Improvements in or Connected with Hopper Barges or Hopper Dredgers.
Year: 1897

page_text: Date of Application, 10th Dec., 1897
Complete Specification Left, 7th Sept., 1898-Accepted, 5th Nov., 1898
BUY IDIONAL SPECIFICATION.
Improvements in or Connected with Hopper Barges or
Hopper Dredgers.
I, ANTHONY GEORGE LYSTER, Dock Yard, Coburg Dock, Liverpool, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to so construct or fit the hoppers of hopper
barges or hopper dredgers, used in suction dredging, that the escape of solid
material with the overflow water shall be more effectually prevented than is at
present the case.
For this purpose I form the hoppers with coverings, watertight or nearly so,
and I provide one or more hollow shafts or trunks leading from the interior of
the hoppers to a certain height above the covering, through which shafts or
trunks the overflow water rises and escapes over the upper edge. The number,
area, height, and shape of the shafts or trunks are 80 proportioned that the
velocity of the water rising therein is not sufficient to carry with it any, or if
any, only a very small quantity, of solid material and the time, too, occupied
by the water in passing from the discharge pipe to the upper edge of the shafts
or trunks is such, and the water in the shafts or trunks is so removed from the
commotion in the hopper, that the material in suspension has plenty of time
and opportunity to deposit, and it is therefore left behind in the hoppers.
is advantageous that the discharge pipe from the pumps should be at as great
a distance as possible from the overflow shaft or shafts.
Dan N1.
1000
It
Improvements in or Connected with Hopper Barges or
Hopper Dredgers.
I, ANTHONY GEORGE LYSTER, Dock Yard, Coburg Dock, Liverpool, in the
County of Lancaster, Civil Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, reference being
had to the accompanying drawings: -
The object of this invention is to so construct or fit the hoppers of hopper
barges or hopper dredgers used in suction dredging, that the escape of solid
Price S/1

page_text: material with the overflow water shall be more effectually prevented than is at
present the case.
For this purpose I form the hoppers with coverings, watertight or nearly so,
and I provide one or more hollow shafts or trunks leading from the interior of
the hoppers to a certain height above the covering, through which shafts or
trunks the overflow water rises and escapes over the upper edge. The number,
area, height, and shape of the shafts or trunks are so proportioned that the
velocity of the water rising therein is not sufficient to carry with it any, or if
any, only a very small quantity of solid material, and the time also occupied
by the water in passing from the discharge pipe to the upper edge of the shafts
or trunks is such, and the water in the shafts or trunks is so removed from the
commotion in the hopper caused by the inflow of the dredgings that the
material in suspension has plenty of time and opportunity to deposit, and it is
therefore left behind in the hoppers. It is advantageous that the discharge
pipe from the pumps should be at as great a distance as possible from the over-
flow shaft or shafts.
DESCRIPTION OF THE DRAWINGS.
of so much of a
Fig. 1 is a longitudinal section at the line AA on Fig.
hopper dredger us is necessary to illustrate my invention, and Fig. 2 is a trans-
verse section at the line BB on Fig. 1. a is the hopper of any usual form,
and provided with the usual dropping doors at the bottom operated by chains
in any usual way. The hopper is provided with a watertight covering C. The
covering c has an opening at the centre, of an oblong form, extending nearly
the whole length of the hopper, and which is surmounted by a hollow shaft or
trunk d. The height of the shaft d is adjustable by means of movable
coamings e at each side. These coamings can be moved up or down in the
guides by means of the screws and handwheels g so as to increase or diminish
the head of water in the shaft d. The sectional area of the shaft d is such that
the velocity of the escaping water is not sufficient to carry with it any substantial
quantity of the solid material, which material consequently settles down in the
hopper. The head of wator in the shaft also reduces to a great extent
the agitation of the water in the hopper due to the rush of water from the
discharge pipe h of the dredging pump. By raising or lowering one end of the
coaming more than the other end the escape of water from the shaft can be
regulated at different points to any desired degree and thereby the deposit of
material in the hopper may be varied in amount at different points so as to
enable the dredger or barge to be trimmed as desired. The coamings may be
'made in separate pieces if desired each independently movable. If desired the
movable coamings may be dispensed with altogether where the dredgings are
of uniform quality. Suitable packing is provided when required between the
movable coamings e and the sides of the shaft d to prevent escape of water
between them. Instead of one shaft d, several smaller shafts may be used,
disposed at various points on the covering care being taken that the total
sectional area of such shafts is sufficient to allow of the water escaping at a
proper rate.
The discharge pipe h is of any usual kind, preferably with valves
and openings at different points as usual so that the dredgings may be discharged
into the hopper at various points.
Fig. 3 is a longitudinal section at the line c, c, on Fig. 4 and Fig. 4 is a
transverse section at the line D, I), on Fig. 3, of a modification of my invention.
Like letters indicate similar or equivalent parts as in Figs. 1 and 2. In this 5
modification instead of one shaft d, several are used, placed over openings at
various points in the covering r and instead of adjustable coamings, valves e
are employed. The valves e are operated by means of lovers, screws and hand-
wheels g, so that the discharge of water from the various shafts can be regulated
as desired.

page_text: I do not confine myself to the particular arrangements shown and described
as it will be obvious that many modifications may be made without departing
from my invention.
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 combination with the hoppers of hopper barges or hopper dredgers
of coverings and hollow shafts or trunks rising to a height above the coverings
substantially as and for the purposes set forth.
Second. The combination with the hoppers of hopper barges or hopper
dredgers of coverings and hollow shafts or trunks, such shafts or trunks being
provided with adjustable coamings or like devices substantially as and for the
purposes set forth.
Dated this th ..
1000