IV. CONCLUSIONS AND RECOMMENDATIONS 



The first conclusion drawn from examining the field experiences is that de- 

 sign information in this field is not being properly disseminated. Too many of 

 the Goodyear FTBs built in the late seventies employed construction techniques 

 and materials determined to be ineffective several years earlier. Regardless 

 of who shares the blame, whether designer, permit agency, or researcher, this 

 fact is inescapable and has needlessly caused much money and effort to be 

 wasted. A comprehensive, updated FTB bibliography is available free from the 

 URI Marine Advisory Service, Narragansett Bay Campus, Narragansett, Rhode 

 Island, 02882. 



The successful field experiences thus far seem to indicate that an FTB 

 should employ conveyor belting for coupling and nylon or galvanized bolts in 

 saltwater or freshwater, respectively, for fastening. Reserve flotation should 

 rely on poured polyurethane foam for both freshwater- and saltwater-based de- 

 signs. Trapped air may provide sufficient buoyancy, however, for short-term or 

 noncontinuous uses. Most conventional mooring systems are adequate if the site 

 conditions are fully understood. Unfortunately, conventional anchoring systems 

 have been shown to fail in several cases, indicating that a more conservative 

 design approach is required. 



Siting must be done judiciously. Few floating structures can be expected 

 to survive in a terribly exposed position or where currents are incredibly 

 strong. Once in place, an FB will cast a cone-shaped shadow of protection 

 largely dictated by its length. Designers must take into account the ability 

 of waves to diffract around the ends of an FB and designate a length which will 

 ensure protection to the entire facility. Similarly, designers must realize 

 that an FB's beam is functionally related to the length of the waves the struc- 

 ture is able to suppress. Based on the survey data, a better than a 50-percent 

 reduction should not be expected in wave height of any incident wave two or 

 more times the width of the FB. Again, a thorough understanding of offshore 

 conditions and access to current state-of-the-art information are necessary for 

 a designer to develop an effective breakwater. 



A professional attitude should also be taken in the construction, instal- 

 lation, and operation of an FB. Volunteer labor was occasionally cited as poor 

 quality and inconsistent work. A paid work force, while more expensive than 

 volunteers, may save the operator money in the long run. Once installed, an FB 

 should be regularly maintained. This maintenance must include monitoring the 

 structure and immediate correction of faults. With the exception of severe 

 storm conditions, there are usually reliable indicators of when an FB is about 

 to fail. Good maintenance will discover such signals and provide the avenue 

 for saving the structure. 



When the above factors are adequately taken into consideration, field ex- 

 periences indicate that an FB can act as a highly effective breakwater and can 

 also pass along added benefits to the operator. These conditions appear most 

 easily met in freshwater where the environment is not as harsh as that found in 

 saltwater. Nonetheless, as technology has advanced, the FB has proven itself 

 more capable in saltwater. However, the operator must fully realize that even 

 under the best of conditions, an FB is only a temporary structure relative to a 

 fixed rubble-mound breakwater. This aspect of transiency demands that an oper- 

 ator maintain the structure and account for its eventual disposal. Too often, 



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