IMPROVEMENTS IN APPARATUS FOR EXCAVATING OR DREDGING UNDER WATER, AND AN IMPROVED DREDGING HOPPER FOR RAISING AND REMOVING THE MATERIAL, EXCAVATED " PROVISIONAL SPECIFICATION
Year: 1882

page_text: LETTERS PATENT to William Smith, of Aberdeen, North Britain, Civil
Engineer and Resident Harbour Engineer for an invention of "IMPROVEMENTS
IN APPARATUS FOR EXCAVATING OR DREDGING UNDER WATER, AND AN
IMPROVED DREDGING HOPPER FOR RAISING AND REMOVING THE MATERIAL,
EXCAVATED
"
PROVISIONAL SPECIFICATION left by the said William Smith at the Office
of the Commissioners of Patents on the 24th March 1882.
WILLIAM SMITH of Aberdeen, North Britain, Civil Engineer and Resident
Harbour Engineer "IMPROVEMENTS IN APPARATUS FOR EXCAVATING OR DREDGING
UNDER WATER AND AN IMPROVED DREDGING HOPPER FOR RAISING AND REMOVING
THE MATERIAL EXCAVATED
"
The first part of this invention is based on the system of ploughing by means of
two steam engines working a plough backwards and forwards with wire ropes and
pulleys. For the plough is substituted a truck constructed of wood, iron or other
suitable materials, consisting of two vertical sides connected across the middle by
a vertical plate. The sides are turned in at the bottom edges to form two ledges
on which a bottom plate rests, forming a bottom for only one division of the
truck at a time. The truck is supported and borne on a pair of large wheels at
the middle, and has a pair of rollers or wheels at each end adjustable vertically by
screws.
The truck is to be drawn by a rope attached to the middle plate above the centre
of rotation of the middle wheels, and a rope attached to the bottom plate is also
to be drawn so as to keep the bottom in its place while it scrapes the soil or sand
and gradually fills the truck as it advances across the channel. On reaching the
side of the channel the bottom plate is to be drawn to the other end of the truck
and the contents of the full division deposited. The truck will then be drawn in
the opposite direction by ropes attached at the opposite side of the vertical plate
and the other end of the bottom; the tension of the upper rope draws the end of
the truck down to bear on the rollers or wheels at the end towards which the truck
advances and the process of filling and emptying goes on as before.

page_text: By this truck it is proposed to dredge and maintain a clear channel of any
required depth and to work independently of the state of the weather; raising and
removing the sand or soil which accumulates on the sides of the channel when the
weather is favourable.
To facilitate the operation of removing the sand or soil from the sides of the
channel I propose to construct steam dredging hopper barges on the following
principles and construction.
The raising apparatus consists of a basket digger nearly hemispherical in shape,
lowered open by gravitation and closed by hydraulic pressure. It is lowered and
raised through a cylindrical well in the hopper barge and is raised by a hydraulic
Jigger and chain, and then opened by hydraulic pressure, allowing the soil to drop
into a semi-cylindrical waggon. This waggon runs fore and aft on rails over the
well and hopper. It is made in two segments hung on centres so that, on tipping
the catch holding the segments together, the weight of the soil opens the waggon
allowing the soil to drop into the hopper; and then the weight of the segments
closes it. It is then run back by the hydraulic jigger simultaneously with the
raising of the basket digger. When full the waggon is started by the pressure of
a buffer forming a hydraulic ram supplied with the exhaust water and worked by
the back pressure of the hydraulic Jigger, thus completing the automatic
simultaneous action of the basket digger and waggon.
The doors of the hopper bottom are in segments each of which is raised by
hydraulic power and kept shut by a pitched chain and pulley with a toothed
pinion on the same shaft as the pulley, retained by a paul. The pauls are tripped
with a lever to open the hopper doors. The hydraulic power is supplied by an
accumulator, the engines of which will be worked from the same boilers that supply
steam to the propeller engines.
The hydraulic communication is made between the accumulator and the hydraulic
cylinders of the basket digger, by means of high pressure flexible hose pipes winding
on two sets of pulleys.
The upper set of pulleys works on the same shaft as the upper chain pulley the
motion of the chain winding the hose; the lower set is hung on a moveable shaft
which rises and falls with the winding of the hose; the pulleys and lose working
like blocks and tackle, while the end. of the hose next to the accumulator remains
fixed, the end fastened to the cylinder rises and falls with the basket digger.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Smith in the Great Seal Patent Office on the 19th September
1882.
