IMPROVEMENTS IN MACHINERY FOR EXCAVATING SOIL
Year: 1842

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DUNCAN, of Great George Street, in the City of Westminster, Gentleman,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Seventh day of March, in the fifth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto mo, the said
John Duncan, Her especial licence, full power, sole privilego and authority,
that I, the said John Duncan, my executors, administrators, and assigns, and
such others as I, the said John Duncan, my executors, administrators, or
assigns, should at any time agree with, and no others, from time to time
and at all times during the term of years therein mentioned, should and
lawfully might make, use, exercise, and vend, within England, Wales, the
Town of Berwick-upon-Tweed, and in all Her Majesty's Colonies and Plan-
tations abroad, and in the Islands of Jersey, Guernsey, Alderney, Sark, and
Man, an Invention of "IMPROVEMENTS IN MACHINERY FOR EXCAVATING SOIL,"
being a communication from a foreigner residing abroad; in which said Letters
Patent is contained a proviso, obliging me, the said John Duncan, by an
instrument in writing under my hand and seal, particularly to describe and
ascertain the nature of the said Invention, and in what manner the same is
to be performed, and to cause the same to be inrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately

page_text: after the date of the said in part recited Letters Patent, as in and by the
same, reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, 1, the said
John Dunenu, do hereby declare that the nature of the said Invention, and the
manner in which the same is to be performed, are particularly described and
ascertained in and by the following description thereof, reference being lad
to the Drawings hereunto annexed, and to the letters and figures marked
thereon, that is to say:-
This Invention may be divided into two parts, consisting, firstly, in a novel
construction and arrangement of machinery, whereby earthly inatters may be
cut away or excavated and removed for the purpose of constructing or forming
railways, canals, docks, harbours. fortifications, ditches, intrenchments, and
other similar works, which require the removal of large quantities or masses of
earth; and, secondly, in certain variations in the arrangements of some of the
parts of the machinery, and also making some additions thereto, whereby the
Invention will be found exceedingly useful for dredging or deepening rivers,
harbours, and other under water works. The principle, upon which the
machinery for both these purposes is constructed, is essentially the same. but
it must be obvious that precisely the same arrangement or construction will
not be applicable to both. I will therefore, in the first place, describe the land
machine, or that employed in constructing railronds, canals, and other similar
works, as above mentioned, and afterwards describe such parts of the machine
employed for deepening rivers, &c. as are not required in the land machine.
Sheet I. represents a geometrical elevation of the land machine as it would
appear when taken longitudinally.
Sheet 1. represents the opposite side of the machine. In this last-mentioned
Figure some of the parts are shewn in different positions to those represented
in the preceding Figure.
Sheet . is a horizontal view of the machine, as seen from above, some of
the upper parts being removed and shown by dots to avoid confusion.
In Sheet IV. various parts of the machine are shewn detached, in order that
their construction may be more clearly understood.
In Sheet V the shovel or scraper, and the scraper arms, together with
various other parts connected therewith, and some other parts of the machine,
are shewn detached and in detail.
The machine is principally composed of the following parts, namely:-
First, a strong horizontal wooden or other framing a, a, a, placed upon wheels
b, b, by means of which the machine may be moved along a temporary railway
(previously laid down for that purpose) as the machine excavates or digs away

page_text: and removes the earth before it. Second, a strong crane c, d, e, placed at one
end of the framing, to which it is firmly connected at its base in any convenient
manner. This crane is constructed in such a way, that it may be turned round
on a centre either to the right or left, and beyond a right angle, for purposes
hereafter explained. Third, a scraper, scoop, shovel, excavator, or digging tool
f, g, h, or instrument for loosening and collecting the earth.
This scraper,
shovel, or excavator, being suspended by chains or ropes at the outer end of
the crane, may be raised or lowered by means of these chains and certain
apparatus in connection with the steam engine which actuates the whole
machinery. Fourth, an arrangement of wheelwork communicating with various
parts of the machine, and also with the steam engine which actuates it, and by
means of this wheelwork or gearing, the attendants who work the machine
may direct its movements with the greatest precision. The framework or
base of the machine is rectangular, as shewn at a, a, a, a, and supported upon
running wheels b, b, b, b, by means of which the whole apparatus may be moved
along a temporary railway laid down for that purpose; c, c, is the crane post
standing perpendicularly at one end of the framing a, a, and scen detached at
Fig. 7, Sheet V. At the upper end of this post is mounted the crane jib d, d, d,
the outer end of which crane jil is supported and strengthened by diagonal
arins e, e, e, which are also employed for carrying wheelwork and apparatus,
whereby certain evolutions or movements of the scraper, shovel, or excavator f,f,
are effected. The scraper or shovel, which is made of stout boiler iron, is shewn
detached in Sheet V. Fig. 1 is a plan view thereof; Fig. 2, a side elevation;
Fig. 3, a front view; and Fig. 4, a back or end view. It is furnished in front
with four or more projecting steel points g, g, for loosening the earth. At the
base or root of these points the scraper or shovel is also provided with a finely
tempered steel edge g*, which is hardened so as to resist the action of stones
or other hard substances it may come in contact with, and which (unless some
such provision is made) would soon destroy the cutting edge. The scraper or
shovel is suspended from the crane jib, d, d, Sheets I. II. and III. by chain
tackle j, j. which passes up over a pulley k at the end of the crane jib along
the upper side of the crane, and over another pulley 1, situated at the opposite
end of the crane, and immediately over the centre of the crane post c, c; from
thence it passes down through the crane post, which is made hollow for this
purpose, and under another pulley m mounted in bearings affixed to the crane.
post, from whence it proceeds to the main drum or windlass n, around which it
is wound when the shovel or scraper is being raised; rotary motion is com-
municated to the main drum or windlass n through the intervention of the
wheelwork which gears into the large spur whcel o on the axle of main drum;

