IM- PROVEMENTS IN THE CONSTRUCTION OF SHIPS AND OTHER NAVIGABLE VESSELS
Year: 1875

page_text: LETTERS PATENT to François Colomban Etienne Marie Bénic, of
Boulevard de Strasbourg, No. 23, Paris, for the Invention of "IM-
PROVEMENTS IN THE CONSTRUCTION OF SHIPS AND OTHER NAVIGABLE VESSELS."
Sealed the 6th October 1875, and dated the 3rd July 1875.
1.
PROVISIONAL SPECIFICATION left by the said François Colomban
"Etienne Marie Bénic at the Office of the Commissioners of Patents,
with his Petition, on the 3rd July 1875.
;
I, FRANÇOIS COLOMBAN ETIENNE MARIE BÉNIC; of Boulevard de
Strasbourg, No. 23, Paris, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF SHIPS AND OTHER
NAVIGABLE VESSELS," to be as follows :—
My Invention relates to the construction of ships and other navigable
vessels in such a manner as to secure facility of steerage and turning,
statical stability, and especially small resistance to movement. For this
purpose I adopt a peculiar form for the submerged part of the structure,
a peculiar arrangement of the upper works, and a particular shape of
the load water line or plane at which the submerged structure terminates,

page_text: and on which as a foundation the upper works are reared, the whole
construction resulting from the combination of these several features as
I will now explain.
For the submerged portion forward I adopt the form of a conoid
having its apex at the front point of the keel and its axis inclined
upwards from that point backwards. The conoid swells towards the
middle body, presenting nowhere hollow water lines, but lines overywhere
convex, and from its greatest width, which is somewhat behind the
middle of the vessel's length, preferably about one-tenth, the conoid
again diminishes towards the stern, still presenting water lines of convex
curvature. The form of the conoid in conjunction with the inclination
of its axis affords an easy run for the displaced water, and the absence
of hollow or flat water lines has the effect of dispersing the molecules of
fluid, and thereby diminishing their resistance to displacement. The load
water line presents a curve which is very pointed towards the bow, has
its greatest width about one-tenth behind the middle of its length, and
is considerably more bluff aft than it is forward. For the extreme
width of this horizontal section I employ a much greater proportion of
the length than is usually adopted. For the longest vessels I make this
width about one-fifth of the length, and for small vessels it may be one-
fourth, one-third, or even one-half. Thus I am enabled to get a very
large midship section with great stability and very small resistance.
The upper works of the vessel instead of rising vertically or spreading
out above the load line in the usual manner are drawn much inwards,
so that a portion of the side of the vessel above the load line is an
inverted repetition of the portion below, and this arrangement by
affording little or no hold to the waves enables the vessel to act as well
in a sea way as on still water, and contributes in a high degree to the
safety and stability of the whole structure.
SPECIFICATION in pursuance of the conditions of the Letters Patent 3
filed by the said François Colomban Etienne Marie Bénic in the
Great Seal Patent Office on the 13th October 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANÇOIS
SPECIFICATION in pursuance of the conditions of the Letters Patent 3
filed by the said François Colomban Etienne Marie Bénic in the
Great Seal Patent Office on the 13th October 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANÇOIS
COLOMBAN ETIENNE MARIE BÉNIC, of Boulevard de Strasbourg, No. 23,
Paris, send greeting.
36

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of July, in the year of our
Lord One thousand eight hundred and seventy-five, in the thirty-ninth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said François Colomban Etienne Marie Bénic, Her
special license that I, the said François Colomban Etienne Marie Bénic,
my executors, administrators, and assigns, or such others as I, the
said François Colomban Etienne Marie Bénic, my executors, adminis-
trators, 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 THE CON-
STRUCTION OF SHIPS AND OTHER NAVIGABLE VESSELS," upon the condition
(amongst others) that I, the said François Colomban Etienne Marie
Bénic, my executors or administrators, 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 François Colomban Etiènne Maric
Bénic, do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement thereof, reference being
had to the accompanying Sheet of Drawings, and to the figures and
letters marked thereon, that is to say :-
-
My Invention relates to the construction of ships and other navigable
vessels in such a manner as to secure facility of steering and turning,
statical stability, and especially small resistance to movement. For this
purpose I adopt a peculiar form for the submerged part of the structure,
a peculiar arrangement of the upper works, and a particular shape of
the load water line or plane at which the submerged structure terminates,
and on which as a foundation the upper works are reared, the whole
construction resulting from the combination of these several features as
I will now explain.
For the submerged portion forward I adopt the form of a conoid

