Improvements in Dredgers and Barges.
Year: 1895

page_text: Date of Application, 11th Mar., 1895
Complete Specification Left, 18th Mar., 1895-Accepted, 4th May, 1895
Improvements in Dredgers and Barges.
We, JAN SMIT V, and LEONARDUS JOHANNES SMIT, trading under the style
of L. Smit and Zoon, of Kinderdik, in the Kingdom of the Netherlands,
Shipbuilders, do hereby declare the nature of this invention to be as follows:-
This invention has reference to a construction of suction hopper dredger whereby
the dredged material, hereinafter called spoil, can be discharged as desired either
on to the bank, or into barges lying alongside, or into a particular compartment of
the dredger from which it can be afterwards discharged by suction, at a place other
than that at which it was dredged, either onto the bank, or into barges.
Dredgers as heretofore constructed with a hopper spoil suction apparatus can
deliver the spoil either into barges lying alongside, or into their own holds, or
through a foreing delivery pipe directly on to the bank. When the spoil is
delivered into the hold of the dredger itself, it can be discharged therefrom at
another place, for instance, when the hopper-vessel goes out to sea, by opening the
bottom flaps or trap-doors.
A hopper suction-dredger according to this invention, fulfils by reason of its
peculiar construction and arrangement, all these requirements, and its main feature
consists in that it is capable after it has delivered the dredged spoil into its own
hold, of again itself discharging the said spoil by suction without the employment
of a separate centrifugal water pump and appurtenant machinery so that when the
suction hopper dredger has filled up its own hold by suction at the dredging place,
it is capable, without auxiliary machinery, of again discharging itself by suction at
another place, either by there discharging the spoil ipta barges, or by forcing the
same through a delivery pipe onto the bank.
In the accompanying drawings,
Fig. 1 is a part longitudinal section, Fig. 2 a part plan, and Fig. 3 a cross section
illustrating a suction hopper dredger constructed according to this invention.
Figs. 4 and 5 are cross sections illustrating various modes of operation of the said
dredger.
For dredging sand and other material, herein called spoil, from the bed of
a river, there is provided in the central line of the dredger a suction pipe A
arranged in a tunnel B that extends longitudinally and centrally of the dredger.
At the rear end of the dredger the suction pipe terminates by means of a movable
coupling C and pipe with sluice valve e, in a five-way pipe connection D. The
other end of the pipe A, that is to say the suction end, is hung on a chain a by
which the suction pipe can be completely drawn up into the tunnel B. The space
or hold E for the dredged spoil, extends above and on both sides of the tunnel B
its longitudinal or side walls being inclined downward towards the middle so as to
allow the spoil to slide down easily. The bottom of the hold E at each side of the
tunnel B, consists of loose flaps or trap-doors K K¹ (Fig. 2) adapted to open
downwards. Above these trap-doors K there are arranged a series of other but
smaller trap-doors k, k' also adapted to open downwards. The trap-doors k k¹ are
double or folding, and are separated from the tunnel B by passages b b¹ which are
open at top and bottom and extend throughout the length of the hold E on both
sides of the tunnel and serve as passage-ways for the hauling-up chains c of the
trap-doors K K'. The superficial area of the double flaps k and k¹ is consequently

page_text: smaller than that of the flaps K and K' by the width of the passages 661. The
trap-doors kk are attached to chains d d respectively which unite together in a
yoke-piece and are drawn up from the deck by means of winches or other means,
as are also the chains c for the large lower trap doors K K', so that the said doors
can be opened and closed as desired (Fig. 2).
Between the closed flaps K and k and K¹ k¹ there are formed passages F FI
respectively which are located at opposite sides of the tunnel and are hereinafter
referred to as the flap-passages. These flap-passages communicate at their rear
ends by means of pipes G G fitted with sluice valves 9 9', with the five-way pipe
connection D. At their front ends, the flap-passages are arranged to open into a
transversely arranged chamber H which communicates directly with an open
passage located at the front end of the tunnel B. Normally the flap-passages are
separated from the reservoir H by sluice valves s s', by suitably opening which
water can be admitted at a regulated rate into the said flap-passages.
