IMPROVEMENTS IN WAR SUIPS OR VESSELS, AND IN APPLYING ARMOUR PLATING THERETO, OR TO OTHER Surs, OR TO FORTS
Year: 1877

page_text: LETTERS PATENT to Francis Wentworth Brewster, of Greenstond Hall, Halstead,
in the County of Essex, for tho Invontion of "IMPROVEMENTS IN WAR SUIPS
OR VESSELS, AND IN APPLYING ARMOUR PLATING THERETO, OR TO OTHER Surs,
OR TO FORTS."
Sealed the 8th September 1877, and dated the 21st March 1877.
PROVISIONAL SPECIFICATION left by the said Francis Wentworth Brewster
at the Office of the Commissioners of Patents on the 21st March 1877.
FRANCIS WENTWORTII BREWSTER, of Greenstend Hall, Halstead, in the County of
Essex. "IMPROVEMENTS IN WAR SHIPS OR VESSELS, AND IN APPLYING ARMOUR
PLATING THERETO, OR TO OTHER SHIPS, OR TO FORTS."
This Invention, which relates generally to improvements in the construction of
ships or vessels of war, comprises as a principal feature an improved method of
placing and securing armour plating thereon, this feature of the Invention being
also applicable to other ships or vessels, and to forts.
It is well known and has been demonstrated that a perfect hemisphere of iron of
about 100 feet diameter and 264 inches thick will just be able to float on water,
thus drawing almost exactly 50 feet, and that if the lower 30 feet of this hemisphere
were removed, and the upper 20 feet were made with a flat bottom, the vessel thus
formed will not float, or unless its thickness is reduced to about 184 inches, and
that if this vessel made of an elongated for its thickness must be further reduced
to about 13 inches (whereby the weight of the vessel is lessened by 1100 or 1200 tons,
which may be allowed for the superstructure) to enable it to float itself. Now three
of such circular vessels as are above alluded to would therefor unitedly support
between 3000 and 4000 tons; place these vessels in a line, side by side, and connect
their sides by tangential lines, and we obtain a vessel 300 feet long by 100 feet
wide, having semicircular extremities. The additional displacement obtained beneath
the surfaces between the circular and tangential lines affords a great increase in the
floating power, rendering it more than or equal to double that of what has been
shown to be the aggregate weight which the three circular vessels are capable
of sustaining.
I propose to construct the vessel some 50 feet shorter than the length above
mentioned, and to form its bottom (all that part below the point of its greatest

page_text: width) of a comparatively shallow segmental shape; this further increases its
floating power, making it equal to the task of supporting the great weight which
would result from a superstructure such as I propose, and which I purpose designating
"The Wentworth impervious (or impenetrable) Testudo Ironclad."
I form a continuous spur line round the vessel, at its greatest width, of iron of
about 3 feet in greatest width and at an angle of about 45 degrees; the vessel does
not present at any other part of its exterior a greater angle with the horizon than
of about 35 degrees. The greatest strength of the vessel lies immediately in the
rear of this spur line; the vessel could thus be used effectively in ramming attack,
and in itself would successfully rosist attacks from rams, which, as at present
constructed, would merely slip under the horizontal spur line and break the force of
their blow.
With such an extent and disposition of bottom as a ship of this size and shape
would have, four propellers could well be adapted and used, two shafts being used
with a propeller at each end; these and the rudder might be placed in countersunk
rocessos in the vessel's bottoin, in safety from all projectiles which might strike
below the spur line.
The armour plating of the superstructure I propose to have of a thickness of
about 12, inches, and steel faced; this, if applied on the "Testudo" principle,
would be sufficient to resist projectiles from guns even of enormous calibre.
The "Testudo" principle involves the laying every alternate row of plates in
such a manner that the joints of each row are immediately above the centres of the
plates forming the next row immediately beneath it, thus resembling an inverted
slate roofing.
The plating is laid on such a thickness of teak backing as is required, and each
plate is overlapped and formed with a heel which is sunk or stepped into the teak.
This obviates all tendency to slip from their places, and relieves the bolts from all
cross strain, which exists to a considerable extent in all known systems of securing
armour platos; these bolts, therefore, need only be of such a size as is necessary to
counteract the jump which inevitably ensues on ariuour plates being struck by
heavy projectiles; the number of bolt holes pierced in each plate is thus also con-
siderably reduced, and the plates are correspondingly strengthened. This peculiar
system of placing the plates vastly strengthens the armour, from the fact that no
bolt heads are exposed on the surface, and a projectile fired horizontally would have
to penetrate nearly 8 inchos or more of plating before it struck any bolt head. The
platos might be made of about five feet six inches in depth, and of any practicable
and desirable length.
Armour laid on this principle would of course only be applied above the spur
line.
Armour applied as above will present in a horizontal plane an actual thickness of
about 21 inches of iron to the projectile. A conically-headed shell or shot would
glance off, but flat-headed projectiles would be certain to inflict a certain amount of
damage on the surface struck, but the peculiar combinations of plating, the
resistance of which it would have to meet, would destroy its effect and prevent it
penetrating.
On the smooth inclined surface of the sides may be built wooden galleries or
platforms, or structures which might be deemed necessary for gangways, stowing of
boats and other ship's articles, and on the ends may be constructed cutwaters or
wave boards, to obviate or intercept the sens when cut by contact with the spur line
rushing up above it, or, these might even be so built as to almost render the vessel's
appearance more like that of other vessels, by constructing them all round, which
would improve the sea-going properties; it would also be more convenient for all on
board, and might deceive an eneiny as to the class of ship being engaged.
The batteries I make of about 12 feet in height, and nearly the full length and
width of the vessel, and at a necessary height above the sea level.
The ends of the vessel may be inade of various forms, but a semicircular shape I
prefer.