page_text: This wheelwork is actuated by a steam engine, which, in order to prevent
confusion is not shewn in the Drawings, but is to be situated on the base
framing between the main drum or windlass n and the boiler. The details of
the main drum or windlass, with the other parts connected with it, are shown
detached in Division 2 of Sheet IV. On the shaft of the main drum, which is
cut with an helical groove throughout its periphery, is mounted a friction
pulley 49, furnished with a friction band or break 50 (see Sheet III.) This
band is connected to the tumbling shaft 51, hereafter described. The shaft of
the main drum » is made hollow nearly throughout its whole length, as seen in
Fig. 1, Division 2, Sheet 1V., and is furnished with a ratchet wheel 52, which
is firmly secured to it, and provided with palls or clicks 53, (as seen in the
side and plan views, Sheets I., II., and III.,) for the purpose of preventing the
main drum from unwinding when the scraper has attained its proper altitude.
There is also on the main drum shaft, and close against the ratchet wheel 52,
a coupling clutch 54, which slides on the main shaft, and is connected with
the ratchet wheel 52 by two turned pins 55, as seen in the detailed views.
Division 2, Figures 2, 3, 4, and 5, in Sheet IV. These pins are firmly fixed to
the ratchet wheel, and pass through holes in the coupling 54. The outside or
periphery of the coupling 54 terminates in four arms, as shewn in Figures 4
and 5; on two of these arms are placed stout wrought-iron catches 56, which
pass through slots 57 in the side of the ratchet wheel, as shown in Fig. 2.
The large spur wheel on the drum shaft revolves loosely on the shaft
when the scraper is not being raised, on the inner side of which wheel o is
fastened the ratchet wheel, shown detached at Fig. 6. This wheel has its
teeth formed on its face, and by sliding the coupling or clutch 54 on the
drum shaft, close to the ratchet wheel 52, the catches 56 of the coupling slide
through the slots 57 in the ratchet wheel 52 until they gear into the teeth on
the face of the ratchet on the spur wheel, whereby the driving power of the
steam engine is communicated from the spur wheel to the main drum.
The coupling piece or clutch 54 is affixed to a sliding rod 58 (Fig. 1,
Division 2, Sheet IV.), which rod passes through the hollow shaft of the main
drum. This sliding rod 58 is connected at its right-hand end by a swivel
joint 59 (see plan view, Sheet 11J., and side view, Sheet I.,) to an arm or lever
on the upright tumbling shaft 60; lower down on this shaft 60 another arm
is placed, to which is connected a rod 61, leading backwards to a hand lever 62
at the hinder part of the machine, and is used for throwing the coupling or
clutch 54 into gear with the ratchet on the spur wheel o, and thereby causing
the drum to rotate. On the right-hand end of the drum shaft is placed a
pinion 68, which gears by an intermediate wheel 64 into the spur wheel 65,

