Improvements in or connected with Blasting and Blasting Cartridges.
Year: 1893

page_text: Date of Application, 15th May, 1893
Complete Specification Left, 14th Mar., 1894-Accepted, 12th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in or connected with Blasting and Blasting
Cartridges.
We, JAMES MACNAB of 6 Red Lion Square, Holborn, in the County of
Middlesex, Engineer, and JAMES DICKSON of Towsend, St. Albans, in the County
of Herts, Contractor, do hereby declare the nature of this invention to be as
follows:-
Our invention relates to improvements in mining and blasting gunpowder
cartridges and the apparatus employed therein in combination with gunpowder or
other similar-acting slow or medium-burning class of explosives in contra-
distinction to the high or quick-burning violent explosive compounds such as
dynamite, gun-cotton &c. although this latter class of explosives may be combined
with the gunpowder to obtain extra power under certain given conditions and
suitable arrangements herein afterwards described, and which is specially adapted
for mining and blasting rock, getting coal and other minerals, a modification of
which is also employed for "pillaring" slate-rock.
These improvements essentially consist in the employment of a metallic device-
action enclosed in the gunpowder case for the purpose of effectually preventing
blown-out-shots of gunpowder or other similar-acting class of slow-burning or
medium-burning explosives, and also for obtaining by this device-action or means
all the pressure-power developed by the ignited gases and which are entirely
concentrated on the sides or lateral division of the bore-hole and by this method
the longitudinal pressure at either end of this combination cartridge is neutralized
especially at the tamping or near-end of the blast-hole and which device-action
materially contributes to efficiently relieve the usual heavy pressure or strain on the
tamping or stemming at this vital point by completely preventing the same from
being blown out by the explosive pressure and which frequently takes place when
the ordinary gunpowder cartridge or charge employed is unable to blown down the
coal or rock and thus a "blown-out-shot" is the result and which forces its
dangerous tongue of flame into the working place and too often ignites the
fire-damp and coal-dust of the mine when an explosion invariably follows.
For the purpose of obtaining extra power and safety we also combine with this
device-action, when desired, a charge of liquid ammonia varied for certain work
with a solution of nitrate of ammonia in chemical combination with the liquid
ammonia and which the latter will dissolve or they may be used separately and
independently or other similar-acting liquid or fluid even water may be employed.
These liquids are hermetically sealed or closed in glass tubes or other vessels in
proportionate quantities or charges to the amount of gunpowder or other explosive
employed.
The device-action of this combination gunpowder cartridge simply consists of two
strong discs of mild steel or other metal and which are the full diameter of the
cartridge case and are connected rigidly or firmly together by a strong or
proportionate central binding rod of the same metal from being blown separate and
which may be screwed on each end of the rod or the action inay be made in one
piece by being pressed into shape while the metal is in a fusible or molten state.
In one or both discs there is a hole or opening at the side for charging the case or
for running in the gunpowder in a loose state or it may be compressed round the

page_text: central rod if desired. Into one of these holes or openings the igniting fuse is
inserted and by preference a detonator cap is employed for securing more reliable
ignition and also for obtaining greater power through instantaneous combustion
and detonation of the gunpowder and which charge may be mixed or combined with
very fine and coarse-grained gunpowder.
To obtain still more rapid combustion and strength we also combine or mix
together very fine-grained and meally gunpowder for certain descriptions of work
to obtain further extra power. We also employ dry or wet gun-cottou-the
latter sealed or closed in a tube or vessel-or other high explosive in combination
with gunpowder, if desired, in which case the metallic device-action is protected or
separated by a division cartridge or charge of gunpowder.
