IMPROVEMENTS IN PROTECTING. SHIPS, FORTS, AND OTHER VESSELS OR STRUCTURES AGAINST INJURY FROM PROJECTILES
Year: 1876

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
PROTECTING. SHIPS, FORTS, AND OTHER VESSELS OR STRUCTURES AGAINST
INJURY FROM PROJECTILES." A communication from abroad by Edouard
Pierre Tardy, of Paris, in the Republic of France.
|Scaled the 4th May 1877, and dated the 30th December 1876.
PROVISIONAL SPECIFICATION left by the said. John Henry Johnson at
the Office of the Commissioners of Patents on the 30th December 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN PROTECTING SHIPS, FORTS, AND OTHER VESSELS
OR STRUCTURES AGAINST INJURY FROM PROJECTILES." A communication from
abroad by Edouard Pierre Tardy, of Paris, in the Republic of France.
This Invention relates to the protection of ships, forts, and other vessels or
structures against injury from projectiles, and consists of a system of cells for con-
taining the armour plates, the backing, and an elastic cushion, one of the walls of
the cells constituting an inner skin to the armour, and the opposite walls con-
stituting an outer skin therefor.
The cells, which may be constructed in the shape of a parallelopipedon, truncated
pyramid or prism, or of other suitable form, are arranged on the outside of metal
plates, constituting a second or inner skin, and connected thereto by means of
vertical sheet metal ordinates or partitions shaped to correspond with the internal
curves of the vessel. The backing, cushion, and armour plating are placed in each
cell, and are retained therein by a sheet metal cover firmly secured to the sides of
the cell, all round its periphery, by means of angle iron or metal of other suitable
form attached by rivets. The whole of these covers are firmly connected together
side by side and constitute a second external skin.
The ordinates and the horizontal sides or plates of the calls are secured to the
inner and outer skins, and the horizontal plates are united to one another by means
of angle irons or other suitable connections rivetted or bolted together.
The backing is arranged within the cells next to the inner sides, and is composed
of beams of oak, teak, or other wood of like nature, of a length corresponding to the
distance between the ordinates, and arranged horizontally, each beam being separated
[Price Bd. 1

page_text: by a plate of sheet iron secured to the plates of the inner skin; with a view to in-
creasing the power of resistance of the inner skin and the rigidity of the internal
curves horizontal webs of semicircular form, internally supported by angle irons or
other projections of suitable form, are provided inside the vessel and attached to the
inner skin at points about midway between the top and bottom of the cells, which
webs act as arches, serving to strengthen the internal skin. The cushion within the
cells is arranged so as to be in contact with the backing, and is composed of a sheet
of india-rubber of less dimensions, that the internal dimensions of the cell in order
to render it susceptible of compression without breaking the sides of the cell, or it
may be perforated with holes in the direction of its thickness, or be provided with
internal cavities or air chambers so as to admit of the india-rubber contracting, or
of its being more readily compressed.
The armour plating of iron, steel, or any other metal of any suitable thickness,
but of a length and breadth equal to that of the interior of the cell, is arranged so as
to bear against the cushion, and is secured by a metal cover (constituting one of the
outer skins) of any suitable thickness, strengthened by a projecting frame or border
formed of angle iron, or metal of other suitable form, secured by rivets or bolts to
the vertical ordinates or partitions, and to the horizontal partitions of the cells.
Between the armour plate and the plate forming the cover there may be interposed
a sheet of india-rubber or other suitable elastic material, for the purpose of deaden-
ing the shocks which might be transmitted to the cover from the plate or fragments
of the plate by reaction. This cover is filled up to a level with the external edge
of the angle irons with caulked planking or other suitable materials secured by bolts
to the plate of the cover.
The covers are rivetted or bolted together, and to the vertical ordinates or
partitions as well as to the horizontal plates or partitions, and thus constitute a
second external skin without any break in its continuity, a sheathing or outer cover-
ing of zinc or other suitable metal being provided, which constitutes the continuous
external skin of the vessel for the purpose of ensuring its preservation.
For protecting surfaces having a single or double curve, such, for example, as
certain ports of a ship and of a turret, the system of cells herein-before described
may likewise be applied by making the cells of a prismatic form or in the shape of
a truncated pyramid.
In order to better ensure the invariable position of the plates secured as hercin-
before described, bolts may in certain cases when required be fixed to the armour
plates, such bolts passing through the cushion and the backing as well as the inner
skin.
The cellular system herein-before described may be likewise applied when
employing a backing, or cushion, or both, constructed of inflexible materials, such,
for example, as wood, or constructed of elastic material, such, for example, as india-
rubber, cork, or other elastic medium.
The cells may be provided with either a single thickness of armour plating as
herein-before, or several thicknesses of armour plating may be placed one
over the other, separated or not by cushions of any suitable substance. The
covers of the cells may be placed in direct contact with the plates, or separated
from them by the interposition of a cushion of any suitable elastic or non-elastic
material,
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 29th Juno
1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. “IMPROVEMENTS IN PROTECTING SHIPS, FORTS, AND OTHER VESSELS
OR STRUCTUREs against InjJURY FROM PROJECTILES." A communication from
abroad by Edouard Pierre Tardy, of Paris, in the Republic of France.
5

