The second shot runs taut horizontally 3698 feet from Station 1 

 to Station 2, which contains temperature and pressure sensors. 

 Station 2 (see photo in Figure 3-5) is required to be at least 

 200 meters off the bottom to avoid sensing shoaling effects on the 

 wave characteristics. This cable shot, like the entire taut array 

 from Station 1 to Station 4, is floated to slightly positive buoyancy 

 with 5. 15 lb. buoyancy floats on 16 foot centers. 



The third shot runs taut horizontally 3292 feet from Station 2 to 

 Station 3 (see Figure 3-6), which contains a temperature sensor. 



The fourth shot runs taut horizontally 3200 feet from Station 3 to 

 Station 4, which contains temperature, pressure, and tension sen- 

 sors. Station 4 (see photo in Figure 3-7) is secured to the Head 

 Frame (see photo in Figure 3-8), which transmits the signal cable 

 tension to the outer mooring cables and which prevents rotation of 

 the ends of the signal and mooring cables. 



3.1.2 Inner Mooring Assembly 



The Inner Mooring Assembly is designed to anchor the shore 

 end of the taut array and to prevent rotation and chafing of the 

 signal cable. A schematic is given in Figure 3-2. Table 3-3 pro- 

 vides a summary of the calculated loads on the inner mooring and 

 the clearance of Station 1 above the coral bottom for critical current 

 conditions. It is seen that the mooring must resist dragging loads 

 up to 6400 lbs. and lifting loads of nearly 1000 lbs. These numbers 

 and the bottom material which may be encountered govern the moor- 

 ing design. The worst bottom material likely to be found in the area 

 is hard, smooth coral and dictates a very heavy coral-penetrating 

 anchor preceded by enough heavy chain to isolate the anchor from 

 lifting forces. This anchor, which we call a Coral Hook, has been 

 fabricated by cutting and welding together scrap I-beams available 

 at the Bermuda Naval Station. The Coral Hook should also serve 

 well in the event it is implanted on clay, sand, or in a region of 

 irregular topography. With proper respect for nautical traditions, 

 a 90H Hi-Strength Danforth anchor is provided. The width and 

 height of the Coral Hook were minimized to lessen water drag and 

 virtual mass forces while the mooring is being lowered to the bottom. 

 The inner mooring Coral Hook is shown in Figure 3-9b. The heavy 

 chain wrapped around the structure was added to build up the weight. 



203 



