to which the structure will be subjected the largest percentage of time during 

 its operational life. Since the test fixtures and test details associated with the 

 hydrostatic testing of capsule specimens varied to some extent between the 

 model and large-scale specimen tests, they will be described separately. 



Testing of Models. Fifteen-inch capsule models were subjected to a 

 large variety of hydrostatic tests in order to provide experimental data on as 

 many facets of capsules' structural response to hydrostatic loading as possible. 

 The hydrostatic pressure tests to which the model capsules were subjected 

 can be divided into three general categories: (1) short-term tests, (2) long- 

 term tests, and (3) cyclic tests. In addition to the hydrostatic tests, a single 

 axial compression test was also performed. 



Figure 59. Hatch for the operational 15-inch-diameter model capsule: open. 



91 



