Improvements in the Manufacture of Explosives.
Year: 1899

page_text: Date of Application, 12th May, 1899
Complete Specification Left, 1st Feb., 1900-Accepted, 3rd Mar.,
1900
Improvements in the Manufacture of Explosives.
I, HIRAM STEVENS MAXIM, of 18, Queens Gate Place, in the County of Middle-
sex, Chevalier of the Legion of Honour, Civil and Mechanical Engineer, do
hereby declare the nature of this invention to be as follows:-
This invention has reference to the manufacture of explosives for artillery.
It is well known that the products of combustion of the cordite and ballistite
used in the British Government services consist largely of carbon di-oxide, a
very heavy and dense gas which by reason of its great heat erodes the barrels
of guns much more rapidly than carbon monoxide. It is therefore advantageous
to have as little as possible of the carbon di-oxide present in the products of
combustion, in fact it is better to produce a little smoke than to erode the gun
too much.
According to my invention I prevent or diminish the erosion by making one
of the constituents of the explosive of some resinous or other substance that
is rich in carbon or hydrogen or both, which will cause the evolution of carbon
mon-oxide instead of carbon di-oxide when the explosive is fired.
Many nations object to the use of nitro-glycerine as a constituent of their
smokeless explosives for artillery purposes and prefer to make them from gun-
cotton or tri-nitro-cellulose. When however a smokeless explosive is made
altogether from gun-cotton by dissolving the latter in the well known manner
the explosive in its finished condition is liable to be very hard and to burn too
slowly for artillery purposes. If on the other hand the explosive be made from
Fulped gun-cotton, that is to say with the cotton in a fibrous condition, it is
found that the explosive burns altogether too rapidly. Now, from experiments
which I have instituted I find that the cotton fibres can be reduced to a very
fine condition by a grinding operation and can be combined with the resinous
or other material employed and be pressed into a solid mass, to form an explosive
that will burn no faster than if made from the dissolved cotton and very much
slower than if made from the pulped cotton. And I can by varying the pro-
portions of the ingredients obtain an explosive capable of burning at any re-
quired rate either slow or quick. If the nitrated cotton pulp is ground under
edge rollers to very great fineness in the presence of from 2% to 15% of the
resinous or other material, it may be pressed into a hard condensed block of
explosive of comparatively slow burning quality and of a size suitable for use
in large guns. In order to make a still slower burning explosive, solvents
such as acetone or acetone and ether combined, may be used which will dissolve
only a portion of the nitrated cotton. In most cases tri-nitro-cellulose is con-
taminated with about 10% of di-nitro-cellulose, and it is known that a mixture
of equal parts of ether and alcohol will dissolve this di-nitro-cellulose. There-
fore by the addition of ether and alcohol to the explosive material the di-nitro-
cellulose may be dissolved and will serve to consolidate and hold together the
entire mass.
Or a small portion of nitro-glycerine may be added which will also
dissolve the di-nitro-cellulose and assist in consolidating and adding density to

page_text: the mass.
About 1% to 20% of the nitro glycerine may be employed for this
purpose.
To make an explosive that shall be progressive in its action, the compressed
grains sticks or blocks of very finely ground gun cotton may be subjected (in
a vacuum or otherwise) to the action of acetone or acetone and ether, which will
partly or wholly gelatinize or soften the external layer or surface thereof. Then
by drying the blocks and so evaporating the solvent, the external parts of the
said blocks will be covered with a very dense and slow burning shell. When
this burns off the inside and more fibrous part of the blocks will burn much
quicker than the outside.
When the nitrated cotton. has been ground in water together with the resinous
or other material employed, it may be compressed directly into blocks or tablets
without drying, and may be dried after the compression; or it. may be dried
first and then compressed in its dry state. In any case the dies used for
compressing the explosive material and the explosive material itself, should
be heated to about the boiling point of water.
It will be understood that I regulate the rapidity with which the explosive
burns by the density, the size of the fibres and the amount of resinous or similar
material present in the explosive material and that when it is desired to make
it progressive in its burning, I convert the external layer into a hard and horn
like substance by subjecting it to a solvent and then drying it.
The resinous material I prefer to use is American resin mixed with about one
seventh part of its weight of vaseline; I do not however wish to confine myself
to these substances.
The aforesaid progressive action may be obtained by making each particular
block or tablet in three pieces, comprising two exterior shells of an extremely
slow burning character and great density, and an interior disc made of a quick
burning character and fibrous nature. The three pieces being put together in
a mould and pressed are converted into a single block or tablet, the exterior
part of which is slow burning and the interior quick burning.
In some cases the tablets may be subjected to comparatively light presure
while wet, then dried and heated and subjected to further compression after the
drying. Or the further compression may be effected after the tablets or the
fibrous portions thereof have been submitted to the action of solvents in a vacuum
or otherwise.
The compressed blocks or tablets are preferably made in the shape of discs
having a series of concentric annular depressions in each face thereof, the portions
between the said annular depressions being formed with tapered indentations.
The indentations in one face preferably break joint with those in the other.
This form of the blocks or tablets permits the blocks to have a large area of
burning surface without the liability that exists with ordinary multiple per-
forated blocks, to accumulate sufficient pressure when the powder is fired in
the gun, to blow the blocks into atomis.
Datal this 19th Jan L V
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C..
Agents for the Applicant.
anufacture 01 Explosives.
I, HIRAM STEVENS MAXIM, of 18, Queens Gate Place, in the County of Middle-
sex. Chevalier of the Legion of Honour, Civil and Mechanical Engineer, do
hereby declare the nature of this invention and in what manner the same is

page_text: to be performed, to be particularly described and ascertained in and by the
following statement:-
This invention has reference to the manufacture of explosives for artillery.
It is well known that the products of combustion of cordite and ballistite
used in some of the naval and military services consists largely of carbon di-oxide,
a very heavy and dense gas which by reason of its great heat erodes the barrels
of guns much more rapidly than carbon monoxide. It is therefore advantageous
to have as little as possible of the carbon di-oxide present in the products of
combustion, in fact it is better that there should be a slight production of smoke
than that by attempting to avoid it the explosive should be made excessively
erosive.
According to my invention I prevent or diminish the erosion by making one
of the constituents of the explosive of some resinous or other hydrocarbonaceous
substance that will cause the evolution of carbon, mon-oxide instead of carbon
di-oxide when the explosive is fired. The resinous material I prefer to use is
American resin mixed with about one seventh part of its weight of oil such as
that used for lubricating engine cylinders; I do not however wish to confine
myself to these substances.
Many nations object to the use of nitro-glycerine as a constituent of their
smokeless explosives for artillery purposes and prefer to make them from gun-
cotton (tri-nitro-cellulose). When however a smokeless explosive is made
altogether from gun-cotton, by dissolving the latter in the well known manner,
the explosive in its finished condition is liable to be very hard and to burn too
slowly for artillery purposes. If on the other hand the explosive be made from
pulped gun-cotton, that is to say with the cotton in a fibrous condition, it is
found that the explosive burns too rapidly.
Now, from experiments which I have instituted, I find that if the gun cotton
fibres be reduced mechanically to a very fine condition-that is to say, to a
condition very much finer than that to which they have usually hitherto been
reduced by powder manufacturers, the said fibres can be readily combined or
incorporated with the resinous or other material and be pressed into a solid mass,
to form an explosive without the use of solvents. An explosive so manufactured
will burn no faster than if made from the dissolved gun cotton and very much
slower than if made from the pulped gun cotton. And I can, by varying the
proportions of the ingredients, obtain an explosive capable of burning at any
required rate, either slow or quick.
In carrying my invention into practice I take a suitable quantity of pulped
gun cotton to which I add from 2% to 15% (two to fifteen per cent.) of the
resinous material, according to the rapidity with which the explosive is required
to burn. These ingredients are then subjected to a grinding or other operation
in the presence of water until they are reduced mechanically to a very fine
condition. By this I mean that the tubular structure of the fibres of the gun
cotton has been completely destroyed, so that the gun cotton will be in the
condition of an absolutely impalpable dust. The material is then removed from
the grinding mill and compressed directly into grains, sticks, blocks or tablets
of the required form and dimensions, without the use of solvents and afterwards
dried or it may be dried first and then compressed in its dry state. In any
case the dies used for compressing the explosive material and the explosive
material itself, should be heated to about the boiling point of water.
In order to make a still slower burning explosive, solvents such as acetone
or acetone and ether combined, may be used, which will dissolve only a portion
of the nitrated cotton. Tri-nitro-cellulose is usually contaminated with about
10% (ten per cent.) of di-nitro-cellulose, and it is known that a mixture of equal
parts of ether and alcohol will dissolve this di-nitro-cellulose. Therefore by the
addition of ether and alcohol to the explosive material the di-nitro-cellulose
may be dissolved and will serve to consolidate and hold together the entire
mass. Or a small portion of nitro-glycerine may be added which will also dissolve

