5. BERMUDA INSTALLATION 



The installation procedure was as follows: The Outer Moorings were 

 first placed on site in the taut, vertical configuration. Later, additional 

 floated wire rope shots were attached at the top ends and winched to- 

 gether to form the inverted "v", which remained below the sea sur- 

 face. Next the Signal Cable /Sensor Array was attached to the Head 

 Frame at the apex of the "v" and played out on the sea surface while 

 steaming for shore. When Station 1 was put over the stern, a small 

 barge moved in to connect the Inner Mooring Assembly to Station 1 

 and lower the Inner Coral Hook. The main barge continued toward 

 shore paying out signal cable. When the main barge was approximately 

 one mile inshore from the small barge, the Inner Coral Hook was 

 implanted using a carefully coordinated procedure in which the main 

 barge held sufficient tension to pull down the entire array while the 

 small barge lowered the Inner Coral Hook to the bottom. Once this 

 was accomplished, the remaining signal cable was laid on the bottom 

 to a point just outside the reefs where its bitter end was sealed and 

 left on the bottom in 14 fathoms. Later the tug boat came out with 

 a heavy cable which was connected to the smaller signal cable in a 

 splice box and laid in through the reefs to shore. 



5.1 Depth Determination 



Because of the steep slope and irregular bottom topography in the 

 installation area, we did not trust the wide beam, sound echo depth 

 information available. We therefore sounded the depth and several 

 profiles at each anchor site by lowering a weighted, metered wire 

 from the R/V Panulirus I (see Fig. 5-1). 



5. 2 Navigation 



Position information during all sea operations was obtained in 

 the form of ship bearings radioed from the Mt. Hill and Paynters 

 Hill optical tracking stations on shore (see Fig. 5-2). Position 

 fixes could be obtained once per minute when necessary, and the 

 error was generally less than 20 ft. These fixes were plotted manually 

 on specially constructed plotting charts from which steering instructions 

 could be readily determined if required. The helmsman was usually 

 able to maintain station without steering instructions by simply monitor- 

 ing the radioed bearing data. 



5 . 3 Cable Barges and Loading Procedure 



The Outer Moorings and Signal Cable /Sensor Array were installed 

 off the YC-1378, a 120 ft. barge whose cable handling equipment had 

 been specially designed for the COLOSSUS ARRAY. This barge had 

 generous working space and winching power, but the large, vertical 

 axis cable drums were not suited for winding small diameter cable. 



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