IMPROVEMENTS IN ARMOUR FOR FORTS AND FLOATING BATTERIES
Year: 1863

page_text: LETTERS PATENT to James Chalmers, of 8, Knight's Place, Vauxhall,
for the Invention of "IMPROVEMENTS IN ARMOUR FOR FORTS AND FLOATING
BATTERIES."
Sealed the 24th November 1863, and dated the 1st June 1863.
PROVISIONAL SPECIFICATION left by the said James Chalmers at the
Office of the Commissioners of Patents, with his Petition, on the
1st June 1863.
I, JAMES CHALMERS, of 8, Knight's Place, Vauxhall, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN ARMOUR FOR FORTS
AND FLOATING BATTERIES," to be as follows:-
This Invention has for its object to combine economy in cost with strength,
and consists of the following improvements:-The backing to support the
armour plates shall consist of layers of iron plates, so manufactured that they
will bind or unite into a compact body when built up and forced together.
And for this purpose I propose to use iron of the cross section shown in the
margin, or any other suitable section that will bind when two plates are laid
together. Commencing at plate a,
a
which may be
securely attached to the permanent work, the plate 6 is placed upon it, and is
by the lower flanges attached thereto prevented from shifting edgeways.
Another plate a is then placed upon plate b, and is bound by the upper
securely attached to the permanent work, the plate 6 is placed upon it, and is
by the lower flanges attached thereto prevented from shifting edgeways.
Another plate a is then placed upon plate b, and is bound by the upper

page_text: flanges, and as the thickness of plate a is double the depth of the recess
between the flanges on one side of plate 6, half of its thickness is left pro-
jecting upwards, and is in turn covered by another plate b, and so on until the
desired surface be covered. These plates or bars may be of any convenient
length, from 6 to 12 inches broad, and from " to 2 inches in thickness, all
more or less. I propose that the flanges of the bar or plate 6 be rolled with
a taper inside, in order to facilitate the manufacture of the bars and the
building up of the layers. The bar a, in order to make a good fit, should have
a corresponding taper.
I propose in binding the layers together to use vertical bolts, such as I
have described in my Invention for "Improvements in the Use, Combination,
and Application of Iron and Timber as Armour for Vessels of War and
Fortifications," and for which I obtained Her Majesty's Letters Patent,
No. 3105, bearing date the 19th day of November 1862. Or I may use bolts
in one length; or the layers of backing may be put together without bolts.
I also propose in putting the layers together to use some such substance as
india-rubber glue between them to fill up interstices, prevent rust, and aid
cohesion. This backing should have its inner surface bearing upon an
intermediate or second armour plate, such as I have described in my Invention
aforesaid, but as it is not advisable to introduce a perishable material like
timber into permanent structures if avoidable, I propose to place between the
second armour plate and the structure to be protected by armour a layer or
layers of felt, or some other yielding substance, to counteract rigidity; but
when practicable, I prefer to use timber for the back cushion, as described in
my said Invention. I propose that the whole armour, consisting of the outer
armour plate, the layers of backing, the second plate and cushion, be attached
to the structure by bolts having screws and nuts, such as I have described in
my Invention aforesaid; or it may be attached fastening bars, such às are
also described in the said Invention, or by other methods of fastening. To
prevent rust, assist cohesión, and lessen rigidity, I propose to use a coating of
some such substance as before mentioned between the different parts of the
At all port-holes I propose to have as few joinings around or about
the hole as possible, and for this purpose I would prefer to cut the hole out of
the centre of a large plate, or cut half of the hole out of the edges of each of
two plates which come together, or otherwise I would increase the thickness
of any small plates that were required to complete the hole, and allow their
edges to dovetail, or match into, lap over, or rest upon the larger plates
forming the other sides of the port-hole.
armour.
In attaching armour to stone works, I propose, first, to rivet. the outer

page_text: armour plate and backing to the second plate, placing the whole against the
stonework with a cushion between them; and, second, I propose to fasten the
armour to the stonework in the following manner:-Bars of iron 4 inches
square, more or less, should be built into the walls, and have one end pro-
jecting outwards of a length sufficient to pass through the second plate, the
said end being slotted for a key, which shall, when driven, draw the armour
against the stonework. The backing bars in this case may be placed vertical
so that the key may be passed down through an opening left between them at
the place where a key bar passes through the second plate, and the key may
be driven by a ram from the upper part of the works. The recess or opening
to receive the key bar may be formed by two bars of H iron, or the whole
backing may be bars of H iron placed together, having the spaces between
them filled with powdered asphalte put in hot and rammed down, or a sub-
stance similar to that used for coal tar pavements. The bar attached to the
masonry can pass through one or more courses, and for convenience, the inner
end can be secured at a joint by a key and washer plate. An opening may
be left in the wall similar to a common chimney opening, through which the
key can be entered or withdrawn from above, thus obviating the necessity for
permanently attaching the armour during the erection of the walls, and
permitting its removal if necessary for repairs or other purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Chalmers in the Great Seal Patent Office on the
30th November 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
CHALMERS, (late) of 8, Knight's Place, Vauxhall, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of June, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Chalmers, Her special licence that I, the said James
Chalmers, my executors, administrators, and assigns, or such others as I, the
said James Chalmers, 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

