Table 9 



Portland Harbor Breakwaters 



Portland, Maine 



Date(s) Construction and Rehabilitation History 



1836 A 2,000-ft-long stone breakwater was constructed on the south side of 

 the Portland ship channel (Figure 10, location map). Since construc- 

 tion, the majority of the breakwater has been backfilled forming the 

 eastern end of the South Portland waterfront. 



1950- An additional 900-ft-long stone breakwater was constructed easterly 

 1951 of the original structure (Figure 10). The cross section consisted 

 of a 15-ft crown width with a +15 ft mlw crest el and slopes of 

 1V:1.25H and 1V:2H on the harbor and sea sides, respectively. The 

 core stone was 0.5 to 5 tons each and the cover stone, comprising 

 75 percent of total tonnage, was 5 to 11+ tons each. Total stone 

 placed was 48,000 tons at a cost of $198,700. 



1967- During this time frame, visual inspections indicated that both 



1985 breakwaters were in good condition. The newer 900-ft-long breakwater 

 had some slope stone slippage. 



1986 The breakwaters have no known repair history. 



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