Improvements in Dredging Apparatus.
Year: 1894

page_text: Date of Application, 25th Sept., 1894-Accepted, 27th Oct., 1894
COMIDELE
DI DUIFICATION.
[Communicated from abroad by THE MINING AND DREDGING POWER Co.,
a corporation organized under the laws of West Virgina, and located and
doing business at No. 68, Broad Street, in the City, County, and State of
New York, U.S.A.]
Improvements in Dredging Apparatus.
I, HENRY HARINGTON LEIGH, Assoc. M. Inst. C.E., Fel. Ch. Inst. P.A.,
F.I. Inst., practising as Phillips and Leigh, at 22 Southampton Buildings, Chancery
Lane, in the Administrative County of London, Engineer and Patent Agent, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to an improved dredging apparatus, of that class which
is arranged on a barge or scow, and in which the usual well-known parts, such as
the excavating device, a receiving tank of the dredged material or spoil, a pump
and a boiler for supplying steam to the pump and to the pumps by which water is
supplied to the receiving tank are combined in such a manner that the excavated
material is supplied in liquefied and easily-flowing condition to the pump, so that it
can be readily drawn through the suction-pipe in the vacuum pump and conveyed
through the discharge-pipe and a suitable conveyer-pipe to the place of deposit ;
and the invention consists of a dredging apparatus which comprises a barge or
scow, an excavating-device arranged on said barge, an open receiving tank on said
barge, means for supplying mixing and agitating jets of water to the upper part
and bottom of the receiving-tank, a steam vacuum-pump, the suction-pipe of
which is connected with said tank, and a conveyer-pipe connected with the
discharge-pipe of the pump.
The invention consists further of a dredging apparatus comprising a barge
or scow, an excavating-mechanism arranged on said barge, an open comminuting-
tank on said barge, an open mixing-tank in connection with said comminuting-tank,
a comminuting mechanism in said comminuting-tank, means for supplying water
to both of said tanks, a steam vacuum-pump, a suction-pipe leading from the
mixing-tank to said pump, and a conveyer-pipe connected with the discharge-pipe of
the pump.
In the accompanying drawings
Figure 1 represents a vertical longitudinal section of a barge or scow,
arrangement of the working parts of my improved dredging apparatus.
Figure 2 is a side-elevation of the same.
Figure 3 a plan view.
Figure 4 a vertical transverse section on line 4-4 Figure 3.
showing the
Figure 5 an end-elevation of the barge with its hoisting-devices, all the fore-
going figures showing the dredging apparatus arranged in duplicate on the same
barge.
Figures 6 and 7 are respectively a plan-view and a side-elevation of the receiving-
tank and the nozzles for mixing and agitating the material in the
same, said figures
being drawn on a larger scale.
Figure 8 is a plan-view of a modified construction of dredging apparatus showing
the receiving-tank connected with a comininuting-tank, and

page_text: any suitable manner at the point where the dredging operations are to be carried on.
At one end of the barge are arranged the excavating and hoisting-devices for the
material to be dredged from the bottom or tank of the water course to be excavated,
said hoisting-devices consisting of a swinging-crane B, a bucket B' for the grappling
of the material or spoil and a steam-operated hoisting-engine B2 by which the bucket
is raised so that it can be transferred by the swinging-crane to the receiving-tank C,
which is arranged back of the swinging-crane in the body of the barge, as shown
clearly in Figure 3.
All the parts of the dredging-mechanism are arranged in duplicate on the barge,
preferably in such a manner as to be located symmetrically to the longitudinal axis
of the same.
The swinging-cranes and the hoisting-engines for the buckets are
arranged at one end of the barge, the cranes being rigidly connected by a frame F
between the cranes, as shown in the plan-view Figure 3 and end view Figure 5.
The buckets B' act as a counter-balance to each other, while the swinging-cranes
being arranged adjacent to each other at the end of the scow, permit the material
to be discharged directly into the receiving-tanks without requiring chutes for
carrying the material to the tanks. The arrangement of two buckets and
hoisting-devices permits also the cutting of a wider channel without moving the
dredge.
A steam vacuum-pump D is arranged sideways of each receiving-tank C and
connected by its suction-pipe D' with the same, the suction-pipe being curved in
downward direction so as to take up by suction the material near the bottom of
the tank. The discharge-pipe D2 of each steam vacuum-pump D is connected
with a conveyer-pipe D³ through which the material discharged by the pumps is
conveyed to the place of deposit. The conveyer-pipe D³ is composed of a number
of jointed sections, which are suspended by chains from a mast or boom on the
barge and supported by suitable floats up to the point where the material is
discharged. The conveyer-pipe D³ is connected with the discharge-pipe D2 by a
ball and socket-joint so that the end of the conveyer-pipe can always be retained
stationary at the point of discharge, while the dredge itself can change its
position to some extent as required by the progress of the excavation. At the
opposite end of the barge are arranged the steam-boilers E, from which the
steam is supplied for operating the vacuum-pumps, hoisting-engines and the pumps
by which the required quantity of water is supplied to the receiving-tanks C.
The vacuum-pumps, water supply pumps and steam-boilers are protected by a
suitable superstruction on the barge, which superstruction also contains the necessary
cabins for the engineers and employees generally.
The receiving-tank C is shown clearly in Figures 6 and 7, and consists of a
hopper-shaped body, the inner side-wall of which is extended to greater height so
as to prevent the scattering of the material over the higher side-wall into the barge.
Near the bottom of each receiving-tank B are water supply-pipes b, which are
passed through the side-walls and provided at the inside of the tank with slightly
curved nozzles 6, through which jets of water are forced, so that the material as it
is dropped into the tank by the hoisting-bucket is kept in motion by the agitating
jets, and prevented from packing at the bottom of the tank. While the material is
thus kept in agitation by the jets, the water required for mixing with the material
so as to keep it in liquid state, is supplied by a large pipe 62 having a nozzle ³
which extends over the side-wall of the tank C. The water for the agitating jets
is supplied by a smaller pump p, while the water for the mixing jet is supplied by a
larger pump p. The mixing and agitating jets supply the required quantity of water
for keeping the material dropped into the tank in a liquid state, so that it can be
sucked with great facility through the suction-pipe D' into the pump D and
discharged freely through the discharge-pipe D' and conveyer-pipe D³ at the place
of deposit.
The suction and discharge-pipes D', D2 of the steam vacuum-pump D are
provided with gates or valves, which are operated by suitable steam or other
cylinders of any approved construction. The discbarge-pipes D¹ of both vacuum-