page_text: The armour plates employed for protecting the sides of ships or the walls of
fortifications are ordinarily secured by screws or by bolts; in some cases wood
screws are employed, which are passed through the plates and simply fixed in the
backing and in the cushion, or to one of them only; in other cases bolts are used,
passing through the cushion, the backing, and the inner skin, the plate being fixed
by means of nuts situate inside the ship or battery.
Plates attached by the former method are insufficiently secured, and are liable
to become detached under comparatively moderate strains, carrying with them.
sometimes portions of the cushion or of the backing to which they are attached by
the screws. According to the latter method of securing the plates the inner skin is
greatly weakened by the holes for the bolts of the armour plates, and rendered
incapable of resisting the occasionally severe strains which are transmitted to it
from the plates under the blows of projectiles and the reaction which follows such
blows. In all cases, however, whatever may be the method ordinarily adapted for
attaching the plates, there results a diminution, to a greater or less extent, of the
power of resistance, either of the plate or plates or of the backing or inner skin, or
of both.
As the arrangements adopted are usually based upon the principle of placing the
plates externally upon the side of the vessel or wall of the fortification, it results
therefrom that when the impact of a projectile causes the rupture of the plates
fragments of plates are projected in all directions, large pieces boing sometimes
detached from the backing, especially when heavy projectiles are employed, leaving
the backing exposed, without protection, to the blows of succeeding projectiles
which may strike it at this point.
The injury inflicted on the inner skin and backing is much greater when a pro-
jectile strikes the plates (even without perforating them completely) below the
water line, in consequence of the more or loss serious leakage which may ensue
therefrom. Now the said Invention has for its object providing against the dis-
advantages herein-before in part enumerated, by establishing a system of cells, one
of the walls of which constitutes an inner skin, whilst the opposite wall forms an
outer skin, the backing, cushions, and armour plates being arranged between
the two.
The cells, which may be constructed in the shape of parallelopipedon, truncated
pyramids, or prisms, or of other suitable forms, are arranged on the outside of metal
plates, constituting the inner skin, and are connected thereto by means of vertical
sheet metal ordinates or partitions fitted externally to the inner skin, and shaped to
correspond with the internal curves of the vessel. The backing, cushion, and
armour plating are placed in cach cell, and are retained therein by a sheet-metal
cover firmly secured to the sides of the cell all round its edge or periphery by means
of angle iron or metal of other suitable form attached by rivets or otherwise. The
whole of these covers are firmly connected together side by side, and constitute a
second or outer skin.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents a longitudinal section taken
along the line A, C, D, E, (Figure 2) illustrating the improved arrangement of
armour plating; Figure 2 is a sectional plan of the same, the section being taken
along the line F, G, (Figure 1); and Figure 3 is a transverse section taken along
the line H, I, Figure 1.
The vertical external ordinates or partitions A. made of sheet metal are shaped to
correspond with the internal curves of the vessel. The horizontal divisions or
partitions B are also formed of sheet metal, and their length is equal to the interval
between the ordinates or partitions A, and their width equal to that of such
ordinates or partitions. The partitions A and the horizontal plates B are secured to
the inner skin C, as well as to the outer skin D, and the plates B are united to one
'
"

