Improvements in Scouring and Removing Sand or Mud from Tidal Stream and River Beds, Bars, or Submerged Banks, and Apparatus Employed therefor.
Year: 1886

page_text: Date of Application, 24th Nov., 1886
Complete Left, 23rd Aug., 1887.
Complete Accepted, 23rd Sept., 1887.
Improvements in Scouring and Removing Sand or Mud from Tidal
Stream and River Beds, Bars, or Submerged Banks, and
Apparatus Employed therefor.
I, NATHANAEL ROBERT GRIFFITH, of Westminster Chambers, Wrexham, in the
County of Denbigh, Mining Engineer do hereby declare the nature of my said
invention to be as follows:-
According to my Invention I use jets, or streams for water under pressure applied
and directed as hereafter described and by apparatus such as herein set forth for
Scouring and removing sand, or mud from tidal stream and river beds bars, or sub-
merged banks. The water under pressure being distributed in an extended line over
the surface of the bed bar or bank to be scoured, or removed and directed so as to
impinge on the sand, or mud in such a manner as to disturb and throw the sand, or
mud upwards and into mechanical suspension in the water to such an extent that the
so suspended sand, or mud will be carried away by the tide, or stream.
To effect the distribution of water under pressure as above described I preferably
employ an articulated and buoyant duct, or flexible pipe, the buoyancy of the duct
being only sufficient to prevent the duct sinking into the sand, or mud which has to be
removed. The duct is provided with suitable orifices, or nozzles for directing the
issuing water which is supplied to the duct by suitable water pumping, or forcing
machinery.
A convenient form of apparatus for carrying my Invention into practice may consist
of a series of metal pipes provided with nozzles so arranged that the water issuing
therefrom on the sand, or mud will disturb it and drive it in an upward direction.
The metal pipes are connected by short lengths of hose pipe, or other flexible connection,
the whole forming an articulated duct which is fastened to and carried by a wire rope,
or hawser, one end of which is moored to the surface to be removed and the other end

page_text: is carried up to and connected to a steam tug, the duct being connected to a pump, or
other water forcing apparatus on the steam tug. The articulated duct is supported by
providing the duct with air chambers, or equivalent floatative power sufficient to prevent
the duct from sinking into the sand, or mud, or the duct may be provided with a series
of wheels to support it and facilitate its movement. In working the strain on the duct
is borne by the wire rope hawser and it is by the steam tug swept over the surface to
be removed, the water issuing from the nozzles, and throwing up the sand, or mud
which it then carried away by the tide, or stream.
Instead of mooring the duct, it can be dragged by the steam tug over the surface to
be removed. In this case I attach the duct to a boom instead of a hawser.
Dated this 23rd day of November 1886.

page_text: Improvements in Scouring and Removing Sand or Mud from Tidal
Stream and River Beds, Bars, or Submerged Banks and
Apparatus Employed therefor.
I NATHANAEL ROBERT GRIFFITH, of Westminster Chambers, Wrexham, in the
County of Denbigh, Mining Engineer, do hereby declare the nature of my said
invention and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
According to my Invention I use jets, or streams of water under pressure applied
and directed as hereafter described and by apparatus such as herein set forth for
Scouring and removing sand, or mud from tidal stream and river beds, bars, or sub-
merged banks. The water under pressure being distributed in an extended line over
the surface of the bed, bar, or bank to be scoured, or removed and directed so as to
impinge on the sand, or mud in such a manner as to disturb and throw the sand, or
mud upwards and into mechanical suspension in the water to such an extent that the
so suspended sand, or mud will be carried away by the tide, or stream.
To effect the distribution of water under pressure as above described, I preferably
employ an articulated and buoyant duct, or flexible pipe, the buoyancy of the duct
being only sufficient to prevent the duct sinking into the sand, or mud which has to
be removed. The duct is provided with suitable orifices, or nozzles for directing the
issuing water which is supplied to the duct by suitable water pumping, or forcing
machinery.
A convenient form of apparatus for carrying my Invention into practice may consist
of a series of metal pipes provided with orifices, or nozzles so arranged that the water
issuing therefrom on the sand, or mud will disturb it and drive it in an upward
direction. The metal pipes are connected by short lengths of hose pipe, or other
flexible connection, the whole forming an articulated duct, which is fastened to and
carried by a wire rope, or hawser, one end of which is moored to the surface to be
removed and the other end is carried up to and connected to a steam tug, the duct
being connected to a pump, or other water forcing apparatus on the steam tug. The
articulated duct is supported by providing the duct with air chambers, or equivalent
floatative power sufficient to prevent the duct from sinking into the sand, or mud, or
the duct may be provided with a series of wheels to support it and facilitate its
movement. In working the strain on the duct is borne by the wire rope or other
hawser and it is by the steam tug swept over the surface to be removed, the water
issuing from the orifices, or nozzles and throwing up the sand, or mud which is then
carried away by the tide, or stream.
Instead of mooring the duct, it can be dragged by the steam tug over the
surface to be removed. In this case I attach the duct to a boom instead of a hawser.
In order that my Invention may be clearly understood I have hereunto annexed
four sheets of Drawings which are marked with letters and figures of reference

