Improvements in Submarine Mines or Torpedoes, and in Sub- marine Shells for the Protection of such Mines.
Year: 1892

page_text: Date of Application, 26th Jan., 1892-Accepted, 5th Mar., 1892
COMPLETE SPECIFICATION.
Improvements in Submarine Mines or Torpedoes, and in Sub-
marine Shells for the Protection of such Mines.
I, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of
Middlesex Gentleman do hereby declare the nature of this invention which has
been communicated to me from abroad by George Franklin Elliott, 1st Lieutenant
of the United States Marines at present stationed at the Brooklyn Navy Yard in
the State of New York, United States of America, 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 submarine mines or torpedoes used for the defence of
harbours and the like: and also to submarine shells designed to protect submarine
torpedo fields against searchers, or parties who may attempt to sweep or drag such
fields.
The mine which is made according to this invention while adapted to be planted
in any depth of water has been particularly designed as a deep water mine which
while containing a comparatively small charge of explosive will be effective when
planted at a depth very much greater than has heretofore been deemed practicable.
It is in effect a fixed mine which when brought into action becomes a moveable
torpedo.
To this end the mine consists of a gui or case to be planted at the bottom of the
stream or other body of water to be protected, which gun is provided with a firing-
mechanism connected to a distant observation point or shore station from which it
may be operated to effect the discharge of the gun by the observer there
stationed and a shell containing the charge of high explosive adapted to be
contained in and discharged from the gum which shell is provided with means
by which it can be exploded at any predetermined point after it leaves the gun.
With some modifications the mine can be converted into a shell for the pro-
tection of torpedo fields such shell being intended as an offensive protector having
its destructive radius on and above the surface of the water in which it is planted.
In the accompanying drawings
Figure 1 is a part elevation and part longitudinal central section of the mine and
Figure 2 represents the same set up in a frame or base in which it assumes a
vertical position whatever may be the inclination of the base due to the unevenness
of the ground on which it rests.
In these Figures A is the barrel and B is the .base of the gun the latter con-
taining the powder chamber a for the explosive (such as gun cotton, rocket com-
position, gun powder or the like) by which the shell is expelled; b is an air space
of such dimensions as to provide an air cushion between the powder chamber and
the shell sufficient to prevent shock which might cause premature explosion of the
shell; and c is a chamber below the powder chamber to receive the coiled draw
wire or lanyard m hereinafter referred to.
The body of the gun is built in one piece and it is loaded from the breech which
is closed by a screw plug C having a lead grommet on its inner shoulder to make
a water tight joint. The base of the breech plug is pierced at c for the reception
of a key wrench, and has in it a cone shaped recess which forms the chamber c¹
the said chamber being closed at its bottom by a metal plate C¹ also screwing into
the breech.
To the plate C¹ is rivetted a vertical metal spindle c on which is loosely placed
a wooden cone shaped spool and on this spool the draw wire m is coiled
helically.
On the bottom of the plate C
filling the remaining space at the
is poured Portland or other suitable cement c
base of the gun and a cover (say of thin iron)

page_text: may be placed over the cement. The cement when it sets and hardens makes a
water tight joint.
.
The bore of the barrel A is tapered at the muzzle to receive a wooden plug or
stopper D from that point it is cylindrical to receive the shell D until the
chamber for receiving the wooden sabot D is reached where it again tapers flaring
to the rear until the air chamber or space is reached. Over the muzzle plug D₁
is a layer of cement such as hydraulic or Portland cement to make that point
watertight.
The sabot D is split lengthwise into two or more sections; and this also is the
preferred construction of the muzzle plug D¹.
Between the sabot and the breech plug is a wooden cartridge case D³ which
contains the propelling charge of powder, and at the same time supports the sabot
thus keeping the shell or torpedo D in place..
The shell D itself consists of a hollow metallic body which contains the
high explosive and is provided with a forged steel head. The body of the shell
is tapered at its base and is provided with feather fins d¹ to insure its proper
course.
Within the body of the shell and at its bottom or lower end is the case d (pre-
ferably of copper) to contain the detonator for the high explosive and within this
case is the firing tube F which at its base screws through the bottom of the
detonator case.d and the bottom of the shell. Within the upper part of the tube F
is fixed a cartridge tube to contain a cartridge such as a pistol cartridge; and
above the cartridge tube is fixed, to the top of the firing tube, the open bottomed
small case which contains the fulminate by which the detonator is ignited or
exploded.