page_text: I propose to use steam as the sole motive power, and to rely on the peculiar
application of a certain thickness of plating to render the vessel proof against the
projectiles of guns of enormous calibre.
The funnels, as regards the exposed portions, I propose to have telescopic, so as to
be lowered out of sight in action.
The anchors can be weighed and got without the exposure of a single one of the
crew, and when going into action all the exterior wooden structures would be
abandoned to the fire of the enemy.
Amongst the advantages accruing from the above improvements are the
following:-
-
The vessel would have no masts or sailing gear, but would rely solely on steam.
Her shape would be such that no part of the exterior surface (except the spur
line) would have a greater inclination than an angle of 35 degrees with the
horizon.
That the waves would be levelled instead of cut, which would enable the vessel
to go out in all weathers.
That the great beam, coupled with the fact that the greatest weight would be
placed along the vessel's centre, and immediately above the line of the keelson
(thus rendering the sides the more buoyant), would obviate any disposition to roll
in heavy seas, and consequently that steady firing could be ensured from tho
batteries in all weathers.
That she is eminently a fighting vessel, and her two guns, each of 200 tons, would
ensure an all-round firo, a very great desideratum.
That her armour plating will be impervious or impenetrable to projectiles from
guns of enormous calibre.
The above-described method of placing and securing armour plating may bo also
applied with advantage to other ships or vessels, and also to forts.
SPECIFICATION in pursuance of the conditions of the Letters Patent filod
the said Francis Wentworth Brewster in the Great Soal Patent Office on the
21st September 1877.
"
Francis Wentworth BREWSTER, of Greenstend Hall, Halstoad, in the County of
Essex. IMPROVEMENTS IN WAR SHIPS OR VESSELS, AND IN APPLYING ARMOUR
PLATING THERETO, OR TO OTHER SHIPS, OR TO FORTS."
This Invention, which relates generally to improvements in the construction of
ships or vessels of war comprises, as a principal feature, an improved method of
placing and securing armour plating thereon; this feature of the Invention being
also applicable to other ships or vessols, and to forts and similar defensive
structures.
I would here remark that the annexed diagrains are simply illustrative of the
general principles of iny Invention, and not of the details of the construction of the
vessels, these being altogether subsidiary to the said general principles, which are
herein-after fully described and are sufficiently illustrated on the accompanying
dingrains.
It is well known that a hemisphere of iron of about 100 feet diameter, and 28
inches thick (see Figure 1) will just be able to float on water, thus having a draught
of about 50 feet, and a displacement of about 7480 tons, and that if the lower 30
feet of this hemisphere were removed, and the upper 20 feet were provided with a
flat bottom (see Figure 2), and its thickness is throughout reduced to about 19 inches,
it will be of about 4250 tons displacement, and will just float, and that if a vessel
is inade of an elongated or ordinary form, and of the saine weight or displacement
as the flat botton circular vessel of 19 inches thickness, to enable such a vessel to
Hoat its thickness must not exceed about 134 inches. The difference in thickness

