Improved Means for use in the Removal of Subaqueous Sand-banks, Bars, and the like, in the Prevention of their Reformation, and for Cutting, Deepening, or Widening Water-courses.
Year: 1891

page_text: Date of Application, 17th Oct., 1891-Accepted, 21st Nov., 1891
COMPLETE SPECIFICATION.
Improved Means for use in the Removal of Subaqueous Sand-banks,
Bars, and the like, in the Prevention of their Reformation, and for
Cutting, Deepening, or Widening Water-courses.
I, ROBERT MELVILLE SCOTT, of Balmain, near Sydney, in the Colony of New
South Wales, Contractor, 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 the removal of bars, shoals, sand, mud-banks and like
deposits from harbours, rivers and estuaries, to preventing the reformation thereof, to
deepening and widening rivers and creeks, to cutting and clearing canals and other
water-courses, and to maintaining channels in rivers, canals, races, and the like in
which the velocity of the water is insufficient to carry away the sand, mud, tailings
and other solid matters which pass therein.
That part of the present invention which relates to the removal of bars, banks,
and shoals in harbours, rivers and estuaries, and to maintaining channels, consists in
the employment of a permanent water-service pipe or pipes, provided with nozzles,
and set upon or under or contiguous to the obstruction, or in the channel. The
removal and clearing or maintaining is effected by the action of jets of water under
pressure which are forced out through the nozzles, and disturb, loosen, break up
and agitate the sand, mud, silt or other deposit, causing it to be first suspended in
the water and then carried away with the stream, or, if the jets be set obliquely,
with the current of water which they induce. In lieu of a permanent service, a
temporary pipe line or lines capable of being moved about and temporarily fixed
by anchoring, guying, or otherwise may be provided. Such a device is specially
intended for operating on bars, banks, and shoals which shift their position from
time to time, or through which it is only required to open or maintain a temporary
channel. In some cases, I secure the service pipes to hollow floats, which are all
connected to suitable pumping gear, whereby they are filled with water or emptied,
in order that they, with their attachments, may be sunk on the place to be operated
upon, and lifted again to the surface when required.
When the construction is not permanent, the joints or couplings of the service
pipes should be made flexible.
When a permanent channel is required through any obstruction which is liable
to be reformed through the operation of a water-scour or other natural cause, a
channel is first cut to the necessary depth, or, if thought advantageous, deeper than
is actually necessary, by means of apparatus of the kind described, or otherwise;
and then midway or approximately so in the bar, bank, shoal or other obstruction,
or contiguous thereto, piles are driven to a firm footing; the permanent service
pipes being secured on these piles. A clear passage may be maintained through
any obstruction of the kind referred to by forcing the water while the tide is
ebbing or while a fairly fast outward current is flowing. But the water jets will
induce a current if the nozzles are fixed obliquely in the pipe, and the current
thus induced will carry away the solid particles which have been forced up by
the jets.
During the flow of the tide, and while the water is sluggish, pumping may be
discontinued, and recommenced at the turn of the tide or the start of the stream.
Where the obstructions are not quickly formed, it may be found sufficient to carry
on pumping operations periodically.
When continuous pumping is not maintained, clack-valves may be fitted to the

page_text: nozzles. When pumping is discontinued, the pipes are exhausted of air so that
a total or partial vacuum may be created within them, whereby the valves are
made to close tightly and prevent the entrance of mud, sand and like matter into
the pipes.
In operating upon a bar, shoal, bank, or other deposit of considerable length
or area, I prefer to use two or more service pipes, each being connected to separate
sources of supply, so that any one or more of them may be used independently
of the others. In this way, it is possible to confine operations to any particular
part.
According to another method of carrying out the invention, I fit a boat, barge,
or punt of shallow draught with sinking tanks and suitable pumping apparatus,
and carry through the shell of the vessel a number of nozzles through which
water under pressure is forced. The vessel is steamed into position and pumping
operations commenced; the vessel being kept steaming to and fro over the
obstruction until a channel is cleared. If the channel is to be deepened,
the sinking tanks are wholly or partially filled as may be required, and the
course retraversed; the clearing water being forced through the nozzles as before.
The motion of the vessel has also a disturbing effect, which aids the operation of
the jets.
When a submerged mound or peak or a spit or crossing is to be removed, the
methods already described may be found more or less unsuitable. A special
construction of apparatus is then employed, which may also be used for deepening
channels, or where the scour-boat before described can not operate. Such an
apparatus consists of one or more leading-down pipes, swivel-socketed to the pump-
delivery on a punt or lighter, and a service pipe or pipes swivel-socketed to the
leading-down pipes, and provided with a series of nozzles; a derrick or jib from
which these pipes are supported by means of suitable tackle, and mechanism for
moving the service pipe or pipes about in its or their swivel-sockets, so as to alter
the position of the nozzles and bring them into more effective play over or on the
sides of a shallow bank or on the bottom of a channel being provided. This form
of apparatus is of special utility where a channel is being considerably deepened,
as the punt or lighter may be steamed or warped up to the work while in progress.
A like arrangement of apparatus may be employed in the formation of canals and
the clearing and opening of water-courses, for which purpose also the scour-boat
might also be used. Where a stream or water-course runs too slowly to carry off
the solid matter which passes into it, a creeper pipe is laid into the
bed and pumping carried on continuously or at intervals as may be required;
an artificial bottom current of considerable speed being thus induced, which
sweeps the solid matter toward the end of the pipe to which the jets are
directed.
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"
In cases where the service pipe is of considerable length, or where it furnished
with a large number of nozzles, feeder-pipes may be led into it at convenient
points.
The pressure under which the water is forced may vary within wide limits.
Deposits of light material may be removed by comparatively small streams of water
under low pressure; whereas banks and shoals of heavy material will require a
considerable quantity of water under high pressure.
The nozzles on the pipes may be set so as to discharge jets of water at right
angles to the length of the pipe, or at any desired angle relatively thereto, and
either up and down stream. When it is required to induce a current for the
purpose of scouring the bed of the channel, the nozzles should be directed down
stream. The number and size of the nozzles, and their disposition, may also be
varied. The pipes shown in the drawings are furnished with nozzles on both sides
and on the top.
The most advantageous and economical way of applying the invention in any
particular case will depend upon local circumstances and requirements, and the

