IMPROVE- MENTS IN DREDGERS AND DREDGING AND IN THE MACHINERY OR APPARATUS THUPLOYED THEREFOR " PROVISIONAL SPECIFICATION
Year: 1874

page_text: LETTERS PATENT to John Widger Barns, Superintendent of Canal
Irrigation, Bhawulpur, Punjaub, India, at present residing at Elm
Park, Broadhempstone, in the County of Devon, and William Simons
and Andrew Brown, both of the Town and County of Renfrew, North
Britain, Engineers and Shipbuilders, for the Invention of "IMPROVE-
MENTS IN DREDGERS AND DREDGING AND IN THE MACHINERY OR APPARATUS
THUPLOYED THEREFOR
"
PROVISIONAL SPECIFICATION left by the said John Widger Barns,
Williams Simons, and Andrew Brown, at the Office of the Com-
missioners of Patents, with their Petition, on the 3rd November
1874.
We, JOHN WIDGER BARNS, Superintendent of Canal Irrigation,
Bhawulpur, Punjaub, India, at present residing at Elm Park, Broad-
hempstone, in the County of Devon, and WILLIAM SIMONS and ANDREW
BROWN, both of the Town and County of Renfrew, North Britain,
Engineers and Shipbuilders, do hereby declare the nature of the said

page_text: Invention for "IMPROVEMENTS IN DREDGERS AND DREDGING AND IN THE MACHINERY
OR APPARATUS EMPLOYED THEREFOR," to be as follows, that is to say :-
This Invention relates to and consists in a new or improved form and
arrangement of the hull and machinery, and of the discharging shoot or
pipe of dredgers for excavating and deepening channels, canals, rivers,
basins, docks, or other similar works, and for depositing the dredged
materials on the adjacent banks or wharfs, or into barges or other
receptacles, and also to a new or improved system or mode of working
the dredgers whilst performing these operations.

page_text: times round a capstan or other suitable purchase situate on the point
or pivot whereon the dredger is centered.
The bucket ladder may either pass through a central well in the hull
or it may be situated at one side, or bucket ladders may be placed at
two or more sides, and the shoot or tube into which the dredgings are
delivered by the buckets is made to project in the direction of the land
or bank; or towards any suitable receptacle into which it is desired to
deposit the dredgings, the dredger being so constructed that the portion
of the hull intervening between the point of discharge from the buckets
and the point whereon the dredger is centered is employed to support
the tube or shoot.
In some cases the dredger is provided with a receptacle, into which
the dredgings fall from the shoot. In this receptacle an agitator may
be placed which mixes the dredgings with water, in which state or con-
dition they are forced through a line of pipes and deposited on to or in
from the banks adjoining or at the sides of the work, or into receptacles
by the action of centrifugal or other pumps.
In combination with the dredger herein-before described any arrange-
ment of apparatus other than the usual bucket ladder which is suitable
to the nature of the soil to be dredged may be employed. Instead of
forming the hull of the dredger of two triangles, as herein-before
described, it may consist of one such triangle in form, or it may
be made angular on two sides and curved on the third side without
interfering with the efficient working thereof.
In lieu of anchoring each end of the hauling or warping chain or
rope, or chains or ropes, by which the dredger is moved through an arc
from one side of the work to the other, as herein-before described, bights.
or loops may be formed on the extremities of the said chain or rope, or
chains or ropes, through which guide ropes or chains stretched tightly
along the banks of the work pass, and by this means the necessity of
shifting the anchorage of the aforesaid hauling chain or rope, or chains
or ropes, when the dredger is moved forward is obviated.
The steam after it has passed from the engines which drive the
ejecting pumps, when such are used, may be conducted through and
caused to actuate the engines which drive the dredging buckets.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Widger Barns, William Simons, and Andrew
Brown, in the Great Seal Patent Office on the 1st May 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
WIDGER BARNS, Superintendent of Canal Irrigation, Bhawalpur,
Punjaub, India, at present residing at Elm Park, Broadhempstone,
in the County of Devon, and WILLIAM SIMONS, and ANDREW BROWN,
both of the Town and County of Renfrew, North Britain, Engineers and
Shipbuilders, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of November, in the year
of our Lord One thousand eight hundred and seventy-four, in the
38th year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said John Widger Barns, William Simons, and
Andrew Brown, Her special license that we, the said John Widger
Barns, William Simons, and Andrew Brown, our executors, admini-
strators, and assigns, or such others as we, the said John Widger Barns,
William Simons, and Andrew Brown, our executors, administrators, or
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, usc, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN DREDGERS AND DREDGING AND
IN THE MACHINERY OR APPARATUS EMPLOYED THEREFOR," upon the condition
(amongst others) that we, the said John Widger Barns, William Simons,
and Andrew Brown, by an instrument in writing under our hands and
seals, or under the hand and seal of one of us, 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 we, the said John Widger Barns, William Simons,
and Andrew Brown, do hereby declare the nature of our 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

