IMPROVEMENTS IN CONSTRUCTING SHIPS AND VESSELS PROPELLED BY SCREW OR SUCH LIKE PROPELLERS
Year: 1858

page_text: LETTERS PATENT to Augustin Normand, of Havre, in the Empire of
France, Shipbuilder, for the Invention of "IMPROVEMENTS IN CONSTRUCTING
SHIPS AND VESSELS PROPELLED BY SCREW OR SUCH LIKE PROPELLERS."
Sealed the 22nd March 1859, and dated the 30th September 1858.
PROVISIONAL SPECIFICATION left by the said Augustin Normand at the
Office of the Commissioners of Patents, with his Petition, on the 30th
September 1858.
I, AUGUSTIN NORMAND, of Havre, in the Empire of France, Shipbuilder,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
CONSTRUCTING SHIPS AND VESSELS PROPELLED BY SCREW OR SUCH LIKE PROPELLERS,"
to be as follows:-
My Invention has for its object to provide a means of closing the well hole
of screw steam vessels, whether the screw be working or not, and at whatever
depth the well hole may be situate below the water line, in such manner that
the surface of that part of the stern of the vessel may be unbroken, and thereby
obviate the evils arising from open well holes.
In carrying out this improvement, I close the bottom opening of the well
hole by two sliding side doors (made either of wood or metal, or both), taking
the form of the under part of the vessel or screw framing. These doors are
capable of meeting or separating from each other, and they may be worked from
within or from the deck of the vessel.
If thought desirable the sliding doors may be divided into several parts

page_text: fitting together, and either worked altogether or separately, and they may be
opened or closed by means of endless chains, racks and pinions, screws, or
other means found most suitable, according to the size, form, and arrangement
of the vessel, and of the various parts of the apparatus.
I also propose to change the form of the opening of the well hole, making
it follow the profile figure of the screw when viewed from above, the screw
being turned to bring the central portion of its blades into a vertical line.
This novel arrangement has the advantage of reducing as much as possible
the internal size of the well hole, and consequently the surface which the
sliding doors have to cover, the grooves in which they run being at the same
time lengthened.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Augustin Normand in the Great Seal Patent Office on the
30th March 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, AUGUSTIN
NORMAND, of Havre, in the Empire of France, Shipbuilder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of September, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Augustin Normand, Her special license that I, the said Augustin Normand,
my executors, administrators, and assigns, or such others as I, the said
Augustin Normand, 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
CONSTRUCTING SHIPS AND VESSELS PROPELLED BY SCREW OR SUCH LIKE PROPELLERS,"
upon the condition (amongst others) that I, the said Augustin Normand,
by an instrument in writing under my hand and seal, 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 Augustin Normand do hereby declare
the nature of my said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the follow-
ing statement, reference being had to the Drawings hereunto annexed, and
to the letters and figures marked thereon (that is to say):-
One of the main advantages possessed by screw over paddle wheels as a
propeller consists in the facility it affords for converting (when required) a
steam vessel into a sailing and steaming ship, or into a sailing ship only, when
a favourable wind is blowing.
Another advantage of the screw, and one of very great importance for
vessels of war is, that it is far less exposed than the paddle wheel, to the
enemy's shot.
The arrangements generally adopted in the mounting of the screw propeller
is to render it moveable between two stern posts, so that it may at pleasure be
brought into position for working alone or with the sails, or raised out of
action.
This arrangement as hitherto carried out presents the disadvantage of
causing malformation of the sterns of the vessels, either, first, by terminating
the faces before and behind the well, between the two stern posts by a kind of
breastwork, more or less immersed in the water, which occasions considerable
dead water, and increases the resistance to the vessel's progress, besides impeding
the action of the screw; or if the run of the ship is raised, so as materially to
diminish these evils. Second, by leaving all the weight of the stern without a
corresponding displacement to sustain it, and thus deteriorating the nautical
qualities and the strength of the hinder parts of the vessel. Or, third, by
leading to a great diminution in the breadth of the blades of the screw and
the distance between the stern posts which considerably increases the slip.
These evils would disappear if the lower part of the opening of the well hole
could be closed and opened at pleasure, so that the form of the hinder
portion of the vessel would be continuous as if the well hole did not exist.
Hitherto every apparatus used to close the lower part of well holes has been
found inconvenient and difficult to work in small vessels even in ordinary
weather, and impracticable with large vessels, especially in bad weather,
and they have therefore been generally abandoned.
Now, my Invention has for its object, to provide a means of closing the
well hole of screw steam vessels, whether the screw be working or not at all
times, and at whatever depth the well hole may be situated below the water
line, in such manner that the surface of that part of the stern of the vessel
may be unbroken, and thereby to obviate the evils above mentioned.
To carry out this improvement, first, I give to the part of the stern com-
prised between the two stern posts on each side of the central plan of the

