Improvements in Extinguishing Fires in Ships' Holds.
Year: 1891

page_text: Date of Application, 21st Dec., 1891
Complete Specification Left, 21st Sept., 1892-Accepted, 22nd Oct., 1892
PROVISIONAL SPECIFICATION.
Improvements in Extinguishing Fires in Ships' Holds.
I DAVID STEWART of 132 Murraygate, Dundee in the County of Forfar
North Britain Iron Merchant do hereby declare the nature of this invention to
be as follows :-
This invention relates to improvements in extinguishing fires in ships holds and
consists in the employment of carbonic acid gas in the following manner :-
Carbonic acid gas in the liquid state can now be obtained in large quantities
contained in cast iron bottles or cylinders. In accordance with my invention I
employ a malleable iron or other tube leading from the bottom of the ship-along
the skin of the ship-(inside) up to the top of the deck. One or more pipes can be
put in each hold. The carbonic acid gas being liquid is in the bottles under very
high pressure I employ a coupling with a cock on each bottle and have four pipes
for example fitted into each cargo hold, leading as already stated from the top of
the deck to the bottom of the hold-any metal will do that will not melt with heat.
The bottles or cylinders containing the liquid gas can be strapped down to the deck
and permanently fixed to the pipes or they can be stored in some convenient place.
on deck, should a fire take place in any hold, a number of these bottles are at once
attached to the pipes and the cocks opened when the gas is at once relieved and by
the pressure is forced suddenly down the pipes to the bottom of the hold. 1 H by
weight of liquid gas occupies in the gaseous form 8 cubic feet. Suppose the
cargo to be coals or jute, or cotton then there are only the interstices to fill up.
between the pieces or the bales.
Carbonic acid gas being heavier than common air will rise same as water would
do if water was poured into the pipes until it expels the common air and fills the
hold.
The hatches are kept on and the compartment of the hold being by the bulk-
heads hermetically sealed so to speak, all that has to be done is to inject enough
gas which is easily done out of the bottles or cylinders by its own expansibility.
Dated this 21st day of December 1891.
JOHNSONS,
115, St. Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in Extinguishing Fires in Ships' Holds.
I, DAVID STEWART, of 132 Murraygate, Dundee, in the County of Forfar
North Britain, Iron Merchant, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
This invention relates to improvements in extinguishing fires in ships holds and
consists in flooding the hold with carbonic acid gas in the following manner :-
Previous attempts to put out fires in ships by carbonic acid gas have consisted in
generating the gas at the bottom of the hold by means of an acid and an alkali,
driven down from the deck by means of force pumps, when, these substances mixing
at the bottom carbonic acid gas is liberated. The objection to that plan is the
danger of carrying sulphuric acid on deck, and, if there is a heavy sea on, the
difficulty of pumping down the chemicals. These difficulties are, however entirely
done away with by my method which has only been made possible by the present
method of manufacturing liquid carbonic gas on a large scale and at a moderate
[Price 8d1

page_text: price. To liquify the gas it is only necessary to subject it to a very high pressure,
when it is stored in malleable iron cylinders or bottles, cach containing thirty to
thirty-six pounds weight of the liquid gas, at a pressure of seven hundred and fifty
pounds, but the bottles are strong enough to resist more than four times that
pressure. Each bottle or cylinder is about four feet long and five to seven inches
diameter, and each pound by weight of the liquid gas will, when liberated occupy
eight and a half cubit feet of space.
These cylinders containing the liquid gas can be easily stored on deck, at any
convenient place, where they can be readily got at, if required to extinguish a fire.
When the ship is being built or at any time when the hold is empty, malleable
iron gas tubes, say one inch or one inch and a quarter bore, would be put in,
leading from the deck to the bottom of the hold, close down to the inside skin of
the ship, so as to be out of the way. At the top of each pipe and coming through
the deck, would be a brass coupling ready in case of fire for attaching to the
coupling which is provided on each of the cylinders or bottles already referred to.
Suppose a fire to take place in the hold, the cylinders are brought out and the
couplings on them are attached to those on the top of the tubes, the cock is opened
to liberate the gas, which the pressure at once forces down the tubes, and instantly
on being liberated at the bottom of the hold the liquid assumes the gaseous form,
the contents of each thirty-six pound bottle filling over three hundred cubic feet of
empty space in the hold with carbonic acid gas, a substance nearly twice as heavy
as common air, and which, as it rises will expel the common air and fill the hold
with a substance that will effectually extinguish any fire. The number of pipes
fitted up would be regulated by the size of the hold, but six in moderate sized
holds, and probably ten in very large holds, would be ample, as the gas has only to
fill the interstices or blank spaces between the pieces of coal in a coal laden ship,
or between the bales if the cargo is cotton or jute. The same remark would apply
to any cargo. A cargo hold being, so to speak, hermetically sealed between two
watertight bulkheads, there is no chance of the gas spreading all over the ship, as
the same means applied to keep out water will keep in carbonic acid gas. As to
extracting the gas after the fire is extinguished, this can easily be done by an
exhaust or ventilating fan, or it can be left in the hold till the ship reaches her
destination thus preventing any further outbreak of fire in the hold. The adoption
of my plan is a much more certain method of putting out a fire than by pouring in
water, which often feeds the flames when the heat is so intense as to decompose the
water into its two component parts viz., oxygen (a supporter of combustion) and
hydrogen (a combustible,) while carbonic acid gas will cause no damage whatever
either to ship or cargo.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is :-
1st. In the extinguishing of fires in ships holds, the employment of carbonic acid
gas, substantially in the manner as described.
Dated this 20th day of September (899
Or sentember 189
JOHNSONS,
115, St. Vincent Street, Glasgow, Applicant's Agents.