Edgefield advertiser. [volume] (Edgefield, S.C.) 1836-current, 1896-04-15
LIGHTHOUSE AT SEA.

Difficult Piece of Engineering of Cape
Hatteras.
A difficult and costly piece Of engin.
eering has been undertaken by the
United States Government il the pro-
jected establishment of great light
house in the open ocean Of Diamond
Shoal, seven miles from the present
Hatreras light, and bearing almost
due east.
This is one of the most daring
schemes that army officers have dealt
with since General Casey, Chief Of
Engineers, successfully undermined
the great Washington monument and
placed there solid foundation expect
ed to support that structure for ages
to come.
Surrounding this new plan, however,
there is foreboding Of failure, and 1t
is predicted this early that $1,000,000
is to be literally as well as metaphoric-
ally sunk in the sea.
If the structure is placed there, and
stands without serious damage the on
slaughts of the seas for five years, ac-
cording to q leading army engineer,
this government will have accomplish
ed it's greatest triumph in this branch
Of science.
The height Of the local plane above
the water in the prospectus will be just
100 feet, and the structure is to stand
in thirty-three feet of water, and Is to
be supported on disk plates sunk to
q depth Of thirty feet in the sand. The
diameter from center to center Of YER
teal members Of the foundation Sc
ries is to be sixty feet, and the height
Of the floor Of the house above water
forty-seyen feet. The main portion Of
the structure is to be constructed OF
forged steel members with principal
joists and connections formed Of steel
castings.
A special feature of the design Is to
make all essential parts below the
water line Of massive dimensions, as
well as all those parts above the water
line, which will be subjected to the ac-
ton OF wind and waves. The use OF
bolts, keys, Serews.and other small Sec
ton or dimensions, which would be
rapidly weakened by corrosion, win
be avoided as far as possible. Joints
and connections are to be made abso-
lutely rigid to all possible strains, and
are to be as strong as the members
themselves. This Is to be effected by
Joining ends of members to steel-cast
hubs by the means Of massive steel
rings shrunk on in q manner approxi-
mating that followed in "built-up" gun
construction.
In the foundation series, besides the
massive members necessary for the
strength of the tower when In place,
there will be certain other tie rods Of
lighter section, which are added for
greater security to stiffen the frame
work while it is floated, and while be-
ing placed and grounded on the shoaL
1t is proposed by the board to construct
the screw. pile structure in the harbor
and float it out by steel cylindrical cais-
sons calculated to give draught Of
thirty feet when at sea. This part OF
the light is to be sunk probably fifty
: >eet down in the bottom by hydraulics,
until q firm hold is secured. 1t Is then
proposed to build up from the skeleton
arrangement until the llghtkeeperD
apartments have been completed and
the height secured for the great lens,
which is to throw its light twenty-five
miles In all directions.
The work is to begin this winter, and
1t is proposed to complete the light In
two or three years. -