TEST OPERATION IV 



This operation was conducted to determine 

 anchor performance in a coral seafloor and then in 

 very deep water (10,000 feet). All tests were 

 performed off Hawaii from the USCG Cutter Btittom- 

 wood. 



Tests 13-15 (26-28 Jun 73) 



These three attempts resulted in misfires. All were 

 attributed to malfunctions in the safe-and-arm device. 

 There were no leaks in the anchor system, and the 

 touchdown firing mechanism was functioning as 

 intended. In each misfire the gold shear disk (refer to 

 the equipment description in the main text) was 

 bowed to incipient failure. Either the shear disks were 

 rated at a higher pressure than 400 psi or the gas 

 cartridge was leaking, causing pressure reduction to a 

 point less than the required 400 psi. Another 

 possibility was that one of the solenoid valves was 

 operating improperly. All new components were sub- 

 sequently brought to Hawaii by the S/A designer, and 

 a series of bench tests was performed; on board the 

 ship the S/A functioned correcdy each time. Since 

 the primary reason for this operation was a deep- 

 water trial, one attempt would be made at 10,000 

 feet. 



aluminum inflators were not pressure-tight; the gas 

 was leaking through the casting seams. This was not 

 detected earlier because the leaks were very slow, and 

 all previous tests had been generally accomplished 

 quickly. But each test in Hawaii took a considerable 

 period of time. In the shallow-water coral tests the 

 anchor remained suspended above the seafloor for 

 long periods, because it was difficult to locate 

 reasonably clear, coral sites. In deep water, the S/A 

 was enabled for almost 2 hours before touchdown. 



This problem was quickly solved by first elimi- 

 nating the aluminum inflators and replacing them 

 with stainless steel seamless inflators. The entire 

 valving assembly is immersed in a dielectric fluid to 

 detect leakage prior to assembling the S/A. 

 Eventually the inflator and gas cartridge were 

 replaced by a gas canister with a one-way valve. There 

 have been no problems with this assembly since these 

 improvements. 



TEST OPERATION V 



The purpose of these tests were twofold; first, to 

 verify performance of the S/A subsequent to the 

 modifications, and second, to generate test data in 

 soft clay. All tests were performed from the CEL 

 warping tug. 



Test 16 (29 Jun 73) 



The seas were rough (sea state 4"*"); however, the 

 captain was sure that the anchor could be handled 

 safely. The anchor was lowered by cathead with a 

 backup set of bitts to 10,000 feet m 75 minutes. 

 Firing was not detected by a hydrophone placed at 

 about 100 feet; however, the ship was allowed to 

 drift until load was applied in case firing had 

 occurred. After an hour the anchor was retrieved 

 when it became certain that the ship was not 

 anchored. Anchor retrieval took 3-1/2 hours; it was 

 long, but not tedious. The anchor had not fired, but 

 it was in a safe condition. Again the unit was 

 completely dry internally, and the misfire was caused 

 by an S/A malfunction. The gold shear disk was 

 bowed but did not fail. 



Upon return to CEL, the S/As were thoroughly 

 checked, with the problem being detected. The 



Test 17 (4 Dec 73) 



This test was performed at the CEL shallow-water 

 test site in 150 feet of water. Firing occurred, with 

 the fluke penetrating about 20 feet to the fluke tip. 

 Load was increased slowly until the anchor down- 

 haul cable parted at 58,000 pounds.* The actual 

 capacity was, therefore, undetermined in this silty 

 sand seafloor. 



Test 18 (5 Dec 73) 



At the CEL 1,200-foot site, a 2 x 4-foot sediment 

 fluke was embedded, using a 3.25-pound charge, into 

 soft clay to a depth of 34 feet. Load was applied in a 

 slow, continuous manner until pullout at 20,000 

 pounds; this load was lower than expected. It is 

 possible that the fluke causes significantly more dis- 

 turbance to the soil during dynamic penetration. This 



* 58,000 pounds is exactly the line breaking strength. 



29 



