Iм- PROVEMENTS IN DREDGING MACHINES, AND IN APPARATUS CONNECTED THEREWITH
Year: 1868

page_text: LETTERS PATENT to David Elder, of Newcastle-upon-Tyne, in the
County of Northumberland, Engineer, for the Invention of "Iм-
PROVEMENTS IN DREDGING MACHINES, AND IN APPARATUS CONNECTED
THEREWITH."
PROVISIONAL SPECIFICATION left by the said David Elder at the
Office of the Commissioners of Patents, with his Petition, on the
16th June 1868.
I, DAVID ELDER, of Newcastle-upon-Tyne, in the County of Northum-
berland, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN DREDGING MACHINES, AND IN APPARATUS CONNECTED
THEREWITH," to be as follows:-
The object of my Invention is to facilitate the sinking of cylinders or
caissons for the foundations of bridges or other works where ground has
to be removed from below the level of water, or for shafts, and other

page_text: similar excavations where earth has to be raised vertically in the interior
of a cylinder.
The nature and description of my Invention consists in the application
of an endless chain of buckets driven and carried by apparatus fixed on
a turntable, which is made to rotate upon a foundation plate temporally
fixed on the top of the cylinder or caisson to be sunk. In operation
the apparatus has to be removed when a length of cylinder has to be
added and extended to the required length when replaced. The bucket
chain is formed of links and pins easily detachable in any ordinary
manner to be extended when required. It is driven by the rotation of
the top tumbler, which is carried on bearings on side frames, and passes
round a bottom tumbler which is carried on bearings on the lower end
of the bucket ladder. The bucket ladder consists of a central shaft or
spear for stretching the bucket chain, and for keeping the tumblers
parallel to each other, having a crosshead on top guided by guide frames
fixed on the turntable, and thus made to turn with it. It is constructed
in lengths corresponding to the lengths of the cylinders to be sunk, and
jointed together with keys or bolts so as to facilitate its extension. The
buckets on passing over the top tumbler deliver the dredged material
into a moveable shoot wrought in any ordinary manner by the gearing,
so as to allow the buckets to pass. The actuating gearing is carried on
side frames which are fixed to the turntable. The turntable is carried
on rollers moving on an ordinary and suitable rail or track on the
foundation plate. The foundation plate is formed to fit the flange of
the cylinder or caisson to be sunk, to which it may be temporally
bolted; it is furnished with a toothed wheel in gear with the actuating
machinery. The motive power would be supplied by a steam engine and
boiler fixed on the turntable. When set to work the buckets dig out
the materials at the bottom of the cylinder, deliver it outside over the
top, and the cylinders with the superincumbent operative machinery
sink together as the excavation of the interior progresses. The bucket
ladder being hung pendulously is deflected from the vertical position
by the resistance of the material at the bottom towards the side of the
circumscribing cylinder, against which it may press by ordinary guide
rollers to keep the buckets clear of it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
'
filed by the said David Elder in the Great Seal Patent Office on
the 10th December 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
ELDER, of Newcastle-upon-Tync, in the County of Northumberland,
Engineer, send greeting.
,
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of June, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto the said David Elder, Her special licence that I,
the said David Elder, my executors, administrators, and assigns, or
such others as I, the said David Elder, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, excrcise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "IMPROVEMENTS IN DREDGING MACHINES AND
IN APPARATUS CONNECTED THEREWITH," upon the condition (amongst others)
that I, the said David Elder, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said David Elder, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement :-
The object of my Invention is to facilitate the sinking of cylinders
or caissons for the foundation of bridges and other works where ground
has to be removed from below the level of water, or for shafts or other
similar excavations where earth has to be raised vertically; also for
excavations where carth has to be raised and removed for docks, canals,
or similar obiects.
.

