IMPROVEMENTS IN CON- STRUCTING FORTS, FORTIFICATIONS, OR OTHER DEFENCES
Year: 1868

page_text: LETTERS PATENT to Thomas Russell Crampton, of Great George
Street, Westminster, for the Invention of "IMPROVEMENTS IN CON-
STRUCTING FORTS, FORTIFICATIONS, OR OTHER DEFENCES."
Sealed the 5th January 1869, and dated the 7th July 1868.
PROVISIONAL SPECIFICATION left by the said Thomas Russell
Crampton at the Office of the Commissioners of Patents, with his
Petition, on the 7th July 1868.
I, THOMAS RUSSELL CRAMPTON, of Great George Street, Westminster,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN CONSTRUCTING FORTS, FORTIFICATIONS, OR OTHER DEFENCES," to be as
follows:-
In constructing forts, fortifications, or other defences according to
this Invention a mould or moulds of the form of defence required is
prepared on its site, and on or near the same one or more furnaces for
melting iron, or steel, or other metal is erected. The iron, steel, or
other metal as melted is conveyed into the mould or moulds, as in
ordinary casting. Forts, fortifications, or other defences of any desired
extent or form and of any thickness can thus be cast either in one piece.

page_text: or in blocks cast separately side by side in the position in which they
are to be used. The castings may also be formed from steel or pure
iron produced by the Bessemer process. Casemates, cupolas, and
similar defences can thus be cast on the site which they are to occupy.
It will be seen that by this process weights can be cast which it would
be impracticable to transport from a foundry, and that forts, fortifica-
tions, or other defences of a massive character may thus readily be
constructed in any position desired. Wrought iron or steel armour
plates may also be fixed in front of forts or defences constructed as
above described.
"
In some cases forts may be constructed of an annular form, both
the inside and outside walls of the ring being corrugated, the number
of corrugations being equal to the number of guns to be employed,
each corrugation having one or more holes pierced so that the gun can
take an extended range allowing of concentrating several guns on one
point; the corrugations of the inner wall being also pierced for guns
these guns can fire over the opposite side of the fort, and enable in some
cases some of the guns to fire from the outside and some from the
inside, and be so concentrated on one object; the inner and outer walls
may either be made separately and the space between them remain
uncovered, or this space may be covered over with an arched roof
either cast in one piece with the walls or otherwise.
Forts may
also be made of a series of cupolas of a mushroom or dome form, or
of other convenient form, separate or joined together, with or without
a communication between them, each cupola containing one or more
guns, which may fire from any port hole; these cupolas may be
isolated or placed in a circle or other convenient arrangement, so
that one or more guns on the inside and outside can be concentrated in
certain cases on one point.
In some cases one or more holes sufficiently large may be left in
the top of the casting to allow of the guns being lifted through them
when required to be fired. Port holes may be used in the side in com-
bination with those on 'the top. It will be seen 'that 'this mode of
constructing defences offers great facility for giving such curves to the
structure as may be found most efficient in deflecting missiles projected
against it. In those cases where the weight is not too great defences
may be cast on floating structures. In those cases where the iron or
other metal is of that hard nature that ordinary tools will not cut it

page_text: provision should be made for attaching anything to it that may be
required by casting projections or recesses for that purpose in. the..
casting.
SPECIFICATION in pursuance of the conditions of the Letters Patent,-
filed by the said Thomas Russell Crampton in the Great Seal
Patent Office on the 7th January 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS.
RUSSELL CRAMPTON, of Great George Street, Westminster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her-
Letters Patent, bearing date the Seventh day of July, in the year of
our Lord One thousand eight hundred and sixty-cight, in the thirty-:
second year of Her reign, did, for Herself, Her heirs and successors,.
give and grant unto me, the said Thomas Russell Crampton, Her
special licence that I, the said Thomas Russell Crampton, my exe-
cutors, administrators, and assigns, or such others as I, the said Thomas.
Russell Crampton, 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 law-
fully 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 "IMPROVEMENTS IN CONSTRUCTING FORTS, FORTIFICATIONS, OR
OTHER DEFENCES," upon the condition (amongst others) that I, the said'
Thomas Russell Crampton, 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 Thomas Russell Crampton, do
hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement thereof, that is to say :-
In constructing forts, fortifications, or other defences according to
this Invention a mould or moulds of the form of defence required is

