.3 to 8.9 centimeters in order to fit into the 

 testing machine. 



Force displacement relationships for MS-1 and MS-2 were obtained by ten- 

 sioning the insert, using a large dump truck, and determining deflection and 

 force, using a measuring tape and a dial force gage. The results are plotted 

 in Figure 27. Corresponding relationships for MS-3 were not determined, but 

 observations indicate that the elastic properties of MS-3 are between those of 

 MS-2 and MS-1. 



A mooring bridle utilizing both truck and automobile tires is shown in 

 Figure 26. This unit was not tested at CERC; however, it has been used in 

 field installations. 



3. Test Procedure and Conditions . 



This experimental program is limited to two designs, the PT-1 and PT-2 

 modules, and two water depths, 2.0 and 4.7 meters. The summary of the test 

 conditions shown in Table 3 lists one other breakwater design — the PT-DB mod- 

 ule; this design is simply a PT-1 breakwater that has been lengthened in the 



30 



