Improvements in Hopper Dredgers.
Year: 1890

page_text: Date of Application, 22nd July, 1890
Complete Specification Left, 22nd Apr., 1891-Accepted, 23rd May, 1891
PROVISIONAL SPECIFICATION.
Improvements in Hopper Dredgers.
I, ANDREW BROWN, of London Works, Renfrew, in the County of Renfrew,
Engineer and Shipbuilder, do hereby declare the nature of this invention to be as
follows:-
The main object of my invention is to render hopper dredgers more stable and
seaworthy when navigating.
The said object is effected in an improved and advantageous manner, by providing
on the vessel, in addition to the usual gear for raising and lowering the lower end
of the bucket ladder, means for lowering and raising the upper end of the said
bucket ladder, and the chain of buckets, to or from the deck level, or other suitable
position, by chains, screws and nuts, racks and pinions, or other suitable devices,
riven by hand, steam, or other power.
Dated this 22nd day of July 1890.
AMBROSE MYALL,
21, Cockspur Street, London, S. W., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Hopper Dredgers.
I, ANDREW BROWN, of London Works, Renfrew, in the County of Renfrew,
Engineer and Shipbuilder, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
The main object of my invention is to render hopper dredgers more stable and
seaworthy when navigating.
The said object is effected in an improved and advantageous manner by providing
on the vessel, in addition to the usual gear for raising and lowering the lower end
of bucket ladder, apparatus for raising and lowering the upper end of the said
bucket ladder and the chain of buckets, to and from the deck level, or other suitable
position, by means of chains, wire ropes, screws and nuts, racks and pinions, or other
suitable devices, driven by hand, steam, or other power.
In the accompanying sheet of drawings,
Fig. 1 is an elevation, and Fig. 2 a plan, of part of a hopper dredger shewing my
invention applied thereto.
Similar letters of reference denote similar parts in both figs.
A, is the main framing, on which the upper end of the bucket ladder
traverses.
B, B, is the bucket ladder.
C, is the upper tumbler on the bucket ladder in its uppermost position.
D, is the lower tumbler in its lowest suitable working position.
C, D, show the upper tumbler lowered and the lower tumbler raised on deck, so
that the bucket ladder lies parallel, or nearly so, with the deck, thus lowering the
centre of gravity of the vessel.
C, D, show the bucket ladder with the upper tumbler at its highest position, and
the lower tumbler dredging in advance of the hull.
The apparatus for lowering and raising the upper end of the bucket ladder, as
shewn in the drawings, consists of chains or wire ropes E, E, E, three in number,
the two outer chains, or ropes, being used for the purpose of raising the upper end
EDC1

page_text: ladder, and the centre chain, or rope, for the purpose of lowering it.
F, F, F, are three drums for operating the said chains or ropes.
shears for lowering and raising the lower end of bucket ladder in the usual
G are the hoist
manner.
As before described, screws and nuts, racks and pinions, or other suitable devices
may be employed in place of the chains or ropes shewn for lowering and raising
the upper end of the bucket ladder, and such traversing gear may be worked,
either by the main engines, or by auxiliary engines, as may be found most
suitable.
By effecting certain modifications in the construction of the main framing to that
shewn in the accompanying drawings, the following advantages are obtained by the
use of my invention.
lowest position, it is enabled to dredge to a greater depth, and (Secondly) when
(First) When the upper end of the bucket ladder is at its
necessary the main framing can be constructed of sufficient height to permit of
debris being easily discharged on shore, by means of dredger shoots.
These advantages are gained without interfering with the stability and sea-
worthiness of the dredger.
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
1. In a hopper dredger, the combination with the usual gear for raising and
lowering the lower end of the bucket ladder, of means for lowering and raising the
upper end of the said bucket ladder.
2. In a hopper dredger, the apparatus for lowering and raising the upper end C,
of the bucket ladder B, on the main framing A, by means of chains or wire 2
ropes E, E, E, substantially as herein described and shewn with reference to the
accompanying drawings:
Dated this 22nd day of April 1891
AMBROSE MYALL,
21, Cockspur Street, London, S. W., Agent for the Applicant