page_text: pumps D are connected with one conveyer-pipe D³ so that by the action of both
pumps a nearly continuous flow of liquefied material is kept up, and discharged
at the place of deposit, the alternating action of the pumps producing a great
saving in time and labour, accelerating the flow of material and imparting an
increased capacity to the dredge.
Live steam is supplied from the steam-boilers E to the vacuum-chambers of
the pumps C, to the cylinders by which the gates or valves of the suction and
discharge-pipes of the pumps are operated, to the pumps which supply the mixing
and agitating jets of water and to the hoisting-engines by which the dredging-
buckets are raised, said steam supply-pipes being clearly shown in the plan-view
Figure 3. When the material or spoil to be dredged consists of large and hard
lumps or pieces, it is necessary to pass the same through a comminuting tank G
which is arranged on the deck of the dredge alongside of the receiving-tank
and connected by an inclined chute G¹ with the receiving-tank C. The com-
minuting apparatus consists of rollers G2 having pointed teeth g, said rollers
being arranged near enough to each other so that the material is broken up and
comminuted sufficiently so as to pass through the suction-pipe without danger of
choking the same. The toothed rollers G³ are arranged in the comminuting-
tank G, into which the excavating mechanism discharges its contents, said
comminuting tank being located at such a distance from the axis of the crane
that by swinging the excavating-device over it will arrive above the tank of the
comminuting apparatus. The tank and rollers of the comminuting apparatus are
supplied with water by means of pipes g¹ from the pump p¹ by which the water
is also supplied to the receiving-tank C. The water supplied thereby serves to
lubricate and dissolve the dredging material or spoil, while the rollers break it
up, liquefy it and prevent thereby the clogging of the suction and discharge-
pipes of the
pump.
By arranging two sets of excavating mechanisms, two receiving-tanks and two
pumps on the barge and locating the receiving-tanks or comminuting-tanks
respectively near the end of a radius formed by the swinging of the excavating
mechanism, a wide cut can be excavated in the water without swinging or moving
the dredge, while by regulating the water supplied to the comminuting and
receiving-tanks different kinds of material can be excavated at the ends and sides
of the dredge without moving the same.
My improved dredging apparatus can be used to great advantage for increasing
the depths of lakes, reservoirs, slips, or for deepening the channel of a river,
canal or other water course, as the material is readily transferred from the point
of excavation to the barge and from the barge to a distant place of deposit.
Large quantities of material can be dredged and disposed of by the duplication
of all the parts on one barge and delivered in a comminuted condition to the
pump so that it can be discharged in an almost continuous flow through the
conveyer-pipe at the place of deposit. By duplicating the dredging apparatus,
the operation of the dredge can be continued even if one dredge should become
disabled so that the dredging operation need not be suspended, but can be
continued with one dredge while the other is repaired. By the double arrange-
ment of the dredging parts the barge is balanced and forms in connection with
the remaining accessories a structure by which the dredging operation can be
carried on in a quick, effective and a comparatively less expensive manner than
by the dredging apparatus heretofore in use."
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination of a dredge, an excavating mechanism arranged on the same,
an open receiving-tank for the dredged material or spoil, means for mixing the
material in the receiving-tank with water, a steam vacuum-pump having valved
suction and discharge-pipes, the suction-pipe being connected with the receiving-

page_text: tank, and a conveyer-pipe connected with the discharge-pipe of said pump,
substantially as set forth.
2. The combination of a barge, an excavating mechanism on the same, a
receiving-tank for the dredged material or spoil, means for mixing the material in
said tank with water, agitating jets at the bottom of the receiving-tank a steam
vacuum-pump, the suction-pipe of which is connected with said tank, and a
conveyer-pipe connected with the discharge-pipe of said pump, substantially as
set forth.
3. A dredging apparatus consisting of a barge, an excavating mechanism for the
dredged material or spoil on said barge, an open comminuting-tank, an open
receiving-tank in communication with said comminuting-tank, a comminuting
mechanism in said comminuting-tank, means for supplying water to the comminuting
and receiving-tanks, a steam vacuum-pump, a suction-pipe leading from the
receiving-tank to the vacuum-pump, and a conveyer-pipe connected with the
discharge-pipe of said pump, substantially as set forth.
4. A dredging apparatus composed of a barge, an excavating mechanism for
the dredged material on said barge, a comminuting-tank on said barge into which
the dredged material is discharged, a comminuting-mechanism in said tank, a
receiving-tank, an inclined chute connecting the comminuting-tank with the
receiving-tank, pipes for supplying water to both tanks, a steam vacuum-pump, a
suction-pipe connecting the pump with the receiving-tank, and a conveyer-pipe
connected with the discharge-pipe of the pump for conveying the excavated
material to the point of discharge, substantially as set forth.
Dated this 25th day of September 1894.
HENRY H. LEIGH, C.P.A.