CERTAIN IMPROVEMENTS IN PROPELLING VESSELS
Year: 1853

page_text: LETTERS PATENT to George Thornton, of the Grange, Gargrave,
in the County of York, Civil Engineer, for the Invention of
"CERTAIN IMPROVEMENTS IN PROPELLING VESSELS."
Sealed the 30th March 1853, and dated the 21st January 1858.
PROVISIONAL SPECIFICATION left by the said George Thornton
at the Office of the Commissioners of Patents, with his Petition,
on the 21st January 1853.
I, GEORGE THORNTON, of the Grange, Gargrave, in the County of
York, Civil Engineer, do hereby declare the nature of the said Invention
for "CERTAIN IMPROVEMENTS IN PROPELLING VESSELS" to be as follows:-
My Invention has for its object the propelling of vessels by means
of the stroke of a piston working air-tight within a cylinder against
the water admitted into such cylinder, a vacuum being formed on the
opposite side of the piston; and I accomplish this object by means
of cylinders of equal dimensions fixed in the hinder part of the vessel,
their outer end being open to admit the water, and their inner end
being closed by means of an ordinary cylinder cap fitted with a

page_text: stuffing box for the piston rod to pass through. The piston rod extend-
ing from the air-tight piston in each cylinder is connected by means
of a connecting rod with the crank of the steam engine or other
first mover in such a manner as to balance the pressure from the
pistons in the pair of water cylinders on the crank, in order to remove
impediments to the effectual power of the engine being exerted upon
the water pistons-through-the-crank; and in order to propel in the
opposite direction -I place similar water cylinders. in such a position
of the vessel as to allow of the water being admitted into them, and
acted upon by the pistons within them in the opposite direction to
that above described.
The arrangement of the working parts of the engine or prime mover
so as to work the water pistons with most effect, to increase the length
of stroke, &c., may be varied in detail according to the build and capacity
of the vessel to which my Invention may be applied. The air is with-
drawn from the side of the water piston not in contact with the water
by means of an air pump, as in the ordinary case of a steam piston in a
steam cylinder. And I place in the cap of the water cylinders a valve
opening inwards, through which the air and any small quantity of water
getting behind the water piston (by leakage) may be discharged by the
back or inward action of the said piston.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Thornton in the Great Seal Patent Office
on the 21st July 1853.
TO ALL TO WHOM. THESE PRESENTS SHALL COME, I,
GEORGE THORNTON, of the Grange, Gargrave, in the County of York,
Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria,-by Her
Letters Patent, bearing date the Twenty-first day of January, in
the year of our Lord One thousand eight hundred and fifty-three, in
the sixteenth year of Her reign, did, for Herself, Her. heirs. and
successors, give and grant unto me, the said George Thornton,

page_text: Her special license that I, the said George Thornton, my execu-
tors, administrators, and assigns, or such others as I, the said
George Thornton, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "CERTAIN IMPROVEMENTS IN PROPELLING VESSELS," upon the con-
dition (amongst others) that I, the said George Thornton, by an instru-
ment in writing under my hand and seal, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
sanie was to be performed, and cause the same to be filed in the Great
Scal Patent Office within six calendar months. next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Thornton, do hereby declare
the nature of my said Invention, and in what manner the samic is to
be, performed, to be particularly described and ascertained in and by
the following statement, reference being had to the Drawings hereunto
annexed, and to the letters and figures marked thereon (that is to say):
My Invention of "Certain Inprovements in Propelling Vessels is
intended to form a substitute for the ordinary propellers by which the
effectual power of the engine or first mover may be exerted with less
impediment or connter action from the propeller, which in the present
instance is so constituted as to have a balance of forces resting upon it
until disturbed by the action of the prime mover; and this object is
accomplished by means of the stroke of a piston or pistons working air-
tight within a cylinder or cylinders against the water (in which the
vessel is floating) admitted into the cylinder at the external side or face
of the piston, a vacuum being formed on the opposite or inner side of the
piston. The propeller is constituted by the arrangement of cylinders of
equal dimensions fixed in the hinder part of the vessel, their outer end
being open to the water at the stern of the vessel, and their inner end
closed by an ordinary cylinder cover. In each of these cylinders (which,
for the sake of distinction, I term "water cylinders,") there is a piston
or plunger, the rod of which is connected with the crank of the engine