page_text: Sheets T. and III., and 'Division 10, Sheet IV. On the wheel 65 there is
placed a pin 66, which by the rotation of the drum is brought into contact with
a projecting piece 67 on the rod 61, and by thus throwing the drum out of gear
prevents it from winding up the chain too far. This pin on the wheel 65'is
only placed there as a precaution, in case the attendant does not throw the
drum out of gear by means of the band lever 62. After the scraper or shovel
has deposited its load, it must be brought down again for a second operation,
and to effect this the palls or catches 53 must be raised from the teeth of the
ratchet wheel 52, in order to allow the main drum n to turn back and uncoil
the chain j, j. This is effected by means of the horizontal tumbling lever 51,
at one end of which is fixed the lever arm or rod 74, furnished with pins for
raising the clicks 58, as seen in Sheet I., and at the other end an arm 68 pro-
jects downwards, as seen in the side view, Sheet I., and is connected to one end
of a long rod 69, which leads to a foot lover 70 at the back part of the machine.
The rod 69 may also be worked by the short rod 71, connected at one end to
the long rod 69, and having at its other end a pinion 72 that turns on a stud on
the inside of the framing. On the inside of this pinion are placed two pins that
operate as cranks, and a catch is made on the back end of the rod 71, which
takes hold of one of the pins on the pinion 72. Motion is given to the pinion
by means of a toothed segment 73, which is fastened on to the axle of the hand
lever 62, so that when this lever is moved forward to throw the main drum n
into gear the segment 73 turns the pinion 72 partly round, thereby moving the
rod 69 and the tumbling shaft 51, and raising the palls or catches 53 by means
of the small lever arm 74 at the opposite end of the tumbling shaft 51. At the
same time the band or break 50 on the friction pulley 49 is by the tumbling shaft
turning on its axis made to bind more firmly on the friction pulley, and thereby
prevent the chain on the main drum from uncoiling too rapidly and letting the
scraper fall suddenly. The movements of the scraper or shovel fare produced
and regulated by the wheelwork or mechanism attached to or mounted on the
diagonal arms e, e, and this mechanism is actuated in the following manner :-
The periphery of the pulley 7 at the top of the crane post is intended or has
interstices formed in its groove, which interstices fit the links of the chain j, j,
so that as the chain is moved one way or the other the pulley is made to
revolve. On the same shaft as the pulley is mounted a bevel pinion p, seen
5 best in the side view, Sheet I., and in Division 4 of Sheet IV., and also in dots
in the plan view, Sheet III. This pinion p gears into another pinion q mounted
on the upper end of the diagonal shaft r, at the lower end of which is mounted
a similar bevel pinion s, gearing into a corresponding one at the end of the
shaft t. The diagonal shaft r, with its pinions 7 and s, and their proper

page_text: bearings, aro shewn detached and in detail at Division 3, in Sheet IV. The
shaft and bevel pinion, with the parts in immediate connection, aro shewn in
Division 6 of Sheet IV. is tho bevel wheel on the shaft t, into which the
pinion & gears; this pinion is mounted loosely on the shaft t, and on the back
thereof a flange about one inch thick is cast. A recess formed on the peri-
phery of this flange constitutes the groove of the pulley seen at v, which
receives a friction break w, that may be tightened or loosened at pleasure in
the manner and for the purposes hereafter described. The bevil pinion and
its break or friction pulley v may therefore revolve without causing the shaft t
to rotate. Immediately behind the pulley va revolving arina is mounted on
and firmly fixed to the shaft t, and one end of the friction break or band w is
connected to one end of this arm a by a small crank lever y. The mode of
tightening the friction band. and thereby causing the shaft and other jarts to
rotate, is as follows:-The shaft t is mado hollow and furnished with a slot
throughout the greater part of its length, and contains in it a sliding rod :.
The inner end of this sliding rod is attached to a small rack 1 by means of
a pin passing through the slot in the hollow shaft t. The rack 1 slides
freely on the shaft t, and gears into a small pinion 2, which is mounted in
bearings on the revolving arm a before mentioned, and the same shaft which
carries the pinion 2 also carries a bevel pinion 3, that gears into a bevel
sector rack 4, whose centre of motion is 5, being the same as that of the
small crank lever y which connects the friction break or band w with the
arma. To the left-hand end of the sliding rod a lever 6 is connected, as
seen in the plan view, Sheet III., and in the detailed views, Division 8,
Slicet IV; this lever vibrates on a centre, and is connected at its opposite end
to a hand lever 7, by which the mechanism is worked. Near the left-hand
end of the hollow shaft t, and firmly affixed thereto, is the friction pulley 8,
which is provided with a band similar to w on the pulley v, above mentioned.
The friction band of the pulley 8 is connected to one end of the horizontal
shaft 9 (sce Division 8, Sheet IV.), and the other end of this shaft is furnished
with a hand lever 10, by means of which the friction band is tightened on
the pulley 8. On the extreme end of the shaft is mounted the pinion 11
(see Sheets 11. and 111., and Division 6, Sheet IV.); this pinion geers into a
spur wheel 12 on the shaft 19. on which shaft is also mounted the drum 1.4,
the periphery of which is formel with a right and left handle helical groove 3
(as shewn in the plan view, Sheet III., and in detail in the Division 7, Sheet
IV.), for the purpose of receiving the chains 15, which pass once round it, and
are connected at both ends to the moveable arms 16, that carry at their forked
end the shovel or scraper f. The moveable arms 16 are shewn detached

