IMPROVEMENTS IN DEFENSIVE ARMOUR
Year: 1862

page_text: LETTERS PATENT to Charles Hodge Hudson, Merchant, of the City of
Roxbury, in the County of Norfolk, in the State of Massachusetts, one
of the United States of America, for the Invention of "IMPROVEMENTS IN
DEFENSIVE ARMOUR."
Sealed the 11th November 1862, and dated the 27th May 1862.
PROVISIONAL SPECIFICATION left by the said Charles Hodge Hudson
at the Office of the Commissioners of Patents, with his Petition, on the
27th May 1862.
I, CHARLES HODGE HUDSON, Merchant, of the City of Roxbury, in the
County of Norfolk, in the State of Massachusetts, one of the United States
of America, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN DEFENSIVE ARMOR," to be as follows:-
The object of my Invention is to lessen the result of the percussion of pro-
jectiles on the support of metallic armor by the introduction of water between
the said armor and its support and around the fastenings of the armour, which
I-effect by covering the surfaces exposed to the impingement of projectiles
with a cellular structure, presenting a heavy metallic surface to the action of
projectiles, and capable of retaining water within its cells or between the
exposed metallic armor plates and their support.
This system of defensive armor is applicable to all kinds of fortifications,
and even to personal armor, as well as to vessels, to which it has peculiar

page_text: adaptation. The beneficial results arising from the introduction of water
between metallic armor plates, and their support, are based upon two of the
well-known properties of water, viz., its almost total incompressibility and its
mobility, by which force applied to water is distributed in all directions equally
throughout its mass. The division of the water behind the armor by the
cellular structure is preferred, because without it the rupture or perforation of
the armor might, under some circumstances, injure its efficiency by depriving
the whole of the armour of the solid resistance of the backing of the water.
It is not necessary that the subdivision should be very minute, but it is
necessary that the cellular system should sufficiently prevent any very great
amount of armoured surface from becoming less efficient consequent upon a
single break in the armour.
The gist of this Invention does not consist in the detail by which it is
carried into effect, which detail is susceptible of a great variety of changes, but
in the introduction of water or other liquid behind metallic armor, and
between it and its support, or the surface or material which the metallic
plating is intended to protect for the purpose of lessening the effect on the
said support surface or material of the percussive action of projectiles.
In the use of my Invention, protection from the action of projectiles is not
obtained by water alone, or by metallic armour alone, but by the use of both
in combination, the water acting to reinforce the heavy armour, and to dis-
tribute the force of blows from projectiles equally in all directions and over
large surfaces, so as to diminish the destructive effects of the blows on
the support of the armour, and on its fastenings, and the heavy metallic
armour acting to prevent penetration of the water backing, and of the thing
protected.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Charles Hodge Hudson in the Great Seal Patent Office
on the 27th November 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HODGE HUDSON, Merchant, of the City of Roxbury, in the County of Norfolk,
in the State of Massachusetts, one of the United States of America, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of May, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Hodge Hudson, Her special licence that I, the said Charles
Hodge Hudson, my executors, administrators, and assigns, or such others as I,
the said Charles Hodge Hudson, 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 "IMPROVE-
MENTS IN DEFENSIVE ARMOR," upon the condition (amongst others) that I, the
said Charles Hodge Hudson, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should parti-
cularly 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 Charles Hodge Hudson, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the fol-
lowing statement :-
The object of my Invention consists chiefly in the use of certain means,
appliances, and arrangements for the purpose of lessening the percussion of
projectiles upon the backing or supports of metallic armour, by the introduc-
tion of water between the said supports and the protecting armour, and also
around its fastenings. I effect this by covering the surfaces exposed to the
action of projectiles with a metallic structure of a cellular form presenting a
strong surface to the action of the projectile, and, from its construction,
capable of holding and retaining water within its cells or between its inner
surface and that of the supports or backing. This arrangement or system of
defensive armour is applicable to all kinds of objects, whether moveable or
fixed on land or water, although chiefly applicable to ships.
The beneficial results to be obtained from the introduction of water between
the armour plates and their supports are based upon two well-known pro-
perties of water, its almost total incompressibility and its power of transmitting
force equally and in every direction. I prefer that the water should be
distributed, whether within or behind the structure of the armour, in divisions
or compartments, so that the destruction of any one division would not
materially affect the perfect action of the others.
In carrying out the principle of introducing water in compartments between
the supports and the armour, or within the structure of the armour, several

