Table 37 



Block Island Harbor of Refuge Breakwaters 



Block Island, R.I. 



Date(s) Construction and Rehabilitation History 



1870- The east and west rubble-mound breakwaters were constructed to 

 1894 lengths of 1,950 and 1,100 ft, respectively (Figure 41, plan view). 

 The east breakwater was built to +10.9 ft mlw with an 1 1 -ft top 

 width, and the west breakwater was built to +8.9 ft mlw with a 20-ft 

 crest width. The sea and harbor side slopes on both structures were 

 1V:1.5H and 1 V: 1H, respectively. A total of 107,400 tons of stone 

 was used in constructing the east breakwater, and at least 

 18,400 tons of stone were used on the west breakwater. In 1890 minor 

 repairs were made to the east breakwater using 420 tons of stone. 



1903- The east breakwater was repaired using a total of 19,970 tons of 

 1906 stone at a total cost of $42,900. 



1914- Repairs were made at the landward and seaward ends of the east 

 1916 breakwater using a total of 5,930 tons of stone. 



1939 Repairs were made to the east breakwater using 3,360 tons of stone 

 for a total cost of $21,000. 



1950 The west breakwater was repaired to its design cross section using 

 0.25- to 6-ton cover stone and "run of quarry" core stone. Typical 

 crest elevations prior to repairs were from 1.5 to 3.0 ft below the 

 design elevation of +8.9 ft mlw. Total cost of the repair was 

 $127,100 using 12,900 tons of stone. 



1955 An 800-ft section of east breakwater was repaired and sand tightened 

 by placing 0.75-in. to 200-lb core stone and 1- to 6-ton cover stone. 

 The stone was placed on the breakwater's seaward side slope beginning 

 at a point opposite the northeast corner of the inner basin and 

 terminating about 750 ft from the structure's seaward end. The cross 

 section had a crown elevation of +11 ft mlw, the crown width extended 

 seaward 25 ft from the existing breakwater center line, and the side 

 slope was 1V:1.5H. A total of 12,000 tons of stone was placed for a 

 total cost of $125,000. 



1962- The seaward 842 ft of the east breakwater were repaired using 4- to 

 1963 8-ton stone. Prior to repair, center-line elevations were from +9 to 

 -2 ft mlw on the seawardmost 200 ft, +9 to +12 ft mlw along the 

 remaining 642 ft of repairs, and +10 to +12 ft mlw landward of the 

 repairs. The repair crown section consisted of a +11 ft mlw crown 

 elevation, an 18-ft crown width, and slopes of 1V:1H and 1 V: 1 . 5H on 

 the harbor and sea sides, respectively. Most of the stone was placed 

 on the sea-side slope. A total of 11,700 tons of stone was used for 

 a total cost of $138,000. 



(Continued) 

 83 



