in b
Year: 1897

page_text: Date of Application, 15th July, 1897
Complete Specification Left, 16th May, 1898-Accepted, 18th June, 1898
JAMES MACNAB, of 6, Red Lion Square, in the County of Middlesex, Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in blasting and in blasting cartridges and in
the improved cartridge cases employed whereby extra efficiency in the explosive is
obtained in combination with a novel tamping or flame-cooling pellet which is added
or placed upon the explosive cartridge or charge employed thereby producing extra
safety while at same time a greater amount of strength is imparted to the special
class of high explosive charge or charges employed the same being used in conjunction
with a non-explosive flame and fume-destroying or cooling-down solution or body
confined or imprisoned together in a cartridge case suitably arranged for this purpose
whereby the dangerous flame and deleterious fumes given off by the fired explosive
employed are partly or wholly neutralised or rendered harmless followed by other
useful effects which are simultaneously and instantaneously produced as hereinafter
described.
For this important safety object the class of explosives herein referred to are
combined in the said cartridge case with a proportionate charge of the flame and fume
neutralising solution or body referred to. For this particular purpose ammonia
solution is preferred owing to its safe and reliable instantaneous action which will
render such fiery or flame-generating explosives more powerful and efficient safety
agents for blasting operations than as at present employed in fiery and dusty coal-
mines or elsewhere underground. They are also eminently adapted for surface work
especially for driving badly-ventilated tunnelling operations. For dangerous work in
coal pits these combination blasting cartridges are further combined with an efficient
and suitably formed strong cartridge case preferably made of tinned sheet steel or
iron (or other suitable metal or substance)-the explosives or charge being inserted in
the interior of this case and are firmly enclosed to assist in enforcing its efficient
working and to also secure the self-detonation or complete decomposition of the high
explosive employed therein, this being brought about by the instantaneous and
abruptly developed combustion of the intense heat generated, which is accomplished
by this novel arrangement and manner of application without the aid or necessity of
a fulminate of mercury detonator cap as absolutely required and employed for
detonating such high explosives class as at present made and used in blasting-
although, when desired, for extra-strong work a detonator cap may be usefully
employed. To obtain these safe and efficient effects with reliability, and which
combined charge is practically unaffected by climatic changes, my improved and
novel method simply consists in the employinent, by preference, of dry meal gun-
cotton (or other suitable permanent form of dry nitrated cellulose) as the unchange-

page_text: able base or actuating class of explosive for this purpose, but the gun-cotton must be
essentially employed or applied in a special manner or condition, namely-while it is
in the primary or early form of dry nitrated cotton waste pulp, but especially after
the same has been ground into a fine powder or state of meal. It is strictly used in
this loose meal condition or stage prior to the gun-cotton being compressed into
pellets or discs in the usual manner for ordinary blasting or mining work.
While in this dry meal state it is made up into cartridges of the required
dimensions combined with a proportionate charge of ammonia solution (880) contained
in tubes securely closed or hermetically sealed, and may be embedded in the explosive
meal and placed together in suitable cartridge cases made of tinned sheet metal (or
other desirable metal or substance) the side edges of these cylindrical cases being
rigidly overlapped or strongly bound together and closed at both ends with a hollow
cap or cover of same metal turned up at the edge and tightly overlapping the
cylindrical ends.
The top or near end cap or cover is furnished with a suitable central hole for holding
the igniting fuse firinly in position, the said hole being closed by cemented paper
until required for use.
For strong work and to further contribute extra power to the gun-cotton meal also
for facilitating rapid ignition, I sometimes add or place a small charge of potassium
chlorate (or other similar-acting explosive) for furnishing the gun-cotton meal with
an extra supply of oxygen, but for absolute safety the said chlorate is carefully
secured in a tube of waterproof paper closed or tied at both ends and cemented in to
entirely cut off all connection between it and the gun-cotton meal. The cartridge
case with its combined charge is then placed into the borehole and tamped firmly
in position, first with a pellet of ground rock-salt or fine common salt contained in a
case furnished with a metallic cap or disc at its base-similar to the cap or disc
employed in the cartridge case; and already described, which contains a central hole
for the fuse, or the rock-salt may be compressed instead into the form and dimensions
of a blasting gunpowder pellet with a corresponding central hole to admit of the fuse
being inserted and connected to the cartridge or charge for firing the same. On the
top of the supplimentary pellet or case of salt a pellet of ordinary damp plastic clay is
placed, this is followed by the usual hard tamping. The charged borebole is now
ready for ignition by any of the well-known methods or by electricity.