page_text: within wide limits according to judgment.
Referring to the annexed sheet of explanatory drawings,
Figure 1 is a plan of a river-mouth showing the general arrangement of clearing
pipes, and their position upon the bar.
Figure 2 is a section showing a permanent pipe line.
Figure 3 is a section showing a Hoating pipe line.
<<
Figure 4 is an enlarged side elevation of a flexible jointed creeper " pipe.
Figure 5 is a section showing a punt operating upon a crossing.
Figure 6 is a plan corresponding with Figure 5.
Figure 7 is a section representing a scour-boat operating upon a crossing.
Figure 8 is a side elevation of a fragment of a service pipe, showing the way of
laying the same.
Figure 9 is a transverse section through the pipe and sleeper illustrated in the
previous figure.
The arrangement of the pipes in Figure 1 may be varied at will. The service
pipes in Figures 1 and 2 are provided with nozzles, such as 8, Figure 4, which are
set obliquely, so as to deliver the jets of water obliquely, and thus produce, in
addition to breaking up and disturbing the sand, mud, or other deposit, an artificial
under-current which sweeps the broken-up or disturbed substances toward the end
of the pipe.
In the arrangement shown in Figure 3, 2 are boxes, barrels, or like hollow floats;
3 is an air-pipe; 4 are flexible pipes; 5 are hanging chains; 6 is a service-pipe;
7 are flexible couplings; 8 are nozzles; and 9 is the bank or shoal which is being
operated upon. The flexible pipes 4 which connect the boxes, are placed as shown,
so that when pressure is applied the water is driven out of each vessel successively,
thus causing them to float. When the pressure is withdrawn, or a vacuum formed,
the water can enter each successively and sink each in turn. In laying such a
system, the empty vessels are floated into position, with the service pipes suspended
by the chains, clamps or like attachments 5, and then the vessels are allowed to
fill and sink.
The number of jets and the size are varied according to the description of work
to be done. When the obstruction forms slowly, a few jets may be found ample;
but when the obstruction to be removed is considerable a proportionate water
service must be used.
In Figures 5 and 6, 10 is a punt or lighter, 11 is a pump thereon, 12 and 13 are
swivel-sockets, 14 are leading-down pipes, 15 is a service pipe, 16 are nozzles, 17 is
a derrick, 18 is tackle connected to the service pipe, 19 is tackle connected to the
nozzles, and 20 is the crossing which is being operated upon. The leading-down
pipes are rotated in the swivel-sockets 13 by means of the tackle 19, so that
the direction of the jets may be varied.
In Figure 7, 21 are the nozzles projecting through the shell of the boat.
Referring to Figures 8 and 9, 22 is a service pipe, 23 is a bearer or sleeper, 24 is
a perforated pipe or casing secured to the under part of the sleeper, 25 are
orifices therein, and 26 is a supply pipe leading thereto. When water under
pressure is supplied to the pipes or casings 24, the underlying sand, mud, or
other deposit is removed, a similar action also taking place at the same time in the
main service pipe, and the whole construction sinks until a solid bottom is reached.
The pipes 26 may then be disconnected. When branch pipes are added to mains
already existing, they are sunk in a similar manner.
Although I have described and illustrated several constructions of apparatus for
carrying out my invention, I would have it understood that I do not in any way
restrict myself to the use thereof precisely as set forth.
I am aware that it is well known that earth banks may be cut down and swept
away by the action of jets of water under pressure directed on them, such method
being commonly called "hydraulicing."

page_text: Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. Washing or sweeping away bars and shoals or other subaqueous deposits by
means of water-jet apparatus constructed and operating substantially as describe
with reference to the accompanying drawings.
2. The employment of one or more pipe lines, having nozzles or orifices, in com-
bination with a source of water supply, and placed or fixed on, in or contiguous to
harbour or river bars or shoals, or other subaqueous deposits, for effecting the
removal thereof and preventing their reformation, substantially as described with
special reference to Figures 2 and 3 of the accompanying drawings.
3. The method of and apparatus for effecting the removal and preventing the
reformation of harbour and river bars, and shoals or other subaqueous deposits,
substantially as described with reference to Figures 1 and 2 of the accompanying
drawings.
4. The combination, with a flexible-jointed water service pipe of the kind
described, of a series of hollow floats connected together, and means whereby
said floats may be filled or discharged, substantially as and for the purposes set
forth.
5. In apparatus for washing or sweeping away bars and shoals and other
subaqueous deposits, the employment of a service pipe or main fitted with water-
nozzles placed obliquely, substantially as described with. reference to the accom-
panying drawings.
6. The improved apparatus for removing crossings and like obstructions, and for
forming and deepening water-courses, substantially as described with reference to
Figures 5 and 6 of the accompanying drawings.
7. A vessel provided with water-nozzles projecting through the bottom and sides,
and means for forcing streams or jets of water under pressure through such nozzles,
substantially as and for the purposes set forth.
8. The improved apparatus for sinking clearing pipes on to a channel-bed,
substantially as described with reference to Figures 8 and 9 of the accompanying
drawings.
Dated the 16th day of October 1891.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.