IMPROVEMENTS IN DREDGING MACHINERY
Year: 1882

page_text: LETTERS PATENT to Henry Christian Lobnitz, of Renfrew, in the County of
Renfrew, North Britain for an Invention of IMPROVEMENTS IN DREDGING
MACHINERY in part communicated to him from abroad by H. Hersent,
PROVISIONAL SPECIFICATION left by the said Henry Christian Lobnitz
at the Office of the Commissioners of Patents on the 18th August 1882.
HENRY CHRISTIAN LÖBNITZ, of Renfrew, in the County of Renfrew, North
Britain, "IMPROVEMENTS IN DREDGING MACHINERY," which Invention has in part
been communicated to me from abroad by H. Hersent, residing at Paris, France,
and is in part any own Invention.
This Invention has for its object to improve the construction and arrangement
of dredging machinery; and the improvements are applicable to dredging
machines of the well known kind in which a boat or floating vessel is provided
with one or two endless chains of buckets, each chain being carried on a ladder
capable of being set at different inclinations so that its bottom end may reach down
to different depths.
One of the present improvements consists in arranging one or more large guide
wheels under the descending part of each endless chain of buckets, this having the
effect of producing a more complete inversion of the buckets as they pass round
the upper pulleys or tumblers of the ladder and causing them to empty their
contents in a better and more complete manner. The arrangement also allows of
the ladder being adjusted at a steeper inclination so that its bottom end may
reach a greater depth than in ordinary machines without the descending buckets
touching the discharge trough. Each guide roller may conveniently consist of a
pair of disks or wheels braced together by diagonal ties, the buckets bearing on
the edges of the disks when passing partly round the guide wheel.
Instead of the usual heavy and expensive shafting and bevil gearing for driving
the upper pulleys of the ladder, endless pitch chains are by this Invention
employed to transmit the power from the engines to the said pulleys.

page_text: A third improvement relates to the mooring of the dredger boat and to the
shafting thereof to a certain extent without disturbing the moorings. Four
mooring chains are employed which enter the boat by four swivelling tubes fitted
in fixed tubes, there being a pair at each end of the boat and one of each pair
being on each side. Each swivelling tube has a pulley at its bottom end for
guiding the mooring chain up the centre of the tube; and over the top of the tube
there is a pulley for leading the chain from the centre of the tube horizontally to
the winding machinery. The winding machinery comprises for each mooring chain
two grooved barrels, and the chain is passed or looped round the two barrels a
sufficient number of times to be held by friction whilst the chain leaves the barrels
at the other end, and an unlimited length of chain can be hauled over by the
barrels without accumulating on them.
A fourth improvement is designed to allow of the dredger working in a narrow
channel where there is not room for the mud barges to be placed at the sides, and
it is applicable to dredgers having either one or two chains or buckets. A duct or
trough is provided to receive the matters brought up by the dredging buckets
which operate at one end of the vessel, and from this trough the matters are
conveyed to the other end of the vessel where the mud barges are stationed by an
endless couloir or jointed channel which is in a nearly horizontal position. This
couloir consists of short sections each made with a bottom and sides, and the
sections are jointed together to form a chain with parts of the bottom and sides of
each overlapping or projecting into the next one. The couloir is mounted and
worked like the endless chain of dredging buckets; and it and its supports may
be made movable so that it can be adjusted to convey the dredged matters in any
required direction from the trough which first receives them from the dredging
buckets. With this arrangement the couloir may when desired be adjusted so as
to deliver the dredged matters on the banks of the canal or channel which is being
dredged.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Christian Lobnitz in the Great Seal Patent Office on the
16th February 1883.
"
HENRY CHRISTIAN LÖBNITZ, of Renfrew, in the County of Renfrew, North
Britain "IMPROVEMENTS IN DREDGING MACHINERY Partly communicated to
me from abroad by H. Hersent, residing at Paris, France, and partly my own
Invention.
The said Invention has for its object to improve the construction and arrange-
ment of dredging machinery; and the improvements are applicable to dredging
machines of the well known kind in which a boat or floating vessel is provided
with one or two endless chains of buckets, each chain being carried on a ladder
capable of being set at different inclinations so that its bottom end may reach down
to different depths.
One of our present improvements consists in arranging one or more large guide
wheels under the descending part of each endless chain of buckets, this having the
effect of producing a more complete inversion of the buckets as they pass round
the upper pulleys or tumblers of the ladder and causing them to empty their
contents in a better and more complete manner. The arrangement also allows of
the ladder being adjusted at a steeper inclination so that its bottom end may reach
to a greater depth then in ordinary machines without the descending buckets
touching the discharge trough.
A second improvement consists in using endless pitch chains or wire or other
ropes for driving the upper pulleys of the ladder.
A third improvement relates to the mooring of the dredger boat and to the
shifting thereof to a certain extent without disturbing the moorings. Four
mooring chains are employed which enter the boat by four swivelling tubes fitted
in fixed vertical tubes, there being a pair at each end and one of each pair being
on each side. The winding machinery comprises for each mooring chain two
grooved barrels, and the chain is passed or looped round the two barrels a sufficient
number of times to be held by friction whilst the chain leaves the barrels at the
other end, and an unlimited length of chain can be hauled over by the barrels
without accumulating on them.
A fourth improvement is designed to allow of the dredger working in a narrow
channel where there is not room for the mud barges to be placed at the sides, and
it is applicable to dredgers having one or two chains of buckets. Provision is
made for conveying the matters brought up by the dredging buckets along to the
further end of the vessel by means of a couloir or endless channel which consists
of short sections made with bottoms and sides and jointed together. This couloir
is mounted and worked like the endless chain of dredging buckets; and it and its
supports may be made movable so that it can be adjusted to convey the dredged
matters in any required direction from the trough which first receives them from
the dredging buckets. With this arrangement the couloir may when desired be
adjusted so as to deliver the dredged matters on the banks of the canal or channel
which is being dredged.
And in order that our said Invention and the manner of performing the same
may be properly understood I hereunto append five sheets of explanatory drawings
to be hereinafter referred to and representing examples of dredging machinery
embodying our improvements.
Figure 1, on sheet 1, of the accompanying drawings is a diagram showing in
side elevation parts of the first, second and fourth improvements. Figures, 2, and 3,