page_text: upwards from that point backwards. The conoid swells towards the
middle body, presenting nowhere hollow water lines, but lines everywhere
convex, and from its greatest width, which is somewhat behind the
middle of the vessel's length, preferably about one-tenth, the conoid
again diminishes towards the stern, still presenting water lines of convex
curvature. The form of the conoid in conjunction with the inclination
of its axis affords an easy run for the displaced water, and the absence
of hollow or flat water lines has the effect of dispersing the molecules of
fluid and thereby diminishing their resistance to displacement. The
load water line presents a curve which is very pointed towards the bow,
has its greatest width about one-tenth behind the middle of its length,
and is considerably more bluff aft than it is forward. For the extreme
width of this horizontal section I employ a much greater proportion of
the length than is usually adopted. For the longest vessels I make this
width about one-fifth of the length, and for small vessels it may be one-
fourth, one-third, or even one-half. Thus I am enabled to get a very
large midship section with great stability and very small resistance.
The upper works of the vessel instead of rising vertically or spreading
out above the load line in the usual manner are drawn much inwards,
so that a portion of the side of the vessel above the load line is an in-
verted repetition of the portion below, and this arrangement by affording
little or no hold to the waves enables the vessel to act as well in a sca
way as on still water, and contributes in a high degree to the safety
and stability of the whole structure.

page_text: The first concerns the front submerged portion, which whether in a
sea way or on still water is contrived to realize in the most complete
manner the three conditions, namely, facility of steering and turning,
statical stability, and particularly reduction of resistance.
The second feature relates to the upper work which is contrived to
obtain dynamical stability or equilibrium in a rough sea by presenting
littlo resistance to waves. I will describe these two features, referring
to the Drawings.
.
The front submerged portion is of the form of a conoid inclined
downwards towards the bow, its apex S being the lowest point of it's
volume, except such additional parts as the keel or lower futtock
curves, which may be varied in form and depth without affecting the
principal shape above. This shape is therefore a conoid, the lower
sections of which successively rise in level from the bow backwards to
the stern post; these sections in the front part of the vessel being of pear
shape and having their lower limbs nearly circular in form, and their
upper limbs drawn inwards to form the upper works. Towards the
middle of the vessel these sections widen out, becoming more and more
flattened in their lower parts, their sides still presenting a convex
curvature, and beginning to retreat inwards from about the level of the
load line. From the middle of the vessel to the stern the submerged
form presents no peculiarity, being a continuation of the form in front.
The dotted line S, S³, Fig. 1, indicates the mean line of the lower side of...
the conoid.
The whole of the submerged portion of the hull formed as above.
described is contrived to present at every part an equilibrium between
the load and the impulse of the liquid in which it is immersed, that is to
say, if the vessel were divided into a number of transverse slices each
slice would be self-supporting as if it were separated from the rest, and
as the forward slices have a full wide section in their lower parts they
necessarily diminish in their upper parts, so that the equilibrium may
be maintained. About the middle of the vessel and towards the stern,
on the other hand, the hull has to be widened above the load line
because there is less volume in the lower parts of its submerged sections.
Besides providing for equilibrium of floatation, the form described
provides also for reduction of resistance, as may be understood from the.
following considerations. The molecules of water being mobile and in-.