Opposite the suction pipe there is mounted against the five-way pipe connection D
a centrifugal spoil pump L from which a pipe M extends vertically upwards
beyond the deck of the dredger. By means of the pipe M the dredged spoil can be
discharged either through a cone connecting piece O and a force-pipe connected
thereto, on to the bank, or through two horizontal pipes N N' arranged above the
hold E, into the hold itself, or through pipes P P arranged on both sides of the
dredger, into barges. The pipes M N N, P and P¹ can be closed by means of
sluice valves m, n, n¹ p and respectively. The pipes N N' are each provided on
their lower sides with apertures through which the dredged spoil can fall into the
hold E.
The pipes P P have rotary tee-shaped discharging ends which can be turned
down so low into barges located at each side of the dredger, as to prevent any
possibility of the spoil being blown away by a high wind (Figs. 2 and 4). When
the pipes P P are not in use, their rotary discharging ends can be moved into the
position indicated by dotted lines in Fig. 4, or be laid flat on the deck.
To enable the hopper suction dredger to unload a barge lying alongside it, there
is also connected to the five-way pipe connection D, a pipe R which extends over
one side of the dredger, and is provided with a rotary suction inlet pipe R¹ hung
by a chain by which it can be let down into a barge. In order that the spoil in the
barge to be discharged may be readily sucked up, it must be diluted with water.
For this purpose there is provided a centrifugal water pump S (Fig. 5) which by
means of a pipe T, to which two vertical delivery pipes are connected, delivers
water at both sides of the suction inlet pipe R₁ on to the spoil which thereby
becomes considerably diluted and rendered suitable for being sucked up. The spoil
thus sucked up can then be discharged by means of the centrifugal spoil pump L
on to the bank, or into the hold E of the dredger. The suction pipe R is connected
to the centrifugal spoil pump L and the water pipes Tt provided, only when the
suction hopper dredger is required to discharge spoil from barges lying alongside
of it, at which time the said dredger will lie up against the bank. The pipe R when
used is connected by means of a valve u with the centrifugal water pump, in order
that water may be forced through the suction pipe R for the purpose of starting
the centrifugal sand pump.
To deliver spoil through the delivery pipe on to the bank, there is provided, as
above mentioned, a cone O on the pipe M. On the bank and suspended by means
of balance weights, there is mounted on a suitable framing, a pipe connecting piece
which is flexibly connected to a delivery pipe on the bank, and is let down upon the
cone, so that a tight joint is provided with the cone O at all water levels.
The various functions which can be performed by the suction hopper dredger
herein before described are the following:-
(a) It can suck up spoil from the river bed and deliver the same
1 into its own hold,
2, into a barge or barges lying alongside, or
3 through a delivan nim

page_text: (b) It can discharge itself, after it has become filled in the manner indicated
under a, 1 in such a way that the spoil can be discharged at a place away from the
dredging place, either on to the bank, or into a barge lying alongside.
(c) It can suck up dredged spoil from a barge or barges lying alongside and then
force such spoil on to the bank, or deliver the same into its own hold.
(d) It can discharge itself by opening the two sets of bottom trap-doors K K'
and k k¹.
(a) For dredging a river bed, the suction pipe A is let down on to the bed of the
river the trap-doors, and also the sluice valves g, g', are closed the sluice valve e is
opened, and according as the spoil is to be discharged into a barge or into the hold
of the dredger, or direct on to the bank, the corresponding sluice-valve p, p', n, n',
or m, is opened, and the others closed.
(6) When the hold E is filled, and the dredger is to be discharged at another
place, either into barges or on to the bank, the sluice valves e, n and n' are closed,
and the sluice valves s s' in the flap-passages F, F' more or less opened. The
flap-passages thus become filled with water, and then the upper trap-doors k k¹ are
partly opened whilst the lower ones K K remain closed. By this means spoil in
the hold E will fall into the flap-passages which are filled with water. The supply
of water to the flap passages can be regulated by means of the sluice-valves s s¹.
The centrifugal spoil pump L upon being set in action, will now tend to empty the
Alap-passages, spoil continually sliding down and becoming mixed with the water
admitted to the said passages from the chamber H and becoming sucked up
through the pipes G, G¹ until the hold E is empty. By partly or entirely opening
the trap-doors k, k', the rate of delivery of spoil into the flap-passages can be
regulated so as to obtain the proper mixture of spoil and water in these passages.