page_text: being had to the accompanying Drawings, and to the letters and figures
marked thereon, that is to say :-
Our said Invention relates to and consists in a new or improved form
and arrangement of the hull and machinery, and of the discharging
shoot or pipe of dredgers for excavating and deepening channels, canals,
rivers, basins, docks, or other similar works, and for depositing the
dredged materials on the adjacent banks or wharves, or into barges or
other receptacles, and also to a new or improved system or mode of
working the dredgers whilst performing these operations.
The hull of our improved dredger is in plan of a double triangular
form, that is to say, it is composed of two triangular shaped figures
having their bases united.
When in operation the hull of the dredger is attached at one side or
end of the line whereat the bases of the triangles meet, to a point on
which it is capable of moving as on a pivot or centre, so that the outer
ends or apeces of the triangular figures and the bucket ladder or
suction pipe, according to the character of the dredging mechanism is
moved in a curved arc across the face of the work which is being
excavated or dredged. The dredger is drawn across the face of the work
which is being excavated or dredged by one or more ropes or chains
stretched across the channel, canal, or river, in a line forming a chord of
the arc described by the outer end of the bucket ladder or suction pipe.
The said rope or chain or ropes or chains is or are at one end fixed or
anchored to the banks, and it (or they) is (or are) turned one or more
times round a capstan or other similar purchase preferably placed at or
near the fore part of the vessel, so that when motion is communicated to
the capstan the fore part of the dredger is hauled to either side of the
work by winding on the chain or rope. The position however of the
said capstan is not confined to the fore part of the vessel, as it may be
placed at any other suitable point thereon, and instead of one capstan
two or more such capstans may be used and operated either from the
engine direct or from a donkey engine provided for that purpose.
In lieu of anchoring each end of the hauling chain or rope or chains
or ropes by which the dredger is moved from side to side of the channel
as herein-before described, bights or loops may be formed on the
extremities of the said chain or rope or chains or ropes, and these are
thereby coupled to the guide ropes or chains stretched tightly along the

page_text: banks of the work, and by this means the necessity of shifting the
anchorage of the aforesaid hauling or warping chain or rope or chains or
ropes when the dredger is moved forward is obviated.
The dredger is moved in the direction of the length of the channel,
canal, or other work by another rope or chain fixed at its two extremities
on the land or near the bank, in a direction parallel to the length of the
channel or canal being excavated, or the guide rope or chain herein-
before referred to may be used for that purpose, that portion of the
chain or rope intermediate between the fixed extremitics being passed
one or more times round a capstan or other suitable purchase, situated
on the point or pivot whereon the dredger is centred.
The bucket ladder may either pass through a central well in the hull
or it may be situated at one side, or bucket ladders may be placed at
both sides, and the shoot or tube into which the dredged spoil is
delivered by the buckets is made to project in the direction of the land 1
or bank, that is to say, at right angles or otherwise to the length of the
dredger, or towards any suitable receptacle or placo into which it is
desired to deposit the dredgings.
In some cases the dredger is provided with a receptacle into which the
dredgings are discharged, and thereafter mixed with water by an
agitator and forced by centrifugal or other pumps through a line of
pipes, and so deposited on to the banks adjoining or at the sides of the
work, or into any suitable receptacle.
In combination with the dredger herein-before described any arrange-
ment of apparatus other than the usual bucket ladder may be employed, a
according to the nature of the soil to be dredged, and instead of forming
the hull of the dredger of two triangles as herein-before described, it
may consist of one such triangle in form, or it may be made angular on
two sides and curved on the third side without interfering with the
efficient working thereof.
Another part of our said Invention consists in utilizing the steam
which passes through the engines which operate the ejecting pumps
(when such are used) by conducting the steam when exhausting from the
ejecting engines through and causing it to actuate the engines which
drive the dredging buckets.
And in order that our said Invention may be properly understood we
now proceed more particularly to set forth the system, mode, or manner

