IMPROVEMENTS IN THE FORMS OF THE HULLS OF SHIPS
Year: 1873

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN THE FORMS OF THE HULLS OF SHIPS."-A com-
munication from abroad by Eugène Corentin Béléguic, of Paris, in
the Republic of France, late Superior Officer in the French Navy.
Sealed the 15th July 1873, and dated the 26th May 1873.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 26th May 1873.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE FORMS OF THE HULLS OF SHIPS," a com-
munication to-me from abroad by Eugène Corention Béléguic, of Paris,
in the Republic of France, late Superior Officer in the French Navy, to
be as follows :—

page_text: hulls of vessels, which forms are based on the following principal
conditions:
First. To shape the front part of the bottom so that it may offer the
least obstacle to the ascent of the liquid which it displaces in moving
forward, as this liquid must of necessity rise to the surface; to effect
this an almost entire inversion of the forms in use is involved. The
extreme head which is designated the cut water has to divide the
waves in head seas, and to divert them to the right and to the left, so as
to prevent their dashing against the elevated portions of the vessel, and
retarding its progress.
Second. To combine the forms abaft so as to draw the water which
has to fill the space left by the bottom in retiring directly from the
surface and laterally, the replacement water being in fact able only to
come from the surface. This also involves the inversion of the existing
aft forms in their immersed part.
Third. To employ almost exclusively vertical' convex in lieu of
concave generating lines, approximating as much as possible to semi-
circumferences, on every elementary portion of the immersed bottom,
such form being intended to remove the water in order to make way for
the bottom, and admit of its passing along with every facility. To
employ but few plane surfaces, and the least possible of concave
surfaces, the resistances they occasion for the same extent in projection
being in about the proportion of the numbers 1, 3, 9.
Fourth. To diminish as much as possible the extent of the surfaces
on the immersed bottom which form an angle with the longitudinal axis
which are the only surfaces that produce a resistance or obstacle to the
progress of the vessel, also to reduce the span of the angles which
cannot be obviated in order to obtain the smallest sines and cause the
least resistance to the progress of the vessel; this resistance being equal
to the square of the sines of the angular surfaces. If a bottom could be
made which should offer no annular surfaces to the longitudinal axis,
it would experience no other resistance than that due to the friction of
the water which is insignificant against smooth surfaces. This is the
ideal to which it is requisite to approximate as closely as possible,
but which has never been applied completely to existing ships' bottoms
or hulls.

page_text: Fifth. To diminish as much as possible the width of the unimmersed
portion of the extremities in order so to reduce the pitching and the
shocks of the sea as to render them harmless, more particularly at the
bow, to bulge out on the contrary the mean and deep portions of the
immersed extremities (reduced to nothing in existing ships), in order to
impart to them a displacement which may sustain them sufficient always
to prevent their falling suddenly into the wave hollow with head or
stern seas, as at present takes place.
Sixth. To dispose the lateral portions throughout their length so as to
prevent a wave coming crosswise from ever violently striking against
them or imparting the motions termed rolling to the ship, and to prevent
the wave reaching the elevated portions, so as to flow over the upper
deck. Also, every plane surface of any extent should be obviated at the
unimmersed parts as far up as the gunwale in bottoms for sea-going
vessels, because the wave strikes the plane surfaces everywhere
simultaneously in the same direction, and subjects the vessel to violent
shocks, which put the strongest joints out of order in a few hours of
bad weather.
Seventh. To give a less draught of water to the stern than to the bow.
on which the ship pivots, in order to expedite and facilitate the evolutions
of large long bottoms, and to prevent all further danger of touching the
ground when the bow of the vessel has passed. This is an indispensable
condition of safety in navigation.
Eighth. To impart such strength and firmness to the extreme head of
the vessel as to enable it to destroy, without experiencing serious
damage, the obstacles which it may encounter, or which almost stop the
vessel short if the obstacle be too unyielding. The breasts of the vessel,
which are more or less vulnerable, are protected from any encounter; the
two external working parts of the stern, namely, the screw and rudder,
which are the most important parts of all from the point of view of
manoeuvering and actuating the vessel are also protected.
By conforming to these directions, the highest speeds will be obtained
whilst the dangers and fatigue of the longest voyages will be
obviated.
The novel forms of bottoms are moreover applicable to every
description of vessels, whether sailing or steam ships, and whatever may

page_text: be their dimensions or the particular purpose to which they are to be
applied, they being equally suitable for ocean and river navigation,
it will be understood that the relative dimensions of the different parts
of these vessels would vary according to their dimensions, their nature,
and the particular conditions under which they are required to operate,
but the general principles given remain constantly the same.