page_text: on sheet, 2, are a side elevation and horizontal section showing on an enlarged
scale a construction of guide wheel which may be used in carrying out the first
improvement. Figures, 4, and 5, are an enlarged side elevation and a horizontal
section of the sprocket wheel and pitch chain used in carrying out the second
improvement, figure, 6, being another view of the pitch chain. The improved
mooring arrangements and machinery constituting the third improvement are
shown on sheets, 3, and 4, figure, 7, being a plan of the hauling or warping
machinery, and figure 8, a corresponding side elevation; whilst figure, 9, is a
vertical section showing the vertical tubes or wells for the passage of the mooring
chains down through the hull of the dredger; and figure, 10, is a plan showing the.
deck arrangement. Figure, 11, on sheet, 5, is a plan, partly corresponding to a
part of figure, 1, and showing a mode of carrying out the fourth improvement. In
these drawings the same reference numerals are used to mark the same or like
parts wherever they are repeated.
The dredger partly shown in figures 1, and 11, is of the kind having two ladders
and endless chains of buckets, one, 12, of these ladders with its chain, 13, of
.buckets, 14, being shown in figure, 1; in which figure is also shown the position
of the guide wheel, 15, employed according to our first improvement to cause the
descending part of the endless chain, 13, to pass nearer to the ladder than in
ordinary arrangements. A suitable construction of the guide wheel, 15, is shown
in figures, 2, and 3, also the manner in which each bucket bears on the rins of the
guide wheel when passing in contact with it. Each guide wheel consists of a pair
of wheels or rings connected to a centre by spokes and braced together by diagonal
and other ties, 16, 17. The bearings of the guide wheel, 15, are fitted upon
brackets or soles, 18, secured to the beams of the hull and are by preference
adjustable horizontally thereon or capable of being fixed in different positions to
, suit various circumstances. With the improved arrangement of guide wheel, 15,
the ladder, 12, can be set more nearly vertical than in ordinary arrangements,
whilst at the same time the buckets will be more completely inverted on passing
round the upper tumblers or pulleys, 19, and will more certainly empty their whole
contents into the trough or duct, 20. The guide wheel also relieves part of the
strain on the joint pins of the descending part of the chains, 13.
In carrying out the second improvement according to one modification, a large
sprocket or toothed wheel 21, shown in figures, 4 and 5, and indicated by a dotted
.circle in figure, 1, is in the case of each ladder, fixed on the axle or shaft of the
upper tumblers or pulleys, 19, and is geared by an endless pitch chain, 22, to a
similar but smaller wheel or pinion, 23, indicated by a dotted circle in figure, 1,
and which pinion is driven by the dredging engines. The pitch chain, 22, as
represented, is made up of plate links connected by transverse joint pins which
pins gear with the teeth of the wheels, 21, 23, the plate links being arranged in
two parallel series which pass on the sides of the sprocket teeth. Any other
suitable construction of pitch chain may be employed; or endless ropes of wire or
other suitable material may be substituted for the pitch chains, the wheels or
pulleys, 21, 23, being modified to correspond; and provision being made for
transmitting the required strain by employing a number of endless ropes on barrels
or multiple pulleys, or by increasing the size of the upper pulley, 21, or otherwise
modifying the relative proportions.
For the purpose of carrying out the third improvement there are constructed in
the hull of the dredger, and as shown in figures 9, and 10, four vertical tubes or
wells, 24; and these wells are formed with internal guides for frames, 25, which
can be lowered and raised in them. Each frame, 25, carries a vertical tube, 26,
fitted so that it can turn or swivel and partly supported by a footstep bearing in a
bracket, 27, projecting down from the frame, 25. At the lower end of the
swivelling tube, 26, there is formed a lateral enlargement, 28, within which there
is fitted a pulley for guiding the mooring chain from a horizontal or nearly
horizontal direction into the vertical direction and so that it may pass up the centre
of the swivelling tube, 26, and of the fixed well or tube, 24. At the top of each

