An Improved Method of and Apparatus for Deepening Rivers, Waterways, and Harbours, and Removing the Material Deposited therein.
Year: 1890

page_text: Date of Application, 6th Aug:, 1890
Complete Specification Left, 6th May, 1891-Accepted, 20th June, 1891
PROVISIONAL SPECIFICATION.
An Improved Method of and Apparatus for Deepening Rivers,
Waterways, and Harbours, and Removing the Material Deposited
therein.
I, HUGO ROESSLER of Erbach on the Rhine, Germany, Government Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates to means for deepening rivers and other waterways and
for removing the sand, mud, and other material deposited, and which in some
harbours form bars which greatly impede navigation.
The invention is based on the fact that the sand and such like material deposited
on the bed of the river or harbour may be removed or dispersed by a sufficiently
powerful stream of water directed against the material to be removed, and to this
end my invention consists in the employment of what I may term dredging plant
consisting of a barge or vessel provided with a centrifugal pump or pumps driven
by a steam engine and whose delivery pipes are furnished with prolongations
adapted to direct the water discharged by the pumps on to the material to be
removed.
A pair of pumps placed horizontally to enable the suction and delivery pipes to
be arranged in as close proximity to the hull as possible are preferably employed
and the delivery pipes pass through a casing or enlargements on the hull of the
vessel. These pipes are provided with suitable stop valves, and their prolongations
are connected to them by ball and socket joints so that they may be readily
adjusted to direct the stream of water from the pump to the point required.
In case the material is too solid to be acted upon efficiently by the stream
from the pumps, 1 may employ cutters or other approved means for loosening
the soil.
Dated this 6th day of August 1890.
H. ROESSLER.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
An Improved Method of and Apparatus for Deepening Rivers,
Waterways, and Harbours, and Removing the Material Deposited
therein.
I, HUGO ROESSLER, of Erbach on the Rhine, Germany, Government Engineer,
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 means for deepening navigable rivers and other water-
ways and harbours, and particularly for removing the sand, mud, and other material
deposited in places where, by reason of the slight gradient, the current is sluggish
and which in some harbours forms bars which greatly impede navigation.
The invention is based on the fact that the sand and such like material deposited
on the bed of the river or harbour may be removed or dispersed by the scouring
action of a sufficiently powerful stream of water directed against the material to be
removed, and to this end my invention consists in the employment of what I may
term dredging plant consisting of a barge or vessel provided with a centrifugal
pump or pumps driven by a steam engine and whose delivery pipes are furnished

page_text: with prolongations adapted to direct the water discharged by the pumps on to the
material to be removed.
A pair of pumps, placed horizontally, to enable the suction and delivery pipes to
be arranged in as close proximity to the hull as possible are preferably employed,
and the delivery pipes pass through casings or lateral extensions of the hull of the
vessel. These pipes are provided with suitable stop valves, and their prolongations
are connected to them by ball and socket joints so that they may be readily
adjusted to direct the stream of water from the pump to the point required.
In case the material is too solid to be acted upon efficiently by the scouring
action of the stream of water alone, I may employ cutters, or other approved
means, for loosening the soil, preparatory to, or in conjunction with, the same.
In any case the soil dislodged and removed by the current of water is not raised,
but is merely washed away, and becomes deposited again in some other place. It
must therefore be driven away to such a distance that its deposit will not impede
navigation, or where it will be taken up and carried away altogether by a natural
current.
Reference is to be had to the accompanying drawings, forming part of this
Specification, wherein the scouring dredger of this invention is represented in
Figure in elevation, in Figure in diagrammatic plan, and in Figure 3 in rear
elevation, as arranged for forming a channel up to say, three metres deep in sand
deposits. Figure 4 shews three positions of the dredger in cutting across a sand
bank or bar.
The dredging plant herein illustrated by way of example, comprises a steam
boiler A. of about 40 HP. which supplies the steam engines G, G of two centrifugal
pumps B B each of which throws 280 litres of water per second, with a velocity of
2.15 metres, through delivery pipes D, D each of 400 millimetres internal diameter,
under a maximum head of about three metres. In a less depth of water, and con-
sequently under a smaller head of water, with the same amount of power, the
velocity, and therefore the volume, of water thrown can be increased up to the
limit allowable for the engine and pump. 1.5 metres is amply sufficient for moving
sand, but a greater velocity is preferable in order to set in motion as large a quantity
of water as possible and thus produce an artificial scouring current along the river
bottom or other part to be cleared. A certain amount of current at the place of
operation is produced by the suction of the water towards the pumps.
The centrifugal pumps are arranged horizontally, in order to enable the suction
and delivery pipes CD to be directed as close as possible to the hull of the vessel.
The suction and delivery pipes respectively pass through the fore and aft ends of
lateral extensions E, E of the hull, and the delivery pipes D, D are provided with
ball and socket joints to enable them to be raised and lowered by means of
davit tackles F and the jets of water to be directed where required. They are
made of such length that they may be made to project obliquely downwards to
any requisite depth, in this case to a maximum depth of 2.83 metres, below the
surface of the water.
It is preferable to provide two jets, and consequently to provide two pumps,
one at either side of the hull, as represented in the drawings. The suction
pipes can be shut off by means of screw down valves. The scouring jets of
water should always be directed down stream, in order that the natural current
of the waterway may supplement the scouring current and so assist in carrying
off the material dislodged. To effect a lateral to and fro movement of the
dredger, side anchors and windlasses are provided, as usual with ordinary dredgers,
and a forward anchor may also be used, according to circumstances.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what [
claim is
The herein described method of, and apparatus for, deepening navigable channels
or water-ways by the scouring action of a jet or jets of water produced by means

page_text: of a pump or a head of water directed against the material to be removed whereby
to wash it away, substantially as herein specified.
Dated this 6th day of May 1891.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.