IMPROVED MEANS FOR MAINTAINING THE BUOYANCY OF SHIPS WHEN THEIR SKINS HAVE BEEN PIERCED
Year: 1878

page_text: LETTERS PATENT to John Young Buchanan, of Edinburgh, North Britain,
Gentleman, for the Invention of "IMPROVED MEANS FOR MAINTAINING THE
BUOYANCY OF SHIPS WHEN THEIR SKINS HAVE BEEN PIERCED."
Sealed the 22nd October 1878, and dated the 27th April 1878.
PROVISIONAL SPECIFICATION left by the said John Young Buchanan at
the Office of the Commissioners of Patents on the 27th April 1878.
JOHN YOUNG BUCHANAN, of Edinburgh, North Britain, Gentleman. "IMPROVED
MEANS FOR MAINTAINING THE BUOYANCY OF SHIPS WHEN THEIR SKINS HAVE
BEEN PIERCED,"
In order to diminish the risk of a ship's sinking when her skin has been pierced
below the water line, I propose to connect by pipes the various water-tight com-
partments of the ship, especially those situated below the load water line with a
pump or pumps, whereby air can be forced into the compartment or compartments
where a leak may occur.
All openings into the compartments should be fitted with covers (fitting as nearly
air-tight as possible), so that on the occurrence of a leak, all openings into the
compartment or compartments affected may be closed. Air is then forced into the
closed compartment by means of the pump or pumps at a sufficient rate and with
sufficient power to overcome the tendency of the water to enter by the leak, and as
far as possible to drive it back again out through the leak.
The ordinary ship's water suction pumps which have connection with all the
water-tight compartments would assist in removing water which might have
lodged at a lower level than the leak.
The air force pump or pumps must be of sufficient size and power to throw a
sufficient quantity of air.

page_text: <t
In the case of ships of war of modern construction, in which the inner skin is
carried up to the water-tight deck at a distance of several feet from the outer skin,
leaving what are known as wing spaces" between it and the outer skin, I fit
these wing spaces in addition with air bags made of suitable flexible material, and
connected by pipes with the air force pump. These air bags must be of such
number and proportions as when inflated to fill completely the compartment, and
in the event of an extensive breach occurring, such as might be caused by the ram
of a hostile ship or the explosion of a torpedo, causing damage to the inner as well as
to the outer skin, one or more of these bags could be inflated, and so not only
eliminate the water to a certain extent, but by interposing between the breech in
the outer skin, and that in the inner skin, also offer an obstruction to the entrance
of the water, and thus tend to stop the leak. By thus reducing the extent of the
leak, the clearing of the damaged inner compartment by means of the air force
pumps and the water suction pumps is much facilitated.
The air is introduced into each bag by means of a pipe passing air-tight through
the material of the bag, and for some distance into the inside.
The inner end of the pipe is closed, and the air escapes into the bag through
holes or cuts made in it at intervals throughout its length.
The end of the pipe outside the bag is united by means of a coupling and pipe to
the reservoir of the air pump.
When not inflated, the bags are compressed into as little space as possible, and
are stowed in the bottom of the compartments to which they belong.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Young Buchanan in the Great Seal Patent Office on the 20th
October 1878.
"
JOHN YOUNG BUCHANAN, of Edinburgh, North Britain, Gentleman. IMPROVED
MEANS FOR MAINTAINING THE BUOYANCY OF SHIPS WHEN THEIR SKINS HAVE
BEEN PIERCED.
The object of this Invention is to diminish the risk of a ship's sinking when lier
skin has been pierced below the water line. To this end I propose to connect by
pipes the various water-tight compertments of the ship, especially those situated
below the load water line, with a pump or pumps, whereby air can be forced into
the compartment or compartments where a leak may have occurred.
All openings into these compartments should be provided with covers (which
will fit as nearly air-tight as possible), so that on the occurrence of a leak, all
openings into the compartment or compartments affected may be closed. Air is
then to be forced into the closed compartiment by means of the pump or pumps at a
sufficient rate, and with sufficient power to overcome the tendency of the water to
euter by the leak, and as far as possible to drive it back again out through the
leak.
The ordinary ship's water suction pumps which have connection with all the
water-tight compartments would assist in removing water which might have lodged
at a lower level than the leak.
The air force pump or pumps must be of sufficient size and power to throw a
sufficient quantity of air.
"
In the case of ships of war of modern construction, in which the inner skin is
carried up to the water-tight deck at a distance of several feet from the outer skin,
leaving what are known as wing spaces " between it and the outer skin, I fit
these wing spaces in addition with air bags made of suitable flexible material, and
connected by pipes with the air force pump. These air bags must be of such
number and proportions, as when inflated to fill completely the compartments in
which they are severally situate, and in the event of an extensive breach occurring,
such as might be caused by the ram of a hostile ship or the explosion of a torpedo
causing damage to the inner as well as to the outer skin, one or more of these bags
could be inflated, and so not only eliminate the water to a certain extent, but by
interposing between the breach in the outer skin and that in the inner skin, also
offer an obstruction to the entrance of the water and thus tend to stop the leak.
By thus reducing the extent of the leak, the clearing of the damaged inside com-
partment by means of the air force pumps and the water suction pumps is much
facilitated.
The air will be introduced into each bag by means of a pipe passing air-tight
through the material of the bag, and for some distance into the inside thereof.
The inner end of the pipe I propose to close to make lateral openings in the pipe
for the discharge of air into the bag.
The end of the pipe outside the bag is united by means of a coupling and pipe to
the reservoir of the air pump.
The bags are compressed when uninflated into as little space as possible, and are
stowed in the bottom of the compartments to which they belong, but being attached
to the inflating pipes, they will be ready for instant use on an emergency.
In the accompanying Drawing my Invention is illustrated in connection with an
armour-plated ship.
The figure represents a cross section of the vessel, the fittings unnecessary to the
explanation of the Invention being omitted.
a, a, is the armoured and water-tight deck; b, b, is the longitudinal middle bulk-
head; c, c, are wing bulkheads fitted with air bags d, d, the normal state of which
will be as shewn on the left-hand side of the diagram that is collapsed and stowed

