An Improved Method of Blasting in Coal Mines and other Places and Improved Materials to be Used therein.
Year: 1887

page_text: Date of Application, 22nd Aug., 1887
Complete Left, 17th May, 1888
Complete Accepted, 22nd June, 1888
An Improved Method of Blasting in Coal Mines and other Places
and Improved Materials to be Used therein.
I, GEORGE TRENCH, of Standard House, Faversham, in the County of Kent,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for its object an improved method of blasting in coal mines and
other places and improved materials to be used therein.
In order to prevent or lessen the risk of fire when blasting in fiery mines the
cartridge has in some cases been placed in an india rubber bag and surrounded by
water and the cartridge thus enclosed is placed in the bore hole. In some cases also
the water in the india rubber bag has been rendered semi-solid by the addition of
soap.
According to my invention attain a like result more efficiently and more con-
veniently dispensing with the india rubber bag by ramming into the bore hole so as
to completely surround the cartridge a suitably prepared fire extinguishing powder.
The powder which I prefer to employ consists of sawdust saturated with a solution
containing alum, sal-ammoniac, and common salt. This powder is stored for use in a
damp state and so that it binds together when exposed to pressure it is thus easily
consolidated around the cartridge.
Other salts and materials having like properties may be employed in place of those
named but these I find to be very suitable.
In some cases in place of ramming the fire resisting powder into the bore hole
around the cartridge I insert both in a paper case and in this state put all together
into the hole-this latter method will often prove the more convenient.
Dated. this 22nd day of August 1887.
CARPMAEL & Co.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Method of Blasting in Coal Mines and other Places
and Improved Materials to be Used therein.
1. GEORGE TRENCH, of Standard House, Faversham, in the County of Kent.
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:-
This invention has for its object an improved method of blasting in coal mines and
other places and improved materials to be used therein.
In order to prevent or lessen the risk of fire when blasting in fiery mines the
cartridge has in some cases been placed in an india rubber bag and surrounded by
water and the cartridge thus enclosed is placed in the bore hole. In some cases also
the water in the india rubber bag has been rendered semi-solid by the addition of
soap.
According to my invention I attain a like result more efficiently and more con-
veniently dispensing with the india rubber bag by ramming into the bore hole so as
to completely surround the cartridge a suitably prepared fire extinguishing powder.
The powder which I prefer to employ consists of sawdust saturated with a solution
containing alum, sal ammoniac, and common salt, in the following proportions :-
This is incorporated with sawdust in the proportion of 2 parts of solution to 1 part
of sawdust of a per cent. of black lead being added. This powder is stored for use
in a damp state and so that it binds together when exposed to pressure it is thus
easily consolidated around the cartridge.
Other salts and materials having like properties may be employed in place of those
named but these I find to be very suitable.
In some cases in place of ramming the fire resisting powder into the bore hole
around the cartridge I insert both in a paper case and in this state put all together
into the hole-this latter method will often prove the more convenient.
It will be understood that the tamping of the charge and other details of the
blasting operation are conducted as heretofore.
When making use of a case to contain both the cartridge and the fire extinguishing
powder I first prepare a cylindrical bag of paper or other material of a diameter to
enter the bore hole freely and of a length to enclose the cartridge with the fire
extinguishing powder around it. I put a small quantity of the fire extinguishing

page_text: powder into the bag and ram it with a cylindrical rammer made to enter the bag
freely and having an end of a smaller diameter corresponding to that of the cartridge
to be placed in the bag. I then insert the cartridge centrally into the bag with its
lower end in cavity formed by the rammer in the fire extinguishing powder. I then
ram more of the fire extinguishing powder into the bag around the cartridge taking
care that the cartridge shall remain central in the bag. I also fill in the powder into
the bag above the cartridge so that the cartridge is completely surrounded with
rammed powder. I then close in the neck of the bag and tie it around the fuse.
In the annexed drawings Figure 1 is a longitudinal section of the bag prepared to
receive the cartridge.
Figure 2 is a longitudinal section and Figure 3 is a transverse section of the bag
and cartridge ready for use.
Figures 4 and 5 show the rammers employed in filling the bag.
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 method of blasting consisting in firing the cartridge in the bore hole in
the midst of fire extinguishing powder surrounding the cartridge substantially as
described.
2. The method of blasting consisting in firing the cartridge in the bore hole in the
midst of a powder surrounding the cartridge and consisting of sawdust or like
absorbent powder saturated with a solution of alum salt and sal ammoniac or an
equivalent salt solution substantially as described.
3. The method of blasting consisting in firing in the bore hole a cartridge contained
in a bag or case together with fire extinguishing powder such powder surrounding the
cartridge substantially as described.
1000