page_text: corresponding with those used in the following explanation, like letters and figures
being used to denote the same, or corresponding parts throughout the various views
and figures.
In the carrying out of my Invention the articulated and buoyant duct may be
arranged to be drawn, swept, or placed over the surface to be removed in various ways.
For example it may be arranged and constructed in the manner shown at Figure 1 of
the annexed Drawings in side elevation and at Figure 2 in plan, in which a is the
articulated, or flexible buoyant duct. The end a of the duct a is fastened to the
moored floating buoy 6 and the other end a² is led on board a tug c and there connected
to suitable water forcing machinery such as a steam force pump. The duct a consists
of a series of metal pipes a³, each pipe being about 9 feet in length and 12 inches in
diameter but these dimensions will of course vary according to the amount of water
used, the pressure of the water and other circumstances. These pipes as are each
provided with a buoyant air chamber e fastened to them by straps, or otherwise,
or the air chambers e¹ may be made in one piece with the water pipes a
the air chambers e¹ having floating power sufficient to prevent the pipes a³
from sinking into the sand or mud. The metal pipes are connected together by short
lengths of piping at. These connecting pipes a may for example be of hose pipe. The
ends of the metal pipes as are closed except where the connecting pipes a* enter them.
The metal pipes a extend only along that portion of the duct a which will lay on the
surface to be acted upon. The underside of the pipes a is provided with small orifices
through which the jets of water are discharged from the duct a on to the surface to be
removed to throw the sand or mud iuto suspension, so that it will be carried away by
the current. The orifices in the pipes a' may be simple holes, or they may be provided
with nozzles. The number and size of the orifices depends upon the quantity and
pressure of water used, for example they may be about of an inch in diameter and
and 24 inches apart and the pressure of water about 20 pounds on the square inch
above the atmospheric pressure and the pressure due to the head of water in which
the apparatus is working. The rising ends a' of the duct a are of flexible tube or plain
metal tube only.
The whole duct a is securely fastened to and carried by a hawser done end of which
is fastened to the buoy 6 and the other end to the tug c, or instead of the buoy beach
end of the duct a may be attached to a tug so that the two tugs will drag the duct a
over the surface to be removed.
In the example of my Invention shown at Figure 3 in side elevation and Figure 4
in end elevation the pipes a are attached to a boom e which is made hollow so as to
form an air chamber which has floating power sufficient to keep the pipes a³ from
sinking into the sand, or mud. A duct a is led from the centre of the duct a to the
tug and water forcing machinery and towing hawsers d are led from the tug and
fastened to the ends of the boom e as well as the centre of the boom e.
In the example of my Invention shown at Figure 5 in plan and Figure 6 in side
elevation the pipes a³ with their air chambers e¹ are arranged to drag from the hollow
boom e.
The extreme ends of the pipes a being closed and the pipes being connected
by the chains d¹ and also by the flexible couplings at and distance links d provided
to keep the pipes in position. This form of apparatus is very suitable for keeping clear
of sand, or mud the entrance of docks, or harbours. For this purpose the apparatus
is drawn across the entrance to such dock, or harbour, and water is forced through the
apparatus impinging upon the sand, or mud to be removed. By letting water out of
the dock a current is obtained which will take away the sand, or mud driven into
suspension by the action of the jets of water.
In the example shown at Figure 7 in plan and Figure 8 in side elevation, the duct a,
which is shown broken off, is of considerable length and is towed endways forwards
and backwards along the surface to be acted upon.
The air chambers e of the duct a may be connected together by flexible pipes e
and by a flexible, or other pipe e to suitable air compressing machinery on the tug c
the pipe e being provided with orifices, or nozzles and the air apparatus operating in
the manner, as described in the Specification of my application for Letters Putent

page_text: No. 15,816 dated 24 November 1886. I have shown in Figure 1 of the Drawings an
example of this arrangement. In operation the jets of water from the duct pipes a³ by
preference lead and strike the surface to be removed in advance of the jets of air from
the orifices of the pipes e so that the silt which is disturbed by the action of the water
jets will be also acted upon by the air jets and carried upwards by the air when rising
to the surface.
In cases when the apparatus is connected to a buoyant boom, such as the apparatus
shown at Figures 3 and 4 and 5 and 6 the underside of the boom may be provided
with orifices or nozzles and the boom may be connected by a pipe to air compressing
machinery on the tug.
Although I have described the duct a as being buoyant to prevent it from sinking
into the sand, or mud this is not necessary in all cases, as when the duct is of small
dimensions the buoying can be dispensed with.
Instead of moving the duct a by a tug as above described, it may be moved by other
means, such as by a locomotive, or stationary engine on the land working the duct by
suitable rope, or equivalent connections, suitable water forcing machinery being also
provided.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is :
First. The method herein described of scouring and removing sand, or mud from
tidal stream and river beds, bars, or submerged banks, which method consists in moving
a system of pipes or ducts over the surface of the matter to be removed the said pipes
having nozzles, or orifices through which water is forced such water being directed to
impinge upon the said surface to be removed and such system of pipes being moved,
or towed by a towing vessel, or machine substantially as set forth.
Second. The apparatus for scouring and removing sand, or mud from tidal stream,
and river beds, bars, or submerged banks consisting of a flexible water duct such as a
constructed arranged and operated substantially as set forth and as described with
reference to Figures 1 and 2 of the Drawings.
Third. The apparatus for scouring and removing sand, or mud from tidal stream,
and river beds, bars, or submerged banks, consisting of a water duct such as a con-
structed arranged and operated substantially as set forth and as described with reference
to Figures 3 and 4 of the Drawings.
Fourth. The apparatus for scouring and removing sand, or mud from tidal stream,
and river beds, bars, or submerged banks, consisting of a flexible water duct such as a
constructed arranged and operated substantially as set forth and as described with
reference to Figures 5 and 6 of the Drawings.
Fifth. The apparatus for scouring and removing sand, or mud from tidal stream,
and river beds, bars, or submerged banks consisting of a flexible water duct such as a
constructed arranged and operated substantially as set forth and as described with
reference to Figures 7 and 8 of the Drawings.
Dated this 22nd day of August 1887.