Improvements in and connected with Hopper Dredgers and Barges.
Year: 1898

page_text: Date of Application, 12th Apr., 1898-Accepted, 20th May, 1898
COMPLETE SPECIFICATION.
Improvements in and connected with Hopper Dredgers and Barges.
I, FRED LOBNITZ, Director of Lobnitz & Co. Ltd., Renfrew, County of Ren-
frew, Scotland, 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 hopper dredgers and barges provided with pumping
apparatus for discharging the spoil ashore, or elsewhere, and it has for its object to
facilitate the discharge of the spoil from the hopper of such dredgers and barges.
In carrying out the invention two pumps are used and their pipe connections are
so arranged that the pump used for emptying the hopper and discharging the spoil
ashore, or elsewhere, can be assisted by the second pump, which latter, at will, can be
made to discharge either into the suction pipe of the first pump or among the
material in the hopper.
And in order that my said invention may be properly understood I have hereunto
appended two explanatory sheets of drawings, which show, by way of example, my
invention applied to a hopper-dredger.
Fig. 1 is a longitudinal section of a part of the dredger.
Fig. 2 is a plan view showing the engines for driving the centrifugal pumps.
Fig. 3 is a deck plan view showing the arrangement of the pipe connections of the
pumps.
Fig. 4 is a cross section on the line x-x Fig. 1.
Fig. 5 is a cross section on the line Y-Y Fig. 1.
Referring to the drawings whereon the same reference letters wherever repeated
indicate the same parts.
a is a suction pipe, which is jointed, at b, to the pipe c, leading to the centrifugal
suction-pump d. The discharge pipe e, from the pump d, passes along above the
hopper and is jointed, by means of a connection f¹ as shown clearly at Figs. 3 and 5,
to the end of the suction pipe f of the second or delivery pump g. h is the discharge
pipe from the pump g to the shore or elsewhere. i is a branch from the pipe e
running to the opposite side of the hopper.
The suction pump d is driven by the engine ; whilst the delivery pump g is driven
by the engine k. These engines also drive the propeller shafts l, m. As will be seen
(Fig. 2) the shaft 7 has a bevel pinion on it which gears with a bevel wheel o on
one end of a cross shaft p whose other end has a corresponding bevel wheel o¹ which
drives a pinion m¹ on the shaft m. By this arrangement the engines are caused to
revolve the shafts l, m, and the pumps and propellers at exactly the same speed.
Moreover, should one engine break down from any cause it could be disconnected
and both shafts be driven by the other engine.
The bucket dredging gear is driven from the shaft p by means of the pinions
and pitch chains y.
The suction pipe f of the pump g has, or may have, lateral branches q with valves r
which latter can be operated from the deck by means of long rods or tubes r¹ (Fig. 5)
provided with lever-handles 2 at their upper-ends.

page_text: The discharge pipes e and i of the pump d are provided with valves 8 operated by
levers 8¹.
t, t¹, are sluice valves.
The engines are, by preference, so arranged that the shafts run inwards, i.e., in the
direction of the arrows Z-Z Figs. 2 and 4, when propelling and pumping and in
the opposite direction when dredging.
u are the usual hopper doors.
v is the well of the dredger.
It will be readily seen that, with this arrangement of the pumps and their pipe
connections, whenever necessary the pump d may be made to assist the pump g by
discharging water through the connection into the end of its suction pipe f." In
this case, of course, the valves s of the pipes e, i, would be closed and the sluice
valve opened.
When it is not desired to assist the pump g by discharging water into its suction
pipe the sluice valve t¹ can be closed and water be discharged through the valves s
of the pipes e, i, amongst the material in the hopper.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
consider novel and desire to claim is :-
1. In hopper dredgers and barges the combination with a discharge pump for the
spoil, of a second pump the pipe connections of which are so arranged that this second
pump can be made to discharge, at will, either into the suction pipe of the first pump
or amongst the material in the hopper, substantially as hereinbefore set forth.
2. In hopper dredgers and barges, the combination of a pump (g) for discharging
the spoil, a suction pipe (f) with its inlets and valves connected with the pump (g), a
second pump (d), discharge pipes (e, i,) with their valves and outlets connected with
the second pump (d), a pipe connection (1) arranged between the suction pipe (ƒ)
of the first pump and the discharge pipe (e) of the second pump, and a valve (t¹), or
its equivalent, for closing the pipe connection (f¹), substantially as hereinbefore
described with reference to the drawings annexed.
3. In combination, the pump g driven by the engine k, the pump d driven by the
engine, the gearing connecting the shafts of the two engines, the pipes (b, c,), the
pipes (e, i,), the pipe connection (f), and the pipe f, all constructed and arranged
substantially as herein before described and shown on the drawings annexed.
Dated this 8th day of Anvil 1808
Doted this 8th day of April 1808
H. D. FITZPATRICK,
Glasgow and London, Agent.