page_text: vessel, and on a proper extent, a segmental form, either convex or concave, in
cross section, or a plane surface, whichever will best suit the shape of the
stern of the ship. Secondly, I close the bottom opening of the well hole
by sliding lateral doors or shutters (of wood, or metal, or both), taking the
form of the outside of the vessel, and moveable either from within or from
the deck of the vessel, so as to recede or approach each other. If thought
desirable, the sliding doors may be divided into several parts, and either
worked altogether or separately. They may be opened or closed by means of
endless chains, racks and pinions, screws, or any other means found most
suitable, according to the size, form, and arrangement of the vessel to which
they are fitted.
I also propose to alter the usual shape of the opening of the well hole,.
making it follow the profile figure of the screw when viewed from above, the
screw being turned to bring the central part of its blades into a vertical line,
which is the position it will be required to take when it is raised or lowered.
This novel arrangement has the advantage of reducing, as far as is
practicable, the internal size of the well hole, and consequently the surface
which the sliding doors have to cover, and to give a greater length to the
guides for the shutters.
In Sheet I. of the accompanying Drawings, I have shewn in several views
the manner of applying my Invention to a steam vessel with a stern having
convex lines. Fig. 1 is a vertical longitudinal section taken through the
middle of the vessel; Fig. 2 is a projection of the well hole upon a plane
parallel to the axis of the propeller shaft, and perpendicular to the diametral
plane of the vessel; Fig. 3 is a transverse section taken perpendicularly to
the diametral plane by the line X, X, of Fig. 1; Fig. 4 is an underneath
view in the direction of the line X, X, of Fig. 1, and shewing the three
The blue
positions which the doors of the well hole may assume.
lines
shew the doors of the well hole resting against a
traverse bar T, as seen in the partial transverse section Fig. 5, this is
the position occupied by the doors when the screw is at work. The red
lines
represent the doors open, in the position they would
momentarily assume previously to raising the screw out of the water, or
adjusting it in its place. The black lines -------shew the doors shut, as
they are when the screw is raised and out of work (see also Fig. 3).
A, A, is the well, formed in the stern of the vessel, to permit of the propeller
being let down into and withdrawn from the water. This well is closed by
means of sliding doors B, which are guided and supported by parallel grooves
C, and supported by grooves D.

page_text: The sliding doors B are worked by means of chains G, which are securely
attached to the doors at H, and pass over guide pullies F, and round a
winding drum E, to which latter axial motion is given by means of an endless
screw N, taking into a pinion O, mounted on the shaft of the drum E. The
endless screw N may be worked by a spanner, as shewn in Fig. 3, or by any
other means. The chains and drums are enclosed in a metallic casing, for
the purpose of preventing the water from penetrating to the interior of the
vessel.
The propeller R is mounted in the ordinary manner of screw propellers,
with its front bearing at L, and its hinder bearing at M, (Fig. 2), and to,
facilitate its being raised and lowered, its frame slides between the front
groove I, and the hinder stern post J, which serve as guides. When lowered
into the water or submerged, as indicated in Fig. 1, the upper part T of the
propeller frame forms an abutment for the lips of the sliding doors, as shewn.
best at Fig. 5, but when the propeller is raised out of the water, and the
well hole doors are closed they will butt against each other, as shewn in.
Fig. 3.
The mode of applying the Invention to ships having concave transverse
lines of the stern is shewn in Sheet II., the figures and letters of reference
of which refer to corresponding views and parts in Sheet I., and therefore
need no special description.
Fig. 4 is an underneath view, according to line Y, Y, Fig. 3, of the three
positions which the sliding doors may assume.
It will be understood from the foregoing explanation, that my improvement.
in the closing of the well hole of steam ships is based on the employment of;
sliding doors arranged on opposite sides of the centre of the stern of the
vessel, and in such manner as to be capable of receding from or approaching.
towards each other by any mechanical means, the form of the vessel being.
such as will allow these doors in receding from or approaching each other to
shut and open the well hole.
On reference to Figures 2, 3, and 4 in Sheets I. and II., it will be seen
that, instead of the well hole taking, in the middle of its length, the form of a
rectangle in plan, I have contracted the space by building it with internal
projections, as at A*, A*, having the shape suitable to follow with a proper
clearance the configuration of the screw when its blades are in the position
shewn at Fig. 2. This mode of constructing well holes has the advantage of
giving greater supporting and guiding surface for the sliding doors, and to
diminish the internal volume of the well.
In the above description the Invention has been explained as adapted to a
i

page_text: single screw propeller, but it is equally applicable where the employment of
two or a greater number of lateral screw propellers is contemplated instead of
a central one, as it presents in many cases important advantages, especially in
vessels with a light draught of water, as it allows of the employment of a
greater extent of propelling surface than with a single screw, from which
less slip results; it allows of the greatest amount of displacement being given
to the stern with suitable sharpness.
Fixed lateral screws only have hitherto been used, and, probably never
lateral screws capable of being raised, by reason of the inconveniences
attending lateral screws having wells with their lower opening below the
water line, which has limited their useful application to a small number of
cases.
Side screw propellers capable of being raised would present, among several
other advantages, that of requiring the smallest possible length of well hole;
the fixed guides for the propeller and its frame offering only a slight resistance
to the water coming to the screw or escaping therefrom, will admit of being
arranged so as to provide just sufficient space between them for receiving the
boss of the screw.
The Invention can be applied to vessels already built by a proper alteration
of the formation of their stern and well hole, effected by means of filling and
lining pieces worked out in a suitable manner.
Having now set forth the nature of my Invention of "Improvements in
Constructing Ships and Vessels Propelled by Screw or such like Propellers,"
and explained the manner of carrying the same into effect, I wish it to be
understood that, under the above in part recited Letters Patent I claim, the
application to steam vessels of sliding doors or shutters, operating as above
described, for the purpose of closing the well holes of such ships, whether
the propeller or propellers be raised above or working in the water; and
I also claim the partial filling of the well hole, as described, for the purpose
above set forth.
In witness whereof, I, the said Augustin Normand, have hereunto set
my hand and seal, the Twenty-fifth day of March, in the year of our
Lord One thousand eight hundred and fifty-nine.
(L.S.) AUGUSTIN NORMAND.