page_text: at Figs. 5 and 6, Sheet V. a, a, are the hooks to which the chains 15 are
attached. The moveable arms 16 of the scraper roll forwards or backwards
on this grooved pulley, according to the motion that is communicated to the
pulley and chain by means of the mechanism which actuates the large spur
wheel 12, and which is regulated by the attendant by means of the hand
levers 7 and 10. The attendant that works these levers stands on a platform A,
in front of the crane post, and as the scraper is raised by the chain this latter
actuates the pulley 1, and through it motion is communicated to the pinions p, q,
s, and u: therefore when the attendant, by means of the hand lever 7, causes tho
friction band w to bear tightly on the pulley v, in the manner above described,
the points g of the scraper are by means of the mechanism on the diagonal
armis e, e, forced or pressed forward into the bank. If it is required to hold
the scraper or shovel out in any particular position, the friction band on the
pulley 8 is drawn tight by means of the land lever 10, and then the band w
on the pulley v may be relaxed. If, on the other hand, it should bo necessary
to allow the scraper to run back suddenly from the bank, in order to avoid a
falling stone, or large mass of carth, all that is required is suddenly to relax
both friction bands on the pullies and 8, and the scraper immediately
flies back by its own gravity into the position shown in Sheet I. Now,
suppose that the scraper or shovel having entered the bank at the lowest
point has been raised to the highest, and has thereby become filled with
earth, and requires emptying into a car or waggon, or otherwise deposited
by the side of the machine: In order to do so the shovel or scraper
must be moved round horizontally until it arrives in a position immediately
above the place of deposit. This is effected by the following mechanical
arrangement of parts:-The crane post c, c, (shewn detached at Fig. 7,
Sheet V.) is firmly fixed to the solid framework a, a, and forms the centre of
motion round which the parts hereafter mentioned move; at the top of the
crane post is mounted the large pulley 17, 17, which, from its shape or form
as seen by dots in Sheet 111., is hereafter called the horse-shoe pulley. This
horse-shoe pulley is supported mainly by the crane jib, to which it is fastened
by strong iron and other bracings, as at 18, 18, 18. The lower end of the
diagonal arms e, e, abut against a loose collar 19, at the base of the crane post,
around which the loose collar 19 turns. From this description it will be seen
that the crane jib d, the horse-shoe pulley 17, and the diagonal arms e, e, are
all braced firmly together, and therefore must all turn together. The horse-
shoe pulley 17 is furnished with a double chain 20, 20, both ends of which are
fastened to the wooden bracings 18, 18, (see plan view,) which connect the said
pulley to the crank jib d. This chain 20 passes over the ends of the horse-

page_text: shoe pulley, round the periphery thereof, which is grooved for that purpose,
and to the back of the said pulley; then it passes between two horizontal
pullies 21, 21, and over one of the two vertical pullies 22, 22, seo side view,
Sheet II.; from thence it proceeds downwards, and onco round a pulley 23
mounted loosely on the axle 24 of the pinion 25, as seen in plan view; then
rises up again over the other vertical pulloy 22, between the horizontal pullies
21, round the other side of the horse-shoe pulley 17, to the other wooden
bracing 18. The pulloy 23 on the shaft 24 is formed with. indentations or
recesses in the same manner as the pulley on the top of the crane post.
The details of the pulley 23 and the parts connected with it are shown in
Division 11 of Sheet IV. Connected with the shaft of the pulley 23 there is an
arrangement of shafts and bevil wheels, which are so contrived with coupling
boxes as to admit of this pulley being turned in either direction, in order to swing
round the horse-shoe pulley and crane either to the right or left, as may be
required. In Division 11, Sheet IV., is shewn the shaft and its appendages, in
which the chain pulley 29 is placed: the pinion 25 which gives motion to the
shaft 24 is, together with the friction pulley 26, firmly secured to the said shaft:
This pulley 26 is furnished with a friction band or break, both ends of which are
fastened to the framing of the machino by means of screw nuts, as seen in
Sheets 11. and III. On the side of the friction pulley 26 are two projecting
pieces a, a, with holes bored therein, and close to the friction pulley 26 is
another friction pulley 27, round which in a half round groove is fitted a
friction band b, b, the ends of which pass through the holes in the projecting
pieces a, a, on the side of the pulley 26. The ends of the friction band b, b,
aro fitted with screw nuts to tighten the band on the pulley, and by screwing
up these nuts a greater or less adhesion may be had on the pulley 27, which is
also furnished with a clutch or coupling 28, by which it is connected to the
chain pulley 23. These friction bands and pulleys are employed to prevent the
smaller parts of the mechanism from being broken or strained, when the wholo
power of the engino is brought suddenly to act upon them, in order to move
round the great weight of the crano and scraper with its load; before the power
of the engine begins to act upon this heavy weight it has to overcome the
friction of the band b, b, on the pulley 27; this band being tightened by the
screw nuts just sufficiently to allow it to slip round, until the inertia is so far
overcome as to cause the band to turn the pulley steadily, and therefore the
power is brought gradually to bear upon the chain pulloy 23. The friction
pulley and break 26 is employed to stop the movement the cranó will gain
by its own momentum after the turning power is thrown out of gear. The
turning-round motion above described, and also the motion for moving the