page_text: be used.
prepared on its site, and on or near the same one or more furnaces for
melting iron, or steel, or other metal is erected. The iron, steel, or other
metal as melted is conveyed into the mould or moulds as in ordinary
casting. Forts, fortifications, or other defences of any desired extent or
form and of any thickness can thus be cast either in one piece or in
blocks cast separately side by side in the position in which they are to
The castings may also be formed from steel or pure iron
produced by the Bessemer process; casemates, cupolas, and similar
defences can thus be cast on the site which they are to occupy. It will
be seen that by this process weights can be cast which it would bo
impracticable to transport from a foundry, and that forts, fortifications,
or other defences of a massive character may thus readily be constructed
in any position desired. Wrought iron or steel armour plates may also
be fixed in front of forts or defences constructed as above described.
In some cases forts may be constructed of an annular form, both
the inside and outside walls of the ring being corrugated, the number
of corrugations being equal to the number of guns to be employed, each
corrugation having one or more holes pierced, so that the gun can take
an extended range allowing of concentrating several guns on one point,
the corrugations of the inner wall being also pierced for guns these
guns can fire over the opposite side of the fort, and enable in some cases
some of the guns to fire from the outside and some from the inside, and
be so concentrated on one object; the inner and outer walls may either
be made separately and the space between them remain uncovered or
this space may be covered over with an arched roof either cast in one
piece with the walls or otherwise. Forts may also be made of a series of
cupolas of a mushroom or dome form or of other convenient form
separate or joined together, with or without a communication between
them, each cupola containing one or more guns, which may fire from
any port hole. These cupolas may be isolated or placed in a circle or
other convenient arrangement so that one or more guns on the inside
and outside can be concentrated in certain cases on one point.
In some cases one or more holes sufficiently large may be left in the
top of the casting to allow of the gun being lifted through them when
required to be fired. Port holes may be used in the side in combination
with those on the top. It will be seen that this mode of constructing
defences offers great facility for giving such curves to the structure as
may be found most efficient in deflecting missiles projected against it.

page_text: In those cases where the weight is not too great defences may be cast
on floating structures. In those cases where the iron or other metal is
of that hard nature that ordinary tools will not cut it provision should
be made for attaching anything to it that may be required by casting
projections or recesses for that purpose in the casting.
In carrying out this Invention the foundation will have to be prepared,
on which moulds of the form required will be made of brickwork or other
suitable material in the ordinary manner, and in some cases it would be
desirable to hold the mould together by wrought or cast plates extending
over a part or the whole, or ribs of iron may be secured at intervals for
strengthening it, and where convenient the mould may be backed up
with earth. Ordinary furnaces constructed and worked in the ordinary
manner will also be placed at intervals in convenient positions near the
mould in such numbers and of such capacities for melting the metal as
will cast the whole in the time arranged, that is to say, supposing the
total weight of each casting to be 5,000 tons and that it was required
to be cast in 20 hours, and that each furnace employed would melt 5 tons
per hour, 50 furnaces would be required. Thus the greater the time
allowed the fewer furnaces will be necessary, but the time must be
regulated according to circumstances and the nature of the metal used,
care being taken that the metal remains in a fluid state until the casting
is complete. Scrap wrought iron may be melted up with the pig iron if
desired, or other metals or alloys might be used for constructing the
cast forts. As before stated, it is not necessary in all cases to cast the
defence in one piece, but it may be cast in several massive blocks let into
cach other and each touching its neighbouring block. In some cases a
space or spaces may be left between each block and afterwards filled in
by other metal run into such spaces, or they may be otherwise fastened
together by metal wedges or other convenient means, but I prefer that
each block should have sufficient weight that upon being struck by
heavy projectiles it should be able to sustain the blow without injurious
movement and thereby avoid such methods of connection, one great
object sought being to avoid a built-up structure of many pieces. Built-
up defences of cast iron in blocks of 3 or 4 tons weight has been proposed,
but such small blocks have little effect to resist the heavy ordnance used.
I should prefer that no block should be less than 200 tons in weight.
Where port holes are used each port hole may in some cases be formed of
a massive block of wrought iron or steel or other suitable metal previously

