IMPROVE- MENTS IN APPARATUS FOR DREDGING
Year: 1862

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent, for the Invention of "IMPROVE-
MENTS IN APPARATUS FOR DREDGING."-A communication from abroad by
ealed the 6th April 1863, and dated the 18th October 1862.
PROVISIONAL SPECIFICATION loft by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 18th
October 1862.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN APPARATUS FOR DREDGING," to be as follows:-
The object of this Invention is to render streains, rivers, or other channels
navagable at all times, which otherwise, by reason of the displacement of the
sand or mud' caused by floods, have their channels blocked up by sand banks.
For this purpose I employ a self-acting apparatus disposed to act on the sand
bank, so as to raise the sand or mud and disperse it in the stream, by which
it is carried away.
The principal features of this Invention are, 1st, that it is self-acting, being
actuated by an; bydraulic wheel driven by the current; this wheel commu-
nicates motion by means of suitable gearing to two screws used for raising the
sand, and further the apparatus only works at ebb tide.

page_text: 2ndly, it is only necessary to be about six feet in height, and may be kept
at the mouths of rivers during bad weather.
3rdly, the various parts of which the apparatus is composed always retain
their proper position, therefore its useful effect is always at the maximum.
4thly, its small size preserves the driving wheel from the violence of the sea.
The following is a description of the apparatus:-A framework is formed
of longitudinal beams strongly connected by iron straps and stays; the space
between these beams is covered in with planks parallel with the stream in such
manner that each part shall present no obstacle to the passage of the water;
the framing is furnished with standards or feet for giving it greater stability,
and to prevent the frame from sinking too rapidly into the shifting bed of the
river I dispose two longitudinal screws parallel with and as near as possible
to the framing, which screws always retain the same position, being supported
in bearings in the framework; a driving wheel is mounted at right angles to
the screws, the axis being parallel with the stream, which wheel may be either
wholly or partially immersed in the water. This wheel is fitted with blades
or paddles mounted obliquely, so that the water in its passage creates a
pressure which works the wheel. I make the wheel of iron and mount it on
a fixed axis, on which is keyed a ratchet wheel received in a cavity made in
the boss of the driving wheel; a pall is fixed on said wheel, which gears with
the ratchet above mentioned; the pall being held in gear with the ratchet by
a spring prevents the wheel revolving except in one direction. The driving
wheel being mounted loosely on its axis and controlled by its ratchet and pawl
is set so as to revolve only at ebb tide. Motion is transmitted from the
driving wheel to the elevating screws by means of bevil gearing; a wire
grating encloses the upper part of the apparatus to protect it from injury from
floating bodies.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed.
by the said William Clark in the Great Seal Patent Office on the 16th
April 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME,' WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent. Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of October, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Clark, Her special licence that I, the said William Clark, my
executors; administrators, and assigns; or such others as I, the said William
Clark, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN APPARATUS FOR DREDGING," a communication to me from abroad by
Léon Jean Emile Dupont, of 29, Boulevart St. Martin, Paris, Proprietor,
upon the condition (amongst others) that I, the said William Clark, my
executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said William Clark, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement,
reference being had to the Sheet of Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say):-
The object of this Invention is to render streams, rivers, or other channels
navigable at all times, which otherwise, by reason of the displacement or
accumulation of the sand or mud caused by floods, have their channels blocked
up by sand banks. When a continuous dredging operation is effected on one
portion of a sand bank from below at a point where the current is more rapid
than at others, and if the bed of the river is deeper at this point, the following
is the result:-While the part above the bank is higher than the excavation
produced by the dredging the sand continues to descend, and if it ceases
for a moment to run to the point being dredged it will arise from the too
energetic nature of the operation, and the weakness of the current conveying
an insufficient quantity of sand to the circumscribed area in which the buckets
of the dredger works.
This Invention relates to an apparatus for obviating the above-mentioned
defect in the dredging operation; this apparatus works with infinitely less
power, but at same time it effects the displacement of the sand to an extent
proportionate to the force of the current, while it continually furnishes the

page_text: current with a similar quantity of sand to that which the dredger takes up
and distributes with facility.
The principal features of this Invention are, 1st, that it is self-acting, being
actuated by an bydraulic wheel driven by the current; this wheel commu-
nicates motion by means of suitable gearing to one or more screws used for
raising the sand, and further the apparatus only works during ebb tide.
2ndly, it is only necessary to be about six feet high, and may be kept at the
mouths of rivers during bad weather.
3rdly, the various parts of which the apparatus is composed always retain
their proper position, therefore its useful effect is always at the maximum.
4thly, the small size of the driving wheel renders it little liable to damage
from the violence of the sea.
The
This Invention is illustrated in the accompanying Drawing, Fig. 1 of which
shows a side elevation; Fig. 2 a plan; and Fig. 3, end view of same.
same letters apply to all the Figures.
a, framework formed of iron strongly connected together; the framing is
furnished with standards or feet 6 for giving it greater stability; and to prevent
the frame from sinking too rapidly into the shifting bed of the river, for which
purpose I enlarge and lengthen that part of the framing which rests on the
sand; or I may cover this part with sheet iron almost entirely, and furnish
it with cross ties, as also the remaining parts of the framing, if desired.
c, screw, disposed at the centre of frame a, and having a certain and invariable
degree of inclination; its diameter should be varied and arranged according
to the greater or less force of the current of the river in which it is to be
used. It may further be sunk more or less in the sand according to the
greater or lesser shifting nature of the bed of the river in which it is to
operate. The lower end of said screw is furnished with two steel teeth,
forming a continuation of the thread of the screw which is to raise the sand;
d, d, bearings in which the Archimedean screw c works; e, driving wheel
mounted on a shaft f, turning in bearings g of frame a. This wheel acts
whether entirely or partially immersed in the water; for this purpose it is
furnished with leaves or plates inclined in such manner that the water in
passing through determines a pressure, which works and rotates the wheel.
In order to obtain increased power from the wheel or turbine its diameter
may be enlarged. The number of inclined plates may be varied, twenty-
seven are shown in the Drawing with a wheel having a diameter of three and
a half feet. h, ratchet wheel keyed on shaft f, and furnished with a catch.
The driving wheel e, being mounted loosely on shaft f, is turned solely by the

page_text: aid of said ratchet gear h; i, gearing for transmitting motion from wheel e to
screw c; j, cylindrical casing, which encloses nearly one half of the diameter
of the screw. The casing is open at the upper part to afford an escape for
the sand raised by the screw, whence it is carried by the current through
the plates of the driving wheel e, and so uniformly distributed. The lower
extremity of casing is bent of a curved form at k, so as to form a diaphragm
intended to prevent the sand 'from being carried away by the current before it
is raised by screw c to the upper end of said casing j. I sometimes employ
chambers formed of planking fixed in the bed of the river by weights main-
tained in a vertical position by cork fixed to the upper part of said chambers.
may also sometimes cover the framing placed in the bed of the river with
sheet iron, either tinned or otherwise.
I
Having described the nature of this Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
berein-before in part recited Letters Patent is, the improved apparatus herein
described and represented in the Drawing annexed, or any mere equivalent
thereof, for removing sand and other similar matters obstructing or filling up
the beds of streams & rivers, or for marine dredging operations.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Fourteenth day of April, in the year of our Lord
One thousand eight hundred and sixty-three.
Witness,
JAMES DAISH,
58, Chancery Lane,
London.
W. CLARK. (L.S.)