page_text: between these two differently shaped vessels (both of the same weight or displace-
ment) is therefore about 5 inches throughout, and this represents a weight of
about 1,200 tons. If the said circular vessel were therefore constructed of a thick-
ness of only 134 inches of iron it would have a power of sustaining a weight of 1,200
tons, which may be allowed for the superstructure, engines, and coals; it will thus be
seen that there are 2 vessels of the same thickness throughout, and of the saine total
displacement, yet the one (the elongated or ordinary form) is without any super-
structure, engines, or coals, and the other (the flat botton circular vessel) is provided
with all these, and is in sea-going and fighting order, the advantages of the latter
form are therefore apparent. Now three of such flat bottomed circular vessels
would therefore unitedly support between 3,000 and 4,000 tons, and if placed in a
line side by side, and their opposite sides connected by tangential lines (see
Figure 3) they would form a vessel 300 feet long by 100 feet wide, having semi-
circular extremities. The additional displacement obtained beneath the surfaces 1,
between the circular and tangential lines, would afford a considerable increase in the
floating power, and would render it able to support a much greater weight than the
aggregate weight which it has been shown the three flat bottomed circular vessels
are capable of sustaining.
Now I propose to construct vessels of war about 50 feet shorter (see Figure 4)
than the length above mentioned, and shewn in Figure 3, or of about that length,
and to form its bottom (all that part below the point of its greatest width) of a
comparatively shallow segmental shape (see Figure 5). Such a vessel would be
equal to the task of supporting the great weight which would result from a super-
structure, such as I propose, and which I designate "The Wentworth Impenetrable
Testudo Ironclad," the ends of the vessel may be angular or semi-circular, as shewn
in Figure 3.
2 represents a continuous spur line, which runs round the vessel at its greatest
width and length, and is formed of iron of about three feet in greatest width, and at
an angle of about 90° and of about 45° to the horizon; the vessel does not present
at any other part of its exterior a more vertical plane than an angle of about 35°
to 40°. As the greatest strength of the vessel lies immediately in the rear of the
spur line, the vessel could be used effectively in ramning attack, and would
successfully resist attacks from rams, which as at present constructed would slip
under the horizontal spur line and break the force of their blow.
With such an extent and disposition of bottom as a vessel of this size and shape
would have 4 propellers, 3 could well be adapted and used, two shafts, 4, being used
with a propeller at each end; these and the rudder would preferably be placed in
recesses 5 in the vessel's bottom (see Figures 4 and 5), in safoty from all projectiles
which might strike below the spur line."
The armour plating of the superstructure I apply on what I term the "Testudo "
principle, which involves the laying of each row of plates, 6, in such a manner that
the joints thereof are opposite the centres of the plates forming the adjacent rows
(see Figure 6), this resembling an inverted slate roofing.
The plating I use of about 124 inches in thickness, 5 feet 6 inches in depth,
and any practical length, and lay it on such a thickness of teak backing, 7, as
is required. Each plate (see Figure 7) is overlapped and formed with a heel 8,
which being sunk or stepped into the teak backing obviates all tendency of the
plates to slip from their places, and relieves the bolts 9 from the cross strain
which exists to a considerable extent in most systems of securing armour plates;
these bolts therefore need only be of such a size as is necessary to counteract
the tendency to jump, which ensues on armour plates being struck by heavy
projectiles; the number of bolt holes required in the plates is also considerably
reduced, and the plates are correspondingly strengthened. This peculiar system
of placing the plates vastly strengthens the armour, from the fact that no bolt
heads are exposed on the surface, and a projectile fired horizontally would
have to penetrate more than eight inches of plating before it could strike any
head.

page_text: Armour laid on this principle would only be applied above the spur line, and
would present in a horizontal plane 10 (see Figure 7) an actual thickness of about
21 inchos, composed of not less than two thicknesses to the projectile, which would
render the vessel proof against the projectiles of guns of very large calibre. A
conically headed shell or shot would glance off the inclined surface, but flat headed
projectiles would be certain to inflict a certain amount of damage on the surface
struck, but the peculiar combination of plating, the resistance of which it would
have to meet, would destroy its effect and prevent it penetrating.
On the smooth inclined sides of the vessel, wooden galleries, platforms, gangways,
or other structures may be built for stowing of boats and other purposes, and at
the onds cut-waters or wave boards may be constructed to intercept the seas (cut
by contact with the spur line) rushing up above it. Wooden walls might be so
built as to render the vessel's broadsido appearance more like that of other vessels;
this would be more convenient for all on board, and might deceive an onemy as to
the class of vessel being engaged.
•
11 represents the batteries, which are about 12 feet in height; each battery is
armed with a gun of 200 tons, and has three port holos, 12, ono at oach side, and one
at the end, thus giving the 2 guns an all round fire. The port holes are fitted with
strong sliding ports, two of which would be kept closed constantly in each battery.
The improved form of vessel would thus be eminently fitted for fighting, and
would have great powers of resistance.
13 represents the funnels, which, as regards the exposed portions, are formed
telescopic, so as to be lowered out of sight in action.
In a vessel of this description, the anchors could be weighed and got without the
exposure of any of the crew, and when going into action all the exterior wooden
structures would be abandoned to the fire of the enemy.
The vessel would rely solely on steam for motive power, and would be unprovided
with masts of any description.
The great beain of such a vessel, coupled with the fact that the greatest weight
would be along the vessel's centre and immediately above the line of keelson (thus
rendering the sides the more buoyant) would obviate any tendency to roll in heavy
seas, and consequently steady firing could be ensured from the batteries in all
weathers.
The above described method of placing and securing armour plating may be
also applied with advantago to other ships or vessels, and to forts and other defensive
structures.
Having now described the nature and object of my said Invention, together
with the manner in which the same is to be or may be perforined or carried into
practical effect, I would remark in conclusion that I claim as my Invention,―
The novel and peculiar general construction and arrangement of ships or vessels
of war, substantially as above described and of the form illustrated in Figures 4 and
5 of the accompanying diagrams; and I also claim,-
The above described improved method of placing and securing armour plating on
ships or vessels of war, and on other ships or vessels, and on forts and similar
defensive structures, substantially as described, and illustrated in Figures G and 7 of
the accompanying diagrams.
In witness whereof, I, the said Francis Wentworth Brewster, have hereunto
set my hand and seal, this Eighteenth day of September, in the year
F. W. BREWSTER. (L.S.)