The cartridge is exploded by a firing pin g capable of reciprocation in the
tube F and limited in its rearward movement by a cross pin which is straddled
by the split shank g of the firing pin. The shank g₁ is of spring metal split
lengthwise into two or more tongues normally set so as to stand apart but which
when brought together will fit snugly in the end socket of a hammer rod i which
is capable of reciprocating movement in the firing tube F. The enlarged head of
the hammer rod containing the socket fits snugly in the firing tube-backward
of the head it is smaller in diameter; and its reduced rear end fits snugly in, and
passes out through, the base of the firing tube, having on its exterior portion a
flange for limiting the forward movement of the hammer rod. Between the
base of the firing tube and the head of the hammer rod is confined an impelling
spiral spring k. When the hammer rod is pulled back (or brought to what may
be called cocked position) the firing pin y remains stationary and consequently the
socket draws away from and quits the split shank g' and when this takes place
the sections of the shank spring apart. If now the hammer rod be released it
will be driven forward by its compressed spring k and meeting the spread base of
the shank g will drive the firing pin g forward with the effect of exploding the
cartridge the ball driven from the cartridge will explode the fulminate; this
in turn will explode the detonator, and the latter will cause the explosion of the
high explosive with which the body of the shell is charged.
To insure the cocking of the hammer rod when the shell is discharged from the
gun, and to maintain it in this cocked position until after the shell in its flight
has passed up a predetermined distance through the water various means may be
employed. That which is illustrated in the example shewn in Figure 1 for the
purpose, consists of the lanyard m which may be made fast directly to the rear end
of the hammer rod, but which preferably is attached to a metal or wooden ball, or
drag m connected to the hammer rod by a lanyard m2 which is of less strength
than the main lanyard m. The ball drag m¹ is received in a suitable recess formed
for it in the sabot D' and the auxiliary lanyard m² is coiled around a wooden-
bobbin m³ resting at one end against the hanimer rod and at the other end against
the drag m¹ the object of. this being to prevent the hammer rod from flying back
under the shock of the shell or torpedo starting on its flight.

page_text: The main lanyard m passes down through the air and powder chambers and
through a central hole in the breech plug into the coil chamber where it is spun or
coiled helically upon the freely revolving spool and is covered with a sheet of
lead, or other suitable material m' to prevent it from overrunning or from leaving
the spool by centrifugal force. The lanyard pulls out from under the metal
sheath mat a point near the apex of the spool and its rear end is made fast to
the spool.
The length of lanyard in all should generally be such as to insure the explosion
of the shell at about twelve feet below the low-water level at the place in which
the mine in planted.
"
When the shell or torpedo D is discharged from the gun and after freeing itself
from the sabot is passing up through the water, the drag m³ drops back, the
auxiliary lanyard m² uncoils and then the strain being brought upon the main
lanyard m; the latter draws back the hammer rod i of the torpedo, at the same
time uncoiling as the torpedo proceeds. If the torpedo strikes the bottom of a
vessel it stops, but the drag m continuing its flight gives slack on the lanyard m²
thus allowing the hammer rod to spring forward and explode the torpedo. If the
torpedo strike a glancing blow it runs to the end of the lanyard m but the latter
being made fast the weaker auxiliary lanyard m³ will break thus releasing the
hammer rod and allowing it to explode the torpedo.
It will thus be seen that there is thus provided in effect a fixed mine capable
of being planted in say from one to two hundred feet of water (a depth very
much greater than that which will permit efficient action of ordinary fixed mines)
and which nevertheless is so organized that when put into action its charge of high
explosive before exploding will be brought, within destructive range of objects on
the surface of the water.
Indeed the
The charge required for each individual mine is thus reduced.
charge of high explosive now required for the effective action of one ordinary
deep water mine will suffice for a number of the mines made according to this
invention which may be planted at considerable intervals apart and in this way
with the same absolute quantity of high explosive a much more extensive field can
be efficiently covered and protected than has heretofore been practicable with
ordinary fixed deep water mines.
They may be planted in groups or otherwise as may be desired and each may
have its own individual independent connection with the distant observation point
or shore station from which the mines are fired; or they may be electrically
connected in series and in such manner that they can be successively fired by the
use of a single circuit making and breaking key or button at said distant station.