page_text: are amply illustrated in the accompanying Drawings appended herewith, and
fully given in the following description :―
DESCRIPTION OF THE DRAWINGS.
The first of my plans for carrying out the said principle consists in
covering any part of an object which is to be protected from or against the
action of projectiles with a casing of metallic tubes, consisting of one, two, or
more rows in thickness, or arranged so as to form an angular surface. These
tubes are firmly held to the supports or to the skin of the ship by means of
metallic plates stretching across the surface, and fastened at the bottom to the
skin and frame of the ship under or near the water line, while the upper
portion of the plate being turned inwards, is fastened to the inner part of the
ship's frame, deck, or sheathing.
Figure 1 of the Drawings shews a cross section of a ship, having one row
of the said tubes h, h, affixed on the ship's side m, and held on by the covering
armour plate n, which passes below the water line, and returns over the top
of the bulwark, and is bolted on the inside of it, hence the fixing is not liable
to be loosened by any direct action of a projectile. The same arrangement of
tubes is also shewn applied to the surface of a ship's deck.
Figure 8 shews the same arrangement of tubes, but with two rows fixed on;
Figure 9 shews an arrangement where the tubes are made to form a conical
or angular surface so as to increase the resistance of the armour, and at the
same time to diminish the effect of the projectile by causing it to glance off.
I propose, whenever the ship or other object is about to be subjected to shot,
to introduce at discretion into these tubes, and also when expedient within the
interstices between them, water, which effects a three-fold purpose, that is to
say, firstly, it increases the displacement of the ship, and thus presents less
surface to be acted upon; secondly, it increases the resisting power of the tubes
or armour to the force of the impingement of the projectile; and, thirdly, it
protects the frame, the fastenings, and the supports of the armour. This
armour or parts of the same may of course be used at discretion without the
introduction of water, but in such case its utility might be greatly impaired.
The form I prefer for the armour plates here used to fasten on and cover the
tubes is shewn in Figures 5, 6, 7, 8, and 9. In some cases I propose to form
such armour plates with two hinges, as shewn in Figure 6, in order that they
might be easily thrown back to allow the tubular arrangement to be inspected
or repaired, and for other purposes of convenience and advantage.
The next plan which I propose to adopt, in order to apply the water com-

page_text: partment principle, and also to protect the armour fastenings from the impact
of projectiles, consists in turning and returning the ends of armour plates so
as to form with the side of the ship or other object a hollow and nearly
rectangular compartment. This arrangement is shewn in detail in Figures 2,
3, and 4 of the appended Drawings, Figure 2 being a cross section, Figures
3 and 4 perspective views of several plates, with details of filling up, and the
separation into distinct compartments. It will be thus seen that each plate a
has its end turned at b, and returned at c¹ parallel with the skin of the ship.
A clip or washer bar c is then placed along and over the returned part of the
plate c', to which the bolts are fastened.
The arrangement in Figure 2 differs slightly from that shewn in Figures
3 and 4; in Figure 2 the plates are shewn as vertical, and are also extended
deep under the water to guard against the action of a ram or of a projectile
discharged under the water. In Figures 3 and 4 it will be seen that I
introduce backing or filling up timbers or planks d, d, d, along the skin to
bring the surface flush along the inner side, and also to give additional pro-
tection to the skin, but they may be dispensed with, if preferred. In order to
subdivide the compartments formed by each row of plates, I propose to
introduce a series of hollow boxes or troughs f, f, placed over the joints of
each pair of plates, as at f. These troughs or boxes will not only strengthen
at the weakest point the resistance of the plates, and also the frame of the
ship, but they also serve to separate the compartments for the water, which
may be introduced, as before-mentioned, whenever requisite.
In Figure 4 is shewn a different arrangement of the troughs formed by
double T-beams or girders, which break joint with each pair of plates, and
receive the water, as before-mentioned. Figure 1 shews another arrangement
by means of which the water can be introduced between the skin of the ship
and the armour plates, and also on the deck. In this Figure is also shewn a
method of extending the armour above the side of the ship and over the deck.
If necessary, this can be carried wholly over the deck, the water being intro-
duced between the plates and supports, as before mentioned. . I have not
shewn any particular mode of introducing the water into the compartments, as
this may be effected in a great variety of ways, none of which I claim in
particular.
Having now described the nature of my Invention, and the object of the
same, and how it is carried into effect, and suggested different ways in
which it may be modified in its application according to circumstances, and
the objects to which it is applied, I wish it understood that I do not bind
myself to the exact minute details herewithin shewn of its application, as it is

page_text: evident that these may be in many particulars substituted by many obvious
equivalents; but what I do claim and wish secured by the before in part
recited Letters Patent is, the use and application of a metallic armour to
be applied to ships, batteries, forts, turrets, towers, and defences, either
moveable or fixed, the said armour being so constructed, that when it is sub-
jected to the action of projectiles, it will permit the introduction of water either
within the structure of the said armour, or within and between the said
armour and its supports and the frame of the object to which it is applied,
substantially as herewithin described and more particularly shewn in the
several systems of construction illustrated in the different Figures of the
Drawings herewith appended.
And I also claim, as a defensive armour, the use of plates similar in form
and arrangement to those shewn in Figures 5 and 6, whether the said plates
are used in combination with the tubes, as shewn in Figures 7, 8, 9, or
without them, as in Figures 5 and 6, substantially as herewithin described and
set forth.
In witness whereof, I, the said Charles Hodge Hudson, have hereunto
set my hand and seal, this Twenty-fifth day of November One thousand
eight hundred and sixty-two.
CHARLES HODGE HUDSON. (L.S.)