WILLIAM SMITH of Aberdeen, North Britain, Civil Engineer and Resident
Harbour Engineer ." IMPROVEMENTS IN APPARATUS FOR EXCAVATING OR DREDGING
UNDER WATER, AND AN IMPROVED DREDGING HOPPER FOR RAISING AND REMOVING
THE MATERIAL EXCAVATED."
This Invention relates, first, to a system of dredging resembling the ploughing of
land by means of two winding engines hauling a plough to and fro between them
by ropes, but for the plough as used for cultivating land, is substituted a dredging
plough which, when drawn over the bottom of the waterway, channel, harbour, or
other place, both ploughs or scrapes up the sand or soil and transports it to the
sides of the channel, whence it can be raised when the weather is favorable. The
dredging plough works wholly under water and in all states of the weather, so that
a clear channel of any desired depth can be constantly maintained.
The dredging plough is a sort of open ended truck body constructed of side
frames connected by a central transverse partition and provided with &
longitudinally sliding bottom plate of a length to form a bottom for only one.
compartment of the truck (i.e. the leading one) at a time. It travels upon a central
pair of wheels and a pair of smaller wheels at the leading end. This dredging,
plough or truck is drawn to and fro by ropes, one attached to the frame so as to
tilt it forwards and cause the leading edge of the bottom to scrape up the soil or;
sand; and the other attached to the sliding bottom so as to keep it in its place
beneath the leading compartment of the truck notwithstanding the resistance it
meets with in scraping up the soil which is gathered into the leading compartment
as the truck advances across the channel. The dredging plough is capable of
working either end first, and.on reaching the side of the channel the sliding bottom.
is, by ropes similarly attached but leading to the opposite engine to that by which
it was previously hauled drawn to the opposite end of the truck whereby the
contents of the full compartment are deposited and the truck started to work in
the opposite direction. The removal of the sand or soil thus accumulated near the
sides of the channel is effected by excavating and raising apparatus worked by
hydraulic power on board of steam hopper barges as hereafter described.
The excavating and raising apparatus consists of a basket digger or grab bucket,.
which is lowered open, and closed when it reaches the bottom by hydraulic power
so applied that the bucket is caused to dig into the soil and fill itself in the act of
closing. The hydraulic power is conveyed to the hydraulic cylinders of the bucket,
by flexible hose pipes in two sets of two pipes each, which respectively communi-
cate with opposite ends of a cylinder. Each set is wound on two sets of blocks
and pulleys, like tackle, so as to permit of the hose being paid out and wound in
as the bucket (upon which the cylinders to which they are connected are fixed) is
lowered and raised. The bucket is opened to discharge its contents by hydraulic
power acting in the same cylinders by which it was closed. It is nearly hemi-
spherical in shape and is made in two segments which work.on pivots and open
and close along the longitudinal centre line of the bucket. The hopper barge is
constructed with a well for the excavating bucket to work through, and provided
with hydraulic multiplying tackle herein termed a hydraulic jigger for raising the
bucket. The barge has a second or hopper well, for the reception of the spoil,
closed at bottom by doors raised by hydraulic power and kept shut by locking
gear. A distributing waggon is arranged to run fore and aft on a railway over
:

page_text: this hopper, and over the bucket well in order to receive the spoil from the bucken
and transfer the same to the hopper of the barge. This waggon is nearly semi-
cylindrical in form, and made in two segments hung on centres so that on tripping
the catch, which holds the segments together, the waggon will be opened by the
weight of the spoil and discharge the latter into the hopper, after which the
segments will close together again by their, own weight. This waggon is run back
by the hydraulic jigger simultaneously with the raising of the basket digger, or
bucket, beneath which it comes when the latter reaches its highest position. After
the bucket has discharged into the waggon, the latter is started by the pressure of
a buffer forming a hydraulic ram supplied with the exhaust water and worked
by the back pressure of the hydraulic jigger, thus completing the automatic
simultaneous action of the bucket and waggon..
DESCRIPTION OF DRAWINGS.
Figure 1 is a general view of the dredging operations herein described. Figure 2
is an elevation partly in section, and Figure 3 is a plan of the dredging plough or
truck. Figures 4 and 5 are a general plan and section of the dredging hopper.