We prefer to use a detonator cap of the fulminate of mercury class for firing the
cartridge and which cap has a short length of india-rubber tubing attached to its
muzzle or opening for the purpose of connecting the cap to the Bickford or electric
fuse or other firing method for securing a water-tight joint by binding it round the
fuse or the wires, as the case may be. For the purpose of keeping the fuse firmly
in the case a knotted loop of wire or twine with the loose ends hanging out,
is inserted before the detonator is placed in the case and which when pulled
outwards wedges the fuse or wires, it is then securely tied in at the neck of the
gunpowder case of this novel combination cartridge. The case may be made of
waterproof cartridge paper or Japanese paper or other suitable waterproof material
and which contains or surrounds the aforesaid metallic device-action with its
explosive contents.
When the liquid ammonia or a solution of the nitrate of ammonia or other
similar-acting liquid are employed for cooling down the flame they are attached
or tied round the central binding rod. One or more of these hermetically sealed
glass tubes or vessels may be employed or they may be placed in the case in a loose
or untied condition. The holes or openings in the discs of the device-action also
serve to connect the cartridges and to fire each other when two or more are
employed.
"
This improved device-action cartridge is also admirably adapted for "pillaring
slate-rock and more especially where splits exist in the rock as it can be efficiently
placed close to the split and "pillar" the rock with reliability when the discs will
thus concentrate the entire pressure-power of the powder gases on the sides of the
bore-hole and in a lateral direction and also largely save the gunpowder-a
desideratum in chamber-workings or elsewhere.
The device-action may obviously be modified and employed for "pillaring"
without a case when the connecting rod is fitted with a rigid disc at the inner-end
and with a movable disc at the other-end or outer extremity on which is a thumb-
screw to hold in the action-the disc is actuated by a tubular binding collar with
tightening screws for adjusting it to any desired depth of borehole. After placing
the action in the bore-hole the gunpowder is run down at the side and the disc
adjusted on the top or level of the powder, and screwed or fixed firmly on the
rod. In the event of the disc accidentally slipping up a piece of leaden tubing may
be placed on the rod to work and act as a buffer.
After the fuse has been inserted a little tamping may be placed round the disc
and the charge fired when the device-action will retain its position in the bore-
hole uninjured and by this method save about half the charge of gunpowder usually
employed.
"
For the purpose of getting coal and assisting the undercutting or top-cutting, a
uniform dipping blast-hole is drilled at the "buttock or broken end of the coal-
seam near the floor or roof, as the case may be, and about three or more feet from
the coal face, similar to the description given in my Patent of 1876-No. 3150.
Water is poured into the same to about 18 inches from the. mouth or muzzle--a
water-tight device-action gunpowder cartridge is then inserted till it is completely
surrounded by the water, and then tamped upon the top with plastic clay and the
stemming completed with hard clay tamping. When the shot is fired it will be

page_text: "
found that the coal seam has been started or shaken-perhaps thrown forward-
along the face for two or three times the length of the bore-hole, or according to
the more or less resistance of the seam. The coal will then be found in a friable
or free condition for holing or cutting with the greatest ease and will only occupy
about one third or less of the usual time the laborious pick system takes to do
the work. In the event of fissures or breaks in the seam when the bore-hole will
not hold water it is confined in a case or tube similar to the " water-cartridge
described in my Patent of 1876, already referred to. In this method of working
we prefer to place a case of water, or other suitable liquid, at the far-end and one
at the near-end with the explosive device-action cartridge in the middle division or
between the two "water-cartridges" and tamp upon the near-end case of water
with soft or plastic clay then with the ordinary hard clay tamping-when the same
result will take place. We also sometimes employ a chamber at the far-end of the
blast-hole for throwing out the coal without undercutting and make the chamber
with an "expanding-drill" similar to the tool I describe in my Patent Specifi-
cation of 1875-No. 3281-and also work on the method therein detailed. But for
extra safety while working with our device-action gunpowder cartridge to prevent
the fire-damp or coal-dust from being ignited we drill an inclined or dipping hole
and chamber in or near the middle of the coal face, and sometimes parallel to the
face and charge the chamber with water by means of a tube and funnel and draw
off the air which the water has enclosed in the upper part of the chamber above
the borehole end by an air-suction pump which is attached to a semi-flexible tube
which is bent at the far-end and made to penetrate up into the top of the chamber.
