Improvements in Charging Explosive Shells.
Year: 1894

page_text: Date of Application, 7th Mar., 1894
Complete Specification Left, 29th Nov., 1894-Accepted, 29th Dec.,
1894
Improvements in Charging Explosive Shells.
I JAMES WEIR GRAYDON of 32 The Avenue Bedford Park Chiswick in the
County of Middlesex, late Lieutenant United States Navy do hereby declare the
nature of this invention to be as follows:-
My invention relates to the preparation of the explosive charges for and the
charging of shells with what are known as high explosives containing, or formed
by, nitro-glycerine and compounds thereof, and it has for its objects to isolate
the explosive material in small quantities and enable it to be handled in large
masses with comparative safety in the operation of filling the shell, to ensure the
stability of the charge by preventing the exudation and concentration of the nitro-
glycerine in dangerous quantity at any point, to prevent, in long shells, excessive
cushioning or massing of the charge towards the base of the shell by the effect
of its own inertia at the moment of discharge from the gun and the consequent
development of heat and to obtain the most instantaneous and complete com-
bustion of the whole mass and the greatest possible volume of gases from the
explosion, by so treating the envelope or container of the charge as to render
it capable of contributing to the volume of the gases generated, and assisting
in the instantaneous propagation of the combustion throughout the mass of the
charge.
"
With a view to accomplish the above mentioned objects the charge is prepared
in the form of a roll by first saturating a sheet of thick porous felt with a
mixture of nitric acid and water in the proportion of say three parts of the
former to one part of the latter. The water serves to wash the acid and
facilitates the absorption of the acid by the fabric which is then thoroughly
dried to drive off the water and leave the fabric thoroughly impregnated with
nitric acid. The fabric which is thus rendered explosive or in a condition to
rapidly generate gases by its combustion is then used as an absorbent or carrier for
the explosive material constituting the charge which may be any suitable nitro-
glycerine compound (for instance, dynamite of various grades containing 40 60
or 75% of nitro-glycerine) and which is worked thoroughly into the pores of the
felt by means of rollers. When the felt is thus thoroughly impregnated with the
explosive it is covered on one side with or placed between sheets of paper of a
thickness about equal to thin cartridge paper and which has previously been
impregnated with nitric acid to render it rapidly combustible or explosive and
non-porous, to prevent the exudation of nitro-glycerine.
The felt charged with explosive material and the paper are then rolled up together
upon a mandrel, so as to form a loose roll in which the convolutions of the felt are
separated by the intervening convolutions of non-porous paper, which also completely
envelopes the outer circumference of the roll. The mandrel having been withdrawn
the roll thus formed is dipped for a moment in a bath of melted paraffine wax
which, when cold, serves to hermetically seal up the whole surface of the tubular
roll which is then slipped on to a firing tube occupying an axial position in the
shell. This tube is perforated to give passage to the flame and ensure the

page_text: instantaneous explosion of the whole mass of the charge, and it may be fired by an
electric, time, or percussive contact fuse.
Dated this 7th day of March 1894.
J. W. TRAIDON,
By A. M. & Wm. Clark,
33, Chancery Lane, London, Chartered Patent Agents.
Improvements in Charging Explosive Shells.
I, JAMES WEIR GRAYDON, of 32, The Avenue, Bedford Park, Chiswick, in the
County of Middlesex, 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 the charging of shells with what are known as. high
explosives containing, or formed by, nitro-glycerine and compounds thereof, and it
has for its objects to isolate the explosive material in small quantities and enable it
to be handled in large masses with comparative safety in the operation of filling
the shell, to ensure the stability of the charge by preventing the exudation and
concentration of the nitro-glycerine in dangerous quantity at any point, to
prevent, in long shells, excessive cushioning or massing of the charge towards
the base of the shell by the effect of its own inertia at the moment of
discharge from the gun and the consequent development of heat, and to obtain the
most instantaneous and complete combustion of the whole mass and the greatest
possible volume of gases from the explosion by so treating the envelope or container
of the charge as to render it capable of contributing to the volume of the gases
generated and assisting in the instantaneous propagation of the combustion
throughout the mass of the charge.
With a view to accomplish the above mentioned objects the charge is prepared
in the form of a roll by first saturating a sheet of thick porous felt, such as used
for non-conducting purposes, with a mixture of nitric acid and water in the
proportion of, say, three parts of the former to one part of the latter. The fabric
is then thoroughly dried to drive off the water and leave the fabric thoroughly
impregnated with nitric acid. The fabric, which is thus rendered explosive or in
a condition to rapidly generate gases by its combustion, is then used as an absorbent
or carrier for the explosive material constituting the charge which may be any
suitable nitro-glycerine compound (for instance, dynamite of various grades
containing 40, 60, or 75, per cent. of nitro-glycerine) and which is worked thoroughly
into the pores of the felt by means of rollers. When the felt is thus thoroughly
impregnated with the explosive it is placed between sheets of paper (equal to thin
cartridge paper) which has previously been impregnated with nitric acid to render
it rapidly combustible or explosive and non-porous in order to prevent the exudation
of nitro-glycerine.
The felt charged with explosive material and the paper are then rolled up
together upon a mandrel so as to form a loose roll corresponding in diameter to
the bore of the shell. In this roll the convolutions of the felt are separated by the
intervening convolutions of non-porous paper, the outer circumference and ends of
the roll being completely enveloped in similar paper. The mandrel having been
withdrawn, the roll thus formed is dipped for a moment in a bath of melted
paraffine wax which, when cold, serves to hermetically seal up the whole surface
of the tubular roll which is then slipped on to a firing tube occupying an axial
position in the shell in the head and base of which it is fixed or supported by usual
means. This tube is perforated to give passage to the flame and ensure the

page_text: instantaneous explosion of the whole mass of the charge, and it may be fired by an
electric, time, or percussive contact fuse.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
An explosive charge for shells, formed by first impregnating a sheet of porous
felt with nitric acid, then working the explosive into the pores of the felt, then
coiling it up on a mandrel with alternate layers of paper previously impregnated
with nitric acid wrapping the roll in such paper, and finally sealing it with paraffine
wax, as specified.
Dated this 29th day of November 1894
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.