AN IMPROVED EXCAVATING AND DREDGING MACHINE
Year: 1853

page_text: time prescribed by the Act.)
PROVISIONAL SPECIFICATION left by Arthur Wellington Callen
at the Office of the Commissioners of Patents, with his Petition,
on the 2nd December 1853.-A communication.
I, ARTHUR WELLINGTON CALLEN, of Peckham, in the County of
Surry, do hereby declare the nature of the said Invention for "AN
IMPROVED EXCAVATING AND DREDGING MACHINE" (a communication,) to be
as follows:-
My Invention consists of a machine for excavating earthworks in
docks, railways, and other cuttings, and for excavating under water,
and dredging the beds of rivers and harbours.
The machines are constructed in the following manner, viz. :-When
to be used for excavating under water or dredging, a floating vessel, of
suitable form and dimensions, according to the power of the machine
required, is to be constructed (say, for 10 or 12 horse power, 40 to 50
feet long, 20 to 25 feet wide, and 3 to 4 feet deep). This vessel may
be wholly
partially decked over and roofed, if required. When to be
used for other excavations, in place of a floating vessel, a platform is

page_text: made, properly framed and braced together, the floor planked, and the
whole mounted on wheels for convenience of removal. At one end of
such vessel or platform a steam engine is fixed, which drives a set of
chain drums and the other gearing of the machine, to which the chains
that work the excavator are attached (in place of the steam engine,
horses may be employed if necessary.) At the other end of the vessel
or platform a crane is erected, to the end of which the excavator is at-
tached by the chains above mentioned; theos chains work the excavator
up or down, or forwards or backwards, as herein-after described.
The excavator consists of a long beam, at the end of which is fixed a
strong iron scoop or bucket, the back end of which opens upon hinges,
so as to discharge the material excavated, when it closes by its own
weight, & when closed the end is held secure by strong iron catches
and drop bolts. When it is necessary to let out the material in the
scoop, these bolts are drawn, by means of a strong wire or cord attached
to bell cranks and carried over to the platform. The head and spur
beams of the crane are framed together in two parts parallel with cach
other, and sufficiently wide apart to admit of the excavator beam
working between them. On the under side of the excavator beam there
is a rack, which works on a pinion fixed between the two head beams of
the crane, and by turning this pinion the excavator is raised or lowered,
according to the depth required. This pinion is turned by means of an
endless chain, which passes over a studded wheel fixed on to the pinion
shaft at the side of the frame, and round a second studded wheel or
pinion at the foot of the crane, and is turned by a lever wheel attached
thereto and worked by hand. To the excavator are attached two strong
chains, one of which is fixed to the scoop or bucket, and thence passes
over the end of the crane to the engine, and when the engine is put in
notion this chain draws the scoop or bucket forward, through the
material to be excavated, and raises the scoop and beam to the proper
height. The pinion upon which the rack of the excavator beam works
forms a pivot or centre, and confines the scoop, so as to cut in a seg-
mental line, the radius of which, or in other words the depth of the cut,
being regulated by raising or lowering the rack beam, in the manner
before described. At the bottom of the crane there is a circular plat-

page_text: form, round the edge of which an endless chain passes, and thence
round.a pinion, by turning which, either by hand or by gearing con-
nected with the engine, the crane is swung round to the right or left,
and carries the scoop or bucket to the point required; the wire before
mentioned is then pulled by the man stationed at the platform, the
end of the scoop opens, and the material falls out either into waggons,
if in land excavation, or into lighters or barges when dredging, or in
under-water excavations. The end of the scoop being again closed &
secured, and the crane swung back to tho proper position, the excavator
is drawn back by the second chain, which is attached to the back of the
excavator beam, and "passes. through or by the foot of the crane to a
second drum at the engine. The first drum being thrown out of gear,
and the lead chain before mentioned is let out until the excavator is
again lowered to the required position, when the back chain drum is
thrown out of gear, and the engine is again applied to the head-chain,
and the machine makes another cut, either deeper or to the right or left,
as the case may require, by regulating the rack beam and crane. When
all the material has be excavated within the range of the machine,
it is either moved or floated to the right or left, or backward or forward,
as the case may be, and the operations before mentioned are again
repeated.
1.