b. Moffatt and Nichol Engineers, Ogden Beeman, and International Maritime 

 Associates (1977) Evaluation . This study examined the commercial feasibility 

 of the tethered-float breakwater for use by U.S. merchant ship Lighter Aboard 

 Ship Handling (LASH) operations and for offshore construction operations. 

 Specific applications of the tethered-float breakwater system were investi- 

 gated to derive the cost and possible benefits for each application. The 

 findings relating to system components, methods of deployment, and costs are 

 also documented for potential users of the tethered-float breakwater system. 



(1) Kenitra, Morocco, LASH Operation. The estimated cost of a 

 tethered-float breakwater system suitable for protection of LASH barge-loading 

 operations at this site off the Atlantic coast of Morocco was $15,600,000, 

 which is about $3,695,000 per annual amortization. Since the use of the sys- 

 tem would result in a savings of only $80,000 per year in comparison to pre- 

 sent LASH operations, the tethered-float breakwater to protect LASH and other 

 lighterage operations at the 1977 state-of-the-art could not be justified. 



(2) Lae, New Guinea, LASH Operation . The estimated cost of a 

 tethered-float breakwater system for the protection of LASH barge-loading 

 operations at this site was $10,500,000, which is about $2,519,000 annually 

 with potential benefits of only $90,000 per year. The annual cost was 

 considered too large to justify the use of a tethered-float breakwater. 



(3) Grays Harbor, Washington, Pipeline Dredging Operations. The 

 estimated cost of a tethered-float breakwater system designed for protection 

 of pipeline dredging operations at this site on the Pacific coast was 

 $398,000. Distributing hardware costs over three dredging projects within a 

 10-year period, the total cost of the system installation and use in one 

 project is estimated to be $231,000. The savings due to use of the system in 

 the proposed 3,000,000-cubic yard channel dredging project was estimated at 

 $488,000, producing a net benefit of $257,000, an attractive return for this 

 particular project. 



(4) Ketchikan, Alaska, Small-Craft Harbor . The estimated cost of a 

 tethered-float breakwater system to protect a marina basin at this location 

 was $1,010,000. This cost reasonably approximates that of a concrete pontoon- 

 type floating breakwater already in use in Alaskan waters. Safety considera- 

 tions and the possibility of a better performance could make the tethered- 

 float breakwater a preferable alternative. 



(5) Vandenberg Air Force Base, California, Over-the-Beach Operations . 

 The cost of a tethered-float breakwater designed to protect a landing area at 

 this base would approximate $9,300,000. Insufficient data were available to 

 evaluate the monetary benefits from this application of the tethered-float 

 breakwater system. 



c. Economic Conclusions. Moffatt and Nichol Engineers, Ogden Beeman, and 



International Maritime Associates (1977) concluded that the tethered-float 

 breakwater system shows potential use for a number of possible applications 

 under short-fetch wave exposure conditions. The use of the bottom-resting 

 ballast concept for shallow-water, long-fetch conditions to reduce wave 

 heights in small-craft harbor entrance channels by positioning a system just 

 seaward of the entrance appears to be another feasible application. The 

 practicality of using medium-sized floats (about 3-foot diameter) should be 



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