Improvements in and relating to Dredging Apparatus.
Year: 1899

page_text: Date of Application; 2nd Mar.. 1899 -Accepted, 15th Apr., 1899
Improvements in and relating to Dredging Apparatus.
4.1.
1
329!!
I, WILLIAM HENRY O'HARA, of No. 5, Broadway, in the City of New York,
County of New York, and State of New York, United States of America, Lawyer,
do hereby declare the nature of invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:--
-
1
My invention relates to certain new and useful improvements in dredging
apparatus, and has the following objects in view:
First, the adaptation of a plurality of jibs each carrying an inclined track
supporting trolley carriages, and a series of digging clams suspended from said
carriages in each instance.
Second, to obtain the maximum efficiency of the digging clams by discharging
the spoil into a stationary inclined chute on the dredge, the point of such
discharge being at a minimum distance from the place of dredging.
Third, to enable the digging clams to operate throughout a considerable area
without moving the boat itself.
Fourth, to discharge the spoil from a plurality of digging clams into a
stationary inclined chute without the use of auxiliary chutes.
Fifth, to discharge the spoil from the digging clams always at the same
elevation above the chute.
With these ends in view my invention consists in certain details of construction
and combination of parts such as will be hereinafter fully set forth and then
specifically be designated by the claims.
In order that those skilled in the art to which my invention appertains may
more fully understand the same I will proceed to describe its construction and
operation, reference being had to the accompanying drawings which form a
part of this application and in, which
Figure 1 is a side elevation of my improved apparatus.
Figure 2 a section at the line, r, of Figure 1, looking in the direction of
the arrow.
Figure a broken sectional elevation illustrating a modification wherein the
digging clams are confined and guided within a cage attached to the hull of
the boat.
Figure 4 a view
a view similar to Figure 2, but illustrating a modified construction
whereby the digging clams discharge the spoil at the same elevation above the
inclined chute, and
"
Figure 5 is a broken plan view, illustrating a modification wherein the jibs are
arranged to, swing after the manner of a crane.
SAL.<.
12240

page_text: Similar numbers of reference denote like parts in the several figures of the
drawing.
In all the views of the drawing I have shown the same elevation of the
digging clams for the purposes of a clearer understading of my invention, and I
might further add that the twisting of the cables as the clams are elevated or
lowered causes various elevations to be presented from the same point of view,
and I merely mention this feature in order that it will be clearly understood
that there is no defect in the drawing.
Heretofore dredging apparatus has been provided in which a plurality of
digging clams were carried and operated at one end of the boat in vertical guide
cages and the spoil has been discharged into a movable auxiliary chute prior
to the delivery of such spoil into a conveyor which delivered the spoil into a
scow or any proper receptacle, but great difficulties have attended the use of this
movable chute in that it had to be arranged to swing into and out of position
to receive the spoil and to make way for the hoisting and lowering movements
of the digging clams, and the present invention aims to do away entirely with
this auxiliary chute and to utilize a jib or bow string girder construction carrying
inclined tracks and trolley carriages as the means whereby the digging clams
may be supported and conveyed into proper dumping position above the inclined
chute.
But a serious drawback would exist in the use of such jibs or girders except
in the instance of a single digging clam, for the reason that a gang of such jibs
or girders being of the same hight the spoil from the various clams would be
discharged into the inclined chute at different elevations, the result being that
no chute or dredging boat could withstand the impact of the spoils.
In my present improvement I have succeeded in utilizing a plurality of jibs or
bow string girders in connection with but a single chute, and the spoils are
discharged always at the same elevation above this chute, all of which will be
readily understood from the following description.
I have heretofore used the two terms "jib" and "bow string girder," since
they both answer fairly to the construction which I employ, namely, a curved
arch-like structure secured at the upper end to a vertical support or buttress such
structure being subtended by what might be termed a strut or cord.
But in order to have a uniform term, I shall hereafter refer to this arch
construction as a "jib" while the lower braces I will call struts," but it must
be understood that the matter of mere terms is immaterial and that the upper
structure may be a true arch, a true incline, or might extend in a parabolic curve.
1 is the hull of the boat, and 2 is a vertical frame or buttress properly secured
and braced in any ordinary manner upon the boat and preferably at the bow
thereof.
3 are bow jibs whose upper extremities are secured to the frame, while their
lower extremities are connected, with said frame by struts 4. 5 are tracks sup-
ported by and depending from said jibs and extending throughout the length
of the same, said tracks being in different horizontal planes for the purpose
presently to be explained.
6 are trolley carriages having trolley wheels 7 which rest and are adapted to
travel upon these several tracks, and 8, 9, are pulleys journaled within the
lower portion of each trolley carriage.
The digging clams which I employ are of ordinary construction and operation,
and I will not herein enter into any description of the same, but will merely
designate them by the numeral 10.
The head from which the clams are suspended is designated by the numeral 11
and to this head the cable 12 is secured. 13 is the cable by means of which the
opening and closing of the clams is controlled, and these cables 12, 13, are
passed respectively over the pulleys 8, 9, and thence to the usual winding drums
(not shown which are controlled and operated by any approved. motive power.
14 is an inclined chute supported in position at the forward end of the boat