The spoil may be discharged directly on to the bank, or into barges, the valves m
It will thus be seen that
and, p being suitably manipulated for this purpose.
by reason of the flap passages and connected parts, the dredger is able to discharge
itself without the employment of a centrifugal water pump for mixing water with
the spoil, and without requiring the aid of any other auxiliary apparatus.
(c) When the dredger is required to unload a barge lying alongside it, the
valves e, g g', p, p, and the throttle valve u are closed, the centrifugal water
pump S is connected up, and the suction pipe R is let down into the barge.
The spoil in the barge being diluted with water from the pipes tt', the centrifugal
spoil pump L will suck up the same and force it through pipe M on to the bank, or
delivers it, through the pipes N N¹ into the hold E of the dredger, the valves m
and n n' being suitably manipulated for this purpose.
66
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(d) By opening the two sets of trap doors K, K' and k, k', the hold E can be
discharged in the well known manner at any place where the spoil can be dumped.
Hopper barges may also be provided with flap-passages and appurtenant water
chambers as herein described. The connecting pipes G G are then prolonged
upward beyond the deck, and there connected to a centrifugal spoil pump mounted
on the bank or ou a ship, and by means of which the " 'hopper-barge can then be
unloaded in the manner herein before described.
2002
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50
We, JAN SMIT V, and LEONARDUS JOHANNES SMIT, trading under the style
of L. Smit and Zoon, of Kinderdik, in the Kingdom of the Netherlands, Ship-
builders, do hereby declare the nature of this invention and in what manner the

page_text: same is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention has reference to a construction of suction hopper dredger whereby
the dredged material, hereinafter called spoil, can be discharged as desired either
on to the bank, or into barges lying alongside, or into a particular compartment of
the dredger from which it can afterwards be discharged by suction, at a place
other than that at which it was dredged, either onto the bank, or into barges.
Dredgers as heretofore constructed with a hopper spoil-suction apparatus can
deliver the spoil either into barges lying alongside, or into their own holds, or
through a forcing delivery pipe directly on to the bank. When the spoil is
delivered into the hold of the dredger itself, it can be discharged therefrom at
another place, for instance, when the hopper-vessel goes ont to sea, by opening the
bottom flaps or trap-doors.
A hopper suction-dredger according to this invention, fulfils by reason of its
peculiar construction, and arrangement, all these requirements, and its main feature
consists in that it is capable, after it has delivered the dredged spoil into its own
hold, of again itself discharging the said spoil by suction without the employment
of a separate centrifugal water pump and appurtenant machinery, so that when the
suction hopper dredger has filled up its own hold by suction at the dredging place,
it is capable, without auxiliary machinery, of again discharging itself by suction at
another place, either by there discharging the spoil into barges, or by forcing the
same through a delivery pipe on to the bank.
In the drawings filed with our Provisional Specification
Fig. 1 is a part longitudinal section, Fig. 2 a part plan, and Fig. 3 a cross
section, illustrating a suction hopper dredger constructed according to this
invention.
Figs. 4 and 5 are cross sections illustrating various modes of operation of the
said dredger.
For dredging sand and other material, herein called spoil, from the bed of a
river, there is provided in the central line of the dredger a suction pipe A arranged
in a tunnel B that extends longitudinally and centrally of the dredger. At the
rear end of the dredger the suction pipe terminates by means of a movable
coupling C and pipe with sluice valve e, in a five-way pipe-connection D. The
other end of the pipe A, that is to say the suction end, is hung on a chain a by
which the suction pipe can be completely drawn up into the tunnel B. The space
or hold E for the dredged spoil, extends above and on both sides of the tunnel B,
its longitudinal or side walls being inclined downward towards the middle so as to
allow the spoil to slide down easily. The bottom of the hold E at each side of the
tunnel B, consists of loose flaps or trap-doors K K' (Fig. 2) adapted to open
downwards. Above these trap-doors K there are arranged a series of other but
smaller trap-doors k, k' also adapted to open downwards. The trap-doors k, k¹ are
double or folding, and are separated from the tunnel B by passages b, which are
open at top and bottom and extend throughout the length of the hold E on both
sides of the tunnel, and serve as passage-ways for the hauling up chains c of the
trap-doors K, K¹. The superficial area of the double flaps and k¹ is con-
sequently smaller than that of the flaps K and K' by the width of the passages b, b.
