1.85, and a coarse-aggregate-to-cement 

 ratio of 2.28. The maximum size 

 aggregate used was 3/^ inch (19 mm). 



INSPECTION AND RETRIEVAL 



The operations to inspect and 

 retrieve the spheres were conducted by 

 submersibles. The Navy's deep-diving 

 manned submersibles Turtle and Seacliff, 

 operated by the Submarine Development 

 Group One, were used in all but one 

 operation; Scripps Institution of Ocean- 

 ography used their Remote Underwater 

 Manipulator (RUM) to conduct an inspec- 

 tion in 1972. The last inspection 

 occurred in March 1978. 



During each operation, only a 

 limited number of spheres were inspec- 

 ted. Those checked depended on the 

 number of dive days scheduled for the 

 submersible and on weather conditions, 

 which could restrict the actual number 

 of dives. Hence, some spheres have been 

 inspected more frequently than others 

 (Figure 1). Sphere no. 6 has not been 

 inspected as yet. Table 1 summarizes the 

 data obtained during the inspections. 



Spheres no. 15 and 17 show chain 

 link counts (the number of links suspen- 

 ded off the seafloor) that increased with 

 time in the ocean. This increase in chain 

 link count was due to inaccuracies in 

 counting links. Turbidity sometimes 

 obscured the links near the seafloor, 

 making it difficult for the submersible 

 operators to get an accurate count. Also, 

 the submersible operators were changed 

 with each dive, which caused variations 

 in the data collection procedure. More 

 reliable data have been obtained during 

 recent inspections because chain link 

 counts were sometimes taken two and 

 three times as a check. 



During the sixth inspection in 

 January 1977, Spheres No. 11, 12, and 13 

 were recovered after 5.3 years in the 

 ocean. Two of the spheres had a water- 

 proof coating and were retrieved from 

 depths of 2,635 and 3,1^^0 feet (803 and 

 957 m). The other sphere was uncoated 

 and was retrieved from a depth of 2,790 

 feet (851 m). 



The submersible Seacliff made a 

 separate dive to retrieve each sphere. A 

 reel containing 6,000 feet (2,000 m) of 

 1/2-inch (13-mm) nylon line was attached 

 to the front end of the submersible. A 

 large steel hook was connected on the 

 end of the line. Using a manipulator, the 

 Seacliff attached the hook to the 

 Sphere's tether chain and then payed-out 

 the line as it surfaced. At the water 

 surface, the line was buoyed with a 

 marker. The CEL warping tug was then 

 employed to reel in the line and recover 

 the sphere (Figure 2). Each sphere was 

 subsequently wrapped in wet burlap and 

 plastic sheet to prevent it from drying 

 out. 



A surface inspection of the spheres 

 revealed tube worms and a grass-like 

 animal growth on the coated spheres as 

 well as a few small anemones and a 

 grouping of small scallops. The concrete 

 surfaces, whether coated or uncoated, 

 had considerably less grass-like growth 

 than the steel chains (Figure 3). Figures 

 ^ and 5 show a close-up view of the 

 exteriors for a coated and uncoated 

 sphere. 



These spheres were subsequently 

 tested in the laboratory where they 

 provided data on the actual quantity of 

 water permeating to the inside of the 

 spheres, the short-term implosion 

 pressure and strain behavior of preloaded 

 spheres, and the chemical compounds 

 present in the concrete. 