page_text: at the bottom of the wing compartment. When required, these bags are inflated by
air conveyed to them from the air force pump (not shewn) by the pipes e, e.
In case of the ship's side being breached and the wing bulkhead pierced as on
the right-hand side of the diagram, these bags will be inflated one after the other.
The expanding bag as it passes up in front of the hole in the bulkhead will be
thrust into it by the inward pressure of the water, the second will then be expanded
past the hole, or if it is driven in also, a third will have a good chance of temporarily
stopping the leak; f and f¹ are pipes for the supply of air from the air force pump
to the hold compartments h and . By keeping up the supply of air through these
pipes, the water can be kept down to the level of the leak, and the direction of
water pressure through the leak will be reversed, thereby enabling the bags to
arrange themselves so as to act most efficiently as check valves. The suction
pumps too can now be brought into play to clear the lower part of the vessel of
water, air being supplied to take its place; k, k¹, are air pipes leading to the wing
compartments, and l, l, lead to the double bottom.
If a compartment of the double bottom is broken in, the water is eliminated and
kept out by a sufficient supply of air through the appropriate pipe 7, so long as the
inner skin is whole or unpierced if it also is breached, then the two or more com-
partments so connected are treated as one hold compartment breached from below,
and the water forced out and kept out by the air supply from above.
Under all circumstances and even when not required for the purpose of preserving
the ship from sinking, the air supply will be useful as a means of thoroughly venti-
lating the whole ship. Further, if the pressure of the air in the water-tight
compartments were raised to and kept at a pressure something above that of the
atmosphere, the disastrous effects of perforation of the sides or bottom of the
vessel would be greatly mitigated by the fact that in order to admit the water
the breach would have to give passage to the air to escape. The air so passing out
would occupy a certain portion of the aperture, and would thus diminish the rate of
inflow of the water, thereby affording more time for taking further measures for
stopping the leak.
Having now set forth the nature of my Invention of "Improved Means for
Maintaining the Bouyancy of Ships when their Skins have been Pierced," and
explained the manner of carrying the same into effect, I wish it to be understood
that under the above in part recited Letters Patent, I claim, the arrangement above
described with reference to the accompanying Drawing for supplying compressed
air to the water-tight compartments in the hold, and to the spaces between the
inner and outer skins of the vessel, for the purpose of stopping a leak and main-
taining the buoyancy of the vessel.
In witness whereof, I, the said John Young Buchanan, have hereunto set my
hand and seal, the Twenty-fifth day of October, in the year of our Lord
One thousand eight hundred and seventy-eight.