page_text: machine along the temporary railway, is actuated in the following manner:-
29, in Sheets I., II., and III., and also in Division 1 in Sheet IV., is the fly
wheel of a steam engine (not shewn in the Drawing); 30 is the crank, by which
motive power is communicated from the engine to the shaft 31. Rotary motion
is communicated to the spur wheel o on the axle or shaft of the main drum by
the pinion 32 on the crank shaft, and the mechanism for effecting the. turning-
round motion is actuated by the bevel pinion 33 on the same shaft, which
pinion gears into a similar one 34 at the end of the hollow shaft 35, see
Sheet 111. This shaft and pinion are shown detached and in detail in Division 5
of the Sheet IV. On the hollow shaft 35 are also mounted two small bevel
pinions 36 and 37, either of which may be brought into gear with the large
bevel wheel 38, as required by circumstances. Inside the hollow shaft 85 is a
sliding shaft 39, to which the small bevel pinions 36 and 37 are connected by
means of pins or catches which pass through slots in the hollow shaft: there-
fore, by moving this sliding shaft to and fro in the hollow shaft, the pinion 36
may be thrown out of gear with the bevel wheel wheel 38, and the other 87
thrown in gear, or vice versa. This part of the machine is worked by means of
the short lever 40, which is mounted on the shaft 41, the upper end thereof being
connected to the end of the sliding shaft 39. At the other end of the shaft 41,
and on the other side of the machine, is a hand lever 42, by which the shaft 41
and the lever 40 are worked, as seen in Sheet I. At the back of the large bevel
wheel 38, and on the same shaft, is mounted a cog wheel 43, sce plan view, Sheet
III., and Division 9, Sheet IV. This shaft is made hollow throughout part of
its length, and has also another cog wheel 44 mounted on it. This wheel is
5 connected to a sliding shaft inside in a similar manner to the bevel pinions 36
and 37, and may accordingly be thrown out of gear when required. This latter
wheel gears into the pinion 25 on the shaft of the chain pulley 23, and,
therefore, when motion is communicated to it from the steam engine through
the wheelwork just described, it causes the crane jib and horse-shoe pulley to
O swing round either to the right or to the left, according to which of the bevel
pinions 36 or 37 is in gear with the large bevel wheel 38; and when the
shovel or scraper has deposited its load, the hore-shoe pulley and crane with
the scraper at its end are swung back into their original position by merely
reversing the gearing of the two bevel pinions 36 and 87.
5
I now proceed to describe circumstantially all the evolutions the machine
has to go through in cutting away, turning round, and emptying the shovel of
its load at the proper place. When commencing operation, the shovel or
.scraper stands in nearly a vertical position, with the steel points or teeth
towards the ground, and is forced into it by the weight of the scraper itself;

page_text: then by communicating motion to the large spur wheel o by means of the
pinion 32 on the crank shaft, the main drum is made to rotate and coil
around its periphery the chain tackle j, j, which, through the intervention of
the indented chain pulley and shaft and pinions p, q, r, and s, actuates the
mechanism on the diagonal arms c, e, and when the friction pulley v and
break t, before described, is kept at proper tension by the attendant on the
platform pressing on the hand lever 7, the spiral grooved pulley 14 round
which the chain 15 passes is made to revolve and force forward the shovel or
scraper into the ground. When the shovel or scraper is forced far enough
into the ground, the break on the pulley v may be relaxed, and the break on
the pulley 8 tightened by pressing on the hand lever 10. At the same time
that this is going forward the shovel or scraper is being raised or lifted up by the
chain tackle j,j, at the end of the crane, and thus the shovel or scraper has
a double motion, a thrusting-forward motion from the arms 16. while tension
is on the pulley e, and a lifting motion by the chain tackle j.j. When the
shovel has obtained its proper altitude and become filled, these motions are
stopped, and the actuating parts thrown out of gear, but the shovel is kept
suspended and prevented from running back by means of tho break and pulley
8; then an attendant who stands on a platform at the hinder part of the
machine puts the turning-round motion in gear by pressing forward the hand
lever 49 and bringing one of the small pinions 36 or 37 into gear with the
large bevel wheel 38. But if the attendant behind is inattentive, and does
not do so, then the man in front can throw this part of the machino in or out
of gear by means of the long rod 47, one end of which is furnished with a
horizontal lever having two handles 48, see plan and side views, and the other
end is connected to the upper part of an upright rod 40%, which is a
continuation of the lever 40. When the crane and scraper have been swung
round and stopped over the place for deposit, the scraper is emptied by the
attendant in front of the crane post pulling back the hand lever 45 at the end
of the rod 46, see the detached view of the scraper arms, Figs. 5 and 6, 3
Sheet V. The other end of this rod is connected by means of a jointed rud
or chain to the pin or bolt i, Fig. 8, Sheet V., which holds in the bottom
or end of the scraper by means of a catch; and when this bolt or pin is
withdrawn, the bottom end of the scraper (which is hung upon hinges at h)
falls, and allows the contents thereof to be deposited in their proper position, a
at which time the teeth g of the scraper will be in a position pointing upwards.
When the scraper has discharged its load it must be brought back into
its original position, so as to be ready to commence operations again. This
is elected by loosening or relaxing the friction breaks of the mechanism