The object of placing the pellet or case of fine ground salt (or other similar-acting
flame-cooling salt or substance) is for greater safety and to further contribute to
neutralise the dangerous flame, combined with the metallic cap or disc, which will
prevent the inner surface of the tamping from being disturbed or broken-up before
the explosive charge has done its work, and which will also deflect the flaine and
gaseous pressure laterally.
The caps covers or discs of the case may be usefully employed with paper cases
in lieu of metal ones with efficient results for ordinary work or with simple discs of
metal with or without the edge turned up, as described, and which may be placed in
the interior of the said case.
When the explosion of the combined cartridge takes place the metallic case will
be violently ripped open or burst asunder longitudinally and cause the gaseous
pressure to act laterally in the borehole while the end caps or covers will materially
assist to prevent the flame from penetrating backward or forward in the borehole at
the moment of explosion.
Further, in lieu of placing the supplimentary pellet or case of rock-salt upon the
cartridge externally it may, when desired, be conveniently placed in the interior of
the cartridge case upon the top of the explosive charge and tied in ready for use, but
the safe and useful effect would be materially assisted by being tamped in the bore-
hole with a pellet of damp plastic clay followed by the usual hard tainping to further
contribute to its efficiency.
The safe and efficient practical action of this improved cartridge and tamping
pellet, herein described, will fully realize in actual work all that I have stated and
its useful action may be absolutely relied upon by reason of the materials and means

page_text: employed to effectually secure the important effects enumerated, and which can be
realized without the usual anxiety and uncertainty in consequence of the well-known
permanent and safe character of the class of explosives herein indicated, combined
with the special manner in which they are applied or brought about in conjunction
with the reliable flame and fume-destroying or cooling-down properties of the
ammonia solution, which is permanently sealed from atmospheric absorption.
This combination cartridge will also produce a much larger economy in the gun-
cotton explosive than as it is made and used at present for doing the same amount
of work, besides, by the novel method of treating and employing the gun-cotton, as
described, far better rending results are obtained, including the self-detonation of
the high explosive which important advantage will secure immunity from risk of
accident both in handling and tamping of the same in the borehole.
I, JAMES MACNAB, of 6, Red Lion Square, in the County of Middlesex, Engineer,
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:
My invention relates to improvements in blasting and in blasting cartridges and
cases therefor, the said improvements comprising a novel tamping or flame-cooling
pellet which is added to, or placed upon, the explosive cartridge or charge employed,
thereby increasing the safety of the cartridge and at the same time imparting a greater
amount of strength than usual to the special class of high explosive charge or charges
employed; in conjunction therewith I may employ a non-explosive flame and fume-
destroying or cooling-down solution or body confined or imprisoned in the cartridge,
which is suitably arranged for this purpose, whereby the dangerous flame and
deleterious fumes given off by the fired explosive are partly or wholly neutralised or
rendered harmless, the arrangement also giving other useful effects which are
simultaneously and instantaneously produced as hereinafter described.
In carrying out the invention, explosives of the class herein referred to are
combined in the cartridge case with a proportionate charge of the flame and fume-
neutralising solution or body hereinafter described. A neutralising substance which
I have found to work well in practice is a solution of ammonia which is preferable
owing to its safe and reliable instantaneous action; it will render such fiery or flame-
generating explosives more powerful and efficient safety agents for blasting operations
than explosives at present employed in fiery and dusty coal mines or elsewhere
underground. Cartridges so made are also eminently adapted for surface work and
for driving badly ventilated tunnelling operations.
or
For dangerous work in coal pits the cartridges are placed in suitable strong cartridge
cases preferably made of tinned sheet iron or steel or other suitable metal
substance. The explosive or charge is introduced into this case and firmly enclosed
therein to increase its efficiency and to secure its self-detonation or complete
decomposition. The detonation is brought about by the instantaneously developed
intense heat without the use of a fulminate of mercury detonator cap which is
necessary for detonating similar explosives as at present used in blasting. When
desired, however, for extra strong work for example, a detonator cap may be
employed.