page_text: made to the form desired, and the main defence may be afterwards cast
round it. Where the defence is made in the manner herein-before
described so that the guns have to be lifted up through the top to be
fired, holes of the requisite dimensions may be left at the time of casting
the fort, and be suitably formed to allow of a cover of cast iron or other
suitable cast material or constructed of wrought iron armour plates being
made to slide or move on rollers over the aperture when the guns
descend after being fired, or the tops of defences may be left entirely
open or they may be covered with wrought iron of comparatively small
thickness sufficient to resist vertical fire. The shields should be con-
structed by preference simply to rest on recesses in the main defence
with as few fastenings as possible, as all fastenings are a source of
danger upon being struck, and therefore the number of picces in the
moveable covers should be reduced to a minimum. When the moveable
covers are used with or on rollers arrangements may be made when the
cover is in any fixed place to force in wedges and take the weight off the
rollers. The system of moveable covers to defences where the gun is raised
up through a hole in the top of the defence to be fired is particularly
applicable in ships of whatever material the ship may be protected with,
as it not only protects the gun and men except when the gun is being
fired, but if on a vessel there are several guns so worked it permits any
one gun to fire directly over the site of any other gun when such guns
are covered over after being fired, thereby giving the greatest possible
range to each, the range being limited only by the obstructions on
the ship itself, but with the moveable cupola system, in which the guns
are fired through port holes, if two or more cupolas be employed in close
proximity they cannot fire their guns in all directions, as the fire of the
guns from one cupola or turret is limited to within a certain distance of
the other cupolas or turrets. With the system of lowering the guns
through holes in the tops of forts or turrets to load, and at this time
covering the holes with covers all that is required is to give armour
protection up to a point immediately below where the gun fires from,
but in all port hole systems the armour protection is required to be
continued sufficiently above that point so as to protect both guns and
men, thereby diminishing the weight of armour considerably, this is
particularly advantageous on board ship. Covers to lift vertically may
be used instead of slides, and it is quite practicable to so arrange these
covers that they be closed by the recoil of the gun when fired, but as the
opening and closing these covers can be easily accomplished indepen-

page_text: dently of the guns, I should prefer to keep them separate; the covers can
be moved by the ordinary rack and pinion, by a screw, or by chains not
here necessary to describe in detail, as any good mechanic can adopt the
means according to circumstances, and in cases where the cover has to be
of a curved form, say, to cover the hole in dome-shaped defences, the
cover may be curved and made in halves so attached by gear or chains
that each portion balances the other in descending and uncovering the
hole, or if in one piece it would be well to counterbalance the cover.
It will be obvious that the covers to the port holes in the roofs of defences
may be left open if the nature of the engagement is such as to render it
desirable to do so.
It may be observed that the cost of built up structures of wrought
iron sufficiently strong to resist the heaviest fire now known is very
great, and I estimate that if good cast iron be used in masses as I propose
at least 6 or 7 times the weight or thickness can be supplied for tho
same amount of money expended in wrought iron. The effect of
casting in masses on the site insures a more homogeneous structure
than can be obtained by wrought iron, since heavy wrought plates cannot
with any certainty be made sound and of equal quality, besides the
difficulty of securing such immense plates together in one homogeneous
mass with large bolts and nuts or rivets is almost impracticable (in a
commercial sense), besides which the great number of pieces to form
a built up fort of wrought iron is a great element of danger, as on being
heavily struck the fastenings and other pieces would enter the gun
chamber, this great source of danger would be entirely obviated with a
sufficiently massive structure such as is proposed to be used.
In witness whereof, I, the said Thomas Russell Crampton, have
hereunto set my hand and seal, this Sixth day of January,
in the year of our Lord One thousand eight hundred and sixty-
nine.