Improvements in Indicators for use in Connection or Combination with Torpedoes and in Gunnery.
Year: 1891

page_text: Date of Application, 6th June, 1891
Complete Specification Left, 7th Mar., 1892-Accepted, 4th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Indicators for use in Connection or Combination
with Torpedoes and in Gunnery.
I JOHN SMITH COMRIE of 7 Great Winchester Street in the City of London,
Civil Engineer do hereby declare the nature of the said invention to be as follows:-
This invention relates to improvements in indicators for use in connection or
combination with torpedoes and in gunnery and has for its object to show the
position of a torpedo or a submerged mine or of a projectile when desired, or also
for use in practising the manipulation of torpedos and artillery.
The indicator consists of two portions one, which I hereinafter term the "float"
and the other hereinafter referred to as the "mortar."
The mortar is substantially a chamber containing a small charge of a suitable
explosive, such as gunpowder, a fuse, and where necessary a detonater and from its
centre may rise a hollow or solid rod for holding the float in place before the same
is set free and for a purpose presently to be more fully set forth, and the mortar
and float are firmly connected by means of paraffine wax or similar material as will
hereinafter appear.
The float is a chamber hollow or filled with cork or the like capable of floating
upon water and may either carry a signal-disc or the like or be fitted to emit
dense vapours or flame. For the latter purpose the float consists of two compart-
ments the one hermetically closed and of such size that it will cause the whole
readily to rise to the surface of water when the indicator is operated. The second
compartment contains a material such as say phosphide of calcium, which, when
coming in contact with water developes dense vapours or fumes or flame. The
float with two compartments has a channel passing centrally through it and into
this chamber lead apertures provided at top and bottom of the compartment
containing the material from which the vapours or flame are to be developed. Into
this channel is inserted the rod of the mortar and fills the same being at the top
sealed with paraffine wax or the like to prevent accidental access of water within
the central chamber.
The rod may project and at the upper end be fitted with a nut to prevent
separation of the two portions of this indicator except as hereinafter explained.
If the indicator is to be used for ascertaining the position of a stationary sub-
marinė torpedo the mortar which is fixed to the torpedo, or to an anchoring
mushroom plate or the like near it, is made in the shape of a cup into which is
placed a charge of say gunpowder enclosed in a suitable envelope and suitable
means for exploding the charge by a current of electricity are provided. At one
one end the float is so slaped as to fit well into the mortar which however is not
entirely filled by the charge and the end of the float. The remaining space is filled
with paraffine wax which fixes the two parts together and moreover prevents the
entrance of water to the charge as well as to the central channel in the float if the
latter has two compartments.
Now if it is required to ascertain whether the torpedo is in its proper place, a
current of electricity is sent through the mortar and the charge therein exploded.
The float is consequently driven out of the mortar and rises to the top of the water
but being connected (by a cord or a wire say) with either the mortar the mush-
rooin plate or the torpedo cannot float away thus serving to indicate the position of
the torpedo, either simply by floating on the water or (if in two compartments) by
emitting vapours or flame through the top of the central channel.
Similarly for torpedoes such as discharged from torpedo boats. In this case the

page_text: mortar may form an integral part of the torpedo and be fitted with a time or
other fuse which will be set to explode the discharge and send off the indicator
when the torpedo has run its course and this will facilitate the recovery of the
torpedo.
In gunnery practice the indicator may be fitted to a projectile and be dis-
charged either by a time fuse or a percussion detonator and will show the place
where the shot has taken effect or in some cases the indicator may itself form a
projectile and be fired say solely for range finding purposes.
Dated this 6th of June 1891.
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Indicators for use in Connection or Combination
with Torpedoes and in Gunnery.
I, JOHN SMITH COMRIE Civil Engineer of 7 and 8 Great Winchester Street
in the City of London, do hereby declare the nature of the said 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 relates to improvements in indicators for use in connection or
combination with torpedoes and in gunnery and has for its object to show the
position of a torpedo or a submerged mine or of a projectile when desired, or also
for use in practising the manipulation of torpedoes and artillery.
The indicator consists of two portious, one which I hereinafter term the "float"
and the other hereinafter referred to as the "mortar."
The mortar is substantially a chamber containing a small charge of a suitable
explosive, such as gunpowder, a fuse and where necessary a detonator and from its
centre may rise a hollow or solid rod for holding the float in place before the same
is set free and for a purpose presently to be more fully set forth, and the mortar
and float are firmly connected by means of paraffine wax or similar material as will
hereinafter appear.
The float is a chamber (hollow or fitted with cork or the like) capable of floating
upon water and may either carry a signal disc or the like or be fitted to emit
dense vapours or flame. For the latter purpose the float consists of two compart-
ments, the one permanently hermetically closed, and of such size that it will cause
the whole readily to rise to the surface of water when the indicator is operated.
The second compartment contains a material such as say phosphide of calcium,
which when coming in contact with water develops dense vapours or fumes or flame.
The float with two compartments has a channel passing centrally through it and
into this channel lead apertures provided at top and bottom of the compartment
containing the material from which the vapours or flame are to be developed. Into
this channel is inserted the rod of the mortar and fills the same, being at the top
sealed with paraffine wax or the like to prevent accidental access of water within
the central chamber.
The rod may project and at the upper end be fitted with a nut to prevent
separation of the two portions of this indicator except as hereinafter explained.
If the indicator is to be used for ascertaining the position of a stationary sub-
marine torpedo the mortar which is fixed to the torpedo or to an anchoring
mushroom plate or the like near it is made in the shape of a cup into which is
placed a charge of say gunpowder enclosed in a suitable envelope and suitable
means for exploding the charge by a current of electricity are provided. At one
end the float is so shaped as to fit well into the mortar which however is not
entirely filled by the charge and the end of the Hoat. The remaining space is