page_text: The explosive charge, which I advantageously employ, and which is practically
unaffected by climatic changes, consists of dry meal guncotton (or other suitable
permanent form of dry nitrated cellulose) as the unchangeable base, but the
guncotton must be employed while it is in the primary or early form of dry nitrated
cotton waste pulp and after it has been ground into a fine powder or state of meal.
It is used in the loose meal condition reached prior to being compressed into pellets
or dises in the usual manner for ordinary blasting or mining work. While in this
dry meal state it is made up into cartridges of the required dimensions and is
combined with a proportionate charge of ammonia solution (880) contained in tubes
securely closed or hermetically sealed and which may be embedded in the explosive
meal and placed therewith in the cartridge case. The side edges of the case rigidly
overlap or are strongly bound together and the said case is closed at each
end by a hollow cap or cover of the same material turned up at the edge and tightly
overlapping the said end. The top or near end cap or cover is furnished with a
suitable central hole for holding the igniting fuse firmly in position, the said hole
being closed by cemented paper until required for use.
For strong work and to further strengthen the guncotton meal, as also to facilitate
rapid ignition, I sometimes add a small charge of potassium chlorate (or other
similarly acting explosive) in order to furnish the guncotton meal with an extra
supply of oxygen, the said chlorate being advantageously secured in a tube of water-
proof paper, or other suitable substance, closed or tied at both ends and cemented
in to entirely cut off all connection between it and the guncotton meal.
The cartridge case with its combined charge is then introduced into the bore-
hole and tamped firmly in position, first with a pellet of ground rock-salt or fine
common salt contained in a case furnished with a metallic disc or cap at its base
similar to the cap or disc employed in the cartridge case already described, and
which contains a central hole for the fuse; or the rock-salt may be lightly com-
pressed into the form and dimensions of a blasting gun-powder pellet with a corre-
sponding central hole to admit of the fuse being inserted and connected to the
cartridge or charge. On the top of the supplementary pellet or case of salt a pellet
of ordinary soft plastic clay is placed; this is followed by the usual hard tamping.
The charged bore-hole is then ready for ignition by any of the well-known methods
or by electricity.
The object of the pellet or case of fine salt or other similarly acting flame-cooling
salt or substance, is to obtain greater safety and to further assist in neutralising the
dangerous flame, the metallic cap or disc also preventing the inner surface of the
tamping from being disturbed or broken up before the explosive or gaseous charge
has done its work, and deflecting the flame and pressure laterally.
-common
Furthermore, although I have mentioned above one class only of salts-
salt (sodium chloride)-as an example of a flame-cooling salt it is to be understood
that I can employ for this purpose any other similarly acting flame cooling salt or
substance that may be suitable for cooling-down or neutralising the spent flame of the
explosive. When deliquescent salts or substances are employed they should for
reliability and efficiency be carefully sealed from the atmosphere and damp. This
novel flame-cooling or neutralising safety tamping pellet may be usefully employed
with any other class of explosive, where safety is the important object in view, to
prevent the spent flame from being projected into the workings.
The caps or covers of the case may be usefully employed with paper cases in lieu of
metal ones with efficient results for ordinary work. They can also be formed as discs
of metal with or without the edge turned up as described, and adapted to be placed
in the interior of the case.
When the explosion of the combined cartridge takes place, the metallic case will be
violently ripped open or burst asunder longitudinally and will cause the pressure of
the gases generated to act laterally in the bore-hole, whilst the end caps or covers
will materially assist in preventing the flame from penetrating backwards or forwards
in the bore-hole at the moment of explosion.
Furthermore, in lieu of placing the supplementary pellet or case of rock-salt or

page_text: other similarly acting flame cooling salt upon the top of the cartridge externally, the
said pellet or the like may, for saving the miner's time, be conveniently placed in the
interior of the cartridge case upon the top of the explosive charge and tied in ready.
In this case it will be advantageous to tamp the cartridge in the bore-hole
with a pellet of damp plastic clay, followed by the usual hard tamping to further con-
tribute to its efficiency.
for use.
;
My combination cartridges are more economical than guncotton explosive as at '
present made and, owing to the novel method of treating and employing the guncotton,
far better rending results and the self-detonation of the high explosive are obtained,
the latter important advantage securing immunity from accident both in handling,
the cartridge and tamping it in the bore-hole.
I have found that a suitable proportion or charge of liquid ammonia (880) for
ordinary work may consist of one tube or vessel of about four inches long by about
three-eighths of an inch in diameter filled with that liquid to every four ounces of
meal guncotton or other explosive.
