A NEW OR IMPROVED PNEUMATIC STEAM DREDGING MACHINE
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the
Office of the Commissioners of. Patents, with his Petition, on the
19th March 1866.-A communication from abroad by Emilio Musciacco;
of Brindisi, Italy.
I, WILLIAM EDWARD GEDGE, of the Firm of John Gedge and Son, of
No. 23, Southampton Buildings, Chancery Lane, in the County of Middlesex,
Patent Agent, do hereby declare the nature of the said. Invention for
A NEW OR IMPROVED PNEUMATIC STEAM DREDGING MACHINE," (a commu-
nication to me from abroad by Emilio Musciacco, of Brindisi, Italy,) to be as
follows:-
On the accompanying Sheet of Drawing forming part of this Provisional
Specification, Figure 1 is a section of a hopper boat, part of this improved
dredging machine and apparatus connected therewith; Figure 2, a side view
of same; and Figure 3, plan of same with another boat in which the steam
generator is placed.
A, inside of a covered hopper closed hermetically and air-tight with a
sluice or trap at the bottom inside a boat; B, cock by which a jet of steam
compressed by several atmospheres is admitted to this hopper; C, tube
with cock, by which air escapes as the steam enters, and the lower end of
which should reach the lowest point, or that nearest the bottom of the hopper,
so that when it is seen that steam is fairly issuing from the summit it may be
concluded that the hopper is perfectly full of steam, and consequently suffi-*
ciently free from air for the work. D, D', cylindrical openings, in which are

page_text: fitted exteriorly the tubes of the pumps or suckers; E, E', pump tubes, which
draw and pick up by suction from the bottom of the water, they are fitted
in boxes to the openings of the hopper, and are removeable at pleasure; they
are furnished with gutta percha tubing, which comes over the joint after the
tube is set in the box; they carry a small chain or cord, which is fixed by one
end to the side of the hopper, and serves to keep them in the coupling boxes
without however hindering their movements; F, semisphere at the lower end
of a tube enclosed in each pump tube, but so that it cannot escape by the
orifice which is of a dimension which will permit the tube to move in an
oblique and vertical direction; G, base of the pump tube in form of a square
truncated pyramid, with an envelope or coupling joint of canvas, which serves
to partly intercept the passage of water to its upper orifice; H, head of one
of two beams which project from the poop of the steam boat, and to which
the upper part of the tubes is tied by a chain or cord, so that they are held
suspended to their corresponding or respective beams when removed from the
box of the hopper; I, fastening in shape of an inverted wedge, and covered
so as to close hermetically, it works by means of a turnscrew or wing nut
at the top of the screw rod which upholds it, and thus serves to open or close
the sluice or trap by the turning of this screw; L, opening, sufficiently large
to permit a person to descend into the interior of the hopper in case of
necessity, its fastening is also cuneiform, and is sufficiently lined and covered
with gutta percha to prevent the passage of air; M, steam boat on which
is the generating boiler to furnish steam to the hopper-boat by means of
elbow pipes or tubes bending in every direction to accommodate themselves
to the position of the hopper, and fixed to the cock B. The working of the
apparatus is as follows:-The steam boat is anchored at the spot which is to be
dredged, and very near and astern of this boat is placed the hopper boat as
shewn, Figure 3 of the annexed Drawing. The steam from the first passes into
the interior of the latter by the transmission pipes which are elbowed or bent.
When the filling of the hopper with steam is made manifest by the tube C its
tap is closed, and that of the said steam transmitting tubing at B is opened. In a
few instants the condensation of the steam takes place, and a vacuum is formed in
the hopper, then by the excess of the weight of the column of outer atmospheric
air which naturally presses on the surface of the water, it happens that the
moveable molecules which are in front of the mouths or suckers of the suction
tubes moved by this pressure advance in the direction in which there is no
resistance, rise in the tubes, and pour into the hopper until concurrence of
forces, and consequently until the hopper is filled; but as the mouths or suckers
completely touch the surface of the muddy or slimy bottom, the small fetid

page_text: particles or molecules are the first to rise and ascend the tubes, and con-
sequently the first to be removed; then the heavier sands which are in a
deeper layer rise; and, lastly, part of the mixed gravel rises, and thus the
cleansing and deepening of the bottom is effected; the hopper boat being
thus loaded the chains or cords are detached, the flexible coverings of the
joints are folded on each other, and the tubes are drawn out of the openings,
and left suspended to the beams of the steamboat to which they are attached.
The loaded hopper then leaves for the spot where it is to discharge its load,
and another approaches and is loaded in a similar manner to the first. From
on board the steamboat, and by means of ropes attached to a capstern the
suckers are lifted from one place and carried to another which is to be cleansed
or deepened. The hopper then approaches, the tubes are let in, the joints are
covered with the flexible tubing, the chains and ropes are re-attached and fixed,
the steam-conducting tubes are fitted to the taps, and this being done another
operation like the preceding is recommenced, always by causing compressed
steam to enter the hopper, and so on.