Improvements relating to Canal-boats or Flats and similar Vessels, and to Means for Propelling the same.
Year: 1892

page_text: Date of Application, 12th Nov., 1892
Complete Specification Left, 10th Aug., 1893-Accepted, 23rd Sept., 1893
PROVISIONAL SPECIFICATION.
Improvements relating to Canal-boats or Flats and similar Vessels,
and to Means for Propelling the same.
I, BERTIE CHARLES SCOTT, of Bassin, Bruges, in the Kingdom of Belgium,
Gentleman, do hereby declare the nature of this invention to be as follows:-
The chief object of my invention is to provide improved means for propelling
canal-boats or flats and similar vessels of shallow draught.
One feature of my said invention consists in providing in the stern of the boat or
vessel a chamber or tube in which is arranged a screw-propeller and which is open
at its rear end and is connected at its forward end with one or more tubes through
which water can enter the said chamber freely from the bottom or sides of the ship
or vessel. These parts are so constructed and arranged that the water entering
the said chamber from the bottom or side of the boat or vessel, will be discharged
through the stern of the said boat or vessel by the said screw-propeller.
By this arrangement I provide for the propulsion of the boat or vessel in a much
more efficient manner and at a higher speed than is practicable in cases where a
screw-propeller is arranged within a chamber or tube which communicates at each
end with an aperture in the bottom of the boat or vessel, as, in my improved
arrangement, the water is discharged directly aft in a horizontal or approximately
horizontal direction instead of being discharged in an inclined direction from an
aperture in the bottom of the boat.
I find it advantageous to make the said chamber and the ingress tube or tubes as
short as possible and to construct the same in such a manner that, whilst the said
tubes are of sufficient area in transverse section to permit the water to very freely
enter the chamber, the egress end of the said chamber is contracted so that it is
just sufficient to permit the discharge of the water without undue resistance when
the propeller is rotating at its maximum velocity. By making the chamber and
ingress tube or tubes as short as is practicable, I avoid unnecessary friction
therein and obviate the necessity for carrying a heavy load of water.
The egress
aperture at the rear end of the chamber is made oval or oblong and is so arranged
that even when the boat or vessel is light, the said aperture will be below the level
of the water. When the ingress apertures are at the sides of the boat or vessel,
these apertures also are made oval or oblong and are so arranged that they will at
all times be below the level of the water.
I sometimes arrange the propeller in a steel cylinder the ends of which fit into
annular recesses in the flanges of two end-pieces, in which recesses are placed rings
of india-rubber or other suitable material, the said flanges being secured together
with the cylinder between them by means of suitable bolts. I connect the said
end-pieces with short tubes secured one to the bottom and the other to the stern of
the vessel, or two to the sides and the other to the stern, in such a manner that the
said chamber and end-pieces can be readily detached and removed when necessary.
I find it advantageous to mount the engine or motor for driving the propeller, and
the said chamber upon a single bed-plate or base so that they can be removed
together.
In the case of boats or vessels for use in shallow canals or rivers where the
vessel cannot be made to draw sufficient water to cover the screw-propeller, I com-
bine, with the aforesaid chamber or tube, suitable means, such as an air-pump, for
drawing the air out of the said chamber or tube and thus forming a vacuum or
partial vacuum therein, so that the water within the said chamber or tube will rise
above the level of the water outside the vessel, and will consequently cover the

page_text: screw-propeller. The screw-propeller will, therefore, work efficiently notwith-
standing the small draught of the vessel, and a larger screw-propeller can be used
than would otherwise be practicable in a vessel of shallow draught.
It is evident that, when my invention is applied in this manner, the chamber or
tube in which the propeller works must be air-tight when the vessel is in the
water.