After the water has filled up the air space the tube is withdrawn and the device-
action gunpowder cartridge is pushed through the water till it gets jammed into
the opposite borehole recess and in which its end rests and thus lays across the
entire chamber and is tamped in this position with plastic clay and with hard clay
stemming throughout the remainder of the borehole. The shot is then fired, when
the coal if not sticking too fast to the roof-will be forced forward and be
disintegrated. When the chamber cannot hold water we employ one or more
flexible cases or bags of water and which are placed into the lower and upper
divisions of the chamber combined with a charge of loose gunpowder or with one
or more device-action cartridges placed in the centre and a device-action cartridge
in front of the chamber then tamped in as already described and the shot fired.
Dated this 15th day of May 1893
JAMES MACNAB.
JAMES DICKSON..
COMPLETE SPECIFICATION.
Improvements in or connected with Blasting and Blasting
Cartridges.
We, JAMES MACNAB, of 6, Red Lion Square, in the County of Middlesex,
Engineer, and JAMES DICKSON, of Townsend, St. Albans, in the County of Herts,
Contractor, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
Our invention relates to blasting and blasting cartridges and has for one of its
objects to provide means whereby when blasting especially with gunpowder the
tamping or stemming in the bore holes will be prevented from being blown out,
thereby ensuring that the explosive charges shall exert their expansive power upon
the walls of the bore holes as efficiently as possible and obviating the serious
explosions which frequently occur owing to the ignition of the fire-damp and coal
dust of the mine by the flame which usually accompanies a blown out shot.

page_text: Another object of our invention is to damp or reduce as much as
flame due to the explosion of the charges and at the same time to
explosive power of such charges.
22
possible the
increase the
In carrying out our invention we make use of a "device-action or device com-
prising two discs connected by a rod and we combine with the explosive charge
whether the device is used or not, a flask or flasks or like vessel containing liquid
ammonia, ammonium nitrate, sodium nitrate or their equivalents and hermetically
sealed.
To enable our invention to be fully understood we will describe the same by
reference to the accompanying drawings the figures of which are hereinafter
referred to and in which similar letters of reference indicate corresponding parts.
a is our device which comprises two discs b, b of mild steel or other suitable
material (preferably copper plated and coned or inclined inwardly from their
peripheries towards their axes) connected by screwing or otherwise to or formed
in one piece with a rod c which may be at the centre of the discs; or if more
convenient more or less to one side of the centre. A hole d is formed in one of the
discs through which a fuse e can be passed and through which the explosive
material can be introduced between the discs. It will be obvious that when this
device is placed in a bore hole (the discs being of a size to approximately fit
the said hole) with an explosive charge between the said discs, the gases produced
by the explosion of such charge will be prevented from expanding in a longitudinal
direction in the bore hole and so exert all their expansive force upon the walls of
the said bore hole.
Our device may be made up with the explosive charge in the form of a cartridge
(in the following description we shall refer to a cartridge so made up as a "device
cartridge) or it may be introduced into the bore hole separately and the explosive
charge subsequently introduced.
ff are the flasks, phials or tubes containing the liquid ammonia either alone
or in combination with crushed ammonium nitrate, sodium nitrate, ammoniacal
copper nitrate or chlorate of potash or their equivalents either in solution or in
a crushed or granulated condition. The phials containing these bodies are
hermetically sealed or closed against atmospheric influences in quantities or
charges proportionate to the amount of gunpowder or other explosive employed.
To provide as far as possible against the flasks, phials or tubes being broken
they are advantageously wrapped or rolled in paper previously saturated in a
solution of salt petre or sodium nitrate to make the material readily combustible.