page_text: or prime mover in such a manner that the movement of the engine or
engines may cause one piston to push or thrust against the water while
the other is being withdrawn therefrom. There is also an air pump or
air pumps connected with the water cylinders by which a vacuum is
formed at the same time that the piston is driven against the water, but
on the side of the piston opposed to that which pushes or thrusts against
the water. So that my Invention consists in constituting a propeller
by means of water cylinders with pistons or plungers acting alternately
in opposite directions, a vacuum being formed and maintained on the sido
of the piston opposite to that which is in action against the water.
I am aware that it has been proposed to employ cylinders for the
above purpose with pistons fitting them loosely, leaving a space above
them, also with air introduced on the side of the pistons opposite to that
in contact with the water, but my Invention is distinguished from the
forner of these plans by employing cylinders with pistons working air-
tight within them, and from the latter by causing a vacuum to be formed
on the side of the pistons opposite to that in contact with the water.
In order, however, that my Invention may be most fully understood
I will proceed to describe more particularly its general features by the
aid of the accompanying Drawing, in which are represented, without
attention to detail, portions of a vessel with my improved propeller
applied thereto.
Fig. 1, shews a small portion of the stern or hinder part of thic
vessel in longitudinal vertical section with one of the water cylinders
fixed in its place, with the piston carried to its furthest point inwards.
Fig. 2, is a plan view of the same, shewing two water cylinders,
the piston in one being at its extreme outer end, and the other at its
extreme inner end of its course. Fig. 3, is a stern view of the vessel
and the water cylinders. In each of these Figures the same letters of
reference indicate corresponding parts. A, A, are the water cylinders.
B, B, the propelling pistons or plungers. C, C, the piston or plunger
rods, both which are to be connected by suitable means to the crank of
the prime mover. One mode of such connection may consist of links
uniting the said pistons or plungers to beams or lever arms turning on
a common centre, the connection thereof with the crank. and steam

page_text: piston rods attached thereto being placed so much nearer the centre of
motion of the beams than the point of connection thereof with the said
links as to cause a considerably increased length and speed of stroke to
be imparted to the water pistons or plungers. By this or any other
suitable mode of connection of the water pistons or plungers with the
opposite sides of the crank the said water pistons or plungers are caused
to move with a reciprocating action against the water. The pipe which
communicates with the air pump or air pumps is shewn at D. It will
be seen that the cylinders A, A, are open to the water at their outer
end, but closed at their inner end by means of an ordinary cylinder
cover with a stuffing box for the piston rod to work through, so that
the pistons B, B, may be worked air-tight within the cylinders. On
motion being communicated to these pistons from the prime mover
through the connection referred to, they being in the position shewn at
Fig. 2, for example, and a vacuum formed on the inner or bow-ward side
of the pistons, they will be respectively moved in the directions shewn
by the arrows, the effect of which will be to force the piston which
is at the inner or bow-ward end of its cylinder against the body of water
admitted from the sternward or outer end of the same. But the pressure
of the water combined with that of the atmosphere acting against the
external side of the piston, while on the inner side there is a vacuum,
the water will be found unyielding, or presenting a firm resistance for
the piston to push or thrust against, and thereby to propel the vessel.
At the same time there is a vacuum formed on the inner or bow-ward
side of the other piston by the course of the piston to the outward end
of the cylinder, and maintained by the air pump in the ordinary way of
steam cylinders, and the combined pressure of the water and the atmo-
sphere acts against the external side of the said piston. It will thus be
seen that the combined pressure of the water and atmosphere. on the
aforesaid external side of a piston against vacuum on the other side
is balanced by the same unresisted pressure on the same side of
another piston of equal area, so that the power of the prime mover
may be exerted without impediment or nearly so upon the propelling
piston.
I have described an arrangement of propeller consisting of a pair of

page_text: water cylinders and pistons or plungers as being the simplest form in
which it may be applied. In case, however, it should be found desirable
to. produce steadiness of motion in the vessel, or for other reasons, three
or more cylinders might be employed, care being taken to arrange theni
so as to balance the pressures on the piston. When three cylinders are
used it will be.necessary to adapt the stern of the vessel to this arrange-
ment, and to carry the rudder post backward, but these variations form
no part of my Invention.
.
The
I have also described a mode of connecting the propelling pistons
with the prime mover, so that they may receive their required motion
therefrom by micans of beams or lever arms; but my Invention is not
confined to this mode of connection with the prime mover.
connection or arrangement, however, should, be such as to ensure a
sufficient length and speed of stroke of the propelling pistons to maintain
the adequate progress of the vessel. In order to propel the vessel
backward it will be necessary to arrange other water cylinders and
pistons or plungers acting in an oblique direction through the sides or
bottom of the vessel, with a motion in the contrary direction to that
above described.. These may be placed in any part of the vessel,, but
as near the stern as convenient, and be made to act upon the water at
. an angle, being connected directly with the prime mover, or they may
be fixed at the fore part of the vessel, and be made to act upon the
water in a direction just contrary to that described above in reference
to the pistons at the stern of the vessel. In the latter case the pistons
may be driven by means of other steam cylinders in the fore part of the
vessel supplied with steam by a pipe from the sanie boilers as those at
the stern, or by means of any suitable connection with the engine or
prime mover above referred to.
Having thus described the nature of my Invention, and in what
manner. the same is to be performed, I would have it understood that
I do not mean or intend to confine myself to the precise arrangements
above described, as the same may be varied without departing from the
general principle of my Invention;. but. what. I claim as of my. Invention
is, the constitution of a propeller or propellers by means of: water
cylinders with pistons working air-tight therein, and so disposed or,

page_text: arranged and combined with other apparatus as to be alternately made
to push or thrust against the water, combined with the resistance of the
atmospheric pressure, and to recede therefrom at the same time that a
vacuum is formed on the opposite side of the pistons, as described.
In witness whereof, I, the said George Thornton, have hereunto
set my hand and seal, this Twenty-first day of July, in the year
of our Lord One thousand eight hundred and fifty-three.
Witnessed by
WILLIAM SPENCE,
Patent Agent.
GEO. THORNTON. (L.S.)