page_text: filled with paraffine wax which fixes the two parts together and moreover prevents
the entrance of water to the charge as well as to the central channel in the float if
the latter has two compartments.
Now if it is required to ascertain whether the torpedo is in its proper place a
current of electricity is sent through the mortar and the charge therein exploded.
The float is consequently driven out of the mortar and rises to the top of the water,
but being connected (by a cord or a wire say) with either the mortar, the mushroom
plate or the torpedo cannot float away thus serving to indicate the position of the
torpedo, either simply by floating on the water (or if in two compartments) by
emitting vapours or flame through the top of the central channel.
Similarly for torpedoes such as discharged from torpedo boats. In this case the
mortar may form an integral part of the torpedo and be fitted with a time or other
fuse which will be set to explode the charge and send off the indicator when the
torpedo has run its course, and this will facilitate the recovery of the torpedo.
In gunnery practice the indicator may be fitted to a projectile and be discharged
either by a time fuse or a percussion detonator and will show the place where the
shot has taken effect.
In the accompanying drawings I have illnstrated my invention and have
shewn in :-
Fig. 1. a sectional elevation of an indicator to be fitted into the nozzle-block of a
fish torpedo.
Fig. 2. external elevation thereof.
Fig. 3. sectional elevation suitable for adaptation to the head of a torpedo.
Fig. 3 plan of a portion of the same.
Fig. 4. external elevation thereof.
Fig. 5. is the elevation of an indicator for fixed submarine mines and the like.
Fig. 6. shows a projectile fitted with this invention.
Like letters refer to like parts in all the figures.
Figs. 1 and 2. A is the float, B is that compartment thereof, which may be
filled with cork or the like to enable the float to rise in water, or said compartment,
being herinetically closed, may contain air only. C. is the chamber containing the
flame or vapour producing material, say phosphide of calcium, a, a being the
apertures for admitting water, and b, b, those for emitting flame or vapours when
the indicator is in operation. c is a flange at the bottom of the float, and d. the
rim of the mortar into which said flange fits; d' is a space between the ring A'
and the mortar; said space is filled with paraffine wax or the like so as to cement
the parts together. D is the mortar containing gunpowder or the like, from the
centre of the mortar rises the tube E. having a nipple e; the tube E is filled with a
suitable fuse, not shown in the drawings and at the top has a friction, igniter of any
known construction (or a similar device). The nipple e serves to convey the flame
to the charge in the mortar at the proper time. Below, the mortar carries a
stirrup piece F in which runs a reel G on which is wound a cord H attached to a
ring at the bottom of the float J is a screw for fixing the mortar in the nozzle
block-tube bottom; A is a sleeve connecting the float and mortar and cemented
with paraffine wax or the like as above stated.
Now the operation of this form of my indicator is as follows:-
When the torpedo fitted with this indicator, is launched, the lanyard attached to
the ignition device is, by the rush of the torpedo tautened and operates the igniter,
this starts the fuse in the tube E; when the flame reaches the nipple e the charge
in chamber D explodes and forces the float away from the mortar breaking the
connection at the sleeve A' and at the top where the tube E is secured to the float
by paraffine wax or the like.
The float in rising unrolls the cord H by which it remains attached to the mortar.
The holes a a, b b being now uncovered, water enters at a a and flame etc. issues
at bb as indicated by the arrows. To ensure that the indicator may operate even
when the explosion either fails or is insufficient, or if from any reason whatever the