page_text: The nature and description of my Invention consists in the application
of an endless chain of buckets driven and carried by apparatus fixed on a
turntable, which is made to rotate upon a foundation plate temporarily
fixed on the top of the cylinder or caisson to be sunk or over the shaft
to be excavated. In operation the apparatus has to be removed when a
length of cylinder has to be added and extended to the required length
when replaced.
In order that my Invention may be fully understood I have hereunto
annexed a Sheet of Drawings with letters of reference marked thereon
corresponding with letters of reference in this Specification. The same
letters refer to the same parts in the several Figures.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a sectional elevation of a foundation cylinder A, bucket
ladder B, tumblers C, C', turntable J, and shoots P and Q (one side
frame of the machine being removed for the purpose of showing the
buckets D, &c.) The cylinders A are furnished with an internal flange a
at each end for forming the joints, and which are further utilised for
carrying or fixing the machine at the top and for carrying extra loads
in the form of annular segments of iron, which may be necessary to
impose to effect the sinking operation. The lowest cylinder A¹ has a
cutting edge a' at bottom. The bucket ladder B is formed in lengths
corresponding to those of the cylinder, and is rectangular in cross
section for the purpose of taking the tortion strain off the junction
pins, and the lengths are made to fit into each other internally and
externally or telescopically, so as to enable them to be jointed together
at the required length; they are united by pins or bolts passing
through suitable holes at convenient intervals for adjusting the length.
The lower end of the bucket ladder is bifurcated in form as shown at B¹
in Fig. 2, for carrying the two bearings of lower tumbler C'; it has also
cast or fitted on it double bearings e for carrying the guide rollers E.
The upper end of the bucket ladder is formed with an eye, through
which is passed the crosshead F. The crosshead is guided in slots f
in the side frames of the machine, and is free to rise and fall; the
crosshead and eye piece is removed with the machine when the ladder
has to be lengthened; it is made to fit the various widths of ladder by
introducing suitable slips of iron. The tumblers C, C', buckets D, and
links are of the ordinary construction. The upper tumbler shaft

page_text: has 2 barrels G, G', formed on it, recess'd for receiving pitch chains,
which would be convenient for hoisting the ladder, &c.; it is carried on
the side frames H of the machine, and driven by a disengaging clutch I,
as shown in Fig. 2. The side frames H are fitted and bolted to an
annular sole plate J, and carry the engine and bearings of the gearing.
The sole plate has 2 annular feathers K, K', which carry the per-
pendicular bearing rollers L and the horizontal guide rollers M; these
rollers bear upon the internal bottom flange m and side of the foundation
plate N, sustaining the weight and guiding the rotation of the machine.
The foundation plate N is formed to fit the top of the cylinder A, and
would be bolted or otherwise fixed temporarily on the top flange a of the
cylinder; it is furnished with guide brackets n on the bottom to facilitate
the placing on the cylinder, and a toothed circumference N¹ on the top
for the turning gear; it has also an internal flange ¹ on the top so as
to be lifted with the machine by the guide rollers L or horizontal pins 1,
projecting for the purpose when the machinery is being removed. The
delivery shoot O is fixed to sole plate, and may be furnished with a door
to discharge at intervals. The moveable shoot P is hung on a pivot or
shaft allowing it to oscillate, and kept inclined to the bucket chain by
counterbalance weights Q, so as to save the material raised and allow it
to yield to the pressure of the buckets when passing.
Fig. 2 is a sectional clevation at right angles to Fig. 1, showing
the actuating machinery consisting of boiler R, engine S, main driving
wheel T, and turning gear U. The turning gear is driven by a
disengaging clutch V, and is supported by bearings fixed on side
frames H, and sole plate J; a hand rail W surrounds the sole plate.
Fig. 3 is an elevation of the bucket latter B, with the machine
removed for the purpose of lengthening the cylinder A. The links
are detached by the withdrawal of the pins at the top, and the chain d
is secured by being hung to the ladder by passing cotters ✗ through
suitable holes made in the ladder for that purpose. When the chain
is detached the ladder is allowed to rest on the ground at the bottom,
and is kept in position at the top by a temporary platform Y supported
by brackets, and bearing on the side of the cylinder, this platform is
also utilised for conveniently bolting and making the joints of the
cylinder.