We have found by experiment that a suitable proportion or charge of liquid
ammonia for ordinary work consists of one glass tube about three inches long
by three-eighths of an inch in diameter filled with that liquid for every quarter
of a pound of gunpowder. For still further safety in fiery or dusty mines, about
one inch extra or more may be employed. For gun cotton, dynamite, or other
"high" explosives one glass tube about two inches long and three-eighths of an iuch
in diameter may be used with every two ounces of explosive.
When the crushed or granulated salts are substituted for the liquid or
solution a comparatively larger proportion may be employed, some of which
may be simply enclosed in waterproofed cloth or paper cases and sealed with
suitable cement.
By referring to Figure 1, which is a longitudinal section the general arrange-
ment of our device cartridge with phials of ammonia or the like will be understood,
g indicating the cartridge case and h the explosive charge which may be gun-
powder in a granular or meal form or solid condition. If in the latter case the
gunpowder used is in the form of rings one of the discs b is made removable to
permit of threading the rings on to the rod. The phials containing the ammonia
or the like are represented as being bound on to the rod c. The fuse is by
.preference arranged in connection with a detonator cap e¹ to cause the instantaneous
detonation and combustion of the explosive charge.
In making cartridges we sometimes combine fine and coarse-grained gunpowder

page_text: in alternate divisions in the case, or we place the powder loose or in cases in
the bore hole in alternate divisions of fine and coarse powder to secure uniform
combustion. Figure 2 represents the latter arrangement. A device cartridge
containing tubes of liquid ammonia and meal gunpowder is placed at the bottom
of the bore hole which is filled up with cases or divisions of fine grained gun-
powder and coarse blasting powder placed alternately, each case or division
containing a tube of liquid ammonia. The fuse e and detonator cap el being
inserted, the charge is stemmed down hard with a layer of plastic clay and
with tamping indicated by the letter j.
The discs of the device may be efficiently employed, without the binding rod or
bar for certain descriptions of work, with important effect and safety, especially
with quick-burning gunpowder.
To produce still more rapid combustion and expansive force we sometimes employ
(with or without our device) extra fine grained or meal gunpowder and crushed
blasting powder, either mixed together or separate, and which may be firmly
compressed dry in the cartridge to concentrate its power, or loose in the case and
well shaken down for exceptionally strong work, and with which are incorporated
tubes of ammonia solution or the like. In Figure 3 we represent a meal or extra
fine grained gunpowder cartridge (without the device) placed at the bottom or end
of the bore hole and containing a tube of ammonia solution and then two cartridges
or sections of coarse grained blasting powder, each containing a tube of ammonia
solution, the fuse detonator and tamping being applied as before. This arrange
ment of meal and coarse blasting powder may be employed, when desired, without
the tubes of ammonia solution or their equivalents and the position of the meal
powder cartridge may be substituted for that of the coarse blasting powder
cartridges or sections the coarse powder will then occupy the bottom of the bore
hole when quicker combustion of the coarse powder will be secured.
We sometimes employ a charge of gunpowder in combination with a charge of
gun cotton dry or wet. The latter may be sealed or closed in a glass tube or in a
cloth case either waterproof or otherwise; or other high explosive may be
substituted, such as gelatine, dynamite or ammonium nitrate, the latter in a crushed
or granulated form and sealed or closed from the air, a tube of ammonia solution
and a detonator cap being employed in the gunpowder and "high explosive."
Figure 4 represents a bore hole charge of this description wherein our device
is employed. The gun cotton or the like is placed at the bottom of the bore hole
and the device cartridge at the end next the tamping. A charge of either meal or
fine or coarse grained powder, containing a tube of ammonia solution is arranged
between the gun cotton and the device cartridge and acts as a buffer to the gun
cotton charge in which is a tube of ammonia solution closed and a detonator cap
closed with a piece of fuse in the end. The device cartridge fires this combined
charge with the fuse and detonator cap, the fuse being ignited by a Bickford
safety lighter.