The trap-doors k, k' are attached to chains d, d¹ respectively which unite together
in a yoke-piece and are drawn up from the deck by means of winches or other
means, as are also the chains c for the large lower trap doors K, K¹, so that the
said doors can be opened and closed as desired (Fig. 2).
Between the closed flaps K and k, and K', k¹ there are formed passages F, Fl
respectively which are located at opposite sides of the tunnel and are hereinafter
referred to as the flap-passages. These flap-passages communicate at their rear
ends by means of pipes G, G₁, fitted with sluice valves g, g', with the five-way pipe
connection D. At their front ends, the flap-passages are arranged to open into a
transversely arranged chamber H which communicates directly with an open
passage h located at the front end of the tunuel B and into which water can freely

page_text: pass from the river in which the dredger works. Normally the flap-passages are
separated from the reservoir H by sluice-valves s, s¹, by suitably opening which
water can be admitted at a regulated rate into the said flap-passages.
Opposite the suction pipe there is mounted against the five-way pipe connection D
a centrifugal spoil pump L from which a pipe M extends vertically upwards beyond
the deck of the dredger. By means of the pipe M the dredged spoil can be
discharged either through a cone connecting piece O and a force-pipe connected
thereto, onto the bank, or through two horizontal pipes N, N' arranged above
the hold E, into the hold itself, or through pipes P, P' arranged on both sides
of the dredger, into barges. The pipes M, N, N1, P and P can be closed by
means of sluice valves m, n, n', p and pl respectively. The pipes N, N₁ are
each provided on their lower sides with apertures through which the dredged
spoil can fall into the hold E.
The pipes P, P¹ have rotary tee-shaped discharging ends which can be turned
down so low into barges located at each side of the dredger, as to prevent any
possibility of the spoil being blown away by a high wind (Figs. 3 and 4). When
the pipes P, P' are not in use, their rotary discharging ends can be moved into the
position indicated by dotted lines in Fig. 4, or be laid flat on the deck.
To enable the hopper suction dredger to unload a barge lying alongside it, there
is also connected to the five-way pipe connection D, a pipe R which extends over
one side of the dredger, and is provided with a rotary suction inlet pipe R¹
hung by a chain by which it can be let down into a barge. In order that the
spoil in the barge to be discharged, may be readily sucked up, it must be diluted
with water. For this purpose there is provided a centrifugal water pump S
(Fig. 5) which by means of a pipe T, to which two vertical delivery pipes t t¹ are
connected, delivers water at both sides of the suction inlet pipe R' on to the spoil
which thereby becomes considerably diluted and rendered suitable for being sucked
up. The spoil thus sucked up can then be discharged by means of the centrifugal
spoil pump L on to the bank, or into the hold E of the dredger. The suction
pipe R is connected to the centrifugal spoil pump L and the water pipes T, t, t¹
provided, only when the suction hopper dredger is required to discharge spoil from
barges lying alongside of it, at which time the said dredger will lie up against the
bank. The pipe R when used is connected by means of a valve u with the centri-
fugal water pump, in order that water may be forced through the suction pipe R for
the purpose of starting the centrifugal sand punip.
To deliver spoil through the delivery pipe on to the bank, there is provided, as
above mentioned, a cone O on the pipe M. On the bank and suspended by means
of balance weights, there is mounted on a suitable framing, a pipe connecting
piece which is flexibly connected to a delivery pipe on the bank, and is let down
upon the cone, so that a tight joint is provided with the cone O at all water
levels.
The various functions which can be performed by the suction hopper dredger
hereinbefore described are the following:-
(a) It can suck up spoil from the river bed and deliver the same
1 into its own hold,
2, into a barge or barges lying alongside, or
3, through a delivery pipe, directly on to the bank.
(b) It can discharge itself, after it has become filled in the manner indicated
under a, 1 in such a way that the spoil can be discharged at a place away from the
dredging place either on to the bank, or into a barge lying alongside.
(c) It can suck up dredged spoil from a barge or barges lying alongside
it, and then force such spoil on to the bank, or deliver the same into its own
hold.
(d) It can discharge itself by opening the two sets of bottom trap-doors K, K¹
and k, kl.
(a) For dredging a river bed, the suction pipe A is let down onto the bed of the
river, the trap-doors, and also the sluice-valves g, g', are closed, the sluice valve e

page_text: is opened, and according as the spoil is to be discharged into a barge or into the hold
of the dredger, or direct on to the bank, the corresponding sluice-valve p, p', n, n',
or m, is opened, and the others closed.
