Table 16 



Hampton Harbor Jetties 



Hampton Harbor, N.H. 



Date(s) Construction and Rehabilitation History 



1933- Two stone jetties were constructed by the New Hampshire State Highway 

 1935 Department to lengths of 1,300 and 1,000 ft on the north and south 

 sides of Hampton Harbor Inlet, respectively. 



1966 The Federal government extended the north jetty seaward 1,000 ft, 



repaired the outer 300 ft of south jetty, and constructed a 180-ft- 

 long landward-perpendicular spur at the inner end of the south jetty 

 repairs (Figure 18). Crown elevations of the north and south jetties 

 were +12 and +16 ft mlw, respectively. Crown width and side slopes 

 were 5 ft and 1V:1.5H, respectively. The jetty section was built 

 with a 1.5-ft-thick bedding layer of 1- to 50-lb stone, a core of 1- 

 to 300-lb stone, a 2-ft-thick underlayer of 400-to 1,000-lb stone, 

 and a cover layer of 2- to 3- ton stone. The 150-ft seaward section 

 of the north jetty had a 7-ft crown width and a cover layer of 3- to 

 4-ton stone. The north jetty head semicircle had a 1V:2H side 

 slope. The bedding layer extended 5 ft beyond the cover layer toe. 

 As constructed, the crown consisted of a single row of cap stones. 

 The cost for placing 36,670 tons of stone was $272,400. 



1969 Plans and specifications were prepared for north jetty repairs, but 

 no work was done at this time. The outer 110 ft was in an unraveled 

 condition with typical center-line elevations from +3 to +10 ft mlw. 



1973 The north jetty extension was repaired. Prior to repair, the jetty 



1974 had numerous void spaces and gaps along its entire length. The 

 seaward 300 ft was in a severely unraveled state with typical crest 

 elevations between and +10 ft mlw. The seaward 490 ft was brought 

 up to +12 ft mlw with 6- to 9- ton stone placed to an 8- to 10-ft 

 crown width and 1V:1.5H side slopes. The jetty head semicircle had a 

 1V:2H side slope. The landward 55 ft was rebuilt to the 1 966 design 

 geometry with 2- to 3-ton stone. Void areas on the remaining jetty 

 section were repaired with 2- to 3-ton stone. A total of 8,380 tons 

 of stone was placed at a cost of $165,400. 



1981 Repairs to the north jetty consisted of placing 4- to 9-ton stone on 

 a 535-ft section at its seaward end. The design geometry was 

 essentially identical to the earlier 1973-74 repair geometry. Before 

 the repairs, typical crown elevations varied from +8 to +12 ft mlw 

 with most of the subsidence ocurring at the seaward end of the repair 

 section. A total of 1,290 tons of stone was placed at a cost of 

 $109,905. 



1984 The jetties were inspected and found to be in excellent condition. 



Figure 19 is an aerial photograph of the jetties taken on 16 October 

 1984. 



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