IMPROVEMENTS IN ARMOUR PLATING SHIPS OF WAR AND FORTIFICATIONS
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by James Chalmers at the Office of
the Commissioners of Patents, with his Petition, on the 28th October
1862.
I, JAMES CHALMERS, residing at 8, Knights Place, Wandsworth Road,
Vauxhall, London, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN ARMOUR PLATING SHIPS OF WAR AND FORTIFICATIONS," to, be
as follows:-
i
This Invention has for its object improvements in armour plating ships of
war and fortifications; and consists of the, following combinations of iron with
timber or other light and compact substance, or of the arrangement of iron
alone in the manner herein-after described. The backing for the armour
plates to rest against shall consist of a frame of the following description:
-A
plate or plates of iron an inch in thickness, more or less, shall form the bottom
of this backing frame, and to the said plates shall be attached, longitudinally,
vertically, or diagonally, ribs. of iron, half an inch in thickness and nine inches
in width, all more or less, the said. ribs to have a Tor angle edge for attaching
them to the plates to which they, shall be attached at right angles and six
inches apart, more or less. The spaces between the said ribs shall be filled
...

page_text: with timber or some light and compact substance so that the timber or other
substance will be flush with the outer edges of the ribs, and thus form with
the said ribs and bottom plates to which the ribs will be attached with rivets
or otherwise a backing frame for the support of the armour plate. In cases
where great strength is required there shall be cross ribs inserted between and
at right angles to the ribs aforesaid, thus forming the backing frame into cells
which may either be left empty or filled with timber having the grain at right
angles to the bottom of the backing frame or otherwise, or the cells may be
filled with some other light and compact substance. But in either case the
plate or bottom- of the backing frame shall be placed towards the ship or fort
and farthest from the armour plate. In the case of ships or forts built of iron
timber planking of four inches in thickness more or less, or some other elastic
or yielding substance shall be placed-between the backing frame aforesaid and
the skin of the ship or wall of fort, in order to lessen the rigidity of the com-
bined bodies. In fastening the armour plates to the sides of a ship or iron
fort the backing frame shall be first placed against the said ship or fort, and
shall be bolted thereto independently of the fastenings of the armour plates.
The armour plates shall then be placed against the backing frame and shall be
fastened through said backing frame to the said ship or iron fort by means
of bolts and nuts. The head of the said bolt shall have a stepped conical neck
with three steps, more or less, which neck shall fit into a corresponding hole in
the armour plate so that the shoulders or bearings of the several steps of the
neck may prevent the bolt from being driven through the plate when struck
on the head by a projectile. In the case of stone or brick forts the armour
plate shall first be fastened to the backing frame, and the whole armour
consisting of armour plates and backing frame can be fastened to the walls
of said fort in a manner suitable to the materials of which the walls thereof
are composed. In cases where through bolt fastenings would be injurious, as
in the case of narrow plates or otherwise, the armour plates shall be fastened
to or through the backing frame by fastening bars of two inches in thickness,
more or less, which bars shall be placed between the edges of the armour
plates, the outer corners of the edges of which shall be chamfered, and the
outer edge of the fastening bar shall be provided with a T or longitudinal head
corresponding with the chamfer in the edges of the armour plates. These
fastening bars to be ten inches, more or less, in depth..
- In order to secure the said fastening bars to the ship or fort, bolts with T
heads shall be let into a notch in the inner edge of the said fastening bars
which notch shall correspond with the width of the T head of the bolt. The

page_text: end of the T head bolt shall be secured with a nut as in the case of the
through bolts aforementioned. The said notch shall be one inch more or less
deeper in the lengthway of the bolt than the size of the head thereof, so that
there shall be a space between the head end of the bolt and the metal of the
fastening bar. in order that when a projectile strikes the fastening bar opposite
a.bolt it shall not communicate the jar to the bolt through the fastening
bar.