page_text: in connection with the arms 16, 16, and putting the wheelwork out of
gear by means of the hand lever 7. At the same time, the man behindl
must press forward the hand lever 62, and thereby throw the coupling
or clutch 54 out of gear with the spur wheel o, which then turns loosely
on the shaft, thus releasing the main drum; he must also press down the
foot lever 70, which, by turning the tumbling lever 51 will raise the clicks,
palls, or catches 53 from the ratchet wheel 52, and at the same time tighten
the band 50 round the friction pulley 49, for the purpose of preventing the
main drum from revolving too rapidly. The shovel or scraper will then
descend from its elevated position in a diagonal direction to the ground,
ready for a second operation. The bottom or end of the scraper closes in
its descent by its own gravity, as the points or teeth of the scraper will
then point towards the ground. While the scraper is descending, the
turning-round motion is reversed, and the crane and horse-shoe pulley will
be brought back into their original position. When it is required to move
the machine forward on the temporary railway, the cog wheel 44 at the hinder
part of the machine must be thrown out of gear with the pinion 25, which
forms a part of the turning-round motion, and an intermediato wheel 75, seen
by dots in Slicets II. and III., is brought into gear with the toothed wheel 43
and large cog wheel 76, which is mounted on the axle of one of the running
wheels. The whole machine is steadied and strengthened by bracings of
iron or other materials, and is also firmly secured to the ground by lateral
bracings 77, 77, which extend from each side of the machine, and are firnily
bolted or otherwise fastened to sleepers placed there.for that purpose.
The second part of the Invention, (viz',) the machine for dredging
and deepening rivers, harbours, and other under-water works, is shewn in
Sheet VI. of the accompanying Drawings; Fig. 1 being a longitudinal section
of the apparatus and the vessel containing the same; and Fig. 2, a plan view.
The machinery is actuated by a steam engine, whose boiler is shown at A. The
boiler is provided with a steam chamber B, for the purpose of preventing the
water from the boiler priming or passing over into the cylinders C, C, which
are supplied with steam by the pipes D, D. These pipes are furnished with a
throttle valve E. The cross heads of the engine are shown at F, F, the con-
necting rods at G, G, and the cranks at I, II; each cylinder has an excentric
and rod I. The crank shaft is mounted in bearings J, and is furnished with a
fly wheel K. On the crank shaft is mounted a pinion L, which actuates the
main drum P by gearing into a large spur wheel M on the shaft of the main
drum This shaft is provided with a ratchet wheel O, which is furnished with
suitable palls, clicks, or catches, as in the land machine. The main drum N

page_text: is also provided with a friction pulley and band P, which is connected with
rocking lever Q. This rocking lever has at its other end a small lever R, fo
the purpose of raising the palls, clicks, or catches from the teeth of the ratchet
wheel in a similar manner to that described in reference to the land machine
The wheelwork for turning the crane round is situated at the end of the crank
shaft, and consists of three bevel wheels T, T, and T. The wheel T at the
end of the crank shaft is made fast thereto, but the other two revolve
loosely on the long longitudinal shaft U, on which they are mounted, except
when acted upon by the clutch V. This clutch is moved along the shaft U
and made to gear with either of the two bevel wheels, by means of the rods
S, S, which proceed to the back of the engine, and are terminated by the hand
lever S. On the end of the longitudinal shaft U nearest the bow of the boat
is mounted a cast-iron pulley W, around which a belt X passes from thence
to another similar pulley Y. Resting on the centre of this belt X is a friction
roller or pulley Z, which may be raised or lowered at pleasure to increase
the tension of the band X on the pullics W and Y. On the same shaft as tho
pulley Y is a bevel pinion a, see Fig. 1, that geers into the teeth of the large
bevel wheel b, b, mounted on the lower end of the hollow mast c, to the upper
part of which the crane d is connected by a strong metal socket c. The pecu-
liar construction of the mast and the various parts in connection with it are
shewn detached and upon a larger scale in Sheet VII. Fig. 3 is a section taken
through the centre of the hollow mast c and bevel wheel b; Fig. 4 is a per-
pective view of the upper part of the hollow mast; and Fig. 5 is n similar view
of another portion thereof. From these Figures it will be seen that the hollow
mast consists of several parts, (viz',) first, the inside hollow mast c, c, having at
its upper end the metal socket e for receiving the end of the crane; second, an
outside hollow mast ff, that is firmly secured to the deck of the vessel. Tho
inside hollow mast is supported upon the angular edges of the upper part of
the outside hollow mast ff, and upon which it turns freely in a horizontal
direction, as is clearly seen in Fig. 3. The lower part of the outer hollow mast
ff is surrounded with a strong moveable circular framing or carriage g, g,
furnished with cight anti-friction rollers h, h, (see Figures 1 and 2, Sheet VI.,
aud Fig. 3, Sheet VII.,) which revolve upon a circular iron way firmly fixed to
the deck of the vessel. This movable carriage or framing is formed by the
circular collar g', g', (see Figures 3 and 5, Sheet VII,) which collar is furnished
with cars or sockets h', h', for the purpose of receiving the ends of the radial
arms,, which connect the circular moveable framing 7, 9, to its contro
collar y', g'. The space between this collar and the outside hollow mast f. f, is
furnished with a number of vertical anti-friction rollers j'.j.j.j, to make it turn