page_text: portions alone are presented, thus obviating the shocks from the wave,
and preventing the water from reaching the deck of the vessel by
throwing it off sidewise.
Fifthly. As to the load water line:
The establishing of a load water line, so that the draught of water
shall be greater at the head than at the stern, with a view to prevent
any accident happening to the vulnerable portions of the ship, the head
being constructed in a firm and strong manner, and provided with
water-tight partitions, which result may be obtained with very great
facility.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 22nd November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of May, in the year of our
Lord One thousand eight hundred and seventy-three, in the 36th
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special license
that I, the said John Henry Johnson, my executors, administrators, and
assigns, or such others as I, the said John Henry Johnson, my executors,
administrators, or 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 FORMS
OF THE HULLS OF SHIPS," a communication to me from abroad by Eugène
Corentin Béléguic, of Paris, in the Republic of France, late Superior
Officer in the French Navy, upon the condition (amongst others) that I,
the said John Henry Johnson, my executors or administrators, by an
instrument in writing under my hand and scal, should particularly
describe and ascertain the nature of the said Invention, and in what

page_text: manner the same was to be performed, and cause the same to be
nied 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 Henry Johnson, 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, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
med in the Great Seal ratent mince WIGHLI
هدة
сатопиат
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, 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, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:
-
The said Invention relates to certain novel forms of the bottoms or
hulls of vessels, which forms are based on the following principal
conditions:-
First. To shape the front part of the bottom so that it may offer the
least obstacle to the ascent of the liquid, which it displaces in moving
forward, as this liquid must of necessity rise to the surface; to effect
this an almost entire inversion of the forms in use is involved.
The extreme head, which is designated the cut water, should be so
made as to divide the waves in head seas, and to divert them to the
right and to the left, so as to prevent their dashing against the elevated
portions of the vessel, and retarding its progress.
Second. To combine the forms abaft so as to draw the water which
has to fill the space left by the bottom in retiring directly from the
surface and laterally, the replacement water being in fact able only to
come from the surface. This also involves the inversion of the existing
aft forms in their immersed part.
Third. To employ almost exclusively vertical convex in lieu of
concave generating lines, approximating as much as possible to semi-
circumferences on every elementary portion of the immersed bottom,
such form being intended to remove the water, in order to make way for
the bottom, and admit of its passing along with every facility. To
employ but few plane surfaces, and the least possible of concave
surfaces, the resistences they occasion for the same extent in projection
being in about the relative proportions of the numbers 1, 3, 9.
Fourth. To diminish as much as possible the extent of the surfaces on
the immersed bottom which form an angle with the longitudinal axis,

page_text: which are the only surfaces that produce a resistance or obstacle to the
progress of the vessel, also to reduce the span of the angles which cannot
be obviated in order to obtain the smallest sines and cause the least
resistance to the progress of the vessel; this resistance being equal to
the square of the sines of the angular surfaces. If a bottom could be
made which should offer no angular surfaces to the longitudinal axis,
it would experience no other resistance than that due to the friction of
he water, which is insignificant against smooth surfaces. This is the
ideal to which it is requisite to approximate as closely as possible, but
which has never been fully carried out in the construction of ships'
bottoms or hulls.
Fifth. To diminish as much as possible the width of the unimmersed
portion of the extremities, in order so to reduce the pitching and the
shocks of the sea as to render them harmless, more particularly at the
bow, to bulge out on the contrary the mean and deep portions of the
immersed extremities (reduced to nothing in existing ships), in order to
impart to them a displacement which may always sufficiently sustain
them to prevent their falling suddenly into the wave hollow of head or
stern seas, as at present takes place. The general form and arrangement
of the extremities of existing bottoms of ships' hulls is in fact a
flagrant violation of the primordial law which applies to any body
intended to move in the water; statical equilibrium is their capital
defect; as regards nautical qualities they all lack a basis a support for
the extremities.
Sixth. To dispose the lateral portions throughout their length so as to
prevent a wave coming crosswise from violently striking against them
or imparting the motions termed rolling to the ship, and to prevent the
wave reaching the elevated portions, so as to flow over the upper deck.
Also every plane surface of any extent should be obviated at the
unimmersed parts as far up as the gunwale in bottoms for sea-going
vessels because the wave strikes the plane surfaces everywhere
simultaneously in the same direction, and subjects the vessel to violent
shocks, which strain the strongest joints in a few hours of bad
weather.
Seventh. To give a less draught of water to the stern than to the bow
on which the ship pivots, in order to expedite and facilitate the evolutions
11
1°

