IMPROVE- MENTS IN DREDGING OR REMOVING SAND, SILT, AND OTHER MATERIALS WHEN SUBMERGED
Year: 1876

page_text: LETTERS PATENT to Sir John Coode, Knight, of 2, Westminster Chambers,
Victoria Street, in the City of Westminster, for the Invention of "IMPROVE-
MENTS IN DREDGING OR REMOVING SAND, SILT, AND OTHER MATERIALS WHEN
SUBMERGED."
Sealed the 10th November 1876, and dated the 2nd June 1876.
PROVISIONAL SPECIFICATION left by the said Sir John Coode at the Office
of the Commissioners of Patents on the 2nd June 1876.
Sir JOHN COODE, Knight, of 2, Westminster Chambers, Victoria Street, in the
City of Westminster. "IMPROVEMENTS IN DREDGING OR REMOVING SAND, SILT,
AND OTHER MATERIALS WHEN SUBMERGED."
This Invention has for its object improvements in dredging or removing sand,
salt, and other materials or substances when submerged. +
For this purpose I employ compressed air, which I cause to issue as a jet or jeta
in such manner as to impart rapid motion to the water in the neighbourhood of
the sand, silt, or other substance to be dredged or removed. When it is desired
to raise the sand, silt, or other substance above the surface, and to deliver it into a
barge or other receptacle, I employ a trunk or conducting pipe in which the air
is applied so as to produce a rapid upward current, which draws and conveys
with it from the bottom the substance to be raised. In many cases it is unnecessary
to raise the sand or silt or other substance above the surface, in such cases I
employ similar incans to disturb and raise it to the extent requisite to admit of its
being carried away to a sufficient distance by a tidal or other current.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Sir John Coode in the Great Seal Patent Office on the 1st December
1876.
Sir John Coode, Knight, of 2, Westminster Chambers, Victoria Street, in the
City of Westminster. "IMPROVEMENTS IN DREDGING OR REMOVING SAND, SILT,
AND OTHER MATERIALS WHEN SUBMERĢED.”
This Invention has for its object improvements in dredging or removing sand,
silt, and other materials when submerged.

page_text: For this purpose I employ compressed air alone, which I cause to issue as a jet
or jets in such manner as to impart rapid motion to the water in the neighbourhood
of the sand, silt, or other substance to be dredged or removed. To raise the sand,
silt, or other substance above the surface, and to deliver it into a barge or other
receptacle, I employ a trunk or uptake pipe in which the air is applied so as to
produce a rapid current, which draws and conveys with it from the bottom the
substance to be raised.
In order that my Invention may be properly understood and readily carried into
effect I will proceed to describe the Drawings hereunto annexed, similar letters
having reference to similar parts on the various views.
Figure 1 is a plan shewing an arrangement of dredging apparatus constructed
in the manner I prefer for carrying out my Invention; Figure 2 is a side elevation
and Figure 3 an end elevation of the same.
A, A, is a dredger barge, shewn merely in outline for clearness. This may be
constructed of the shape and character as drawn, or may be any ordinary dredger,
barge, or craft utilized for the purpose, or the dredging apparatus may be fixed to a
travelling carriage working on 'a staging. B, B, are two crab winches, one at
each end of the barge or craft, the one at the bow end should preferably be actuated
by steam, and would be used principally for drawing the barge or craft in the
direction required for dredging. C is a boiler for supplying steam to the air
compressor. D is an air compressor with two inclined steam cylinders and a
central horizontal air cylinder; although this is the type of air compressor I
prefer to use, still any other kind of machine for compressing air may be used,
care being had that the machine is sufficiently large and powerful to supply the
requisite quantity of compressed air to the apparatus. E is an air delivery pipe
taking air from the compressor and into an air chamber or receiver F at the lower
or expanded end of the uptake pipe; part of this air pipe may be advantageously
made of flexible material to accommodate itself to the various angles of the uptake
pipe when used at different depths under water; passing from the air chamber are
small jet pipes C with nozzles H bent in such a way that a stream of compressed
air is delivered into the uptake pipe. One only or any number of these jets may
be employed, but generally three will be found the preferable number. K is a
funnel, or expanded end or scoop to the uptake pipe, and forms a receptacle for the
dredged material previous to its being forced up by the compressed air. This
funnel may be made in one piece with the air chamber and junctions for the air
and uptake pipes. L is a curved scoop with a cutting edge, preferably of steel, for
more easily making its way into the ground when drawn or pushied along. Mis
the uptake pipe or trunk made in one or more convenient lengths well bolted
together, its upper end terminates with a bend so as to deliver the dredged materials
into a hopper or barge, or otherwise, for carrying or conveying away or running
off the same; this pipe may be stiffened by laggings of greenheart or other
timber to give it rigidity and enable it the better to withstand the end pressure
when working; this pipe is also connected to the air pipe at intervals by bands
or clips N, N, or by any other convenient mode. The upper end of the uptake and
the corresponding part of the air pipe pass through and are fixed in a trunnion
hoop O; the trunnions work in the bearings of two hangers, so as to allow the
angle of the pipes to be varied according to the different depths required to be
dredged; the hangers are bolted or otherwise attached to a strong and securely
fixed bracket or frame P, sufficiently strong to bear the thrust of the uptake pipe.
At the side of the barge near the bow end is fixed a small timber overhanging
bracket Q, carrying pulley blocks R to receive a chain or rope from the lower end
of the uptake pipe; the chain or rope passing from the pulleys to the barrel of a
small crab winch S used for the purpose of lifting or lowering the end of the
apparatus when required. A rope or chain T is also attached to the lower end of