page_text: immediately below the jibs at or about the point where they adjoin the frame 2.
The tracks 5 are in different horizontal planes as herein before set forth, but
these planes are in a single inclined plane which is parallel with the plane of the
chute 14 so that it will be readily understood that when the cables have been
operated to lift the clams into positions immediately above the chute said clams
will all be at the same distance from said.chute so that the spoils will, in all
instances, be deposited with substantially the same minimum of impact against
the chute.
In lowering the clams the cables are both slackened so that the clams will
touch the soil to be dredged in open condition; the closing of the clams and
the consequent digging function thereof are accomplished by the winding up
or pulling of the cable 13 in the usual manner and thereafter the hoisting of
the clams is effected by the continued winding of said cable until the head 11
strikes the trolley carriage 6, and then the continued winding of such cable will
cause said trolley carriage to travel upward along its track until the clams have
been elevated and held suspended immediately above the chute; then the
slackening of said cable 13 will effect the opening of the clams and the spoil will
be deposited therefrom immediately upon the chute; whence such spoils are
conveyed to any suitable receptacle.
It will be readily understood that during the initial hoisting of the clams
and until the head 11 strikes the trolley carriage 6 there will be no upward
movement of said, trolley carriage but as soon as said head and trolley carriage
come in contact they will practically become one and the same thing and the
further winding of the cable 13 will effect the elevation of such trolley carriage
and head
It will be noted that the struts 4 for the greater part of their distance overhang
the bow of the boat so that it will be clear that, by providing suitable stops for
the trolley carriages-such as cross pins inserted through the jibs, or stop chain's
whose ends are connected respectively to the trolley carriages and the frame,
or stop blocks sliding on the tracks and controlled by ropes the trolley carriages
may be arrested in their downward sliding movements in various vertical planes,
so that the lowering, digging, and hoisting of the clams may be accomplished
nearer to or further away from the bow of the boat as may be desired.
By arresting and controlling the limits of the downward movements of these
trolley carriages in the manner above described the dredging may be effected
for a considerable distance in advance of the boat without moving the latter,
while, in all instances, the spoil is deposited in the same vertical plane upon a
single inclined chute and from hights always at the same distance from said
chute.
If desired, the clams may operate and be guided within any suitable cage 15
(as shown at Figure 3) secured to the boat, and while such construction may be
advisable, while dredging in a heavy sea, nevertheless it is rather a rare precaution
than a necessity. In case such cage construction should be used the inner
portion of the cage would of course be open so as to permit the hoisting of the
clams along the tracks of the jibs to the point at which the spoils are to be
dumped.
In some instances, it may be found advisable to arrange the jibs so that they
will swing after the manner of cranes, and I have therefore shown at Figure 5
a construction wherein the jibs are pivoted at 16 to the frame at the top thereof.
In this construction shown at Figure 5. I have illustrated two ways in which this
pivoting may be accomplished, the construction at the right of the figure showing
struts 17 pivoted to the frame and to a cross piece 18 which latter is pivoted at
its center to the lower end of the jib while at the left of this figure I have
shown struts 19 rigidly secured at their ends to cross pieces 20, 21, the inner
end of which latter is pivoted to the frame 2 in a direct line with the pivotal
point 16.
In utilizing these constructions shown at Figure 5 the jibs are swung around

