Year: 1888

page_text: Date of Application, 2nd July, 1888
Specification Accepted, 16th Nov., 1888
I, ALPHONSE LANGUET of St. Nazaire, Loire Inferieure, France, Shipbroker and
Contractor for river and ocean navigation, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
My invention relates to a method of and an improved construction of vessel
propelled by steam for excavating the channels of water courses, for cutting through
banks at the mouth thereof, and for deepening the estuaries of rivers.
The construction of the said vessel is shewn on the accompanying drawings, in
which Fig. 1 shews a side elevation of the same Figs. 2 and 3 respectively longi-
tudinal and horizontal sections Fig. 4 a cross section to an enlarged scale, and Fig. 5
a part sectional plan to the same scale as Fig. 4. Figs. 6, 7 and 8 shew respectively
a front view a side view and a plan to a still larger scale of one of the winches for
working the flaps or blades beneath the boat. Figs. 9 and 10 shew an elevation and
plan of the anchoring apparatus.
A A are flaps or blades hinged to the bottom of the vessel and held in inclined
positions as shewn, the angle of inclination being made to vary according to the
nature of the work to be done by the vessel. These blades are arranged in transverse
rows, there being eight such rows shewn on the drawing with five blades in each
row. Each of these blades is worked by means of two toothed racks B B connected
thereto at the lower end by a hinge-joint, and guided at their upper ends in their
varying positions by a special carriage. The blades A A are raised or lowered at will
by means of winches OC, which may either be worked independently of each other,
or all together, and either by hand or by steam power. D is a triple expansion
steam engine, E is the steam boiler, F F are paddle wheels for propelling the vessel,
G is the paddle wheel shaft, driven from the engine through gearing II' with
clutch connection J.
The winches are worked from the engine through bevil gear KK with clutch
connection. L L are the towing winches, worked from the engine by the horizontal

page_text: shafts and the toothed gear OO. SS is the main horizontal shaft for driving
the winches C T T and U are pitch wheels and endless chain by which the shaft S
is driven from the shaft M. Ci y are endless chains by which the motion of the
shaft S S is communicated to the shafts of the winches. Z Z are signal posts indi-
cating the depth of water, A A" are sounding weights, 13 B¹ are drums on which
the towing cables are coiled, which are workel from the engine by frictional gearing,
bevil gear, and a worm and worm wheel.
The evil wheel on the shaft M is held by means of a conical friction clutch
applied by a spring so regulated as to exert upon the cables a strain of about 25 lbs.
This arrangement is necessary on account of the varying surface speed of the drums,
as their diameter increases in coiling on the towing cables.
Cis the regulating apparatus for the winding on of the cables on to the drums,
which apparatus consists of a scrow having right and left landed scrow threads on
which runs a carriage with forks which shift the cables transversely to an extent
equal to their diameter at each revolution of the drums.
"
The mooring apparatus shown at Figs. 9 and 10 consists of float a, carrying a
pulley round which passes a chain to which the towing cables are attached, so
that an equal strain is always maintained upon each. The float a is secured to the
anchor by means of chains de, the chaine serving also for raising the anchor/
when required if necessary a second anchor is also attached by a chain to the
anchor and by a second chain i to a buoy g for hauling it up. The anchors consist
of a cast iron plate to which are pivotted two flakes.
For deepening the estuary of a river or excavating a channel and transporting
the material beyond low water, I proceed as follows.
1 operate at high tide and during the ebb. For this purpose the anchor of the
vessel is dropped at a certain distance up the estuary, and I allow the vessel to descend
without doing work, the blades A being raised, until it arrivos beyond low water
inark. The blades A are then lowered, and the vessel is then made to advanco
against the ebb by winding up the ropes.
By decreasing the sectional area of the water way below the blades A, the velocity
of the flow of water is increased at that point to any desired extent, and by this
means it acquires sufficient force to dislodge the sand gravel, or mud beneath, which
is then carried on down to the mouth of the estuary by the water.
After the vessel has in this manner passed over about 100 yards, the blades A are
raised and the vessel is again allowed to descend the river and the above operation
is repeated, and so on, until the part of the part of the channel operated upon has
been deepened to the required extent.
As it may often happen that the foreshore is too long for the current to carry the
excavated material beyond it, the operation is carried on over only part of its length
at one time, so as to insure the material being washed down into deep water.
The two sounding woights A' A", which are formed as two small iron boats some-
what heavier than the wator, are arranged at each end of the dredging vessel. The
one A', connected to the end of the jibboom, is dragged along the bottom, and has
for its object to indicate the depth of water at the front end of the vessel; a wire or
cord nitached to it is led up over guide pullies to a pulley on the top of the indi-
cating posts ZZ from which the end hangs down and has a weight attached to it
which, in moving up or down over a scale marked on the post, is made to indicate the
depth of the water at the hows of the vessel. The engineer having one of these
indicating posts nonr him, will then be able to effect the raising or lowering of the
blados A nucording as the depth of water increases or decreases. The second
sounding weight A is arranged at the stern and has for its object to indicate the
amount of work done in deepening the channel, that is to say, if the front sounding
weight indicates a depth of three foot, and that at the stern a depth of four feet, the
vessel will have effected a doopening of the channel to the extent of one foot. By
multiplying this measurement with the distance travelled by the vossol and by the
width of the latter, the volume of dislodged material for anch operation of the vessel
can bo uscortained.

page_text: The vessel shown on the drawing is intended for carrying out a considerable extent
of work.
It is applicable for the estuary of the Seine, for example, where the alternate
currents of ebb and flow and of freshets cause the displacement of a large quantity
of material.
The figures given below will afford an approximate idea of the capabilities of this
vessel
In consequence of the narrowing of the water way by the blades a mean velocity
of water of 4 metre per second may well be taken.
In this case the volume of water passing down will be 20 × 0.4 × 4
metres.
=
= 32 cubic
36,000 cube metres, and
= 220,000 cube metres.
Materials in suspension about rd, say, 10 cube metros.
Consequently removal of material per hour 3600 x 10
in 6 hours, corresponding to the ebb current 2.16
In rivers having a continual current, the duration of the daily work may be
extended, and consequently the size and cost of the vessel can be reduced, while
still obtaining a great displacement of material.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. The method of deepening the channels of estuaries and other water ways by
causing a vessel having blades or flaps projecting down beneath its bottom to travel
up stream so as, in narrowing the section of the water way, to effect both an increase
of velocity of the water and to make it impinge upon the bottom, whereby the
material of the latter will be dislodged by the current and carried thereby out to
deep water substantially as herein described.
2. The construction and use, for effecting the deepening of waterways in the
manner sot forth in the preceding claim, of vessels having hinged adjustable blades
or flaps projecting from their bottoms constructed and operating substantially as
herein described.