page_text: in the side frames.
Fig. 5 is a plan of ditto.
Fig. 6 is a vertical section of the foundation plate N, showing
toothed surface N', guide rollers M, lower flange m, guiding flangen,
and lifting flange n.
Fig. 7 is a plan of ditto, showing guide and bearing rollers M and L,
toothed rim to sole plate N', bearing flange m, and upper flange n.
Fig. 8 is a sectional elevation of a cylinder showing the mode of
slinging and of lengthening the bucket ladder and chain. The links d
are secured to the ladder B by cotters X and the ladder hooked by
the chain Z, the same sling serving for the cylinders and the machine.
Fig. 9 is a plan of cylinder A, at cutting edge a¹, showing cross
section of lower end of ladder B, buckets D, friction rollers E, bearers e,
and links d.
Fig. 10 is a sectional plan of side frames H, showing crosshead F
and guides f.
Fig. 11 is a plan of top of cylinder, showing flanges a, cross section
of top of ladder B, kept in position by the temporary wooden platform Y.
In operation the cylinders to be sunk are guided by a frame 1, 1',
and guide piles 2, 2', in the usual manner, but any bias from the
vertical would be counteracted by disengaging the turning gear, and
digging from one side, the resistance of the ground deflecting the
bucket ladder towards the side of the cylinder until it bears on it by
the guide rollers E, insures the removal of the earth from the cutting
edge a¹ of the lower cylinder A', and the rotation completes the entire
excavation from the periphery to the centre. Should the buckets
meet with any unusual obstruction the chain raises the ladder until
they are free, or should they get jammed the ladder can be raised by the
hoisting barrels and chains. The engines are fitted with back and
forward valve gear, driving the dredging and turning gear either together
or seperately, and the boiler is supplied with water by a steam pump
with suction hose to the water in the interior of the cylinder, or to a
tank supplied by the dredging buckets. The cylinders and the machine
would be lifted off or put in their places by a travelling crane overhead
on a fixed staging in the usual manner, or in tidal waters the lifting
and removal may be conveniently done from an overhanging stage

page_text: on a floating barge similar to what is ordinarily used for diving bells,
which need only be of sufficient height to put on a cylinder at low
water and the machine at high water.
When the apparatus is applied to raising earth vertically from shafts,
wells, and other similar excavations, I would place the turntable with
the machine and apparatus over the proposed excavation and proceed
in a similar manner to that herein-before described for sinking cylinders.
When the Invention is employed for raising earth for docks, canals,
cuts, and similar excavations, I would attach the upper end of the ladder
to a turntable to enable the machine to turn to accommodate the hori-
zontal angle of the ladder. The turntable would be on a truck placed
on a railway laid alongside the dock, canal, cut, or land to be excavated.
When applied to excavations under water the lower end of the
ladder would be carried or sustained by hoisting from a raft or floating
barge, the raft being moored or moved by chains leading from crab
winches on machine passing through blocks on raft to anchors fixed
in convenient parts of the ground, the hoisting chains being led in a
similar manner to the machine. When not under water the suspending
chains are fixed similarly to the mooring chains. The truck may also
be made to travel on its rails by driving the wheels as in a travelling
crane, or by heaving on a mooring chain. In order to strengthen the
or ladder I would sometimes on the under sido apply an iron
truss. The buckets would be discharged into waggons placed on a railway.
The buckets, links, ladder, and turntables are all of the ordinary con-
struction, but the apparatus would be carried on a platform carrying
also the engine and boiler, driving and hoisting gear, fixed on a turntable
or turning frame similar to the apparatus herein-before described for
sinking cylinders. When in use the apparatus will not be required to
rotate completely, but move in an arc sufficient to accommodate the
ladder to the slope of the work.
beam

page_text: First. The general arrangement and combination of parts forming
the rotatory dredger with the sole plate, bucket ladder, and other appa-
ratus to be used in sinking cylinders as herein set forth and described.
Secondly. The general arrangement and combination of parts forming
the rotatory dredger with turntable, bucket ladder, and other apparatus
to be used in sinking shafts, wells, and similar excavations as herein
set forth and described.
Thirdly. The general arrangement and combination of parts forming
the rotatory dredger with turntable and other apparatus for raising earth
from docks, canals, cuts, and similar excavations as herein set forth and
described.
Fourthly. The system or mode of rotation as applied to vertical
dredging machines as herein set forth and described.
Fifthly. The mode of constructing the bucket ladder in sections and
uniting them telescopically as herein set forth and described.
Lastly. The mode of resisting the reaction of the buckets when
digging by means of guide rollers acting on the inside of the cylinder
as herein set forth and described.
In witness whereof, I, the said David Elder, have hereunto
set my hand and scal, this Ninth day of December, One
thousand cight hundred and sixty-eight.
Witness,
WILLIAM CAMPBELL,
Civil Engineer,
29, Ashfield Terrace West,
Newcastle-upon-Tyne.
DAVID ELDER. (L.S.)