(170.0 ft) long. It is one log or 0.6 m (2.0 ft) wide. Flotation is 

 aided by a few tires and some polyethylene blocks tied to the structure. 

 Chain is employed to couple the logs. 



Site: 









N 



T 



NEW TERN 

 HARBOR 



|_ 





c 



1 1 J ^ a ==a 





1 1 1 

 1 1 1 





1 1 1 Marina 

 1 lit 



FB 





1 1 1 



30 60m 



Installation: The breakwater is anchored to several large concrete blocks. 

 Mooring lines are of chain and are 3.7 m (12.0 ft) to 4.6 m (15.0 ft) 

 long. 



Field Experience 



Operation: The operator sees many problems with this structure. Foremost 

 among these is inadequate buoyancy which is considered a major problem. 

 Over half of the original breakwater has sunk and the remainder is 

 sinking. The operator has tied polyethylene blocks onto the logs to 

 improve flotation, though this has not solved the problem. Given the 

 opportunity to rebuild the FB, he would suggest filling the tires with 

 polyurethane foam. The structure has also experienced moderate problems 

 with corrosion, structural failure, fouling growth, anchoring system 

 failure, mooring line failure, coupling failure and litter entrapment. 

 Ice damage, instability and interference with boating traffic represent 

 relatively minor problems. Under typical storm conditions with waves 

 0.9 m (3.0 ft) in height and 14.2 m (46.5 ft) in estimated length, the 

 transmission coefficient is 0.33. 



Maintenance: Scheduled maintenance consists of inspecting the couplings in 

 the spring. 



Cost: The original construction cost is unknown. Annual routine maintenance 

 costs $200, split evenly between labor and materials. 



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



boaters' comfort and a negative effect on waterfront appearance. He rated 

 the structure as providing moderate performance in suppressing waves, 

 meeting design goals, and satisfying his needs. Overall performance was 

 rated moderate. 



80 



