As stated in the introduction, one of the primary goals in the 

 development of the vibratory anchor was to achieve a holding capacity 

 between 25 to 50 kips. Results in Table 3 indicate that this goal can 

 be achieved by using the existing 10 kip vibrator with various size 

 flukes for sand and clay. 



The decision as to which size fluke is most suitable for various 

 seafloor conditions depends upon two factors. First the anchor breakout 

 resistance must be from 25 to 50 kips and second the penetration must 

 be sufficient to minimize both the effects of scour around a long term 

 mooring and the effects of minor upward anchor displacements due to 

 unanticipated momentary loads. 



From Table 3, it appears that a 2.5-foot fluke size satisfies the 

 above requirements and is more desirable in sand than the comparable 

 capacity, but shallower embedment of the 3-foot fluke. For clays, the 

 deeper penetration of the 4-foot fluke and its comparable breakout 

 resistance to the heavier 5-foot fluke indicates that a 4-foot fluke 

 is the most suitable. 



The fluke sizes chosen for sand and clay are based upon analytical 

 procedures not yet verified by full scale field tests. When data from 

 full scale tests becomes available these procedures will be updated, 

 if necessary to improve prediction capabilities. 



SUMMARY AND CONCLUSIONS 



Five anchor design concepts have been explored in conjunction 

 with the program to develop an improved deep sea mooring capability. 



The knowledge gained from study of these concepts and the present 

 status of the program are summarized as follows: 



1. The "Free-fall" anchor failed to achieve sufficient holding 

 capacity to make embedment of an anchor by free-fall impetus alone 

 feasible. However, two things of significance to deep sea anchoring 

 capability were gained from the work on this anchor. First, an important 

 new fluke design that is especially suited to a direct embedment anchor 

 was achieved. It is being used in the development of the vibratory 

 anchor concept. Second, the free-fall cable bale payout system proved 

 feasible and is judged to be worthy of further investigation for future 

 placement of deep sea anchors. Elements of the "free-fall" anchor 

 concept as they pertain to handling, placing, and utilizing deep sea 

 anchors will continue to be considered in the program. 



2. The "Pulse-jet" anchor concept was judged to be unworthy of 

 further development. Difficulties with high-pressure, high-temperature 

 seals plus complex critical relationships between the internal working 

 parts of the anchor and the surrounding soil medium were judged too 

 costly to solve. No further development is planned. 



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