We prefer to use a detonator cap of the fulminate of mercury class, or other
suitable detonator, for firing the cartridges or charges which cap may have attached
or fixed on its muzzle or opening a short length of india-rubber tubing, for the
purpose of connecting the cap to the Bickford or electric fuse, as the case may be,
and securing a water tight joint by binding it round the fuse or electric wires.
When desired, and for the purpose of keeping the fuse firmly in the cartridge
when compressed powder is employed, a knotted loop of copper wire or twine, with
the loose ends hanging out, is inserted in the case, before the detonator and fuse is
placed in the hole of the disc, which wire when pulled outwards will wedge the
fuse in so that it can be securely tied round the fuse or electric wires. In the
event of a case being used it is tied in at the neck of this combination cartridge
or charge.
Figure 5 illustrates another arrangement of high explosives in combination with
meal or fine gunpowder cartridges or charges, but without the device. A cartridge
of gunpowder is placed at the bottom of the bore hole on the top of which is a

page_text: cartridge of dynamite containing a detonator cap provided with a piece of fuse
and a tube of ammonia solution, another cartridge of meal or fine gunpowder
containing a tube of ammonia solution, is placed on the top of the dynamite
cartridge and the bore hole filled up with coarse blasting powder containing, at
intervals, two tubes of ammonia solution.
Figure 6 represents a bore hole with two cartridges of meal gunpowder each
containing a sealed tube or case of crushed or granulated ammonium nitrate, which
is substituted for the liquid ammonia, and is exploded by a detonator cap ignited
by a fuse. When a tube or tubes of liquid ammonia or a solution of the nitrate
of ammonia, or other similar acting liquid, or the crushed or granulated salts of the
same are employed, as described, for cooling or damping down the flame of the
explosive, they can be either loose or attached or tied round the central binding
rod of the device when the latter is employed or otherwise fixed or embedded in
the loose or compressed powder. When used with the latter, apertures may be
formed in the powder blocks for containing the tubes.
We sometimes employ more than one device cartridge in a bore hole and in this
case the holes or openings in the discs of the device serve to communicate the fire
from one cartridge to another.
Our improved device cartridge is admirably adapted for "pillaring" or breaking
down slate-rock and more especially where joints or splits exist in the rock, as it
can be placed close to the joint or split and efficiently "pillar" the rock with
reliability, as the discs will cause the entire expansive power of the powder gases
to be concentrated on. the walls of the bore hole in a lateral direction only, and
also largely reduce the charge of gunpowder usually employed, a desideratum
especially in chamber-workings.
Our device may obviously be employed without a case, when the connecting rod c
is fitted with a rigid disc at the inner end and with a moveable disc at the outer
extremity on which is also a thumb-screw or other adjusting device. After placing
the portion of the device having the rigid disc in the bore hole, the powder is run
in and then the loose disc is adjusted on the top of the powder and screwed or
fixed firmly on the rod. In the event of the disc accidentally slipping up a piece
of lead or gas tubing may be placed on the rod to work and act as a buffer. After
the fuse has been inserted a little tamping may be placed around the disc and the
charge fired, the device action retaining its position in the bore hole uninjured.
By this method we save about half the charge of powder usually employed.
For the purpose of getting coal and assisting the under cutting or top cutting, a
dipping blast-hole of uniform diameter is drilled at the "buttock
" or broken end
of the coal-seam near the floor, (as shewn in Figure 7) or near the roof, as the case
may be, and about three or more feet back from the face in a similar manner to
that described in the Specification of Letters Patent No. 3150 of 1876.
Water is
poured into the said blast hole to fill it within about 18 inches of the mouth or
muzzle; a water-tight gunpowder device cartridge a is then inserted till it is
completely surrounded by the water and then the hole is tamped with plastic clay
and the stemming completed with hard clay or other tamping. When the shot is
fired it will be found the coal seam has been started or shaken, perhaps thrown
forward, along the face for two or three times the length of the bore hole according
to the resistance of the seam. The coal will then be found in a friable or free
condition for "holing or cutting with the greatest ease, and will only occupy
about one third or less of the usual time the laborious pick system takes to do
the work.