page_text: in or under which the same is or may be used or practically carried into
effect, reference being had to the annexed Sheets of Drawings, and to
the letters and figures marked thereon, that is to say:―
Figure 1, Sheet 1, of the annexed Sheets of Drawings is a vertical
section of our improved form of dredger, Figure 2, being a plan of the
same. As shewn by these Drawings the dredger consists in plan of a
"diamond" shaped figure, rhombus, or two triangles united at their
bases, the minor diagonal a, b, constituting a base line upon which are
erected the two triangular figures forming the fore, and aft portions of
the hull. Upon the diagonal a, b, and at the port or starboard side of
the dredger hull, a centre or pivot A is situated which may consist of
an eye or block through which the hauling rope or chain B passes, but
which is preferably an upright or horizontal capstan or winch around
which the rope or chain B is coiled once or any greater number of times.
The ends of the rope or chain B are fixed to the bank of the river,
channel, or canal being dredged, so that when the capstan or winch
constituting the pivot A is caused to revolve the dredger hull is moved
backwards or forwards in the line or direction of the works. When a
mere eye or block is employed to connect the dredger hull to the rope
or chain B at the point A auxiliary ropes or chains, must be used,
extending parallel to the guide rope or chain B and having their
extremities either attached thereto or fixed to the bank by means of
separate anchors, kedges, or fastenings.
The auxiliary rope or chain or ropes or chains may be passed into the
hull through a swivel friction sheave, and after being coiled a sufficient
number of times around a capstan or winch barrel is (or are) passed out
of the hull through another friction sheave, but in lieu of either of these
methods for moving the dredger hull in the direction of its length, the
ordinary fore and aft hauling chains or ropes C and D may be employed,
and coiled upon capstans or winches E situated at each end of the hull,
as shewn on the Drawings. A similar arrangement of apparatus is
employed to move the extremities of the dredger, and consequently the
bucket, ladder, or suction pipe across the face of the work. This is
effected by the employment of ropes or chains F the ends of which are
anchored or otherwise fixed to the banks on each side of the dredger
hull. The ropes or chains F are then passed round purchases G, and
coiled upon the rope or chain barrels H of the winches E situated at
each end of the dredger hull. By operating the said winches so as to

page_text: coil on the rope or chain extending from one side of the dredger and
slack out that extending from the other side, the hull is caused to turn
upon the fixed pivot at A, and the ends thereof are so made to describe
an arc as indicated by the dotted lines on Figure 2, whereby the
dredging buckets or suction apparatus is caused to act upon the whole
breadth of the work, as shewn more clearly at Figure 3, which is a
Diagram plan of a dredger hull I fitted with a suction pipe J and
floating between the banks K of a river or canal; Figure 4, Sheet 1,
being an elevation corresponding to Figure 3. The hull I is centred or
pivoted at the point A, and by hauling on the ropes or chains last -]
described the ends of the dredger aro warped across the stream or
channel and the suction pipe cud caused to describe the arc shown at
Figure 3.
Instead of employing two ropes or chains F for each side of the
dredger one such rope or chain may be used at each end of the hull and
passed around a single upright or horizontal capstan or winch situated
thereon, and instead of anchoring or otherwise fixing the extremities of
such ropes or chains to the banks of the works they may be secured to
guide ropes or chains extending along the banks, preferably by means of
an eye, bight, or sheave, and by this means the necessity of shifting the
anchorago of the cross warping ropes or chains at each forward or back-
ward movement of the dredger is obviated, as the loop or bight slides
along the guide ropes or chains as the position of the dredger is
advanced.
As it is necessary that the herein-before described cross hauling ropes :
or chains should be in a constant state of tension, so as to keep the
dredger in its position relatively with the banks of the river, channel, or
canal being excavated the said ropes or chains are preferably attached to
their anchorages on the banks or to the guide ropes or chains last referred
to by means of blocks and tackle, so that as the dredger hull rises or
falls with the water level in obedience to tidal or other influences the
cross hauling ropes or chains may be lengthened or shortened to suit the
height of the water line.
The bucket ladder L, or the suction pipe employed in lieu thercof,
may be suspended in a well M formed in the ordinary manner at the
central part of the dredger and extending towards one end of the hull or
otherwise. The bucket ladder or suction pipe may be situated at one

page_text: side of the hull, as shewn upon Sheet 2 of the Drawings. It is preferred
to place the engines and boiler for actuating the bucket ladder or suction
pipe at one side of the hull, as shewn at Figure 2, Shcet 1, so as to
counterbalance the weight of the shoot or tube into which the dredgings
are discharged from the buckets or suction pipe. The said shoot or
tube (not shewn on the Drawings) is of the ordinary construction, and
is made to project towards the bank from the side of the hull opposite to
that whereat the engines and boiler are situated, the shoot or pipe being
stayed or supported on the hull and allowed to overhang or project over
the bank so as to discharge the dredgings at a sufficient distance in from
the channel, or under another arrangement the dredgings may be dis-
charged into any receptacle provided to receive them. In some instances
such a receptacle is placed on the hull itself and the dredgings discharged
thereinto from the buckets, after which they are mixed with water by
an agitator or equivalent means, and are thereafter forced in a liquified
stato, by centrifugal or other pumps, through a range of pipes Z to the
point of discharge upon the banks.
Under another arrangement of the dredging apparatus, illustrated at
Figures 3 and 4, Sheet 1, the hull I is pivoted upon and traversed back-
wards and forwards by means of the guide rope or chain B stretched
tightly along the bank K, and cross ropes or chains F are employed to
warp the ends of the hull and end P of a suction pipe J across the face
of the work. A centrifugal pump Q is situated upon the hull I, and
agitators are arranged in the suction pipe end P, as more particularly
shewn at Figures 5 and 6, Sheet 1. Figure 5 is a vertical section on an
enlarged scale of the suction pipe end P, at the line a, b, Figure 6, the
dotted lines marked J, Figure 5, representing the position of the main
suction pipe J.
A rectangular compartment R. is bolted upon each end of the portion P,
within which are agitators S composed of a series of arms or stirrers,
arranged at intervals around an axis U supported in bearings from the
sides of the compartment R, and actuated from the hull I by means of
a chain and chain pulley or other suitable gearing or mechanism. While
the pipe end P is progressing across the face of the work, the leading
agitator is caused to revolve and so stir up the silt, sand, or other soil,
which becomes mixed with surrounding water and is drawn up the main
suction pipe J by the action of the centrifugal pump Q. The suction
pipe end P is provided with throttle valves V, V', situated behind the
'

page_text: agitators and arranged so that when the end P is moved in the direction
of x, Figures 5 and 6, the valve V is open, while the valve V¹ remains
closed, whereas when the end P is moved towards y the valve V¹ is
opened and the valve V closed; thus it will be seen that the dredgings
are sucked through only one end at a time, that is to say, through the
opening that leads or is nearest to the bank, towards which the dredger
is being drawn across the face of the work. The suction pipe J is
attached by a movable joint at or near the centrifugal pump Q, and
may be raised and lowered like an ordinary bucket ladder by tackle X
situated near the bows of the dredger. After passing through the
pump the liquified dredgings are forced through a range of pipes W,
and discharged upon the bank K. or into any suitable receptacle.
In dredging with the herein-before described suction pipe J jets of
water may be used in lieu of the agitators S, and as the pipe end P while
in operation is sunk beneath the level of the river or canal bed, the jets of
water are forced into and undermine the soil, which then falls in, becomes
mixed with the surrounding water, and is drawn up through the suction
main as herein-before described. The advantages of thus using jets of
water as an undermining or loosening agent are that thereby the agitators
and mechanism for operating the same are supplanted by means less
costly and less liable to get out of order. When one dredging operation
has been performed by moving the hull towards one bank of the channel
or canal, the end P of the pipe J is raised and the hull advanced the
necessary distance, after which the end P is again lowered into the
material, and the hull moved through an arc so as to dredge towards the
opposite bank.
The Figures on Sheet 2 of the Drawings (herein-before referred to)
illustrate our improved dredger hull with the bucket ladder, or it may
be the suction pipe arranged at one side of the hull instead of in a
central well as herein-before described with reference to Figures 1 and 2,
Sheet 1, of the Drawings.
The other part of our said Invention, viz., that having reference to the
utilization of the exhaust steam from the engines of the ejector pumps
(when such are used) is illustrated on Sheet 3 of the Drawings.
The engines for working the bucket ladder are represented in hori-
zontal section, the high-pressure cylinder being marked A and the low-
pressure cylinder B. Steam from the boiler is led through the pipe C,

page_text: and from the pipe O a branch D feeds the steam into the engine E of
the ejecting pump F. After passing through the engine E the steam
exhausts through the pipe G and passes into the low-pressure cylinder B
of the main engines as indicated by the arrows, or otherwise, the cock g
on the pipe G is turned off, and the cock / on the branch pipe H opened,
so as to feed the exhaust steam (as indicated by the dotted arrows) into
the valve chest of the high-pressure cylinder A of the main engines,
which may be thus driven entirely by the exhaust steam from the
engines E of the ejecting pump F. If however it should be desired not
to use the exhaust steam from the engine E, it is only necessary to cut
off communication with the main engines by means of the cocks or
valves g and h, and allow the steam to escape from the ejecting pump
engines at the ship's side through the pipe I, the cock or valve i being
opened to allow the steam to make its exit into the atmosphere.
Having now described and particularly ascertained the nature of our
said Invention, and the system, mode, or manner in or under which the
same is or may be used or carried practically into effect, we would observe
in conclusion that we do not confine ourselves to the precise form of
dredger hull illustrated on the Drawings, that is to say, that instead of a
"diamond" or rhombus, or double triangular shaped figure, it may be
constructed in the form of a single triangle, or it may be made with two
sides flat and a third rounded; neither do we confine ourselves to the
number or position of the bucket ladders or suction pipes, but what we
do claim as the Invention secured to us by the herein-before in part
recited Letters Patent is,-
First. The arrangements or constructions of dredgers and dredging
apparatus in which the hull is of the forms or shapes set forth, and
swivels or pivots upon a centre at one end of the base line of the tri-
angular figure or figures, and the mode of working the same, substan-
tially as herein-before described and shewn on the accompanying Sheets
of Drawings.
Second. The arrangement and construction of double suction pipe
end, provided with agitators and throttle valves as illustrated at Figures
5 and 6, Sheet 1, of the Drawings, and the employment of the same in
combination with jets of water, as herein-before described and shewn.
Third. Utilizing the exhaust steam from the engine of the ejecting
pumps, and employing the same to actuate or assist in actuating the

page_text: main engines of the dredger by the means and in the manner herein-
before described and shewn on Sheet 3 of the Drawings.
In witness whereof, I, the said Andrew Brown, for and on behalf
of myself and of the aforesaid John Widger Barns and William
Simons, have hereunto set my hand and seal, this Thirtieth day t
of April, One thousand eight hundred and seventy-five.