page_text: ore easily. The outer end of the crane d is steadied and strengthened by
de braces i, i, which pass through or are fastened in ears j, j, at the upper
art of the hollow mast c, c, (see Fig. 4, Sheet VII.,) and are connected at their
ower ends to the movable framing or carriago g, 9, (see Figures 1 and 2,
Sheet VI.) Tho weight of the shovel or scraper at the end of the same is
counterbalanced by the box k, which is placed on the back part of the moveable
arriage g, and is filled with iron or lead, thus taking the strain in some
measure off the mast. This balance box may, however, be dispensed with by
employing a cast-iron rail with an overhanging flange, which must be firmly
secured to the deck, and the conical rollers h of the movable carriage may be
arranged so as to bear against the under side of the said overhanging flange,
and by this means take a portion of the strain off the mast, as before. The
outer end of the crane d, and side braces i, i, aro bolted firmly together, and
supported by the angular centre braco l, l, that is furnished at its lower end with
a double cone roller m, which rolls on the rail n, extending entirely round the
semicircular cud of the boat. The angular brace 1, 1, is further strengthened by
means of upright and oblique stays o, o, and one of the arms of the carriago
9. g, which extends out of the front of the boat for that purpose. The shovel
or scraper p, p, is connected to the end of the long arms 1, 2, by the braces 1.
The shovel is suspended from the end of the crane by chain tackle s, s, in a
similar manner to that described in reference to the land machine. The chain s, s,
passes along the upper side of the crane, over a pulley t at the top of the mast,
then downwards through the centre of the mast, and round a pulley w, mounted
in bearings that turn horizontally on a centre, so as to allow the groove of the
pulley u to accommodate itself to the line the chain takes in being wound on
to the main drum. On the shaft of the pulley t, at the top of the mast, is
mounted a bevel pinion gearing into a similar one on the end of the diagonal
shaft w; at the lower ond of this shaft is another bevel pinion working in a
similar one on the horizontal shaft a, which works the thrusting motion of the
shovel or scraper. The friction clutch or pulley y on the end of the shaft
(see plan view) is the same in principle as that used in the other machine,
but somewhat different in construction, as instead of being cast into the back
of the bevel pinion it is connected to the hollow shaft of the pinion and placed
inside the framing. The other arrangements of the clutch are precisely the
5 same as in the land machine, being acted upon by a sliding rod running
is the holding-fast
through the hollow shaft and worked by hand levers.
break, commanded by the right hand of the attendant, so that by means of the
two handles the workman can with ease send down the shovel with any required
force, according to the nature of the material which they are working, holding

page_text: the shovel or letting it go at pleasure, the whole being at the command of th
breakman. The shaft gives motion to the pinion a' at its end; this piuio
gears into a wheel & on the next shaft, on which same shaft are two pinions c
which gear into racks on the under side of the scraper arms q, q, in the manne
shown at Fig. 6, Sheet VIT. On the shaft of the wheel and pinion c¹ is
triangular metal frame d', which carries a roller e' at each of its upper corner
(see Fig. 1, and shewn by dots in Fig. 6, Sheet VII.), for the purpose of keepin
the racks on the under side of the
scraper arms 9 in gear with the pinions c
When the shovel or scraper has received its load from the bottom of the river
and has been raised above the top of the water to the proper height for
depositing it in a barge or vessel to be conveyed away, the crane and scrape
must be turned round until the latter arrives in a position immediately above
the barge. The machinery for effecting this object is different from that
described in the land machine, the largo horse-shoe pulley and chain, toget er
with the change pulley, cog wheels, and hollow shafts of the reversing or
turning-round motion, is entirely done away with, and in place thereof the
large bevel wheel b, the pinion a, the long longitudinal shaft U, and the bevel
pinion T, T, and T, with the clutch V, are employed; by this menus the
turning-round motion is much simplified. The manner of communicating
rotary motion to the shaft U, either to the right or left for the turning-round
motion, or to actuate the propeller at the stern, has been before explained, and
rotary motion having been communicated to the pinion a on the axle of the
pulley Y, from the pulley W, by means of the band X, this pinion a, by
gearing into the large bevel wheel b, will cause the latter to turn slowly round
on its axis, and as the wheel is fastened to the lower end of the hollow mast,
as seen at Fig. 3 in Sheet VII., this mast, together with the crane & and
moveable carriage 9, 9, may be made to move round in either direction
at the discretion of the attendant in front. The turning-round motion of
the crane is regulated and arrested by means of the friction pulley and band
d', which is connected to the boss or axle of the large bevel wheel b, and is
worked by the engine-man by means of the long rod and hand lover c', e³, e¹,
or it may be controlled by the man in front by means of a foot lever or treadle.
In Figures 6, 7, 8, and 9, in Sheet VII., another method is shewn of effecting
the thrusting-out motion for working the scraper, which differs in some degreo
from either of the plans above described. In this instance the motive power
is derived from the lower part of the mast or crane post c, c. The pinion a is
supposed to have received rotary motion from the main drum or otherwise,
and it gears into and drives a bevel wheel b, connected to a collar c', that
revolves loosely round the crane post. This collar is also furnished with

