First Test Series, 1972. The first test series 

 began on 28 September 1972 with two 1,000-foot 

 tests using the light payload. Sea conditions for the 

 entire 1972 test series were in the sea state 2 range, 

 with waves rarely exceeding a peak-to-trough height 

 of 3 feet and ship-motion response periods averaging 

 between 5 and 6 seconds. This first test has a two- 

 fold purpose — to obtain operating data on the MCLS 

 and also to fine-tune the automatic boom-centering 

 system. Immediately upon launching of the payload 

 and shifting into soft mode, problems were encoun- 

 tered with the boom hitting the stops at the end of its 

 travel limits. After 2 or 3 minutes the boom moved 

 away from the stops and, with a few exceptions, did 

 not impact upon them again during this test. A 

 "hunting" of the automatic boom-centering circuit 

 was observed and later determined to have a period of 

 about 200 seconds and an amplitude of about 4-1/2 

 feet. Upon successful completion of the first test, a 

 second test was conducted the same day using the 

 same payload. On this run no boom impacting of the 

 stops was recorded, and the hunting behavior of the 

 automatic boom-centering circuit was reduced. 

 Apparently this was due to successful tuning by the 

 contractor's technical representative who was 

 on-board throughout the entire test sequence. 



On 2 October, the heavy payload was used in 

 the third test in this series and descended to the same 

 1,000-foot depth as in tests 1 and 2. Problems with 

 the boom impacting the stops were encountered 

 immediately after payload launching and continued 

 for 3 to 4 minutes during payout. Boom-stop 

 impacting was also experienced for two or three short 

 intervals later in the test. Hunting of the automatic 

 boom-centering system was again evident. Later 

 examination of the records for this test showed this 

 hunting oscillation had a period of about 190 seconds 

 and an amplitude at the boom tip of about 5 to 6 

 feet. About 4 minutes after lifting of the payload 

 from the 1,000-foot depth commenced, problems 

 occurred in the traction-winch system that were later 

 determined to be due to a loss of oil from the 

 reservoir, causing cavitation in the hydraulic pumps. 

 The oil loss was due to failure of the main shaft seal 

 of the traction-winch drive motor, allowing the oil to 

 escape into the traction-winch gear box. Post-failure 

 investigation by the contractor determined that the 

 seal failure was due to a massive failure of the main 

 structural housing of the drive motor. It was believed 



that the failure could have been due to some defect 

 or weakness in the motor, possibly one inherent in 

 the specific type used. As a result a redesign of the 

 traction-winch system was undertaken and the MCLS 

 modified accordingly. Other problems that had 

 occurred during the 1972 tests were also examined 

 and fixes incorporated into the MCLS at the same 

 time. 



Second Test Series, 1973. The second test series 

 began on 6 October 1973 with the modified MCLS 

 with a shallow (500-foot depth) test using the light 

 payload. Sea conditions ranged from middle to high 

 sea state 3 during this test. Numerous problems were 

 encountered immediately after shifting into soft 

 mode, including the almost continuous impacting of 

 the boom on the stops combined with an apparent 

 dynamic instability in the automatic boom-centering 

 system. Because of the severity of the problems the 

 test was terminated early and the ship returned to 

 port where the MCLS control circuits were retuned. 

 A 6-week delay in the test program then occurred 

 with the departure of the MV GEAR on a priority 

 salvage call. Testing resumed on 19 November with a 

 repeat of the test attempted on 6 October. The same 

 problems were encountered again, and a major effort 

 was unsuccessfully made to eliminate them by on-site 

 tuning of the control circuits. 



Indications at this point were that internal 

 system friction had increased since the 1972 tests and 

 was causing the control-system problems. It was 

 decided to try again but with the heavy payload, on 

 the theory that with the larger line tensions the fric- 

 tional forces would be relatively smaller and thus 

 have less effect on system performance. This test was 

 conducted on 21 November, again at the shallow 

 500-foot site. Boom-impacting problems were again 

 apparent immediately after shifting into soft mode, 

 and further efforts were made to tune the control 

 system. Approximately 10 minutes after launching, 

 with the payload at a depth of 250 feet, a partial 

 failure of the pneumatic spring cylinder seal occurred 

 and the test was aborted. Almost immediately after 

 starting to lift the payload, problems were encoun- 

 tered with the traction-winch drive system. Emergen- 

 cy payload recovery procedures were again used, and 

 the payload was successfully lifted to a depth of 

 about 60 feet where the traction-winch drive sys- 

 tem failed completely. The payload was then placed 

 on the bottom and later recovered by another vessel. 