page_text: the uptake pipe and passed under the barge to the opposite side where it is
tightened and fastened to prevent any sideway movement of the apparatus; a
fender piece U is fixed to the side of barge for the pipe to lie against.
Figures 4 and 5 shew a means by which the lip or scoop which projects below
the funnel or expanded end of the uptake pipe may be set at the best angle for
cutting and entering the ground whatever the depth of dredging; this is accom-
plished by making the scoop with flat sides and bottom, and fixing to each side a
toothed quadrant actuated by worms; bearings for worm shafts may be advan-
tageously fixed to the side of the funnel and the shafts worked by suitable gearing
from the upper end.
The dotted position of the pipes, Figure 2, is to represent the appearance of the
apparatus when working in shallow water.
I will now briefly describe the method of working my apparatus in actual
practice. The barge or craft having been taken to the required position the head
and stern chains are made fast, so that by working the winch the barge may be
drawn in the required direction, the scoop end is then lowered until it attains the
requisite depth and angle for working and the compressor started, so that the air
begins to pass through the nozzles before they become buried; the barge or craft
is then drawn forward. The scoop enters the ground and the material passing
backward into the funnel is taken through the uptake pipe with a stream of water
the current being forced or induced by the passage of the compressed air alone.
When the craft or barge has been drawn a sufficient distance the funnel should be
lifted clear of the surface before the delivery of air is stopped, so as to leave the
nozzles clear for again commencing work.
Having thus described the nature of my said Invention and the manner of
performing the same, I would have it understood that I do not confine myself to
the exact details described; but I claim-
First. The construction of apparatus for dredging or removing sand, silt, and
other materials when submerged in such manner that a jet or jets of air alone is or
are caused to impart rapid motion to the water in the neighbourhood of the
substance to be dredged or removed, and to carry it into and up a trunk or uptake
pipe, in which the air produces a strong upward current and so to deliver it into a
barge or other receptacle, substantially as described.
Second. The construction of apparatus for dredging or removing sand, silt, and
other materials when submerged, substantially as described and represented in the
annexed Drawings.
In witness whereof, I, the said Sir John Coode, have hereunto set my hand
and seal, this Eighteenth day of October, in the year of our Lord One
thousand eight hundred and seventy-six