Another feature of my said invention is the provision of means whereby the
ingress and egress apertures may be tightly closed and the water removed from the
chamber to permit the inspection of the propeller or the replacing of the same or of
the propeller shaft whilst the vessel is in the water, and also to permit the removal
of the chamber if necessary while the vessel is in the water. For instance, I
provide the openings for the ingress and egress of the water to and from the said
chamber, with doors or sluice-valves whereby they may be tightly closed, and I
provide a pump for withdrawing the water from the said chamber when the said
openings are closed. Or I can remove the water from the said chamber by
admitting or forcing air into the same and thus expelling the water therefrom, the
said openings being then closed to prevent the entrance of water.
Another feature of my said invention is the combination, with the ingress
aperture or apertures, and also, if necessary, with the egress aperture, of directing
or deflecting plates, whereby the water is more efficiently directed towards and
away from the propeller.
•
In some instances, I use propellers of the kind now in common use. In other
instances I use a propeller having a single blade which extends nearly or completely
around the boss or hub. In the latter case I prefer that the internal diameter of
the chamber should be but very slightly greater than the outside diameter of the
propeller, and the propeller, in this case, may be of smaller diameter than would be
necessary with propellers such as are ordinarily employed.
I sometimes make the aforesaid chamber with two egress apertures one ou each
side of the stern-post.
In some instances I arrange twin screw-propellers in the manner above mentioned.
In addition to the advantages above mentioned, my invention affords the
following important advantages, viz. ;-The screw-propeller, when enclosed as above
described, does not produce waves like the screw-propellers as usually employed;
therefore, when my system of propulsion is used in a canal or river, no damage is
done to the banks of the canal or river such as is usually occasioned by vessels
driven by screw-propellers. The screw-propeller in my improved vessel will work
efficiently whether the vessel is loaded or light; this is a very important feature in
vessels for use in shallow waters. Moreover, a larger propeller can be used in a
vessel of shallow draught than can be done with the system of propulsion hitherto
generally adopted; therefore the speed and the wear and tear of the engines will
be reduced without diminution of the speed of progression. And it is evident that
my invention affords very convenient means for propelling canal-boats and the like
(or tug-boats for the same) by means of steam or other motive power instead of by
animal haulage. Furthermore my improved boats can with advantage be used in
place of the stern-wheel river-steamers now in use.
Dated the 12th day of November 1892.
BERTIE C. SCOTT,
D. Young & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements relating to Canal-boats or Flats and similar Vessels,
and to Means for Propelling the same.
I, BERTIE CHARLES SCOTT, of Bassin, Bruges, in the Kingdom of Belgium,
Gentleman, 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 :--
The chief object of my invention is to provide improved means for propelling
canal-boats or flats and similar vessels of shallow draught, or vessels whose draught
varies greatly, say from a few inches to several feet.
My said invention consists partly in providing in the stern of the boat or vessel,
a chamber or tube in which is arranged a screw-propeller and which is open at its
rear end and is connected at its forward end with one or more tubes through which
water can enter the said chamber freely from the bottom or sides of the ship or
vessel. These parts are so constructed and arranged that the water entering the
said chamber from the bottom or side of the boat or vessel, will be discharged
through the stern of the said boat or vessel by the screw-propeller. I make the said
chamber and the ingress tube or tubes as short as possible and 1 sometimes con-
struct the same in such a manner that, whilst the said tubes are of sufficient area
in transverse section to permit the water to very freely enter the chamber, the
egress end of the said chamber is contracted so that it is just sufficient to permit the
discharge of the water without undue resistance when the propeller is rotating at
its maximum velocity. By making the chamber and ingress tube or tubes as short
as is practicable, I avoid unnecessary friction therein and obviate the carrying of an
unnecessarily heavy load of water. And by contracting the egress aperture I
ensure the discharge of the water in a more solid or compact column than would
otherwise be practicable. The egress aperture at the rear end of the chamber is
made oval or oblong and is so arranged that, even when the boat or vessel is light,
the said aperture will be below the level of the water. When the ingress apertures
are at the sides of the boat or vessel, these apertures are also preferably made oval
or oblong and are so arranged that they will at all times be below the level of the
water.
My improvements are also applicable to ordinary sea-going vessels, provided that
the ingress openings are placed so far forward that they will not be lifted out of
the water when the vessel pitches, thus obviating the liability to racing of the
engines, as, in the rolling of the vessel, one or the other of the ingress openings
will always be submerged in such a manner as to ensure the proper flow of water to
the propeller.
By my improved arrangement, I provide for the propulsion of the boat or vessel
in a much more efficient manner and at a higher speed than is practicable in cases
where a screw-propeller is arranged within a chamber or tube which communicates
at each end with an aperture in the bottom of the boat or vessel, because, in my
improved arrangement, the water is discharged directly aft from the stern instead
of being discharged from an aperture in the bottom of the boat.
My said invention also consists partly in the combination, with the ingress and
egress apertures, of improved doors or valves for closing the same.
In the accompanying drawings,
Figure 1 is a vertical central section, and
Figure 2 a plan showing my improved apparatus constructed with two ingress
apertures situated one at each side of the vessel.
Figure 3 is a vertical central section, showing my improved apparatus constructed
with one ingress aperture in the bottom of the vessel, the valve in the ingress tube
being shown in its closed position.

page_text: Figure 4 is a vertical central section, showing one form of door or sluice-valve
for closing the ingress and egress apertures when necessary.
Figure 5 is a horizontal section illustrating another modification of my improved
apparatus in which twin screw-propellers are employed.
Like letters indicate corresponding parts throughout the drawings.
A is the propeller which is arranged in a chamber B in the stern of the vessel;
C, C are the ingress tubes; D is the egress or discharge-tube, the rear end of
which is secured around an opening in the stern of the vessel.
The passage
through the said tube D may, as above stated, be contracted so that it is of just
sufficient transverse sectional area to permit the discharge of the water without
undue resistance.
I sometimes make the propeller-clamber of a steel cylinder B the ends of which
fit into annular recesses in the flanges of two end-pieces or castings B1, B².
These end-pieces are more or less tapered towards the ingress or egress tubes, and
their end surfaces are inclined as shown to facilitate the flow of the water to and
from the propeller, and to avoid the carrying of an unnecessary quantity of water.
The end-piece B' carries a suitable bearing B³ in which the propeller-shaft A¹
rotates, the said bearing being made fluid-tight by means of the gland and stuffing-
box E in the said recesses b' are placed rings c of india-rubber or other suitable
material for the purpose of making fluid-tight joints, the flanges 6 being secured
together, with the said cylinder between then, by means of suitable bolts d. I can,
however, construct the chamber in any other convenient manner.
с
I provide the openings for the ingress and egress of the water to and from the
chamber B, with doors or sluice-valves g, Figures 3 and 4, whereby they may be
tightly closed, and I provide a pump for withdrawing the water from the said
chamber when the said openings are closed, so as to permit the inspection of the
propeller or the replacing of the same or of the propeller-shaft whilst the vessel is
in the water, and also to permit the removal of the chamber if necessary while the
vessel is in the water. Or I can remove the water from the said chamber by
admitting or forcing air into the same and thus expelling the water therefrom, the
said openings being then closed to prevent the entrance of water.
The valve g, which is shown more clearly in Figure 4, is pivoted at gl and is provided
with an operating lever sliding on a quadrant, and with a strip or ring 92 of india-
rubber or other suitable material, held in place by a plate g*, which is secured to
the body of the valve in such a manner that it can be readily taken off to permit
the removal of a worn strip or ring g' and the substitution of a new strip or ring
therefor. The said strip or ring, when the valve is closed, bears against a valve-
seat j. The body of the said valve is loosely secured by a bolt or screw k to the
yoke in such a manner that it will adapt itself to the valve-seat; when pressed
against the same by the water. It is evident that, if desired, the strip or ring g²
and plate may be secured to the valve-seat instead of to the valve, in which case
the said plate must be so shaped as to fit the valve-seat.
I connect the end-pieces B', 132, with the ingress and egress tubes C, C, D in
such a manner that the chamber B and the said end-pieces B1, B2 can be readily
detached and removed when necessary. I find it advantageous to mount the engine
or motor for driving the propeller and also the said chamber B and end-
pieces B, B2, upon a single bed-plate or base F, so that they can be removed
together. With this arrangement, the whole apparatus can, when desired, be at
once transferred from one boat to another, providing the latter be fitted with
similar tubes, apertures and valves. Several boats can thus be worked by one
engine, propeller and chamber; for instance, whilst some boats are loading and
discharging, another can be travelling, and when the latter arrives in port, the
valves can be closed and the water pumped from the chamber, and the engine,
the propeller and the chamber can then be at once transferred to the loaded
boat ready to start, and so on. This is an important feature of the invention,
and is the main object in providing the valves in the ingress and egress tubes.
A further advantage gained by this arrangement is that, in the event of any

page_text: accident to the engine or propeller such as would necessitate long repairs, the
engine, propeller and chamber can be removed without taking the boat out of
the water, and can be replaced by another engine, propeller and chamber, thus
avoiding a long detention of the boat.
When the ingress apertures are at the sides of the vessel, I sometimes provide
adjustable tubes in case the boats should vary in beam and other respects. The
fixed tubes could all be worked up to standard measurements, which would be the
safest and best arrangement, but, if desired, I provide telescopic tubes working
through stuffing-boxes or the like, for the purpose of adjustment where the standard
measurements have not been followed.
In the case of boats or vessels for use in shallow canals or rivers where the vessel
cannot be made to draw sufficient water to cover the screw-propeller, I combine,
with the propeller-chamber, suitable means, such as an air-pump, for drawing the
air out of the said chamber from a point situated at or near its highest part (for
example through the cock e) and thus forming a vacuum or partial vacuum therein,
so that the water within the said chamber will rise above the level of the water
outside the vessel, and will consequently cover the screw-propeller. Or I may close
the valves of the ingress and egress tubes and pump water into the said chamber,
allowing the air to escape at the top of the chamber, as, for instance, through the
cock e.
This cock is then closed and the valves of the ingress and egress tubes are
opened. The screw-propeller will, therefore, work efficiently notwithstanding the
small draught of the vessel, and a larger screw-propeller can be used than would
otherwise be practicable in a vessel of shallow draught. When the vessel is loaded,
the cock e may be opened to allow the air to escape and the water to enter and
cover the screw-propeller in the chamber, provided that the level of the water
outside the boat is as high or higher than the top of the chamber. The cock e
should be in communication with a tube the end of which should always be above
the level of the water.
It is evident that, when my invention is applied in this manner, the chamber
or tube in which the propeller works must be air-tight when the vessel is in the
water.
I sometimes employ, in combination with the ingress aperture or apertures,
suitable directing or deflecting plates m as shown in Figure 5, for the purpose of
directing the water into the said chamber in the most effective manner for the
propulsion of the vessel. In some cases I use a directing or deflecting plate in
combination with the egress aperture or apertures.
In some instances, I use propellers of the kind now in common use. In other
instances, I use a propeller having a single blade which extends nearly or com-
pletely around the boss or hub as shown in Figure 5. In this case, I prefer that
the internal diameter of the chamber B should be but very slightly greater than
the outside diameter of the propeller, as shown in Figure 5, and the propeller, in
this case, may be of smaller diameter than would be necessary with propellers such
as are ordinarily employed. Further, with this kind of propeller, the air-pump
might be dispensed with, as the screw would itself draw in the water required to
cover it.
I sometimes make the chamber B with two egress apertures, one on each side of
the stern-post.
In some instances, I arrange twin screw-propellers in the manner above
mentioned, in separate chambers B, as shown in Figure 5. These chambers are
connected with a single egress tube D; or they may be connected with separate
egress apertures. The ingress and egress tubes may, if desired, be provided with
valves or doors as above set forth.
In addition to the advantages above mentioned, my invention affords the following
important advantages, viz. :-The screw-propeller, when enclosed as above described,
does not produce waves like the screw-propellers as usually employed; when my
system of propulsion is used in a canal or river, no damage is done to the banks of

page_text: the canal or river such as is usually occasioned by vessels driven by screw-
propellers. The screw-propeller in my improved vessel will work efficiently
whether the vessel is loaded or light; this is a very important feature in vessels
for use in shallow waters. Moreover, a larger propeller can be used in a vessel of
shallow draught than can be done with the system of propulsion hitherto generally
adopted; therefore the speed and the wear and tear of the engines will be reduced
without diminution of the speed of progression. And it is evident that my inven-
tion affords very convenient means for propelling canal-boats and the like by means
of steam or other motive power instead of by animal haulage or for propelling tug-
boats for use in canals or rivers. Furthermore my improved boats can, with
advantage, be used in place of the stern-wheel river-steamers now in use.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
First. The combination, with a canal-boat or flat or other vessel, of a propeller-
chamber in the stern thereof, having inclined end walls, a screw-propeller arranged
to rotate in the said chamber and mounted on a shaft which extends through a
stuffing-box in one of the end walls of the said chamber, one or more ingress tubes
connected with the said chamber and with the shell of the vessel, and an egress
tube also connected with the said chamber and extending therefrom to an opening
in the stern of the vessel, substantially as, and for the purposes, set forth.
Second. The combination, in an apparatus for the propulsion of canal-boats or
flats or other vessels, of one or more propeller-chambers having ingress and egress
apertures, a propeller or propellers working in the said chamber or chambers, a
motor or motors for driving the said propeller or propellers, and a base or foundation-
plate on which the said chamber or chambers, the propeller or propellers and the
motor or motors are mounted and which is removable therewith from the boat or
vessel, for the purposes above specified.
Third. The combination of the propeller-chamber or propeller-chambers having
ingress and egress apertures, the tubes connecting the said ingress and egress
apertures with the shell of the vessel, the valves in the said tubes whereby the
ingress and egress passages may be closed, and the propeller or propellers working
in the said chamber or chambers, substantially as, and for the purposes, above
specified.
Fourth. A propeller-chamber consisting of a hollow metal cylinder, end-pieces
having inclined walls and having ingress and egress apertures respectively, packing-
rings in grooves in the said end-pieces and bearing against the ends of the said
cylinder, and means for securing the said end-pieces together with the cylinder
between them, substantially as, and for the purposes, set forth.
Fifth. The combination, with a canal-boat or flat or other vessel, of propeller-
chambers in the stern thereof having inclined end-walls, screw-propellers arranged
to rotate in the said chambers and each mounted on a shaft which extends through
a stuffing-box in one of the end-walls of the corresponding chamber, ingress tubes
which connect the said chambers to the sides of the vessel respectively, and an
egress tube which connects both of the said chambers with an opening in the stern
of the vessel, substantially as, and for the purposes, set forth.
Sixth. The combination, with the propeller-chamber and the ingress and egress
tubes connected therewith, of valves in the said tubes each of which comprises a
pivoted arm or yoke, a body loosely attached thereto, a plate secured to the said
body, or to the valve-seat, and an india-rubber or other packing held in place by
the said plate, substantially as, and for the purposes, set forth.
Seventh. The propeller-chamber constructed substantially as hereinbefore
described with the ingress tube or tubes of such dimensions as to freely admit the
water required by the propeller and with the egress tube having the bore thereof
contracted, as, and for the purposes, set forth.

page_text: Eighth. The improved valve constructed substantially as described with
reference to Figure 4 of the drawings and operating as, and for the purpose,
above specified.
Ninth. The improved apparatus constructed substantially as described with
reference to Figures 1 and 2 or to Figure 3 or to Figure 5 of the drawings and
operating as, and for the purpose, above specified.
Dated the 10th day of Aust 1902
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.