Table 22
Green Harbor Jetties
Green Harbor, Mass.
Construction and Rehabilitation History
Date(
Two rubble-mound jetties were constructed by the Commonwealth of
1899
Massachusetts at the entrance to Green Harbor and have been repaired
periodically since that time (Figure 25, present plan view). Infor-
mation on the original jetty lengths was not found.
The state constructed 196 ft of concrete wall at the east jetty's
landward end.
The Federal government adopted the project under authority of the
River and Harbor Act of
Repairs were made to seaward sections of both jetties, and the west
west jetty repair sections were 494 and 650 ft long, respectively,
and consisted of placing a 3- to
seal blanket of 1- to
quarry
on the seaward slope of the jetties followed by a
layer of cover stone. The cover stone was from 4 to
to
7 tons and
to tons on the east and west jetty repair sections,
respectively. The design geometry, including the west jetty exten-
sion, called for a 6-ft crown width,
side slopes, and crown
elevations of +14 and
ft mlw on the east and west jetties,
respectively. The west jetty extension was built up on a core and
ft-thick bedding layer of 1- to 50-lb stone, followed by a 3-ft-thick
stone, and covered with 4- to 7-ton
underlayer of 500- to
armor stone. The jetties' seaward ends had
side slopes. A
175-ft-long dike of 0- to 25-lb stone was placed at the landward end
of the west jetty repair section. The stone was placed to a 4-ft top
side slopes, and a crown elevation increasing from +12
width,
to +14 ft mlw in the landward direction, Prior to the repairs, crown
to +13 ft mlw on the
to
ft mlw and
elevations varied from
east and west jetty repair sections, respectively. The majority of
the east jetty was in a severely unraveled state. Improvements cost
9,000 using a total of
tons of stone.
Approximately 335
of stone revetment was placed at the landward
end of the east jetty. The contract price for placing 3,400 tons of
stone was ,400.
Inspection reports indicate the east jetty was in good to excellent
was
condition. West jetty inspections showed the outer 350
severely unraveled and other void areas existed landward of this
section. A
topographic survey showed crest elevations in the
(Continued)
52
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