Tile Uniroyal Royalon samples were in salt water in Hempstead Harbor. A long rubber 

 chain was made up using the first, second and third fastening concepts, and this chain was 

 used to hold a navigational buoy in place. A schematic is shown in Figure 8. The fourth 

 and fifth concepts took no service load but were immersed in the water for a longer period 

 of time. Tensile testing began the day after the specimens were removed from the water. 



The Empire State samples were exposed to salt water in Long Island Sound off 

 Mamaroneck in Westchester County. None of the pieces had any marine growth on them. 

 All of these specimens saw an entire winter in the water starting in November and were 

 then exposed to the environment for approximately one month prior to testing. They took 

 a light service load since they ran alongside a length of chain between the mooring and the 

 anchor. Essentially, the load was split between the rubber and chain. 

 Results 



In order to establish a basis of comparison, tensile tests were performed on one sample of 

 unexposed fastening concepts and tensile test specimens from each material. In order to 

 avoid stress concentrations when testing the first three fastening concepts, a steel pipe 3- 

 1/2 inches in diameter by 8 inches long with a 3/16-inch wall thickness was placed inside 

 each loop. This tube beared against the upper and lower crossheads of the tensile tester, 

 and then one end of the particular feistening concept was pulled e^ainst the other end. 

 After one end failed, jaws were placed in the lower crosshead and the remaining 

 connection was tested to failure. To test the fifth concept a special jig was made up to 

 hold the steel at the lower crosshead, while jaws were used to hold the conveyor belt in 

 the upper crosshead. 



The table showing failure loads and mechanisms for the connection control samples is 

 shown in Figure 9. 



The table showing failure loads and mechanisms for the connections after approximately 

 six months' exposure is shown in Figure 10. 



29 



