IMPROVING AND STRENGTHENING SHIELDS OF STEEL, IRON, OR OTHER MATERIAL, FOR SHIPS
Year: 1865

page_text: LETTERS PATENT to Thomas Hay Campbell, Lieutenant-Colonel in the
Royal Artillery, Superintendent Madras Gun Carriage Manufactory,
residing in Madras, East Indies, for the Invention of "IMPROVING AND
STRENGTHENING SHIELDS OF STEEL, IRON, OR OTHER MATERIAL, FOR SHIPS,
"
Sealed the 20th October 1865, and dated the 2nd May 1865.
PROVISIONAL SPECIFICATION left by the said Thomas Hay Campbell at
the Office of the Commissioners of Patents, with his Petition, on the
2nd May 1865.
I, THOMAS HAY CAMPBELL, Lieutenant-Colonel in the Royal Artillery,
Superintendent Madras Gun Carriage Manufactory, residing in Madras, East
Indies, do hereby declare the nature of the said Invention for "IMPROVING AND
STRENGTHENING SHIELDS OF STEEL, IRON, OR OTHER MATERIAL FOR SHIPS, FORTI-
FICATIONS, AND OTHER CONSTRUCTIONS," to be as follows:-
To strengthen the plates, of steel, iron, or other material used by giving
them a backing of water or other liquid, or highly compressed air, confined in
cases or cisterns of iron, copper, or other material, which will not only prevent
the possibility of holes being punched in the outside plating by reason of the
rigid backing provided, but will diffuse the force of the shock caused by a shot
striking the plates over so large a surface as to prevent its doing any injury, to
the ship or other construction upon which the shield is placed. The Invention
is founded upon the almost absolute incompressibility of water and other

page_text: liquids, and the powerful, but at the same time elastic support to be obtained
from highly compressed air. I include in this Provisional Specification the
right to use water and other liquids and compressed air backing separately or
in combination.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Hay Campbell in the Great Seal Patent Office on
the 21st October 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HAY CAMPBELL, Lieutenant-Colonel in the Royal Artillery, Superintendent
Madras Gun Carriage Manufactory, residing in Madras, East Indies, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of May, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Hay Campbell, Her special licence that I, the said Thomas
Hay Campbell, my executors, administrators, and assigns, or such others as
I, the said Thomas Hay Campbell, 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
"IMPROVING AND STRENGTHENING SHIELDS OF STEEL, IRON, OR OTHER MATERIAL FOR
SHIPS, FORTIFICATIONS, AND OTHER CONSTRUCTIONS," upon the condition (amongst
others) that I, the said Thomas Hay Campbell, or my executors or adminis-
trators, 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 Thomas Hay Campbell, 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
following statement :-
My Invention consists in the employment of water or other liquid or
highly compressed air confined in. cases or cisterns of copper, iron, or other

page_text: material as a backing to shields or plates of steel, iron, or other material for
the purpose of strengthening the said shields or plates and preventing holes
being punched through them by reason of the rigid backing provided, 'and
also for the purpose of diffusing the shock caused by a shot striking the
shields or plates over so large a surface as to prevent its doing any injury 'to
the ships or other construction upon which the shields or plates are placed.
My Invention is founded upon the almost absolute incompressibility of water
and other liquids, and the powerful, but at the same time elastic support to be
obtained from highly compressed air, backings of water and other liquids, and
of compressed air to be used either separately or in combination.
The cases or cisterns should be made of great strength and perfectly water-
tight; they can be filled up at once and hermetically closed, or made with 2
pipes of small diameter, conveniently placed, for the purpose of allowing the
case or cistern to be filled by means of a force pump or other contrivance, the
pipes to be closed by screw plugs or other means; the pipes to be carried through
the sides of the ship or other construction on which the case or cistern is
placed in the way most convenient according to circumstances. One of the
pipes from each case or cistern may be connected with a main pipe leading
from a force pump, so that all may be filled or emptied through the main.
pipe; the other pipe is intended for the admission or expulsion of air. The
cases or cisterns will of course vary in form and dimensions according to cir-
cumstances, but as a general rule they should be made of copper, iron, or
other material not less than inch thick; they should be from 3 to 6 inches
wide (width meaning the direction between shield plates and ship's side,) and.
be about 6 feet long and 6 feet broad, but there is no reason why they should
not be made much larger or much smaller according to convenience. When
it is necessary that bolts should pass through the cases or cisterns in order to
fasten these and the outside armour to the ships or other constructions, a tube
or tunnel must be made through the case or cistern for the reception of the
bolt, the sides of the tube or tunnel to be of metal at least inch thick.
The outside of the cases or cisterns should be quite smooth, and they should
be so placed as to afford mutual lateral support to each other; when this is
not practicable a strong iron casing should be placed round the shallow sides
of the case or cistern, so as to prevent the possibility of lateral expansion in
the case or cistern. When this mode of backing is applied to a ship there
should first be a skin of or inch iron placed over the outside of the vessel;
this skin to be free from projections on the outside; next to this should come
the case or cistern; next to it a skin of one inch or 1 inch iron, quite smooth
on the side next the cistern; then alternate layers of iron plates on edge, and

page_text: wooden planks, either vertical or horizontal. The iron plates should be inch
thick, and 10 inches broad, and the wood planks between each should be 10,
by 5 inch; on the outside of this, resting on the edges of the iron and wood
layers, should be placed armour plates from 3 to 5 inches thick; thus the
shield in section would be as follows, taking from the outside, first, 3 to 5 inches
of iron, then alternate iron and wood on edges 10 inches, then iron skin one
or 1 inch, then cistern, say. 4 inch, and, lastly, skin of inch iron, between
cistern and ship's side. The mode of fastening this shield together is not here
described, as it does not form the subject of the Specification.
Though I have described what I consider the best way of adopting iron
plating to my backing of water and other liquids, I reserve to myself the right
to use this backing with any other description of shield or plate of iron, or of
other material, and with any mode of fastening these shields or plates to ships
or other constructions.
When this mode of backing is used in fortifications, the cases or cisterns
should be made much larger than I have described, and of thicker metal, but
the principle of placing them so as to give mutual lateral support should be
observed. Also the description and arrangement of iron shield I have described
should be used, but of much larger dimensions.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim as my Invention the
employment of water or other liquid or highly compressed air, confined in
cases or cisterns, as a backing for shields or plates of steel, iron, and other
materials for ships, fortifications, and other constructions.
In witness whereof, I, the said Thomas Hay Campbell, have hereunto
set my hand and seal, this Twenty-sixth day of 8th mo. August, One
thousand eight hundred and sixty-five.
T. HAY CAMPBELL. (L.S.)