page_text: holes a a do not admit water, I may provide a passage I closed by a stopper L of
say rubber; the rush of the torpedo removes this stopper, or at least loosens it, so
that water penetrates through the passage K into the chamber C.
The construction of the indicator shewn in Figs. 3, 3 and 4 is substantially
similar but the charge is in this case differently exploded.
is intended to be placed in the head of the torpedo.
This form of indicator
The
Instead of having a fuse filling the tube E ignited by a friction-tube or the like
it is fitted with a clockwork contained in a casing M below the mortar see plan
Fig. 3 the clockwork is wound up by the winding arbour m; it acts upon a
hammer N raised by a square spindle n; this hammer when falling explodes a
percussion cap on the nipple e¹ and this sets off the charge in the mortar.
clockwork is so arranged that after it is set off the time for which it will run
without allowing the hammer N to strike, may be regulated. The rod O slipped
into the tube E serves to operate a detent for starting the clock work, the vanes O'
of helical or other forms causing its rotation.
The operation of this form is as follows:-
When the torpedo is to be launched, the clockwork is wound up, a cap being
placed on the nipple e', the cock is raised and the indicator put in place. Upon
launching the torpedo, the rush of water against the vanes O₁ of the rod O rotate
the latter in tube E causing it to depress the detent of the clockwork; the latter
starts and at the proper moment allows the hammer N to drop causing the discharge,
the effect being the same as previously explained. The rod O is either hollow or
made of wood or the like, so that its specific gravity is materially below that of the
float A, this causes it to rise more rapidly than the latter so that uncovering of the
passages or holes abis ensured, although this form may also be fitted with
supplementary means for admitting water into the chamber C. In either of the
two forms of indicator I have specified the cord Hallows the torpedo to be easily
recovered, as the float shows the position, and the cord may readily be made of
.sufficient strength for hauling the torpedo in.
Fig. shows my indicator applied for showing the position of submerged
stationary torpedoes and for similar purposes. The shape of this I prefer to make
conical as shewn. The manner of fitting and uniting the float and mortar is
analogous to that above specified with reference to the other forms. Instead
however of being attached to the nozzle, block, or the head of the torpedo, I have,
as an example of further adaptation, shown this form attached to a mushroom
plate P. The reel G carrying the cord H, is not fitted on the mortar but may be
enclosed in a box R on the mushroom plate. The cord passes to the ring i through
a hole in the mushroom plate. The hole is surrounded by a ring S into which a
button S tightly fitting round the cord H is cemented say by paraffine-wax.
'"'
The charge in the mortar can, of course not to be ignited by a fuse such for
instance as that specified with reference to the first form of this invention. I
therefore employ an electric detonator of any convenient form and wires T convey
current to it.
In Fig. 6 I have shewn the indicator fitted to a projectile. The construction
will be readily understood. The mortar is arranged as in the other forms, E¹ is a
bored wood fuse of the kind well known to military men. The projectile U is
hollowed out for the reception of the indicator, the latter being fixed by the
screw J.
It is protected by the disc U¹ cemented into the aperture of the projectile,
but only so that the force of the explosion of the mortar may suffice to break the
connection.
.
It will be clear from the foregoing that a variety of means may be employed in
any form of this indicator in order to cause explosion of the charge in the mortar,
nor is it necessary particularly to describe the nature of the fuses, clockwork and
detonators employed as these are all well known, and do not in themselves form part
of this invention. It will also be obvious that shape and arrangement will vary
according to the purpose for which the indicator is to be used; the explosive in the

page_text: mortar and the charge in the chamber C (if any) may also be varied, as well as the
manner in which the reel is fitted.
Having now particularly described and ascertained the nature of the said
invention & in what manner the same is to be performed I declare that what
I claim is:-
1. An indicator for fish torpedoes detached from such torpedo when the latter
has run its course (or after a predetermined time) by the explosion of a suitable
charge, substantially as specified and as shewn in Figs. 1, 2, 3, 34, and 4 of the
accompanying drawings.
2. An indicator for fish torpedoes consisting of a float A (with or without a
chamber C enclosing flame producing material or the like), a mortar D a time fuse
or the like, and a reel carrying a cord, rope or wire, the whole constructed, arranged
and operating as set forth and shewn in the drawings.
3. The indicator for submerged mines, fixed torpedoes, or the like consisting of
a float A (with or without a chamber C containing a flame producing material) a
mortar D from which the float is detached by explosion of the charge in the mortar,
and means for retaining the float in suitable connection with a mushroom plate or
with the mine or the like substantially as shewn in Fig. 5.
4. For use in marine gunnery an indicator forming part of a projectile and fitted
with a time fuse exploding at the proper time a charge in the mortar of the
indicator, so as to cause the float of the indicator to be detached from the projectile
substantially as specified and as shewn in Fig. 6 of the drawings.
Dated this 7th of March 1892.
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicant.