Improvements in Apparatus for Propelling Vessels.
Year: 1890

page_text: Date of Application, 23rd May, 1890
Complete Specification Left, 21st Feb., 1891-Accepted, 25th Apr., 1891
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Propelling Vessels.
I, SHOLTO DOUGLAS, of 23, Adelphi Place, Salford, in the County of Lancaster,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention is particularly applicable to propellers for vessels, the object of my
invention being to obtain greater efficiency from the propeller.
In applying my improved propellers to a steam vessel I employ one two or more
propellers placed in any convenient position. I will describe two propellers one
fitted on each side of the keel and placed preferably in the fore part of the vessel,
cach propeller consists of a specially shaped wheel fitted in a cylinder or casing the
arms or floats of which fill and almost touch the interior of the casing which is cut
away at the bottom to allow the floats to act upon the water. The shaft or axle of
each propeller passes through watertight bearings in the side of the casing, in the
body of the propeller are a number of watertight compartments the divisions
between them being preferably radial plates the front portions of which form the
floats; in the casing at each side of the propeller near the water is an opening or
openings connected to side pipes or trunks by which air is conveyed to the water-
tight compartments.
By this construction there is a constant flow of water and air into the lower
portion of the propeller which fills up the space left by the floats as the propeller
revolves, and by the centrifugal force of the latter the water and a great portion of
the air is thrown off in a backward direction, and this with the balance of the air
which escapes by the outlet ports from the trunks flows along under the bottom of
the vessel to the stern where it flows upward with considerable force, still keeping
under the vessel until the air arrives at the surface of the water under the stern
end of the vessel where it causes a wave or swell which travels forward with the
vessel and aids its forward motion.
By the arrangement described the floats of the propeller act on the water about
to the same extent no matter how rough the sea may be and a volume of air fed by
the propeller being normally between the bottom of the vessel and the water allows
the vessel to be more easily propelled through the water.
Dated this 22nd day of Mar 1890
H. B. BARLOW,
Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Propelling Vessels.
I, SHOLTO DOUGLAS, of 23, Adelphi Place, Salford, in the County of Lancaster,
Engineer, 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 is applicable to propellers for vessels the object of my invention
being to obtain greater efficiency from the propeller.
In applying my improved propellers to a steam vessel I employ one two or more
propellers placed in any convenient position, say preferably in the fore part of the
vessel; each propeller consists of a specially shaped wheel fitted in a cylinder or
casing the arms or floats of which fill and almost touch the interior of the casing
which is cut away at the bottom to allow the floats to act upon the water. The
shaft or axle of each propeller passes through watertight bearings in the side of the
Price 8d1

page_text: casing and in the body of the propeller are a number of compartments the divisions
between them being preferably radial plates which form the floats; in the casing
at each side of the propeller near the water is an opening or openings connected to
side pipes or trunks by which air is conveyed to the aforesaid compartments.
And in order that my invention may be fully understood and readily carried into
effect I will describe the accompanying three sheets of drawings reference being had
to the figures and letters marked thereon.
Fig. I is a plan view of the bows of a vessel provided with three of my improved
propellers in the position in which I prefer to place them.
and
Fig. 2 is a diagram of the side of Fig. 1 showing the position of the propellers
Fig. 3 is a diagram or transverse section on the line A B, Fig. 1.
Fig. 4 is a front view on a larger scale of one of my improved propellers and air
passages in connection therewith.
Fig. 5 is a plan of Fig. 4.
Fig. 6 a transverse section on the line C D, Fig. 4, and
Fig. 7 a view of the valvular arrangement for allowing the air to escape from the
propeller.
Similar letters refer to similar parts throughout the several views.
In Figs. 1, 2 and 3,-a represents the hull of a vessel or ship and b b b three
propellers two of which are fitted at the sides and one in the centre and slightly
in advance of the other two and preferably near the bows of the ship as shown;
each propeller b is fitted in a casing c and its shaft d is driven in any convenient
manner.
In Figs. 4, 5, 6 and 7 are shown the construction and arrangement of a propeller
with the ports for admitting and discharging air. In these views the propeller 6 is
mounted upon a shaft d and is provided with floats d¹ connected at each end to a
plate with a number of holes d; the whole is enclosed in a casing c which
surrounds the floats of the propeller excepting for a small space at the bottom.
The ends are bolted to the main portion of the casing c and have holes c¹ near the
bottom corresponding in size with the holes d in the compartments formed by the
floats d' so that as each compartment in its turn comes opposite these holes cair
supplied through side trunks or pipes f is admitted through the holes d³ in the said
compartment and is confined therein until the compartment by the rotation of the
propeller reaches the point x, then as the floats strike the water, the air is com-
pressed in the compartment and is forced therefrom through slots in the ends of
the casing c and along side passages g to a chamber h. The chamber h is provided
with a series of openings and a valve or plate i which is suspended by rods i¹ and
is caused to move automatically so as to discharge the air either through all the
openings or only through certain of these openings as required and this is effected by
two water cylinders jj which communicate with one another by a passage j¹. In the
cylinders are two floats j² connected to a beam k fixed upon a rocking shaft k².
Also secured to the shaft k' is an arm / pivoted to a rod m connected at each end
by an elbow lever n and a dink n' to each rod of the valve or cover i.
In Fig. 7 the ship or vessel is represented on an even keel and the openings /¹
will all be open; when the vessel rolls the water rushing from one cylinder j to the
other raises one float and causes the beam k to oscillate thereby through the various
rods and connections l m n causing the valve plate i to rise or fall and cover some
and uncover other of the openings the movements of these parts being governed
by the rolling of the vessel. The air as it escapes from the chamber h passes
through the openings h¹ and escapes through a slit o, see Fig. 6, between a spur c³
on the propeller casing c and the bottom of the ship the air escaping chiefly
under whichever side of the vessel is most submerged at the time and being
prevented from rising immediately to the surface by means of the false keels a¹ a,
see Fig. 7.
By the arrangement described the floats of the propeller act on the water
about to the same extent no matter how rough the sea may be and the volume

page_text: of air fed by the propeller being normally between the bottom of the vessel
and the water diminishes friction and consequently allows the vessel to be more
easily propelled.
Figs. 4 to 7 show the air arrangement applied to only one propeller; when two
or more propellers are employed similar means would be applied to each for
discharging the air under the vessel.
Although I have shown and described the propellers as placed in the fore part
of the vessel which is the position I consider most advantageous it is obvious that
they might be placed in any other position if desired.
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 :-
1. The combination with a propeller or propellers constructed to form compart-
ments as shown and described, of the air inlet and discharge openings and passages
automatically controlled by valves substantially as and for the purposes herein
set forth.
2. The valvular arrangement for controlling the discharge of air from the
chamber substantially as described with reference to Figs. 4 to 7.
3. The combined arrangement of parts embodying my improvements in apparatus
for propelling vessels substantially as herein shown and described.
Dated this 19th day of February 1891.
H. B. BARLOW,
17, St. Ann's Square, Manchester, Agent for Applicant.
H. B. BARLOW,
17, St. Ann's Square, Manchester, Agent for Applicant.