IMPROVEMENTS IN THE CONSTRUCTION OF. ARMOUR PLATES
Year: 1876

page_text: LETTERS PATENT to William Rowlinson, of Fallbarrow, Windermere, in the
County of Westmorland, Engineer, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF. ARMOUR PLATES."
Sealed the 12th January 1877, and dated the 21st November 1876.
PROVISIONAL SPECIFICATION left by the said William Rowlinson at the
Office of the Commissioners of Patents on the 21st November 1876.
WILLIAM ROWLINSON, of Fallbarrow, Windermere, in the County of Westmorland,
Engineer. "IMPROVEMENTS IN THE CONSTRUCTION OF ARMOUR PLATES."
This Invention relates to an improved construction of armour plate, and
|consists,-
Firstly. In placing upon the exterior of an armour plate a plate or slab of cast
metal, such for example, as cast iron or cast steel, and then placing upon the
exterior of such plate or slab a larger of malleable iron or steel, the thickness of the
cast metal plate or slab being dependent upon the resistance it is desired it should
possess and offer to projectiles.
Secondly. In the building up of a series of two or more layers of combinations of
malleable iron or steel, together with cast iron or cast steel, as before described.
Thirdly. In casting an intermediate layer of either cast iron or cast steel between
a wrought-iron armour plate and an outer sheet of malleable metal, either of iron or
steel, such armour plate and the outer sheet of metal being connected together
previous to the insertion of the molten metal by means of wrought-iron tubes, so as
when such intermediate cast metal has solidified to afford greater facility for boring
and fitting.
It will be understood that the thickness of the exterior plates and of the inter-
mediate strata or layer of cast metal will be dependent upon the degree of resistance
such compound plate should offer to projectiles.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Rowlinson in the Great Seal Patent Office on the 21st May
1877.
WILLIAM ROWLINSON, of Fallbarrow, Windermere, in the County of Westmorland,
Engineer. "IMPROVEMENTS IN THE CONSTRUCTION OF ARMOUR PLATES."
My said Invention relates to an improved construction of armour plates for ships,
forts, and other like vessels or structures, and consists in casting an intermediate
layer of hard metal, such for example, as hematite or other hard cast iron or cast
steel, between a wrought iron inner plate and an outer sheet of malleable metal
either iron or steel, such outer sheet and the inner plate being connected together
previously to the production of the molten metal by means of wrought-iron tubes,
cores, or distance pieces, so as when the intermediate cast metal has solidified to
afford greater facility for boring, for the purpose of fitting the permanent bolts, and
for the application of the latter.
The mode of connecting the outer sheet to the inner plate and the relative thick-
ness of the several layers, and also the total thickness of the compound armour plate
may be varied according to the object to be obtained and the degree of resistance
which the compound plate is required to offer to projectiles.
In the accompanying Sheet of Drawings which I shall now proceed to describe
I have shown by way of example two modes of carrying out my said Invention.
Figure 1 of my Drawings represents a section of the backing of a ship with my
compound armour plate applied thereto, according to one modification; Figures 2
and 3 are similar views illustrating another modification.
Referring to Figure 1, A is a wrought iron inner plate and B an outer sheet of
malleable metal, either iron or steel, which are connected together so as to leave an
intermediate space between them by wrought-iron tubes, cores, or distance pieces C,
screwed into the plate A, and secured to the sheet B by nuts & or otherwise. Into
this intermediate space I introduce molten iron of a hard and strong but fragile
quality, or molten steel of a similar character until the space or such portion thereof
as may be desired is filled therewith, such cast metal forming an intermediate
layer between the plate A and the sheet B. When the cast metal has solidified
the bore of the tubes C which are thus cast in, may if necessary be enlarged, and
holes are bored through the plate A for the passage of the bolts by which the
compound plate is secured to the backing E of the ship. The plates may if required
be embedded in suitable cement which will prevent the corrosion of the metals
taking place.
In the example herein-before described it has been assumed that the compound
plate is applied in its finished condition to the backing E of the vessel; the inner
plate A and outer sheet B connected together by the tubes, cores, or distance
pieces C, may however be first attached to the backing E, and. the intermediate
layer D of hard fragile metal be subsequently cast between them. This arrange-
ment is illustrated in Figures 2 and 3 of my Drawings, Figure 2 representing
a section of a portion of the backing of a ship with my compound armour
plate in course of construction, and Figure 3 a similar view shewing the
plate in its finished condition permanently attached to the side of the ship.
E is the timber backing, and E¹ is a layer of malleable metal, either iron or
steel, attached thereto (and which may be used or dispensed with as desired). Upon
this layer E (or upon the backing E when the layer E' is not employed) I place
the inner plates A of wrought iron which I secure by screws c or otherwise, and I
attach to such inner plates A. a suitable number of wrought-iron tubes, cores, or
distance pieces C, by screwing the same thereinto or in any other convenient
manner. I next place so that it shall bear upon the outer ends of the tubes, cores,
or distance pieces C, the outer sheet B of malleable metal, either iron or steel, the
same being constructed in suitable lengths and temporarily secured to the structure
in course of formation by screws d screwed into the tubes, cores, or distance pieces C.

page_text: Into the intermediate space comprised between the plates A and the sheet B, which
is heated by a blast of hot air or otherwise, I introduce molten iron of a hard and
strong but fragile quality, or molten steel of a similar character, until the space or
such portion thereof as may be desired is filled therewith, such cast metal forming
an intermediate layer D hetween the plates A and the sheet B, the power of
adherence of which may be increased by forming the contiguous surfaces with
corresponding grooves and projections. When additional thickness is required I may
place on the sheet B an outer layer F (Figure 3) of malleable metal, either iron or
steel, and secure the whole to the vessel by bolts and nuts b, the screws & having
either been removed previously to the application of the layer F, or subsequently
bored out in the operation of preparing the holes for the reception of the permanent
bolts b. When the layers E' and F are not used, the thickness of the inner plates A
and the outer sheet B may be increased, the compound plate being permanently
attached to the vessel in a manner similar to that herein-before described; should
the strength or resistance to be offered by the armour plate render it necessary the
compound plate may be built up of a greater number of layers by the alternation
with malleable layers, of layers of hard fragile metal cast in the manner herein-
before described, the object of my said Invention being to provide a layer or layers
of a hard metal which shall resist the complete perforation of the plates by the
projectile and extend its fracture in a lateral direction, such hard layer or layers
being still maintained in position after fracture with its or their powers of resistance
practically unimpaired.
The Invention is also applicable to existing vessels provided with double plates
by removing the outer layer and reattaching it with distance pieces interposed so as
to leave the requisite intermediate space for the introduction of the molten hard
metal.
Having now described and particularly accertained the nature of my said
Invention 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, constructing armour plates by casting metal between
malleable iron plates connected together by malleable iron tubes, cores, or distance
pieces, substantially as and for the purpose herein-before described.
In witness whereof, I, the said William Rowlinson, have to this my Specifi-
cation set my hand and seal, this Fifteenth day of May, One thousand
eight hundred and seventy-seven.
WILLIAM ROWLINSON.
L.S.)