IMPROVEMENTS IN THE CONSTRUCTION OF HOPPER AND OTHER DREDGERS."
Year: 1882

page_text: LETTERS PATENT to Walter Robert Kinipple of Greenock in the Co inty of
Renfrew North Britain and of 2 Westminster Chambers in the County of
Middlesex Civil Engineer for an Invention of IMPROVEMENTS IN THE
CONSTRUCTION OF HOPPER AND OTHER DREDGERS."
"
PROVISIONAL SPECIFICATION left by the said Walter Robert Kinipple at
the Office of the Commissioners of Patents on the 4th September 1882.
WALTER ROBERT KINIPPLE, of Greenock, in the County of Renfrew, North
Britain, and of 2 Westminster Chambers, in the County of Middlesex, Civil Engineer
"IMPROVEMENTS IN THE CONSTRUCTION OF HOPPER AND OTHER DREDGERS.'
This Invention which relates to Improvements in Hopper and other Dredgers has
reference more especially to the construction of the hull of the vessel or dred er
and to the arrangement of the ladder, and of the chain of buckets carried thereon.
I construct the hull of the vessel or dredger with the ladder-well abaft in lieu
of arranging it in the fore part of the vessel, which has been the practice hitherto,
the aft of the vessel being thus necessarily of twin ship form. The vessel can thus
dredge aft and at the same time the fore part of the vessel can be constructed as
perfect as that of an ordinary sea-going steamship, by which construction a better
distribution of weight for steaming is effected and the hull is rendered of stronger
form.
In this construction of the vessel or dredger, I arrange the hoppers in such
positions that the vessel can be trimmed fore and aft or transversely, as required by
employing port and starboard hoppers and a central forward hopper; by this
arrangement the centre forward hopper can be loaded whilst cutting in shallow
water, thus bringing the nose of the dredger down and raising the stern, and when
cutting in deep water the side hoppers can be loaded, and the vessel thus trimmed.
With the hereinbefore mentioned arrangement of the ladder-well aft of the
vessel, I protect the screws and rudders from coming in contact with the bed of the
sea or river during dredging operations, by constructing the aft part of the keels of
curved form from the bottom of the vessel towards the level of the deck.

page_text: A further part of my improvements relates to the construction of the ladder for
carrying the buckets and the arrangement of the buckets thereon, I construct the
ladder of such a width that it can carry two or more lines of buckets, which lines of
buckets are arranged side by side upon the ladder and can be driven either together
or independently of each other by power arranged at both sides of the vessel.-By
this arrangement the whole of the engine power, upon the vessel for dredging and
propelling purposes, can be utilized when necessary for actuating the dredging
machinery alone, and thus the large proportion of the power, which is at present
lost in the case of twin screw hopper dredgers, is utilized, and also by thus
employing more than one line of buckets, one of the lines can be kept working in
the event of the other line or lines being idle during repair.-In lieu of employing
one broad ladder for carrying the lines of buckets, more than one ladder may be
employed, the number of ladders corresponding if necessary to the number of lines
of buckets employed.
A further part of my Improvements relates to means for raising and lowering
the foot of the bucket ladder which I effect by providing a roller or drum mounted
upon a support or framework upon the deck of the vessel, upon which drum is
wound a coil of broad flat rope of wire or other suitable material which is also
attached to the foot of the ladder. By applying gearing actuated by power from
the engines to the said roller or drum, the bucket ladder can be readily raised or
lowered when necessary by coiling or uncoiling the flat rope upon or off the roller
or drum, by which arrangement the raising or lowering of the ladder can be effected
very readily and at the same time, a compact coil of rope upon the roller is
effected.
More than one winding roller or drum may be employed if necessary when more
than one bucket ladder is used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Walter Robert Kinipple in the Great Seal Patent Office on the
1st March 1883.
WALTER ROBERT KINIPPLE of Greenock, in the County of Renfrew, North
Britain and of 2, Westminster Chambers in the County of Middlesex, Civil
Engineer" IMPROVEMENTS IN THE CONSTRUCTION OF HOPPER AND OTHER
DREDGERS
"
My said Invention which relates to Improvements in Hopper and other Dredgers
has reference more especially to the construction of the hull of the vessel or
dredger and to the arrangement of the ladder and of the chain of buckets carried
thereon. Also to the arrangement of ropes or bands coiled on the drum or drums
for lowering and raising the ladders.
The Hull is constructed with the ladder-well abaft in lieu of arranging it in the
forepart of the vessel, which has been the practice hitherto, the aft part of the
vessel being thus by my arrangement constructed of twin-ship form.
The hoppers are arranged in such positions that the vessel can be trimmed fore
and aft or transversely as required by employing port and starboard hoppers and
a central forward hopper.
My improvements consist further in the employment of a double or multiple
arrangement of ladders and buckets and in the application of, and mode of
operating the ropes or bands for lowering and raising the lower ends of the ladders
down to, or up from the material to be dredged.
And in order that my said Invention may be properly understood I now
proceed more particularly to set forth the system, mode, or manner in or under
which the same is or inay be used or practically carried into effect reference being
had to the accompanying Drawings and to the letters and Figures marked thereon,
that is to say :-
Figure 1, of the accompanying Sheet of Drawings represents in side elevation
a Hopper Dredger (shewn broken in the Drawing), constructed according to my
said Invention.
Figure 2, is a plan and Figure 3, a transverse section of the same.
The hull of the vessel or dredger is constructed with the ladder or bucket-well A,
abaft, that is to say, at the stern, this part of the hull being thus rendered of twin-
ship form as shewn more particularly in Figure 2, the forepart of the hull being
constructed as perfect as that of an ordinary sea-going steam-ship.-By this
arrangement the dredging operations are performed in the after part of the vessel,
and a better distribution of weights for steaming is thereby effected, whilst the
hull is rendered of stronger form.
The hoppers B, B1, B2, as shewn in Figures 2, and 3, are arranged at the sides
and in a central forward position, the hopper B, being port, the hopper B¹, star-
board, and the hopper B, being arranged in a central forward position.-By this
arrangement the vessel can be trimmed fore and aft or transversely as required,
thus when the dredger is cutting in shallow water, by loading the central forward-
hopper B³, the nose of the dredger would be brought down and the stern raised,
and when cutting in deep water the side hoppers B, B', could be loaded and the
vessel thus trimmed.-With the herein before described arrangement of the ladder-
well A, aft of the vessel, the propellers C, C, and rudders D, D, are protected from
coming into contact with the bed of the sea or river during dredging operations
by constructing the aft part of the keels of such form from the bottom of the
vessel as to be under and abaft the rudders and continued up to the overhanging
stern of the vessel.