page_text: "IMPROVEMENTS IN ARMOUR FOR FORTS AND FLOATING BATTERIES,"
upon the
condition (amongst others) that I, the said James Chalmers, 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 James Chalmers, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This Invention has for its object to combine economy in cost with strength,
and seeks to attain the desired end, chiefly, by using for the major part of the
armour thin plates or bars, which are comparatively low priced, instead of
such massive and expensive plates or slabs as are generally used in structures
intended to resist heavy ordnance.
DESCRIPTION OF THE DRAWINGS.
Figure 1, vertical section of armour for shields for embrasures or other
iron forts, and with the alterations herein-after described, to lessen the weight,
is also intended for floating batteries; Fig. 2, elevation, chiefly meant to show
the port-holes; Fig. 3, cross-section of backing-bars, a, b, on enlarged scale;
Fig. 4, cross-section of corrugated backing-bars; Fig. 5, plan of port-hole B in
Fig. 2; Fig. 6, vertical section of part of stone works with armour attached,
showing method of attaching the same; Fig 7, sectional plan of Fig. 6.
Figures 1, 2, 5, 6, and 7, are on a scale of 1 inch to the foot, and Figures
3 and 4 are on a scale of 3 inches to the foot.
Commencing at plate f, Fig. 1 (which represents the skin or side of a
floating battery, or the inner plates of a shield for embrasures, or other iron
fortification); or commencing at the stonework n, Fig. 6, I apply, first, in either
case, a cushion of timber planking, such as e, in Fig. 1, or of felt or other
yielding substance, as at m in Figs. 6 and 7, in order to protect the permanent
structure from the effects of the vibration arising from the impact of heavy
projectiles on the outer plates. In carrying forward the work of Fig. 1, (which,
as represented in the Drawing, is chiefly intended for shields or iron fortifica-
tions). I next apply the back or second armour plate d, and then build up
the layers of thin plates a, b, as shown in Fig. 1. The shoulders or flanges of
plate 6, and the edges of plate a, I propose to have rolled or manufactured

page_text: with a draw, as shown on a larger scale in Fig. 3, both to facilitate the manu-
facture of the plates themselves and the construction of the subsequent
works. This backing of thin plates, to support the armour plate c, may be of
any section that will bind or unite together, of which the corrugated plates
shown in Fig. 4 is an example. When a through-bolt passes through the
layers I propose to rivet several layers together, so as to unite one- or
more unbroken layers on each side of the bolt-hole with those intersected
by the bolt, and also secure the ends of the bars outside of the bolt-hole, as
shown at g, Figs. 1 and 2. I also propose to use a sufficient number of such
rivets as will unite those layers firmly together, which are intersected by bolts;
or I may bind the whole layers together by such vertical bolts as are referred
to in the Provisional Specification. I next attach the armour plates c with
through bolts, as shown in Fig. 1, or they may be attached by bars, as men-
tioned in the Provisional Specification, said bars, with the aforesaid vertical
bolts and through bolts, being more fully described in the Specification and
Drawings of my Invention for "Improvements in the Use, Combination, and
Application of Iron and Timber as Armour for Vessels of War and Fortifica-
tions," for which I obtained Her Majesty's Letters Patent, No. 3105, bearing
date the 19th day of November 1862. In order to give greater stiffness to
the structure, whether for iron forts, shields, or floating batteries, I propose to
attach the second armour plate Fig. 1, and the cushion e, to the inner or
skin plate f, by the bolts and nuts p, independently of and additional to the
through bolts which bind the whole together. To fill up interstices, prevent
rust, aid cohesion, and partially lessen rigidity, I propose to use a thin coating
of india-rubber glue, or some other suitable substance, between all iron surfaces
where practicable.
In adapting the section Fig. 1 to floating batteries, I propose, in order to
lighten the structure, to use only the bars or plates 6 as a backing to the
outer armour plate, and place them 5 inches, more or less, apart, filling up the
spaces between them with timber planks fitting into the bars. I would also
increase the thickness of the armour plate c about 50 per cent. Fig. 2,
elevation of part of a shield or wall of an iron fort, and Fig. 5, plan of port-
hole B, illustrate the methods of strengthening the port-holes referred to in
the Provisional Specification, viz., by avoiding joinings as far as practicable,
as at port-hole A, or by attaching the thick top and bottom plates of port-
hole B, without such perforations as must necessarily weaken small plates.
In attaching iron armour to stone works, I propose, first, to rivet the outer
plate c, Fig. 6, and the backing q, to the inner or second plate d, by the rivets h,
and then place the whole in suitable and convenient sections against the stone-

page_text: work n, having the cushion m, already described, between them. In order to
admit the fastening-bar i, the backing may be of H girders, as shown in the
plan, Fig. 7, or if the same as in Fig. 1, placed vertical, spaces can be left for
the bar i, at suitable distances. The keys k may be driven with a ram or bar
from the upper part of the works, and an opening 7 can be left in the stone-
work through which the armour can be attached or detached when required.
The end of the bar i may be secured with a nut and screw, if preferred, in-
stead of a key. The spaces o between the H girders may be filled with
some such substance as powdered asphalte put in hot and rammed down,
which would consolodate and harden, or any other material or composition
that would tend to preserve the iron and strengthen the structure.
The chief features of my Invention are,―
First, the adoption of light and consequently low priced plates or bars of
iron, which will bind or unite together as a backing to support armour plates,
and these, in consequence of the great strength of the backing may also be
lighter and therefore cheaper than the ordinary run of armour plates.
And, second, the method of attaching iron armour to stone works, as shown
in Figs. 6 and 7. I wish it to be understood that I do not limit the application
of these improvements to the particular methods of construction herein-before
described, and also that I do not confine myself to the precise details and
dimensions set forth in the foregoing description of my Invention and the
accompanying Drawings.
In witness whereof, I, the said James Chalmers, have hereunto set my
hand and seal, This thirtieth day of November, in the year of our Lord
One thousand eight hundred and sixty-three.
JAMES CHALMERS. (L.S.)