A gun firing mechanism adapted to secure the result last named is illustrated in
the drawing the organization thereof being such that the discharge of one gun
will bring into circuit the next gun of the series.
Screwed watertightly in the base of the gun with its nose piece projecting
through to the bore of the powder chamber is a metal plug G. This plug is cored
out at its outer end to form a chamber and its nose piece is tubular the inner end
thereof being cored out to a true taper to receive the taper inner end of a metal
plunger L whose stem passes back into the chamber at the outer end of the plug.
The plunger is capable of longitudinal movement. It is guided in these move-
ments by an ebonite or other insulating ring on its taper head and by a saucer
shaped annulus 12 of spring metal (a conductor of electricity) on the outer cbonite-
covered end of its stem which bears normally against the walls of an ebonite or
other non-conducting lining n for the chamber in the outer end of the plug. The
plunger has no contact with any of the parts save through the intermediary of the
devices n and I at all other points it is surrounded by an air space which with
the comparatively feeble electrical current required for the purpose forms an
efficient insulator.
In the outer end of the ebonite lining is a longitudinally split ring o the halves
of which are insulated from each other.

page_text: .
:
To one of these halves is connected the wire leading from the shore battery
where the observer is stationed and to the other half is connected the wire y
leading to the next torpedo in series.
That half of the split ring which is connected to wire a leading from the shore
battery is, by a frail wire a connected to a wire which extends through the
stem I of the plunger L to a suitable fuse wo in the head of the plunger such for
example as a two second delayed fuse made of rocket composition and gun
powder; and from the fuse by a suitable connection to the base of the gun
and out to ground.
Thus when the circuit closing button or key at the shore station is depressed
to close the electric circuit the fuse will be ignited, and in turn will explode the
charge of powder in the powder chamber of the gun.
Normally the plunger L is in the position shewn in the drawing with its saucer
shaped annulus out of contact with the split ring o. When however the-gun
is fired the force of the explosion will drive the plunger L outwardly, far enough
to bring the annulus in contact with the two halves of the split ring o; and
as this annulus is made of conducting material it, in effect, forms a bridge by
which the circuit is closed between the halves which closing is permanent by
reason of the fact that the taper head of the plunger is now tightly jammed
into its taper socket. At the same time, by the rearward movement of the
plunger the frail wire connection will have been broken, thus cutting out the
stem of the plunger. In this way the gun just fired is cut out of circuit while
at the same time the circuit is closed between the shore battery and the gun next
in series.
P
The outer end of the chamber formed in the screw plug G contains a metal
cap lined with non-conducting material which abuts against the cbonite lining :
On the cap rests a soft rubber stopper p'; and into the outer end of the plug
screws a nut p² which compresses the soft rubber stopper and thus forms a water-
tight joint at that point.
In plauting the mine it is essential that it should be vertical at all times. To
this end it is mounted in a carriage by what may be termed a. ball and socket
joint.
A ball bearing K is formed on the gun at a point where the greater weight
of the gun will be between the bearing and the base; and there is provided for
the gun a carriage K having a corresponding convex seat K².
When the carriage rests on the bottom and the gun is placed on the carriage
the gun will assume at once a vertical position irrespective of irregularities of
the ground on which the carriage stands.
The base of the carriage may be of conical form and of any suitable con-
struction. Before the gun is adjusted and just before planting the base of the
carriage has preferably introduced into it Portland or like cement say so that
it is about half full. The gun when placed on the carriage will easily adjust
itself in this cement. This cement prevents any motion of the gun when fired.
It also prevents all chance of leakage through the breech or firing plug.
Figures 3 and 4 illustrate the deep water shell for the protection of submarine
torpedo fields. Figure 3 being a longitudinal central section thereof and Figure 4
a section of an appliance designed to fire. the gun mechanically under certain
circumstances.
This shell is very much like the mine described with reference to Figure 1.
Similar parts in Figures 1 and 3 are designated by like reference letters so that a
detailed description of the shell is unnecessary.
The gun is the same in both excepting that the lanyard m is not used in the
latter case and consequently the coil chamber in the breech plug C is unnecessary
and is dispensed with. The electrical firing attachment may be the same in both.
The shell proper D is similar in a general way to the one shewn in Figure 1.
