IMPROVEMENTS IN APPARATUS FOR PROPELLING SHIPS AND OTHER VESSELS
Year: 1865

page_text: LETTERS PATENT to John Calvert, of the Strand, in the County of
Middlesex, Civil Engineer, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR PROPELLING SHIPS AND OTHER VESSELS."
Sealed the 20th October 1865, and dated the 1st July 1865.
PROVISIONAL SPECIFICATION left by the said John Calvert at the
Office of the Commissioners of Patents, with his Petition,
Petition, on the
1st July 1865.
I, JOHN CALVERT, of the Strand, in the County of Middlesex, Civil Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
APPARATUS POR PROPELLING SHIPS AND OTHER VESSELS," to be as follows:-
The said Invention relates to certain improvements in the construction and
arrangement of apparatus for the purposes of propulsion, and whereby great
propelling power is obtained with the expenditure of a comparatively small
amount of force: Two cylinders or tubes are constructed or placed in the
ship or vessel, the same being situated within the hull, and running from stem'
to stern below the water line. The said cylinders or tubes are open at both
ends, and in the interior of each is placed an archimedean screw mounted on
a suitable shaft. . The shafts are caused to revolve by means of gearing
actuated by any of the ordinary and known machinery applicable to the
purpose. The cylinders or tubes being open at both ends, as before
mentioned, the revolution of the screws causes a continual stream of water

page_text: to be drawn into the same at the forward ends thereof. The water thus
enters the cylinders or tubes at those parts of the ship or vessel at which
there is the greatest pressure from the surrounding water, while it is ejected
by the action of the screws, so as not only to obtain the requisite direct pro-
pulsive power, but also to compensate for the retarding influence occasioned
by the displacement of the water by the forward motion, of the vessel, great
additional speed being thereby gained. The arrangements before described
are perfectly under controul, as the screws can be operated either together or
singly, and can also be reversed, as may be desired, and so that the ship or
vessel can be steered as well as propelled by means thereof.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Calvert in the Great Seal Patent Office on the 1st
January 1866..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CALVERT, of the Strand, in the County of Middlesex, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of July, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Calvert, Her special licence that I, the said John Calvert,
my executors, administrators, and assigns, or such others as I, the said John
Calvert, 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 "IMPROVEMENTS IN
APPARATUS FOR PROPELLING SHIPS AND OTHER VESSELS," upon the condition
(amongst others) that I, the said John Calvert, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Calvert, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-

page_text: formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
My said Invention relates to certain improvements in the construction and
arrangement of apparatus for the purpose of propelling ships and other
vessels, and whereby great propelling power is obtained with the expenditure
of a comparatively small amount of force. Two cylinders or tubes are con-
structed or placed in the ship or vessel, the same being situated within the
hull, and running from stem to stern below the water line.
The said
cylinders or tubes are open at both ends, and in the interior of each is placed
an archimedean screw mounted on a suitable shaft. The shafts are in direct
communication with the engines, and are caused to revolve by means of
gearing of the ordinary and known character applicable to the
purpose. The
cylinders or tubes being open at both ends, as before mentioned, the revolution
of the screws causes a continual stream of water to be drawn into the same at
the forward ends thereof. The water thus enters the cylinders or tubes at
that part
of the ship or vessel at which there is the greatest pressure from the
surrounding water whilst it is ejected, so as not only to obtain the requisite
direct propulsive power, but also to compensate for the retarding influe
occasioned by the displacement of the water by the forward motion of the
vessel, great additional speed being thereby gained. The arrangements before
described aro perfectly under control, as the screws can be operated in either
direction, and either together or singly, as may be desired, and so that the
ship or vessel can be steered as well as propelled by means thereof. If
desired the cylinders or tubes may be placed on the exterior of the ship or
vessel to which my said Invention is applied, and in some cases it may be
desirable to have one cylinder or tube only. In the latter case, however, the
revolving screw can only be applied for propulsion, and not for steering. The
form and arrangement of the cylinders or tubes, as before described, may be
modified by bending or even twisting any portion thereof, and enlarging the
same, so as to form chambers or boxes at right angles with the direction of
the cylinders or tubes. In each of such chambers or boxes are placed one or
two screw wheels, the axes thereof being in communication with the engine,
and by the revolution of which the water will be driven through the ejection
portion of the cylinders or tubes with great force. When two screw wheels
are so employed in each chamber or box, then the supply portion of the
cylinders or tubes must be constructed so as to divide at the points of con-
nection with the chambers or boxes, and follow round the same, entering
above and below the ejection tube. Those parts of the cylinders or tubes
which open into the chambers should of course coincide sectionally in form

page_text: and. size with the portions of the screw wheels which are successively pre-
sented to them during the revolution thereof. In order to prevent extraneous
matters being drawn into or entering the cylinders or tubes, both ends thereof
should be protected by suitable bars or gratings, or other analogous con-
trivances, which will not interfere with the free ingress and egress; of the
water. The cylinders or tubes should also be provided at both ends with
door valves, which may be used when necessary to shut off external com-
munication, and prevent the admission of water, and thus enable free access
to the interior thereof to be obtained:
Having thus described and ascertained the nature of my said Invention,
and the manner in which the same is to be performed, I would observe in
conclusion that what I consider novel and original, and therefore claim as
constituting my said Invention is, the combination and arrangement of
apparatus and mechanism for the purpose of propelling ships and other
vessels, herein-before set forth and described, or any mère modifications
thereof...
In witness whereof, I, the said John Calvert, have hereunto set my
hand and seal, this Thirtieth day of December, in the year of our
Lord One thousand eight hundred and sixty-five.
JOHN CALVERT. (L.S.)