33
When fissures or breaks exist in the seam and the bore hole cannot hold water,
the water is confined in a case or tube similar to the "water-cartridge " described
in the Specification of 1876 already referred to. We prefer in such circumstances,
however, to place a case of water or other suitable liquid at the far end and one at
the near end of the bore hole with the cartridge in the middle division, or between
the two "water cartridge" and tamp upon the near end case of water first with
soft or plastic clay and then with the ordinary hard clay tamping, when the same

page_text: result will take place. We also sometimes employ a chamber at the far end of the-
blast hole for throwing out the coal without under cutting and make the chamber
with an "expanding drill" similar to the tool described in the Specification of
Patent No. 3281 of 1875 and also work on the method therein described. But for
extra safety while working with the gunpowder device cartridge and to prevent.
the fire-damp or coal-dust from being ignited, an inclined or dipping hole and
chamber is drilled in or near the middle of the coal face, sometimes parallel to the
face, in which case the chamber is charged with water by means of a tube and
funnel. The air which the water has enclosed in the upper part of the chamber-
above the bore hole end is drawn off by an air suction-pump which is attached to a
semi-flexible tube, bent at the far end and made to penetrate up into the top of the:
chamber.
After the water has filled up the previous air space the tube is withdrawn and
the powder device cartridge is pushed through the water till it gets jammed into
the recess at the bore hole end, and thus lies across the entire chamber. It is.
tamped in this position with plastic clay and with hard stemming throughout the.
remainder of the bore hole. If when the shot is fired the coal is not sticking too.
fast to the roof it will be forced forward and broken up.
When the chamber cannot hold water one or more flexible cases or bags of
water are employed the said cases or bags being placed into the lower and upper
divisions of the chamber and combined with a charge of loose gunpowder or with
one or more device cartridges placed in the centre and a device cartridge in front.
of the chamber.
Figure 8 illustrates the method of blasting or blowing down coal at the broken
end of a coal-seam and face which is undercut. The device cartridge is placed at.
the far end of the bore hole and stemmed in with tamping and the shot fired by the
fuse and ignited by a Bickford safety lighter.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. The use for blasting of an apparatus or device comprising two discs connected.
by a rod and adapted to receive an explosive charge of either slow burning, medium
burning or quick burning gunpowder, or other similar acting explosive between
them, the said device and explosive charge being made up in the form of a cartridge.
or introduced into a bore hole separately, substantially as herein described.
2. The combination with an apparatus or device and an explosive charge confined
in a case or introduced separately into a bore hole as referred to in the preceding
claiming clause of a charge of either liquid ammonia, ammonium nitrate, sodium.
nitrate, or their equivalents in solution or in a crushed or granular state, separately
or combined and hermetically sealed in tubes or vessels, substantially as herein.
described.
3. The use for blasting of a charge of either meal or fine grained gunpowder or
crushed blasting gunpowder in combination with a charge of either liquid ammonia
or ammonium nitrate, chlorate of potash, or their equivalents in solution, or in a
crushed or granulated state and hermetically sealed or closed in tubes or vessels,.
substantially as herein described.
4. The use in blasting of a device (without a cartridge case) having one moveable
disc and a charge of gunpowder for "pillaring" slate-rock and similar splitting.
purposes, substantially as berein described.
5. The use in blasting of explosive charges made up or composed of sections of
explosive materials adapted to burn at different speeds, each section containing a
tube or phial of ammonia or the like, substantially as herein before described and
illustrated in the accompanying drawings.
6. The improvements in blasting consisting in combining with gunpowder or other
explosives which burn slowly or relatively slowly gun-cotton or other high.

page_text: explosive and tubes or phials of ammonia with or without the device, substantially
as, and for the purposes described and illustrated in the accompanying drawings.
Dated the 14th day of March 1894.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.