page_text: after the bow of the vessel has passed. This is an indispensable condition
of safety in navigation.
Eighth. To impart such strength and firmness to the extreme head of
the vessel as to enable it to destroy without experiencing serious damage,
the obstacles which it may encounter or which almost stop the vessel short
if the obstacle be too unyielding. The breasts of the vessel, which are
more or less vulnerable, should be protected from every encounter; the
two external working parts of the stern, namely, the screw and
rudder, which are the most important parts as regards the mancauvering
and actuating of the vessel should also be protected. This latter
condition, videlicet, the preserving the breasts, and the moving and
steering parts is of the greatest importance.
By conforming to these directions, the highest speeds will be
obtained, whilst the dangers and fatigue of the longest voyages will
be obviated.
The novel forms of bottoms are, moreover, applicable to every
description of vessels, whether sailing or steam ships, and whatever
may be their dimensions or the particular purpose to which they are to
be applied, they being equally suitable for ocean and river navigation,
it will be understood that the relative dimensions of the different
parts of these vessels would vary according to their dimensions, their
nature and the particular conditions under which they are required to
operate, but the general principles given remain unaltered.
The annexed Drawings shew the application of principles and rules
herein-before set forth to a sea-going ship's bottom. These forms may,
however, be slightly modified with facility according to the purpose for
which the ship may be intended, and the particular functions it may be
required to fulfil whether on seas, rivers, or canals, but the principles
and rules upon which these forms are constructed remain as invariable
and fixed as the laws upon which they are founded, and on the
mathematical and natural application of which this Invention is
based.
Figure 1 of the Drawings is an clevation of a ship's bottom on this

page_text: Figure 3 represents a scrics of transverse sections of the improved
form of bottom for a single screw propeller.
And Figure 4 represents similar sections of the improved bottom for
twin screws.
The following are the principal dimensions :-Length of ship, 262 feet;
width, 32 feet 9 inches; draught of water at the bow, 16 feet 4 inches;
draught of water at the stern, 14 feet 1 inch.
L, E, represents the water line; G, A, the forecastle; P, B, the gun-
wale; L, A, the supporting rail; D, the poop; E, the hawsc holes;
2, 7, the increased width for single screw; P, L, the increased width for
twin screws; y, the swan's neck.
Some of the principal conditions to be fulfilled in a properly designed
ship's bottom have been partially and experimentally tried in the advice
boat "Renard," thus resuming these conditions in the order in which
the principles and rules have been already laid down.
"
First. The front part of the "Renard offers little obstacle to the
ascent of the displaced liquid, but it is wholly incomplete, being a simple
head between wind and water; it is neither sufficiently deep to sustain
the bow when the wave hollow presents itself, nor sufficiently high to
divide the wave to its crest, and throw it enough to the right and left to
prevent its reaching the upper portions of the vessel.
In the form of ship shewn in the accompanying Drawing, by giving
the extreme head on the contrary the greatest draught of water with tho
addition of the swan's neck, the head of which rises as high as the
bowsprit which it firmly maintains at its outer extremity, the two
objects mentioned are fully attained.
In the "Renard," morcover, the hawse holes for the chains are 7 or 8
metres in the rear of the stem or cut water, and the chains wear away
the head which the anchors frequently strike against in anchoring. Any
mooring is next to impossible in the " Renard," and the turns which
are formed in the chains when the vessel stems, the wind or the current
are extremely difficult to be unreaved, a work demanding great effort
even in a dead and calm sea.
In the new form of bottom the hawse holes are carried forward to the
stem at the extreme head, and the anchoring as also the whole of the
manoeuvres with the anchors and the chains are performed with the

page_text: greatest facility. It is necessary to add on good authority that this
form of head obviates all pitching of vessels in high seas.
Second. The improved arrangement of the stern portion of the bottom
forming part of this Invention is entirely novel, and constitutes a perfect
anti-roller. These bottoms never roll, even in the most undulated seas,
and they always remain almost absolutely firm and still.
Third. In certain portions of the "Renard" the convex surfaces are
roughly applied to the immersed bottom. In the new bottoms they are
completed to the side parts, and to the stern as well as to the bow.
There is scarcely a trace of them at the stern of the "Renard," that
being one of its great defects with its ungovernable rollings when the
undulations of the sea come from aft midships; the "Renard,” more-
over, lacks stability.
Fourth. The same observation applies to the extent of the angular
surface on the longitudinal axis, and the span of the angles which
cannot be eliminated; they are somewhat diminished in the "Renard"
in certain parts, but much more reduced in the new bottoms both at the
stern and at the bow, which imparts to them unusual speeds. By reason
of the novel forms of bottoms these speeds may be considerably increased
by adding to the length of bottom.
Fifth. In order to obtain at the front part of the bottom, which
directly encounters head seas, a displacement, capable of sustaining the
bow when the wave hollow presents itself, it is absolutely necessary that
there shall be the largest draught of water with a wide base at the deep
portion capable of so opposing itself as to overcome any sudden down-
ward motion. The bottom has also to move forward horizontally without
its extremities being depressed or elevated by the undulations of the sea.
The whole of these conditions are perfectly fulfilled by the herein-before
described novel forms of ships' bottoms.
Sixth. The lateral portions of the improved bottoms, as far as the
gunwale, are so arranged from one end to the other that the wave shall
encounter only a very slight surface at one time, and that each
elementary portion shall be struck in a different direction from the
neighbouring elementary portions, whence concussions and thrusts are
obviated, the joints of the hull are no longer injured by reason of the
shocks of the sea, and as the durability of the ships is increased to an
indefinite extent the damages become nil, or exceedingly rare.

page_text: Seventh and Eighth. (Lastly.) The absolutely novel idea of giving the
largest draught of water to the bow (which may be easily rendered
invulnerable to shocks, in order to protect those parts most liable to
injury, such for example, as the breasts, rudder, and screws) will reduce
to an indefinite extent the dangers incurred by ships on narrow coasts,
and in shallow waters.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,―
First. The so proportioning the depth, height, and thickness under
the water line of the extreme head or bows of a vessel as to prevent its
falling into the wave hollows to facilitate the ascent of the water
displaced, and to admit of the acuteness of the angles of the ship, as
herein before described and illustrated by the Drawings annexed.
Second. The addition of a swan's neck, or its equivalent, destined to
divide the wave, support the bowsprit, and admit of the illumination of
the deep portions of the ship, as herein-before described and illustrated
by the Drawings.
Third. The placing or forming the hawse holes in the stem of
the extreme head, as herein-before described and illustrated by the
Drawings.
Fourth. The peculiar arrangement of the stern part of the bottoms
of ships, whether for one or two screws, so as to constitute anti-rollers,
and to ensure the filling of the space left by the vessel, especially with
water descending from the surface, and partly by the water arriving
from the sides, as herein-before described.
Fifth. The application of convex surfaces throughout the length of
the immersed part of the bottom of a ship, so as to form a continuous
bulging at each side of the vessel, and effect at every part the displacing
and replacing of the liquid, whereby a bottom is obtained, having the lower
surface almost entirely straight and plane, which imparts great stability
to the ship, as herein-before described and illustrated by the Drawings
annexed.

page_text: :
Sixth. The peculiar arrangements of the non-immersed lateral
portions of ship's hulls, wherein all plane surfaces are dispensed
with, and curved portions alone are presented, thus obviating the shocks
from waves, and preventing the water from reaching the deck of the
vessel by throwing it off sideways, as herein-before described and illus-
trated by the Drawings.
Seventh. The so establishing a load water line that the draught of
water shall be greater at the head than at the stern, with a view to
prevent any accident occurring to the vulnerable portions of the ship,
the head being constructed in a firm and strong manner, and provided :
with water-tight partitions, which result may be obtained with great
facility, as herein-before described and illustrated by the Drawings.
Eighth. The general construction and arrangement of the hulls of
ships for sea or inland navigation, substantially as and for the purposes
herein-before described and illustrated by the Drawings annexed.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Twenty-first day of
November One thousand eight hundred and seventy-three.
F
J. HENRY JOHNSON. (L.S.)