TESTS OF EXPERIMENTAL CONNECTORS 



Because the dry-connector concept was 

 mechanically much simpler than the wet, the initial 

 tests of the dry connector moved directly to sea 

 trials, while the wet connector mating functions were 

 being more closely studied under laboratory 

 conditions. 



Experimental Dry Connector 



The details of the NCEL* test and evaluation of 

 the experimental hardware were reported in 

 Reference 4 and are briefly reviewed here. A cross 

 section of the experimental model is shown in Figure 

 3. 



In preparation for the NCEL SEACON-I 

 experiment [5] the experimental dry connectors 

 were tested at sea three times. In the first test the dry 

 connector failed (shorted) at 2,300 feet. In the next 

 two tests at 600 feet the dry connector performed 

 successfully. One dry connector was then installed on 

 the SEACON [5] structure and emplaced with the 

 structure at a depth of 600 feet in the Santa Barbara 

 Channel for one year. During this test the connector 

 was used to power the structure at full voltage every 

 two to three months, and, upon recovery, the connec- 

 tor showed no sign of electrical or mechanical 

 deterioration. 



After repairing the damage from the 2,300-foot 

 test and modifying the strain reliefs, the dry 

 connector was again taken to sea. During this test the 

 connector failed (low insulation resistance readings) 

 at 4,500 feet. Inspection revealed that the connector 

 seals had failed and the interior was flooded with 

 seawater. Review of the connector construction 

 revealed that the compensator volume was too small 

 so that the compensator would fail to function at 

 between 2,000 and 3,000 feet even if filling was 

 perfect and there was no trapped air in the system. 

 Tests with an auxilliary compensator in the pressure 

 vessel showed that the oil contamination problem was 

 correctable, but the cable termination area (potted in 

 polyurethane) still leaked and shorted out. This was 

 attributed to the fact that urethane experiences a 

 compressive set under pressure and does not instan- 

 taneously return to shape as pressure is released. This 



causes water to be literally pumped in around the 

 conductors and penetrator pins as pressure is cycled. 



A set of dry connectors was also assembled and 

 left under full voltage at shallow depth in the tidal 

 zone of Port Hueneme harbor for five months. This 

 test was completely successful and showed that 

 long-term immersion and power had no degrading 

 effect on the connector performance. 



A mechanical test of the cable termination was 

 performed by attempting to lift a 21,000-pound 

 concrete block. The connector lifted the block for 

 about one second and then pulled completely free of 

 the cable. The termination, which had been designed 

 for a 50,000-pound breaking strength, failed com- 

 pletely. 



In summary, the experimental dry connectors 

 had the following major deficiencies: 



1. The polyurethane potting compound 

 provided no effective waterblock for the cable 

 termination/conductor breakout area and penetrator 

 pin splices. 



2. The cable termination design utilizing 

 compression rings on the flared armor was 

 inadequate. (It would also be very difficult to install 

 in the field.) 



3. The compensator design was both too small 

 and unnecessarily complicated (positive overpressure 

 was not required). 



Experimental Wet Connector 



The wet connector and the dry connector have 

 many components in common. The cable strength 

 termination, the conductor waterblock, the 

 penetrator pins and splices, and the basic electrical 

 contacts are nearly identical in both designs (see 

 Figure 4). Therefore, the results of the dry connector 

 tests on termination strength, contact performance 

 and related items were applicable to the appropriate 

 sections of the wet connector; the wet connector test 

 program essentially began where the dry connector 

 tests left off. In addition to the mechanical and 

 electrical performance requirements which must be 

 met by the dry connector, the wet connector has a 

 unique set of problems related to the process of 



* On 1 January 1974 redesignated the Civil Engineering Laboratory (CEL) of the Naval Construction 

 Battalion Center, Port Hueneme, California 93043 