page_text: the di-nitro-cellulose and assist in consolidating and increasing the density of
About 1% to 20% (one to twenty per cent.) of the nitro-glycerine may
the mass.
be employed for this purpose.
To make an explosive that shall be progressive in its action, the explosive
material after being compressed into grains, sticks or blocks of the required
dimensions is subjected (in a vacuum or otherwise) to the action of acetone or
acetone and ether, which will partly or wholly gelatinize or soften the external
layer or surface thereof. The said blocks are then dried so as to evaporate the
solvent, whereby the external parts of the said blocks will be covered with a
very dense and slow burning shell. When this burns off, the inside and more
fibrous part of the blocks will burn much quicker than the outside.
It will be understood that I regulate the rapidity with which the explosive
burns by varying the density of the material and the amount of resinous or
similar substance present in the explosive material, and that when it is desired
to make it progressive in its burning, I convert the external layer into a hard
and horn like substance by subjecting it to a solvent and then drying it.
The required progressive action may be obtained by making each particular
block in three pieces, that is to say, two exterior shells of an extremely slow
burning character and great density, and an interior disc made of a quick burning
character and fibrous nature. The three pieces being put together in a mould
and pressed are converted into a single block or tablet, the exterior part of
which is slow burning and the interior quick burning.
In some cases the blocks may be subjected to comparatively light pressure while
wet, then dried and heated, and subjected to further compression after the drying.
Or the further compression may be effected after the blocks or the fibrous portions
thereof have been submitted to the action of solvents in a vacuum or otherwise.
In the accompanying drawings I have illustrated some of the forms into which
my explosive material can be made.
Figures 1 and 2 are respectively a plan and a transverse section of a tablet of
the explosive made in disc form.
Figure 3 is a cross-section of a stick or rod of the explosive so formed that it
will readily ignite in the gun and that the areas of burning surface will not
greatly diminish during the burning thereof.
Figures 4 to illustrate approximately the manner in which the shape of the
surface of this form of the explosives varies, during burning.
Referring more particularly to Figures 1 and 2 the tablet is made in the
shape of a disc with a series of concentric annular depressions a a in each face
thereof, the portions between the said annular depressions being formed with
tapered indentations b. b. The indentations in one face preferably break joint
with those in the other as shewn. This form of the blocks or tablets permits
their having a large area of burning surface without the liability that exists
with ordinary multiple perforated blocks, to accumulate sufficient pressure when
the powder is fired in the gun, to blow the blocks into small pieces.
Referring to Figures 3 to 7, the explosive here represented is made in the
form of a stick or rod with longitudinal V-shaped notches ce formed in the surface
thereof as shown at Figure 3, so that when the explosive burns it will gradually
pass through the various phases represented in Figures 4, 5 and 6 until it
becomes severed into several pieces in the manner shown at Figure 7. This form
enables the explosive to be used in the condition of a large and stiff rod or
stick with sharp edges at intervals in its circumference to enable ignition thereof
to readily take place when fired in a gun. Moreover this form can be cheaply
and easily manufactured and is such that the area of its burning surface does
not greatly diminish during the burning.
The form represented in Figure may be imparted to the explosive compound
by passing it while in a plastic condition through a nozzle or die of corresponding
shape, or it can be otherwise formed as may be found most convenient. If
desired the sticks or rods instead of being made of sufficiently large dimensions

page_text: to fit the charge chamber of a gun may be made of small diameter and be cut
into short lengths and a sufficient number of them be used to make the necessary
charge. Preferably however I make them of a size to fit the charge chamber of
the gun.
I would state that I am aware that it has before been proposed to reduce gun
cotton to a powdered condition, but so far as I know it has not before been
reduced mechanically to the extreme degree of fineness which is necessary for
my purpose and which I have indicated above.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. The manufacture of an explosive compound from gun cotton reduced
mechanically to the required degree of fineness for the purpose specified.
2. The manufacture of an explosive compound by incorporating with gun-
cotton during its mechanical reduction to the aforesaid degree of fineness, a hard
tough and gummy hydrocarbon and subjecting the finely divided mixture so
obtained to pressure and heat to form it into the requisite sliape for the purpose
specified.
3. The manufacture of an explosive compound by incorporating American resin
with gun cotton during its mechanical reduction to the aforesaid degree of fine-
ness, partly dissolving the said gun cotton by the addition of a solvent and
subjecting the mixture so obtained to heat and pressure for the purpose specified.
4. The manufacture of an explosive compound by incorporating comminuted
gun cotton with from 2% to 15% (two to fifteen per cent.) of American resin,
dissolving the di-nitro-cellulose present in said gun cotton by the addition of
from 1% to 20% (one to twenty per cent.) nitro-glycerine and subjecting the
mixture so obtained to heat and pressure for the purpose specified.
5. An explosive manufactured as described and rendered progressive in its
burning by either subjecting its external surface to a solvent and afterwards
evaporating the latter, or by making the external portion of the explosive of a
slower burning quality than the interior portion substantially as described.
6. An explosive formed into a block having concentric annular depressions in
each face with tapered cavities in the walls of said depression, those on one side
of the block breaking joint with those on the other side, substantially as and for
the purpose specified.
Dated this 1st day of February 1900.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.