page_text: well, 24, there is a guide pulley, 29, to change the direction of the mooring chain
from the vertical to the horizontal. An important advantage of the arrangement
consists in barges or vessels being able to pass over the mooring chains without
their being slackened to an inconvenient extent.
The winding machinery for one side or half of the dredger is shown in figures, 7,
and S, and comprises three separate pairs of grooved barrels for operating on
separate chains, and each pair being connected with the driving gearing by means
of separate engaging and disengaging clutches. One pair of the grooved barrels, 30,
is in a horizontal plane, and the other two pairs, 31, 32, are in vertical planes. In
the case of each pair of barrels (30 for example) the grooves of one barrel are
opposite to the ridges between the grooves of the other barrel and the chain is
looped round the two barrels so as to pass from the first groove of one barrel to the
first groove of the other barrel and then across to the second groove of the first
barrel, whence it passes to the second groove of the other barrel, next to the third
groove of the first barrel and so on. With the arrangement of gearing indicated
in figures, 7 and 8, both barrels, 30, turn in the same direction and the chains pass
horizontally from one to the other alternately above and below and without being
crossed. From the last groove in each case the chain may be led down a hawse
pipe into a locker or hold. Figure, 10, shows the general arrangement of the
mooring chains and winding gear in plan. The wells, 24, and swivelling tubes, 26,
are employed when the mooring chains are connected to mooring anchors or
fastenings under water, but when the chains are to be led to fastenings on the banks
of a canal or river or to other fastenings above water, they are not passed down the
wells, 24, but are led round or in contact with bits, 33.
In carrying out the fourth improvement in the manner shown in figures, 1, and
11, a duct or trough, 20, is provided to receive the dredged matters from the two
endless chains, 13, of buckets, this trough having two branches uniting in one
central discharge end, 35, which is immediately over one end of the endless
couloir, 36. This couloir, 36, consists of short sections each made with a bottom
and sides, and the sections are jointed together to form an endless chain and may
be constructed with small parts of the bottoms and sides of each overlapping or
projecting into the next one. The couloir, 36, is carried on rollers, 37, on a ladder
or beam, 38, and round pulleys at each end of the beam, the parts being arranged
and worked to a great extent like the endless chain of dredging buckets and parts
connected therewith. As shown in figure, 1, the couloir, 30, is placed with an
upward inclination from its inner end where it receives the dredged matters from
the trough, 20, so that it may deliver the matters from its outer end at such a
height, that the delivery ducts or shoots, 39, for leading the matters from it into
the mud boats, 40, may have sufficient downward inclination. As shown in
figure, 11, the delivery end of the dredger is made with sides which are inclined in
plan to facilitate the approach of the mud boats, 40.
Having thus particularly described the said Invention and the manner of
performing the same I have to state that I do not restrict myself to the precise
details herein described or delineated but that what I believe to be novel and
original and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is :-
1. The application of guide wheels to the descending side of endless chains of
dredging buckets substantially as and for the purposes hereinbefore described.
2. The application of endless pitch chains or endless ropes for driving the upper
pulleys of endless chains of dredging buckets substantially as herein before
described.
3. The arrangement for mooring a dredger boat wherein the mooring chains
are led down fixed wells or tubes and through swivelling tubes therein, such
swivelling tubes having guide pulleys at their lower ends, substantially as herein-
before described.
4. The arrangement of machinery for winding or hauling the mooring chains of

page_text: dredgers wherein each chain is led round two grooved barrels substantially as
and for the purposes hereinbefore described.
5. The arrangement of couloir in combination with one or more endless chains
of dredging buckets substantially as and for the purposes hereinbefore described.
In Witness whereof, I, the said Henry Christian Löbnitz have hereunto set
my hand and seal this fourteenth day of February, in the year of our Lord
One thousand eight hundred and eighty-three
Witness,
EDMUND HUNT
Patent Agent
Glasgow
HENRY LOBNITZ (L.S.)