Figures 6. 7. 8 and 9 shew different views of the excavator basket or bucket,
Figure 6. being an elevation closed, and Figure 7 a similar view open, whilst
Figure 8 is a horizontal section just above the basket, and Figure 9 is a part
section, part elevation at right angles to Figure C. Figures 10 and, 11 are
elevations at right angles to one another of the hydraulic hoisting gear for the
excavating basket. Figures 12 and 13 are respectively a plan and end elevation
of the distributing waggon, drawn to a larger scale.
Referring to Figure 1, the hauling or winding engines are represented on
opposite quays of a harbour hauling the dredging plough to and fro. This plough
shown in Figures 2 and 3 is constructed of two vertical side frames A, connected
across the middle into two compartments by a vertical partition plate B. The side
frames are furnished with ledges or flanges a along their lower edges, forming
ways for the sliding bottom plate C. This bottom plate is only half as long as the
plough so as to form a bottom for only one half at a time, and it is capable of
being slid along from one to the other beneath the division plate B. Its edges c
are bevelled so as to cut into the soil, and if made of wood, these edges would be
shod with iron. The plough is mainly carried upon a pair of central wheels D, and
is provided with a pair of smaller wheels D' at each end, and bears down upon the
leading pair for the time being, the height of the bearings of both pairs of wheels
being regulated to give the required depth of cut by adjusting screws d geared in
pairs of right and left hand screws by bevel pinions and a connecting shaft.
The plough is drawn by a rope attached to an eye b on the cross partition B at
a point above the axis of wheels D so as to tilt the plough and depress the leading
edge of the bottom C, and by another rope attached to an eye c¹ fixed to the
leading edge c of the bottom C, the latter rope being so much shorter than the
other as to pull the bottom C to the leading end of the plough and keep it there
while the plough advances scraping the soil and collecting it upon the bottom C.
The two ropes are joined and attached to. hauling lines worked by the steam
ploughing engines on shore, and on reaching the side of the channel, the motion
is reversed, whereby the bottom C is drawn to the opposite end and the previously
collected soil deposited and the plough started in the opposite direction.
Referring to Figures 4 and 5, the hull of the dredging, hopper is constructed
with a hopper well E and an excavator well F, the latter being in the bow of the
vessel. The well F is cylindrical and open at the bottom, and over it a gantry
frame F¹ is erected and fitted with brackets to carry the gearing of the excavator
bucket G. This bucket is hung by a chain rove over a number of sheaves on the
hydraulic jigger H and on the gantry, and is raised and lowered by the chain and
jigger. The bucket is almost hemispherical and is made in two segments (see Figures 6
to 9) and may either be toothed or solid, i.e. made of plate iron without toothed edges

page_text: according to the nature of the soil to be excavated. That shown is constructed of
pointed tynes or curvilinear bars of steel bolted at their upper end to semicircular
frames, the points of the two segments intersecting as shown, when closed. The frames
have centre bosses to receive pins g on which the segments of the bucket swivel, these
pins being fixed in the suspending frame g¹ of the bucket which is provided with a
guard g to prevent the bucket catching against the bottom of the vessel and is braced
by a cross bar g³. g₁g' are a pair of hydraulic cylinders fixed to the suspension
frame gland whose piston rods g5 are connected to a movable cross bar g, the ends of
which work up and down in vertical guides in the suspending frame. This bar is
connected by two pairs of jointed links g' with the two segments of the bucket,
whereby, when the bar g is forced down by the hydraulic pistons, the segments
are closed as shown in Figure 6. The hydraulic power for opening and closing the
bucket is conveyed to the opposite ends of the two cylinders g* by means of pairs
of flexible hose pipes I connected respectively there with by screw couplings. The
hose pipes, which should be able to withstand a pressure of 2000 lbs to the square
inch, are rove over two sets of sheaves i ', the lower blocks of which rise to pay
out the hose as the bucket is lowered, and descend to take up the slack as it is
raised. The two sets of hose are arranged at opposite sides of the gantry and are
connected with, and both controlled by, a double acting supply and exhaust valve
in the valve chest P in front of the hydraulic jigger.
Jis the waggon to receive the spoil from the excavator bucket and distribute it
over the hopper well E. It runs on a railway laid over the wells E. F and is run
fore and aft by the rising, and falling of the excavators.
