Maintenance: Scheduled maintenance included removing entrapped debris and 

 inspecting the couplings. 



Severe Storm Effects: The first anchoring system failed in September 1978 

 under 46-km/hr (25 kn) southwesterly winds producing waves 1.2 m 

 (4.0 ft) high. All anchors dragged and the tire mat ended up on the 

 easterly stone groin. For recovery, the FTB had to be cut out in small 

 sections. One year later, the breakwater with its second anchoring system 

 encountered Hurricane David and survived admirably. Under David, winds 

 were from the south to southeast and reached 139 km/hr (75 kn) . 

 However, 10 days later, Hurricane Frederic arrived and the anchoring ; 

 system failed. Sustained winds from the southwest in excess of 93 km/hr 

 (50 knots) for a period of several hours were noted at the site. Waves 

 were 1.8 m (6.0 ft) to 2.4 m (8.0 ft) high. The moorings gave way 

 sequentially with the danforth anchors and cement blocks dragging first 

 and finally the mooring pennants to the two massive Navy stockless anchors 

 parting. The FTB again ended up on the stone groin. 



Cost: The construction cost of this FTB was $21,000 including the modifi- 

 cations later made. Planning and engineering costs were $6,300 and 

 installation costs were $17,337. These figures translate to a cost 

 of $44.50/m 2 ($4.13/ft 2 ) for the latest design in 1980 dollars. Dis- 

 posal cost of the breakwater in 1979 was $2,375. 



Benefits: The operator felt that the breakwater had a positive effect on 



drawing birds away from the facility. She felt the FTB had a negative 

 effect on waterfront appearance and boaters' comfort. She also noted that 

 there was a decline in the commercial catch of fish in the vicinity of the 

 structure that was not seen elsewhere. The operator rated the FTB as 

 providing poor performance in suppressing waves, meeting design goals, and 

 satisfying her needs. Overall performance was rated poor to ineffective. 



Fouling Characteristics: A variety of marine life inhabited the structure 

 including seaweed, barnacles, sponges, sea-squirts, starfish, snails, 

 mussels, crabs, other shellfish, seagulls, ducks, terns, and other birds. 

 The operator further noted that the dry weight of fouling growth found on 

 each tire was 54.5 kg ± 28.1 kg (120 lb ± 62 lb). She also reported 

 sighting dogs on the FTB. 



Project Analysis: The Little Harbor FTB highlights the troubles which may be 

 encountered by improper siting. In this case, the site was too exposed 

 for any inexpensive anchoring system to survive. A very massive and 

 costly anchoring system would have been required to survive the seas 

 experienced at the harbor entrance. Inadequate buoyancy was the second 

 major problem with the structure relying on outdated or experimental 

 flotation systems. Whether poured polyurethane foam could survive the 

 severe wave conditions and extreme fouling growth is unknown, though it 

 is is expected to fare better than the composite system tried. One 

 important feature of this case history is the total lack of coupling 

 problems despite the stresses placed on the FTB. The rubber conveyor 

 belting couplers fastened by nylon bolts took incredible punishment and 

 seldom gave way. The final bolt failure rate was from 3 to 4 percent 

 over the 2 years of operation. 



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