Table 33 



Sakonnet Harbor Breakwater 



Sakonnet Harbor, R.I. 



Date(s) Construction and Rehabilitation History 



1836 Two hundred feet of the proposed 400-ft-long rubble-mound breakwater 

 was built for a total cost of $14,700 (Figure 36, present plan view). 



1899- The breakwater was extended 200 ft seaward to its authorized length 

 1901 of 400 ft. A total of 18,400 tons of stone was placed in the ex- 

 tension at a total cost of $25,000. 



1939 The breakwater was repaired using 1,120 tons of stone at a total cost 

 of $5,800. 



1957 The breakwater was extended 400 ft seaward (Figure 37, aerial photo- 

 graph), and approximately 800 tons of stone were placed at its land- 

 ward end. The extension and repair sections were constructed with 

 0.5- to 6- ton stone placed to an elevation of +8 ft mlw, a 15-ft 

 crown width, and slopes of 1V:2H and 1V:1H on the sea and harbor 

 sides, respectively. A 1V:2H side slope was also used on the head 

 semicircle. The extension was made in water depths varying from 

 -15 to -21 ft mlw. The 150-ft landward repair section included the 

 landward 50 ft of breakwater. The contract cost for placing an 

 estimated 30,000 tons of stone was $169,500. The remainder of the 

 breakwater was in good condition with center-line elevations of +7 to 

 +9 ft mlw, typical. 



1960 A June topographic survey shows cross sections for the entire 

 breakwater approximately 2 ft above the design cross section used in 

 1957. The reason for the apparent change in datum could not be found 

 (for present report purposes). 



1961 Repairs were made on three sections totaling 86 lin ft, including a 

 25-ft section at the seaward end and 9- and 52-ft sections located 

 approximately 140 and 430 ft from the seaward end, respectively. The 

 repairs were made with 0.25- to 5-ton stone placed to an elevation of 

 +10 ft mlw, a 15-ft crown width, and slopes of 1V:2H and 1V:1H on the 

 sea and harbor sides, respectively. Except for the outermost 15 ft 

 of repairs, which appears to have subsided prior to June 1960, the 

 repair areas were apparently damaged by storm waves sometime between 

 the June 1960 survey and a visual inspection in February. The 

 damaged areas had typically subsided from 3 to 5 ft. The contract 

 cost for placing an estimated 1,200 tons of stone was $14,400. 



1971- Minor harbor-side slope repairs were made near the landward end of 

 1972 the breakwater. The new riprap was placed for a total cost of 



$1400. The overall condition of the breakwater was good, except for 



some seaside slope stone slippage. 



(Continued) 

 72 