The motion of the
excavator jigger chain is communicated from the top centre pulley by a crossed
wire rope K running upon a pair of V grooved pulleys k k¹, each pulley having.
three V grooves for adjusting the ratio of the travel of the distributing waggon to
the depth of stroke of the excavator, the opposing, diameters being arranged
24 inch 22 inch 20 inch
on speed cone shaft k.
in manner as follows:-
3.
16 inch 18 inch
The motion is
20 inch
on Jigger chain shaft k¹.
communicated from the upper speed cone to the lower speed cone by a pitch
chain L running in recesses in the speed cones, the recesses being arranged in a
spiral path round each cone to traverse the pitch chain along the cones, and the
cone hollowed to maintain uniform tension. The cone drives an endless.
chain M to which the waggon is attached by an arm M'. The velocity of the
waggon is so varied by the cones that it travels fastest when under the excavator
bucket G. N is a pair of modified spring buffers against which the waggon
strikes. They are held back by spring checks which are released on moving the
hand of the hydraulic jigger valve p to lower the excavator. The waggon J is
constructed of two segments, each hung on swivelling centres j and opening along
the longitudinal centre line of the waggon. On the aft centres are a pair of
toothed wheels and a disc j' with a recess for the tooth of the tripping lever j².
When this lever is depressed, the tooth is lifted out of the recess and the waggon
is opened by the weight of its contents which drop into the well E. The segments
then close together again by their own weight and are secured by the tooth of the
lever entering the recess in the disc. The tripping lever j² may be depressed at
any point in the journey of the distributing waggon over the hopper well, to
distribute the spoil. The hopper well is closed at bottom by a number of doors
hinged to the keelson and raised by separate hydraulic rams placed in the side
wings and connected to the doors by chains; each door is kept shut by a pitch
chain and pulley with a toothed pinion on the same shaft as the pulley, retained by
a pawl. The pawls are tripped by a lever to open the hopper doors.
The hydraulic power is supplied from a set of high pressure pumps N driven by
the steam engines used for propelling the vessel when not dredging. The pumps
are set on a cistern n containing water or oil which they pump to the valve
chest P, the hydraulic main pipe passing first to an accumulator R, then to the
valve chest, and thence to the second accumulator R¹ the capacity of these'
accumulators being sufficient to supply the hydraulic cylinders for closing the
'

page_text: hopper well doors and to equalise the work of the pumps during the descent and
rise of the excavator bucket. There are five ordinary hydraulic valves in the
chest P, viz-a jigger valve p communicating with the supply and exhaust pipes
and jigger cylinders, two valves p¹ for controlling the hydraulic capstans hereafter
referred to, a hopper door valve p² and a double acting supply and exhaust valve p³
for the excavator cylinders. SS' are the two hydraulic capstans to move the
vessel ahead, astern, or sideways when dredging.. The capstan S has the side
chains rove round it so as to wind it on one side, and pay out on the other.
The capstan S¹ is to haul the vessel ahead against the current or let her move
astern.
Having described the nature of the Invention and the manner of performing the
same, I declare that I do not claim the mechanical parts composing the machinery
herein described, when taken separately or apart from the combination and
application thereof in manner and for the purposes herein described, nor do I claim
the construction and arrangement of the hydraulic machinery as described for
excavating, but what I claim as my Invention to be protected by the bereinbefore
in part recited Letters Patent is.
ist. The dredging plough or truck constructed and operating substantially as
herein described and represented in the drawings, and its employment in combi-
nation with hauling ropes or chains worked by engines on shore, substantially as
herein specified.
i
2nd. The combination with the excavating bucket or basket constructed of two
segments and operated by hydraulic cylinders as herein described, of flexible hose
rove upon sets of sheaves so as to be paid out and taken up as the bucket is
lowered and raised, substantially as shown and described.
3rd. The combination with a dredging hopper constructed with a through
excavator well and with a hopper well to receive the spoil, of a suspended.
excavating bucket, hydraulic jigger for raising or lowering the same, and a waggon
actuated simultaneously with the excavator and travelling over the wells,
substantially as herein shown and described for the purposes specified.
4th. The distributing waggon constructed and operating substantially as herein
described and represented in the drawings, and its employment in combination
with the excavating apparatus herein shown and described for the purposes
specified.
In Witness whereof I the said William Smith have hereunto set my hand
and seal this sixteenth day of September A D 1882