For the safety tamping pellet case or bag a charge of about two to four ounces of.
chloride of sodium (common salt), or other similarly acting flame cooling salt or
substance, may be used with a charge of about two to four ounces of meal guncotton
or other explosive, but these proportions can be modified to suit the various kinds of
work and the diameter of the bore-hole; the larger the diameter of the latter the
larger should be the proportion or length of the pellet so that it occupies a space in
the bore-hole of about one-fourth the length of the explosive charge; it can be varied,
more or less, according to the power and specific gravity of the explosive employed.
To enable my invention to be fully understood I will describe it by reference to
the accompanying drawing in which:
Figure 1 is a longitudinal section of a cartridge made according to the invention:
Figure 2 is a transverse section on the line 2-2 Figure 1:
Figure 3 is a longitudinal section of a tamping pellet; and,
Figure 4 is a longitudinal section of a combined cartridge and tamping pellet made
according to my invention.
Referring to Figures 1 and 2 a is the cartridge case which may be of tinned steel
for example, the joining of the two edges of the blank forming the said case being
made for instance as shewn in Figure 2. h is the paper wrapper which is tied at the
neck as shewn at c. d is the charge of meal guncotton and e, e are two tubes con-
taining liquid ammonia (880) and embedded in the meal guncotton d. f is the cap
or cover which is turned up at the edge and firmly encloses the charge of meal gun-
cotton d, and the tubes of liquid ammonia e in the case a. The cap has a central
hole to receive the fuse, the said hole g being closed with a disc of paper till the
cartridge is wanted for use.
In this example the safety tamping pellet is placed upon the top of the cartridge
case a and the cartridge then ready for the bore-hole and for receiving the firing
fuse.
Figure 3 represents in section the safety tamping pellet. is the paper case or
wrapper; is a flame-cooling charge of finely crushed chloride of sodiumn (common
salt) or other similarly acting flame cooling salt or substance closed in by a metallie
disc having a central fuse hole / and with its edge turned up to deflect the flame.
is a paper or metal tube securely fixed in the centre and open from end to end of
the case for the igniting fuse to pass through for connection with the explosive
division of the cartridge. This tube is closed at both ends with a disc of cemented
paper m till required for use.
In this example the neck is tied upon the igniting fuse which connects with the
cartridge shewn in Figure 1 and is tamped in the usual manner.
In the arrangement illustrated in Figure 4 a paper case a is employed containing
a charge of meal guncotton 6 with one tube e of liquid ammonia. The safety tamping
pellet h containing crushed chloride of sodium i, or other similarly acting flame-
cooling salt or substance is in this instance placed in the interior of the explosive
case, upon the top and in contact with the meal guncotton or other explosive b.
:

page_text: When placed in this position the neck of the explosive case a and the pellet are
tied together upon the Bickford tape or electric fuse conductors and firmly tamped in
the bore-hole.
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 I
claim is:-
=
1. The use for blasting of a cartridge consisting of a charge of guncotton in the
form of meal or in a finely crushed granular state (or of another suitable cellulose
explosive) enclosed in a cylindrical cartridge case of suitable material having its
longitudinal edges overlapped and closed at each end with a tightly fitting cap, in
combination with a tamping pellet consisting of finely crushed common salt, or other
similarly acting flame-cooling salt or substance, substantially as and for the purpose,
herein before described.
2. The use in combination with a blasting cartridge of the kind described in the
preceding claiming clause of a charge of liquid ammonia sealed in tubes and enclosed
in the explosive charge, substantially as, and for the purpose, hereinbefore
described.
3. The employment for blasting of a safety tamping pellet comprising a suitable
case or bag containing a charge of finely crushed common salt (or other similarly
acting flame-cooling salt or substance) provided with a hole for the fuse, substantially
as, and for the purpose, hereinbefore described.
4. The use in blasting of a small charge of finely crushed chlorate of potash or
other suitable oxygen yielding equivalent, the said substance being enclosed in a
case of suitable material and placed in the explosive charge, substantially as, and for
the purpose, hereinbefore described.
5. The manufacture and use of the improved blasting cartridges and tamping
pellets hereinbefore described and illustrated in Figures 1, 2 and 3, and 4 respectively
of the accompanying drawing.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.