DELAWARE
BREAKWATER
The
Delaware Breakwater is situated at the entrance into the Delaware Bay
near Cape Henlopen. The anchorage ground, or roadstead, is formed by
a cove in the southern shore directly west of the pitch of the cape
and the seaward end of an extensive shoal called the shears; the tail
of which makes out from the shore about five miles up the bay , near
the mouth of Broadkill Creek, from whence it extends eastward and
terminates at a point about two miles to the northward of the shore
at the Cape.
The
Breakwater consist of an insulated dike or wall of stone, the
transversal section of which is a trapezium, the base resting on the
bottom, whilst the summit line forms the top of the works. The other
sides represent the inner and outer slopes of the work, that to the
seaward being much greater than the other. The inward slope is 45
degrees; the top is horizontal , 22 feet in breadth and raised 5-1/3
feet above the highest spring tide; the outward or sea slope is 89
feet n altitude upon a base of 1053 feet; these dimensions being
measured in relation to a horizontal plane passing by a point 27 feet
below the lowest spring tide. The base bears to the altitude nearly
the same ratio as similar lines in the profile of the Cherbourg and
Plymouth Breakwaters.
The
opening or entrance from the ocean is 650 yards in width, between the
north point of the cape and the east end of the Breakwater. At this
entrance the harbor will be accessible during all winds coming from
the sea.
The
dike is formed in a straight line from E.S.E. To W.N.W. ; 1200
yards is the length of this portion of the work which is designed to
serve the purposes of a breakwater. At a distance of 350 yards from
the upper or western end of the breakwater ( which space forms the
upper entrance), a similar dike of 500 yards in length , is projected
in a direct line, W. by S. ½ S. forming an angle of 146 degree, 15
min, with the Breakwater. This work is designed more particularly as
an icebreaker. The whole length of the two dikes above described ;
which are now partly commenced will be 1700 yards; they will contain
when finished 900,000 cubic yards of stone, composed of pieces of
basaltic rock and granite weighing from a quarter of a ton to three
tons and upward.
The
depth of the water at low tide is from four to six fathoms throughout
the harbor which will be formed by these works and the cove of the
southern shore. It is calculated to afford a perfect shelter over a
space of water surface of seven tenths of a square mile.
The
object to be gained by the construction of an artificial harbor in
this roadstead are to shelter vessels from the action of waves
caused by the winds blowing from the E. to the N.W. round by the N.
and also protect them against injuries arising from floating ice
descending the bay from the N.W.
Source:
Encyclopedia Americana : Tuesday , November 16, 1830 Issue Charleston
Courier of Charleston, South Carolina.
From
the pen of the Engineer engaged in the construction of the work.
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