Blackfoot news. (Blackfoot, Idaho) 1891-1902, 1896-05-16
OUT IN THE OPEN SEA.
Lighthouse to BE Erected VIII Call
Forth Daring Engineering.


A difficult and costly piece of engi-
neering has been undertaken by the
United States government in the pro-
jected establishment of a great light
house in the open ocean off Diamond
Shoal. seven miles from the present
Hatteras Light and bearing almost due
east. says the Washington Times. This
is one Of the most daring schemes that
army officers have dealt with since Gen.
Casey. chief OF engineers, successfully
undermined the great Washington
monument and placed there a solid
foundation expected to support the
structure for ages TO come. Surround
Ing this new plan, however, there is a
foreboding Of failure, and it is pre-
dicted this early that 100000 is to
be sunk literally as well as metaphor
ically In the sea.
II such structure is placed there and
stands without serious damage the on
slaught of the sea for five years, ac-
cording to leading army engineer, this
government will have accomplished its
greatest triumph in this branch of
science.
The height of the focal plane above
water in the prospectus is given as 100
feet, and the structure is to stand in
thirty-three feet Of water and to be
supported on disk piles sunk to depth
OF thirty feet in the sand. The dame
ter from center TO center of vertical
members of the foundation series is TO
be sixty feet, and the height of the floor
OF the house above water forty-seven
feet. The main portion of the struc-
ture is TO be constructed of forged steel
members, with principal joints and con-
nections formed of steel castings.
A special feature of the design is 10
make all essential parts below the
water-line of massive dimensions, as
we'll as all those parts above the water
line which will be subject to the action
OF the wind and waves. The use Of
bolts, keys. screws and all small Sec
lions or dimensions which would be
rapidly weakened by corrosion will be
avoided as far as possible. Joints and
CnUUtClluHs are W bS huuuS opSotutSiy
rigid to all possible strains and to be as
strong as the members themselves.
This is to be effected by Joining ends
of members to steel cast hubs by the
use of massive steel rings shrunk on In
a manner approximating that followed
in 'built-up" gun construction.
In the foundation series. beside 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 1t is floated and while being
placed and grounded on the shoal. It
is proposed by the board to construct
the screw -pile structure in the harbor
and float 1t out by steel cylindrical cais-
sons calculated to give a draught Of
thirty feet when at sea. This part Of
the light is then to be sunk probably
fifty feet down in the bottom by hy-
draulics until firm hold is secured.
II is then proposed to build up from
the skeleton arrangements until the
lightkeeper's 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
II is proposed to complete the light In
two or three years.