(b) When the hold E is filled, and the dredger is to be discharged at another
place, either into barges or on to the bank, the sluice valves e, n and n¹ are closed,
and the sluice valves, s in the flap-passages F, F¹ more or less opened. The flap-
passages thus become filled with water, and then the upper trap-doors k, k² are partly
opened whilst the lower ones K, K' remain closed. By this means spoil in the
bold E will fall into the flap-passages which are filled with water. The supply of
water to the flap-passages can be regulated by means of the sluice-valves s, s¹.
The centrifugal spoil pump L, upon being set in action, will now tend to empty the
flap-passages, spoil continually sliding down and becoming mixed with the water
admitted to the said passages from the chamber H and becoming sucked up through
the pipes G, G' until the hold E is empty. By partly or entirely opening the
trap-doors k, k', the rate of delivery of spoil into the flap-passages can be regulated
so as to obtain the proper mixture of spoil and water in these passages. The spoil
may be discharged directly onto the bank, or into barges, the valves m and p, p' being
suitably manipulated for this purpose.
It will thus be seen, that by reason of the flap-passages and connected parts, the
dredger is able to discharge itself without the employment of a centrifugal water
pump for mixing water with the spoil, and without requiring the aid of any other
auxiliary apparatus.
(c) When the dredger is required to unload a barge lying alongside it, the
valves e, g, g, p, p, and the throttle valve u are closed, the centrifugal water pump S
is connected up, and the suction pipe R is let down into the barge.
The spoil in the barge being diluted with water from the pipes t, t', the centrifugal
spoil pump L will suck up the same and force it through pipe M on to the bank, or
delivers it through the pipes N, N' into the hold E of the dredger, the valves m
and n, n' being suitably manipulated for this purpose.
(d) By opening the two sets of trap doors K, K' and k, k¹, the hold E can be
discharged in the well known manner at any place where the spoil can be dumped.
Hopper barges" may also be provided with flap-passages and appurtenant water
chambers as herein described. The connecting pipes G G₁ are then prolonged
upward beyond the deck, and there connected to a centrifugal spoil pump mounted
on the bank or on a ship, and by means of which the "hopper-barge" can then be
unloaded in the manner herein before described.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that we
claim is :-
1. A suction dredger constructed as a hopper barge, and provided with a five-
way pipe connection D and corresponding pipes with valves, the arrangement being
such that dredged spoil sucked up by a centrifugal spoil pump L through a suction
pipe A connected with the said five-way pipe connection, can be delivered at will,
either on to the bank, or into barges lying alongside, or into the hold E of the dredger
from which it can be again sucked up by the said centrifugal spoil pump and
discharged onto or into one or other of the two first mentioned places, substantially
as herein described.
2. In the suction hopper dredger specified in Claim 1, the arrangement, at both
sides of the suction-tube tunnel, of the movable bottom flaps K K', and of double
flaps kk arranged above the flaps K K'in such a manner as to leave between them
and the tunnel, passage-ways b for the hauling-up chains of the flaps K K', and
between them and the flaps K K' flap-passages F F which communicate with water
chambers or passages H and h, and from which, upon opening the flaps k k¹, the
dredged spoil falling from the hold above and mixing with water coming from the
said chamber or passages can be sucked away by means of the centrifugal spoil
pump, substantially as herein described.

page_text: 3. In the suction hopper dredger specified in Claims 1 and 2, the arrangement of
the vertically rotatable tee-shaped delivery pipes P P₁ for delivering the spoil into
barges lying alongside the dredger, the said pipes being adapted to be turned very low
down into the barges, and, when not in use, to be laid Hat upon the deck substantially
as described and shown.
4. A hopper barge constructed with flaps such as kk' and K K' arranged above
each other so as to leave between them one or more flap-passages such as F, F1
which is or are adapted to be placed in communication with one or more reservoirs
and passages such as H & h, and with a centrifugal spoil pump, so that the barge
can be discharged by suction when desired and the dredged spoil carried thereby
delivered upon a bank or other place substantially as herein described.
5. The combination and arrangement of parts constituting the improved suction
hopper dredger constructed as described and shown for the purposes specified.
Dated this 18th day of March 1895.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.