page_text: another by means of angle irons or other suitable connections riveted or bolted
together.
The backing E is arranged next to the inner skin C within the cells formed by
the partitions A and plates B, between the inner skin C and outer skin D, and is
composed of beams of oak, teak, or other wood of a like nature, of a length corre-
sponding to the distance between the partitions A, and arranged horizontally. The
beams are separated the one from the other by plates G of sheet metal placed hori-
zontally, and secured to the plates of the inner skin C. With a view to increasing
the power of resistance of the inner skin and the rigidity of the internal curves
horizontal webs H of semicircular form (internally) supported by angle irons or
other projections of suitable form are provided inside the vessel, such webs, which
are attached to the inner skin C at a point about midway between the top and
bottom of the cells, acting as arches, which serve to strengthen the inner skin. I is
a cushion, consisting of a sheet of indin-rubber, arranged so as to be susceptible of
compression without the liability of breaking or bursting the sides of the cell in
which it is placed. For this purpose the said sheet may be made of less dimensions
than the interior of the cell, as shown at i, or it may be perforated with holes in
the direction of its thickness, as shewn at i, or be formed with internal cavities or
air chambers, as shown at ², thereby obviating or diminishing the strain upon the
walls of the cells when the india-rubber is subjected to pressure.
The armour plating K, which may be composed of iron, steel, or any other metal
adapted for the purpose, and be constructed of any suitable thickness, but of a
length and breadth equal to that of the interior of the cell, is arranged so as to
bear against the cushion I, and is secured by a metal cover D (constituting the
outer skin) strengthened by a projecting frame or border M formed of angle iron
or metal of other suitable form, which is secured by rivets or bolts to the vertical
partitions A and to the horizontal partitions B of the cells. Between the armour
plating and the plate D forming the cover there may be interposed a sheet of india-
rubber, or other suitable elastic material, for the purpose of deadening the shocks
which might be transmitted to the cover from the plate or fragments of the plate
by reaction. This cover is filled up to a level with the external edge of the angle
irons with caulked planking N, or other suitable materials, secured by bolts to the
plate of the cover.
All the covers are rivetted or bolted together and to the vertical partitions A, as
well as to the horizontal partitions B, and thus constitute a second or outer skin
without any break in its continuity, an outer covering O of zinc or other suitable
metal being provided, which forms the continuous sheathing of the vessel for the
purpose of ensuring its preservation.
In the arrangement shown in the Drawing the armour plating K is capable of
being displaced under the impact of projectiles and of compressing the elastic
cushion I, which has the advantage of deadening the force of the shock and of
better distributing it over a larger area on the backing and skin and considerably
diminishing its effects.
For protecting surfaces having a single or double curve, such for example as
certain parts of a ship and of a turret, the system of cells herein-before described
may likewise be applied by making the cells of a prismatic form or in the shape
of a truncated pyramid, according to the arrangement which is preferably adopted
for placing the cells upon the surface to be protected.
In order to better ensure the stability of the plates, secured as herein-before
described, bolts may in certain cases when required be fixed to the armour plates,
such bolts passing through the cushion and the backing as well as the inner skin.
The cellular system, herein-before described, may be likewise applied when
employing either a backing or cushion, or both, constructed of inflexible materials,
such for example as wood, or constructed of elastic material, such for example as
india-rubber, cork, or other elastic medium. The cells may be provided with either
a single thickness of armour plating, as herein-before described, or several thick-
nesses of armour plating may be used, placed the one over the other, and separated

page_text: or not from one another by cushions of any suitable substance. The covers of the
cells may be placed in direct contact with the plates or separated from them by
the interposition of a cushion of any suitable elastic or non-elastic material.
The shape of the cells may also be varied as required to adapt them to the form
of the plates which they are to contain, and which may be of a rectangular,
square, or polygonal shape, and of any suitable dimensions.
In some cases, with the view of better utilizing the materials, the plates con-
stituting the sides of the cells may have openings cut or formed in thein, so as to
reduce the weight. The cover of the cells applied externally against the armour
plate may be composed of a metal plate, with a frame or mounting of angle iron, or
other suitable forin, fixed to the plates constituting the sides of the cells; this
cover plate may also have portions cut away in order to diminish its weight, thus
leaving the external face of the armour plate entirely or partially uncovered. The
cover plate may also be wholly dispensed with, the armour plates in this case being
secured to the sides of the cells either by frames or mountings formed of suitable
bars, rivetted or bolted, or by various arrangements of bars, clamps, hooks, stops,
wedges, or any other suitable appliances calculated to fix each plate immoveably
in its respective cell, which may thus remain partially or wholly open or closed.
The external coverings of wood, herein-before referred to, may be either used or
dispensed with, according to circumstances, having regard to the varied position of
the armour consequent upon its different applications, as for example, for the
protection of the hull of a vessel or for internal forts, redoubts, and turrets, or for
fortifications, batterics, and the like.
By means of the said Invention greater power of resistance in the armour
plating is obtained, and the detachment of fragments is prevented when the plates
are subjected to the blows of ordinary projectiles, or of rams, torpedoes, and the
like.
Having now described and particularly ascertained the nature of the said Inven-
tion, 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, the system or mode of protecting ships, forts, and other vessels
or structures, by enclosing the backing cushions and armour plates in cells, within
which they are held in position substantially as and for the purposes herein-before
described.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, this Twenty-eighth day of Juno, One thousand
eight hundred and seventy-seven
J. HENRY JOHNSON. (L.S.)