The Richmond palladium. (Richmond, Ind.) 1906-1907, 1906-11-18

house Board, who shall operate 1t for
four years more at the cost OF the United
States. Eells and his associates shall
then be entitled from the United States
to the sum of S75O,0OO provided the
structure is In substantial and satisfac-
tory condition.
Hartman Brothers, the engineers who
have been intrusted with the designing
and erection of the lighthouse, present
the following description of the proposed
structure.
The foundation for the lighthouse will
be n ssive steel cafsson In the form
of a truncated cone with a cylindrical
base. Upon this will be erected tower
comprising essentially a plate-steel cyl
inder with slight batter from base to
top, which tower will support a lantern
at height of 80 feet above sea level
The foundation caisson will be los feet
in diameter at the bottom, so feet high
and so feet In diameter at the top. 1t
will have a double shell of steel plates
parallel to each other, spaced six feet
apart and attached to "a upright inclined
plate Orders, which will divide the space
between the shells into "a wa tertight
compartments. 1t will have n double
bottom about seven feet higher than the
outer bottom edge of the caisson. The
space between the two floors of the bot
tom, about seven feet apart, is to be di-
yided into "A frames or truSSeS, extending
radially from near the bottom of the "a
outer inclined girders. horizontally, to
within eight feet of the center of the
caisson.
The central part of the caisson will be
In the form of open vertical shaft, 16
feet in diameter, extending from top to
bottom, Enclosed by steel plates riveted
together and riveted to the steel Orders,
extending horizontally from this shaft
to the inner edge of the "a inclined grid
ers mentioned. These horizontal Orders,
being about IS feet one above the other
are to act as temporary floor beams that
will divide the caisson into five large
circular rooms.
The estimated weight of the entire
structure. including the lighthouse and
contents, Is to be 27.0o0 tons. The dis
placement of water viii be about 10000
tons. which will leave an effective weight
resting on the sands of the Diamond
Shoals OF about 1900 tons, covering an
effective area on the base of $3.50 square
feet The caisson is to be built at some
shipyard and towed to it's destination.
The central tube in the caisson, which
extends from top to bottom, is to be
made Of curved rolled steel plates, at
tached TO the ends of the horizontal floor
girders and to the bracings, all of which
when riveted together will form a vessel
like caisson of circular shape, built suf-
nciently strong to stand its voyage
and the wind and wave pressure, after
Its final settlement into the sands.
All the inside horizontal Orders are to
be covered at the different elevations TO
make temporary noor6 ana rooms In the
same caisson. 1t Is proposed to place In
these rooms, at the time of towing. the
boiler. engines, pumps, derricks. dredging
apparatus, concrete mixing machinery
water. sand and cement, and the differ |
ent materials necessary for sinking and |
filing, as well as supplies and equipment |
for the workmen.
portion of the space between the two
outer shells and part of the bottom will |
be filled with concrete before leaving the |
so that the caisson will draw
about p feet of water.
After reaching its destination the CATS |
son will be held In place by suitable |
anchors and cables. 1t will be scuttled |
by pumping water into the interior COM
partments until II rests on the sands In |
about "a feet OF water. leaving the top or |
deck about % feet above the surface of |
the ocean.
The lighthouse will be located some dis |
lance back from the outer edge of the |
shoals, so that II will be protected from /
the unbroken force of the waves in time /
OF storm The shoals below the four /
fathem contour extend over an area Of /
about six miles by two miles, and the To- /
cation selected, as shown by studies of |
the government maps made during the /
asst 50 years, has suffered but slight alter
atoms In depth.
After the caisson has been scuttled.
water ballast will be pumped into the "a /
side compartments above the sea level. /
IL is then proposed to sink the foundation