page_text: another bevel wheel or rack d, that drives the pinion 7 at the lower end
of the diagonal shaft r. This shaft revolves in bearings f, f, fixed to the
diagonal stay or bracing e, e, the lower end of which rests in sockets g,g,
formed on the collar h, h. At the upper end of the shaft r is mounted
another pinion s, that gears into a similar pinion u on the hollow shaft t,.
which being of a peculiar construction is shewn detached and in section,
together with some of the parts connected therewith, at Fig. 9. At the
other end of the hollow shaft is placed a conical cup v, and through this
shaft passes a wrought-iron hollow shaft w, having at its right-hand end a
conical block x, that slides along the shaft, and is connected thereto by a
The block at the
pin 1, which passes through a slot 2 in the shaft w.
end of the shaft w fits into the conical cup v. The shaft w is also provided
with a friction pulley and break y, and at its outer end is mounted the cog
wheel a', which gears into another wheel b', and on the same shaft are
mounted two pinions c', c', that work in racks d', on the under side of the:
scraper arms j. j. Through the centre of the hollow shaft w passes the sliding:
rod k, which is connected to the conical block a by means of the pin 1 that-
passes through the slot 2 in the hollow shaft w, and by means of the hori-
zontal lever 3 at the end of the rod k, the conical block may be slidden, as
above mentioned, along the hollow shaft into the conical cup, where it
binds tightly, and thereby causes the shaft w to revolve, when rotary motion.
is given to the conical cup by the gearing of the bevel pinions into the
pinion u. On the same shaft as the wheel b' is mounted a toothed wheel d
that gears into another toothed wheel e' above. This wheel e' is mounted
on a shaft which revolves in bearings at the end of the strap pieces f'.
On the same shaft as the toothel wheel e¹ are mounted two rollers g', g',
which bear upon the upper sides of the scraper arms j, j, and keep the
racks on the under side thereof in gear with the pinions c', c', thereby forming
a new thrusting motion. Sometimes, instead of using only one pair of
rollers g', y', (as seen in Figures 6 and 7, Sheet VII.,) the cog wheels d² and e¹
are suppressed, and two pair of rollers employed in their place. These rollers
are then mounted in pairs at the two outer corners of a triangular frame (as
seen by dots at f and 9, 9, in Fig. 6, and also at d', e', e', in Figures 1 and 2,
Sheet VI)
Ilaving now described this Invention as applied to the purpose of excava
ting and removing earthy matters, both on land and in the water, it must be
evident that there are many parts in the one machine which may be equally.
applied to the other; for instance, instead of employing the large horse-shoe
pulley and chain gearing, together with the complicated turning-round motion

page_text: at the back part of the land machine, this may be entirely done away with,
and the large bevil wheel b, pinion a, and bevil pinious T, T', and T, of the
under-water machine substituted in its place, or instead of the thrusting
forward motion of the scraper being actuated by the pulley at the top of the
crane post, it may be worked from below, and the whole arrangement of tho
wheelwork on the diagonal arms modified and changed (as shewn at Figures 6
and 7 of Sheet VII.) Many other alterations may also be made in the mecha-
nical arrangements, which I have not thought it necessary to mention.
In conclusion, having now particularly described all the parts of this Inven-
tion of machinery for excavating and removing soil and other earthy matters,
which machinery I believe to be entirely new both in construction and
arrangement as applied to those purpose, I desire it to be understood, that
I do not intend to confine myself strictly to the forms or positions of all the
parts as exhibited in the Drawings, as they may perhaps be varied without
leparting from the general features herein set forth; but that which I do
claim under the above in part recited Letters Patent is, such constructions and
arrangements of parts as will effect the objects of digging, taking up, and
removing earthy matters in the way described, viz', by means of a pendulous
scoop attached to a crane or elevated beam capable of turning horizontally,
such scoop and its appendages being worked in the manner above stated by
chains and toothed gear actuated by a steam engine or other first mover, the
whole of the machinery being mounted upon a moveable carriage or stationary
platform, or in a vessel floated upon the water.
In witness whereof, I, the said John Duncan, have hereunto set my
hand and seal, this Second day of April, in the year of our Lord One
thousand eight hundred and forty-two
JN (L.B.) DUNCAN.
AND BE IT REMEMBERED, that on the Second day of August, in
the
year above mentioned, the aforesaid John Duncan came before our Lady
the Queen in Her Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained, in form above written. And also
the Specification aforesaid was stamped according to the tenor of the Statuto
in that case made and provided.