page_text: compressible, their mobility causing them to yield to a pressure, whilst
their incompressibility makes them resist it. When a surface is of such
a form as to crowd the molecules together or prevent their escape it
necessarily brings their incompressibility into play, that is, it develops
their resistance. Hollow or concave surfaces have this effect, their
normals being convergent, and consequently such surfaces are to be
avoided in the forward part of the hull. Plane or flat surfaces are also
to be avoided, because, their normals being parallel, the water is repelled
by them in the form of a column, having for its base the area of the
repelling surface, offering great resistance, particularly at high speeds
and in deep water, and especially if the reaction of the surface be down-
wards. Convex surfaces having diverging normals tend on the contrary
to separate the molecules or render them free, and thus to diminish the
resistance due to their incompressibility. Convex surfaces are therefore
to be chosen for the forward hull, and at the same time these surfaces
must have such sharpness as may facilitate advance through the liquid.
The cone presenting sharpness longitudinally with convexity trans-
versely fufils the required conditions, but as the submerged portions of
a hull have to be contrived with duc regard to the upper works a conoid
instead of a regular cone may be employed without serious diminution
of the advantages which the cone presents. Furthermore, the conoid
has to be inclined downwards towards the bow to suit the conditions of
the fluid pressure, which being always proportional to the depth is
greater on the lower than on the upper parts of the hull. By inclining
the under surface of the conoid the pressure thereon is rendered
favourable to the advance of the vessel, as is the case only with the after
parts of vessels of ordinary construction. It is true that by thus
inclining the conoid the pressure on its upper surface is opposed to the
advance of the vessel, but as that pressure is much less than the pressure
below, which favours the advance, the gain upon the whole is consider-
able. Thus the conoidal form described has sufficient sharpness for
penetrating the liquid, its inclination renders the under pressure
favourable to advance, and its sections shown at D, D, Fig. 3, are
suited for the free dispersion of the liquid molecules. Moreover the
equilibrium provided between the weight and fluid impulse at every
point by this form of hull distinguishes it from other forms by the
characteristic of its sections presenting rounded lower limbs spreading
more and more outwards to the middle of the vessel, and rising more and
more above the keel from stem to stern; thus giving a free passage for

page_text: water to the helm, and thereby rendering the effect of the helm excep-
tionally powerful for steering. Also by adopting this conoidal form-the
water lines are made sharp throughout a great part of their length in
front, and are wide about the middle so as to give great statical stability.
The general features of this construction may be summed up as
follows: The water lines should in their forward parts be rather convex
than straight, although even a slight concavity might be given to
those lines without affecting the general principles of construction.
The greatest width of the load line should be behind the middle,
preferably by about one-tenth of the length: For dynamic stability the
width even for the swiftest vessels should be at least one-fifth of the
length, but in small vessels it might be increased to one-fourth, one-
third, or even one-half of the length.
3
I will now describe the features of construction adopted for the upper
parts of the hull, of which the base is formed by the load line F, A, F,
Fig. 4, having a shape presenting great static stability on account of its
great width A, B, which much exceeds that of F, N, F, a curve of equal
area. But besides the static stability and easy penetration of the water
présented by the line F, A, F, it has the farther property of providing
for dynamic stability, so that the vessel in a heavy sea can behave as
in still water. Without demonstrating this property, I may say that
the form F, A, F, presents the greatest amount of general equilibrium
that can be attained consistently with the other conditions because it
nearly equalises the lateral and the longitudinal stability. It gives a
great laterál stability but a relatively small longitudinal stability, as may
be understood, by comparing the transverse and, longitudinal ordinates
of the curve F, A, F, with those of F, N, F. Upon this base, resulting
as already described from the adoption of the conoidal form for the
submerged hull, and presenting a maximum of general stability, the
upper hull is reared in such a manner as to disarm the waves and render
their effect in causing the vessel to roll comparatively null. The
narrowing in of the upper hull was practised up to the time that steam
began to be applied to vessels, but was generally abandoned afterwards.
Such a narrowing in has also been to a certain extent adopted in the
stems of ram vessel's, in order to provide for the projection of the ram,
Such narrowing in, however, though it is essential in the construction of
the upper hull, according to my Invention could not by itself provide

page_text: the dynamic stability at which I aim, but only in combination with the
base formed by the load line F, A, F, developed in the manner which I
have set forth.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I claim,-
First. The construction of the submerged hull of a vessel in the form
of a conoid inclined downwards towards the bow, substantially as herein
described.
Second. The construction of the upper hull of a vessel by narrowing
in the same from the load line presented by the horizontal section of the
conoid referred to in the preceding claim, substantially as and for the
purpose herein set forth.
In witness whereof, I, the said François Colomban Etienne Mario
Bénic, have hereunto set my hand and scal, this Twenty-third
day of September, in the year of our Lord One thousand cight
hundred and seventy-five..
Witness,
CHARLES FROSSARD,
23, Boulevard de Strasbourg,
à Paris:
F. C. E. M. BENIC. (L.S.)