page_text: by any suitable means until the vertical plane is reached in which the dredging
is to be effected, and the clams are then hoisted and carried into dumping position
in the manner herein before set forth with respect to the construction shown at
Figure 1, and this hoisting of the clams may be accomplished without swinging
back the jibs.
I do not therefore wish to be limited to the stationary jibs since the gist of
my invention resides chiefly in the broad idea of providing a plurality of jibs
and so equipping them that when the clams are hoisted and carried into dumping
position they will all be at the same hight above the chute.
This proper delivery of the clams prior to dumping with respect to the inclined
chute may be brought about by gradations in the tracks 5 as shown at Figures 1
and 2, or the tracks may all be in the same horizontal plane and the proper
elevations in the digging clams may be effected by making the heads 11 of
different lengths as shown at Figure 4, but I prefer the former construction
since it is more compact, has less weight, will balance on the dredging ground
better, and is probably stronger.
In the operation of my improvement the clams are lowered into digging
position by slackening the cables 12, 13, and the clams are closed and elevated
into dumping position by winding up these cables care always being taken to
keep the cable 13 taut and under strain so that the load is mainly hoisted
thereby.
The spoils pass down the chute into any suitable scow, or they may be delivered
into a pump such as usually employed in the reclaiming of land.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that
I do not wish to be understood as laying any claim in a broad sense to
a jib or bow string girder construction carrying an inclined track which supports
a trolley carriage, but what I claim is:-
'
a
1 In a dredging apparatus, the combination of a plurality of bow jibs carrying
inclined tracks, trolley carriages adapted to travel on said tracks,
series of independent digging clams suspended from said carriages, means for
operating said clams, the single inclined chute supported by the dredging boat,
and means for effecting the delivery of said clams in dumping position at a
uniform distance from said chute, substantially as set forth.
2-In a dredging apparatus, the combination of a plurality of bow jibs secured
to and overhanging the dredging boat and provided with tracks, the inclined
chute supported at the bow of said boat immediately beneath the upper portions
of said tracks, the trolley carriages provided with trolley wheels adapted to
travel on said tracks, the two pulleys journaled in the lower portion of each
trolley carriage, the digging clams, the cables extending from said clams over
said pulleys, suitable mechanism for hoisting and lowering said cables, and means
whereby said clams are held in suspension over said chute at a uniform distance
therefrom, substantially as set forth.
3-In a dredging apparatus the combination of a plurality of jibs secured side
by side to and overhanging the dredging boat and provided with tracks, the
inclined chute supported at the bow of the boat immediately beneath the upper
portions of said tracks, carriages adapted to travel along said tracks, the digging
clams suspended from said carriages, cables attached to said clams, and means
whereby the clams are delivered in dumping position immediately above said
chute and at the same distance therefrom, substantially as set forth.
4 In a dredging apparatus, the combination of a plurality of jibs arranged
side by side and secured to and overhanging the dredging boat and provided with
tracks in different horizontal planes, the chute supported at the bow of the
boat immediately beneath the upper portions of said tracks and inclined to a
plane parallel with the inclined plane passed through said tracks, the carriages
provided with trolleys adapted to travel on said tracks and having journaled

page_text: in their lower portions pulleys, the digging clams, and the cables extending
from said clams over said pulleys to suitable hoisting and lowering mechanism,
substantially as set forth.
Dated this onl
1000
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.