visual surveys, taken between 1960 and 1980, are qualitative and subjective, 

 both in time and between inspections. Repairs to the structures typically 

 involved adding new armor stone to damaged sections, usually returning the 

 structure to the original design geometry or to the existing geometry of 

 surrounding undamaged sections. Repairs or modifications, which include 

 adding a structure or lengthening an existing structure, have been made at 36 

 of the 52 projects. Of the 30 projects which have had structures repaired, 

 several of these could also be considered modified in terms of changes in 

 stone sizes, geometry, or shortening of a structure from its original or pre- 

 viously repaired condition. Where repairs have been fairly frequent, flatter 

 side slopes and/or larger stone sizes have been used to increase the struc- 

 tural stability. Localized damage and subsequent unraveling appear to be the 

 major problem areas concerning NED structures. Several structures have had 

 their landward ends sand tightened with additional stone placed along their 

 seaward side slopes. The following projects best illustrate repair histories 

 of structures within NED: Saco River, Kennebunk River, Isles of Shoals, 

 Hampton Harbor, Newburyport Harbor, Rockport Harbor, Gloucester Harbor, Green 

 Harbor, Cape Cod Canal, Nantucket Harbor, Hyannis Harbor, Sakonnet Harbor, 

 Point Judith, and Block Island. 



6. None of the structures have been model tested for stone slope 

 stability. Hudson's equation and depth- or fetch-limited wave heights are 

 used in selecting armor stone sizes. Case histories of the project structures 

 are included in Tables 1-52. Pertinent summary information on each project is 

 presented in the following listing: 



Location 



Table 

 1 

 2 



Project 



Type 

 & No.* 



B(1) 



B(2) 



Armor 

 Type** 



SSP 



S 



Length 

 485 

 725 



Date of 

 Origin 



1961 



1884, 

 1956 



Improvement! 



Eastport Harbor, Maine 

 Lubec Channel, Maine 



N 

 N 



Moosabec Bar, Maine 3 B(1) S 400 1891 N 



(Continued) 



* Indicates type and number of structures: B-breakwater (B(1) indicates one 



breakwater), J- jetty. 

 ** Indicates armor type: S-stone armor, C-concrete sheet pile or wall, 



SSP-steel sheet pile, B-stone blocks, 

 f N-none (no repairs or modifications since construction), R-repair, 



M-modification. 