page_text: The ladders E, which pass through the well A, and carry the buckets (the said
buckets not being shewn in the drawings) are arranged side by side, each ladder
carrying an independent line of buckets which are operated by gearing e, mounted
on each side of the framing carrying the upper ends of the ladders as shewn by the
dotted lines in Figure 1, and in plan in Figure 2.
The two lines of buckets may be driven simultaneously by connecting together
the gearing e, at either side of the ladders or the said lines of buckets may be
driven independently of each other by disconnecting the gearing.
By this double arrangement of ladders and buckets, the whole of the engine
power upon the vessel for dredging and propelling purposes can be utilized when
necessary for actuating the dredging machinery alone and thus a large proportion
of the power which is at present lost in the case of twin-screw hopper-dredgers is
utilized for hitherto the power necessary for propelling twin-screw hopper-dredgers
has been about double that required for dredging operations and also by thus
employing more than one line of buckets, one of the lines can be kept working in
the event of the other line being under repair.
In lieu of two separate ladders as hereinbefore described, one broad ladder may
be employed to carry two or more lines of buckets or there may be several ladders
each carrying a line of buckets.
The pulleys or drums f, operating the ropes or bands f¹, for raising and lowering
the lower ends of the ladders E, are mounted upon the framing F.-The said
pulleys or drums are operated by gearing which may consist as shewn in Figures
1, and 2, of worm wheels f, keyed on the shaft carrying the drums f, the said
wheels f, being operated by worms f³, actuated by suitable gearing from the
propeller shafting or by auxiliary engines.-The ropes or bands f¹, consist of one
or more lengths of flat rope of steel wire or other suitable material and are
attached to the drums f, and to the lower parts of the ladders E, by means
of the suspenders f*, the crosshead of which may be fitted with adjusting screws
and nuts of brass or otherwise for connecting to and adjusting the lengths of the
ropes or bands.
The flat bands or ropes are wound in a coil upon the drums f, by operating the
gearing f, when the ladders are required to be raised and the said ropes or bands
are uncoiled from the said drums when the ladders are to be lowered.-By this
arrangement the raising or lowering of the ladders can be effected very readily and
as the rope will always lie in a compact coil on the drum any jarring and jerking
with consequent extra straining is avoided and an equable and steady motion is
imparted to the ladders, when being raised or lowered.
When only one ladder is employed only one raising and lowering drum will be
necessary, and when two or more ladders are operated independently of each other,
the gearing at the sides of the winding wheels will be disconnected so that the
drums act independently.
In the drawing I have shewn the boilers G, and engines H, fixed in the fore part
of the vessel, the propellers C, being driven by the shafts c, the power for actuating
the gearing operating the lines of buckets and the drums f, being obtained from
the said engines H, by any ordinary arrangement of gearing or connecting shafting,
or the drums f, may be operated by means of auxiliary engines as hereinbefore
mentioned.
Having now described and particularly ascertained the nature of my said
Invention and the system, mode or manner in or under which the same is or may
be used or practically carried into effect, I would observe in conclusion that what I
consider to be novel and original and therefore clain as the Invention secured to me
by the hereinbefore in part recited Letters Patent is :-
First In the construction of Hopper and other dredgers, the arrangement of the
ladder well in the stern of the vessel to enable the vessel to dredge aft, and the
construction of the hull of the vessel at this part of twin-ship form substantially
as hereinbefore described.
Second-The arrangement of port and starboard hoppers and a central forward

page_text: hopper to facilitate the "trimming" of the vessel substantially as hereinbefore
described.
Third The construction of the ladder or ladders to carry a double or multiple
arrangement of buckets and the mode of operating two or more lines of buckets
either together or independently substantially as hereinbefore descr bed.
Fourth The employment of one or more broad flat ropes or bands of wire or
other suitable material and the arrangement and mode of working the same in a coil
or cuils upon a drum or drums for raising and lowering the ladder or ladders,
substantially as herein before described.
Fifth In hopper dredgers protecting the rudders thereof from injury by means
of the up-turned keels substantially as herein before described.
In Witness Whereof, I, the said Walter Robert Kinipple have hereunto set my
hand and seal this twenty-seventh day of February in the year of our Lord
One thousand eight hundred and eighty-three.
WALTER ROBERT KINIPPLE (L.S.)