It does not however contain merely high explosive but has a bursting charge of
any suitable kind together with balls e of suitable size. Use is made in the shell of
"

page_text: only the drag m¹ and the wire lanyard m³ which connects it to the hammer rod.
The effect of this modified arrangement is as follows:-
When the gun is fired and the shell and sabot pass the muzzle, the sabot (which
breaks in two or more pieces) quits the shell thus leaving exposed the drag. The
latter (inasmuch as it loses its momentum much sooner than the shell and is more
readily held back by the resistance of the water) separates from the shell and by
its dragging action exerts, through the lanyard, a pull upon the hammer rod
sufficient to retract it, separating it from the firing plunger and holding it in, what
may be called, its cocked position
The parts are maintained in this position until the shell has passed above the
surface of the water and the drag is thrown into the air. When this point is.
reached, the spring is free to act, and by its recoil, causes through the inter-
mediary of the hammer rod and the firing plunger the explosion of the cartridge
which in turn brings about the explosion of the shell whose contents thus arc
scattered with destructive effect over and above the surface of the water.
This submarine shell can be fired electrically in the same way as provided for the
mine. It may however be fired mechanically by the drags or sweeps which may
be employed by searchers for torpedo fields.
For this purpose a metallic elbow plug M (Figure 4) is employed which like the
electrical firing plug G is intended to screw into the base B of the gun.
The end,
which screws into the base, communicates with the powder chamber of the gun and
is bored out to receive a fulminate case containing a pistol cartridge. The other
or vertical end of the elbow plug is bored out to a greater diameter, to receive a
tube R containing the hammer or tumbler for exploding the cartridge and the
mainspring therefor. The tumbler is retracted against the stress of its spring,
by a vertically movable firing rod 2 having a notched lower end which engages or
catches under a shoulder on the tumbler. This rod passes out from the top of the
plug M through a watertight cap similar to that which closes the outer end of the
electrical plug G and has on its outer end an eye which by a strong metal shackle s
leads to a metallic plate t of triangular form pierced with three holes, one for the
reception of the shackle s; one for the attachment of a short line 3, (the other end
of which is fastened to an eye on the plug M :) and one for the attachment of a long
line or ropes of about twice the strength of the lines leading to a buoy which
should be say from twelve to fifteen feet below the surface of the water.
This buoy rope s' is armed at intervals with strong hooks for the purpose of
engaging grapnels or the like used by searching parties.
The short line is used to prevent the shackles from pulling on the firing rod
except when the buoy line is engaged and pulled on forcibly.
If under these conditions a sweep or drag used by searching parties grapples or
engages the buoy line s' a pull thereon of say about 100.lbs. will cause the weak
lines to part and thus transfer the strain directly to the shackles with the result
of drawing up the firing rod until it disengages from the tumbler or hammer which
latter when freed will at once fly forward striking the cap of the cartridge and thus
firing the gun.
I do not restrict myself to the precise details of construction and arrangement
hereinbefore described and illustrated for it will be evident that the same can
be varied considerably and in many particulars without departure from this
invention.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed 1 declare that what 1
claim is :-
1. A. submarine mine or an apparatus for the protection of submarine mines or
torpedo fields comprising a gun to be planted in the bed or bottom of the body of
water to be protected, a shell adapted to be contained in and discharged from the
gun, firing mechanism attached to, and carried by the said shell for exploding the
charge therein, and a drag connected to and adapted to operate the said firing

page_text: mechanism to effect the explosion of the bursting charge only after the shell has
travelled a predetermined distance substantially as hereinbefore set forth.
2. The combination of the gun, the shell, firing mechanism attached to, and
carried by, the shell, and the lanyard, or drag wire, attached to the firing
mechanism substantially as hereinbefore.set forth.
3. The combination of the gun, the shell, firing mechanism attached to, and
carried by, the shell, the lanyard attached to the firing mechanism, and the ball,
or drag, attached to the lanyard, substantially as hereinbefore set forth.
4. A submarine gun provided with a firing mechanism combined with a float or.
buoy connected to the said mechanism substantially in the manner and for the
purpose herein before set forth.
5. The combination and arrangement in connection with a series of submarine
guns of the circuit closing plungers and other appliances forming the electrical
firing mechanism, the circuit connections being such that the act of firing one gun
shall effect the closing of the circuit to the wire leading from that gun to the next"
in series substantially as herein before set forth.
Dated this 26th day of January 1892.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.