Improvements in Apparatus for Directing Torpedo Tubes and Ordnance, and for Steering Torpedoes.
Year: 1890

page_text: Date of Application, 26th Feb., 1890
Complete Specification Left, 24th Dec., 1890-Accepted, 26th Mar., 1891
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Directing Torpedo Tubes and
Ordnance, and for Steering Torpedoes.
1, MARK HENRY HURRELL, of 42, Myddleton Road, Hornsey, in the County
of Middlesex, Electrical Engineer, do hereby declare the nature of this invention
to be as follows:
To obtain automatically the adjustment of, the breech sight on a gun, or on a
torpedo tube, or, of the gun, or the tube itself, so that the torpedo, or other
projectile, may be fired at the requisite angle to hit an object moving at any-speed
and at any distance; also to compel the torpedo to move continuously in the same
line, as that which is given to it in the torpedo tube on firing and also in certain
cases to vary this line to any other line that may be required.
To obtain the desired position, of the sight on a torpedo tube, or of the tube itself;
by training three theodolites on any vertical line of the moving enemy.
The training of the theodolites cause, by contact pieces which they carry, a
variation in the electrical resistance of one arm of a Wheatstone bridge, which
variation is balanced only when an electro motor has moved the sight or the breech
of the tube, to an angle corresponding to this variation. The operators of the
theodolites, with the sighting Wheatstone arrangement, are supported on shipboard
by an electro mechanical gyroscopic table. The torpedo is constrained to
follow its given line by a gyroscopic electro mechanical apparatus. contained
within itself. I obtain the position of, the sight on the breech of a gun firing
projectiles of high velocity, or of the gun itself, by the training of two theodolites
on any vertical line, or point, on the enemy; the two theodolites being combined
with a double bridge arrangement and two electro-motors.
The construction of the sighting apparatus for torpedo tubes is as follows:-The
sight, on the breech of the tube, slides on a bar, which bar, carries a small electro-
motor, the terminals of which are, with a battery in circuit, connected to the stop
pins of a galvanometer. The sight carries a sliding contact piece resting on some
one of a number of insulated pieces of platinum minutely divided in the direction of
the motion of the sight. Motion is given to the sight by the rotation of the motor,
in one direction, or the other, according to whether the galvanometer needle is
deflected to touch its stop pins on the right or on the left. The galvanometer is
part of a Wheatstone bridge arrangement; the adjustable side of the bridge being
formed by lengths of wire and by certain coils proportioned to the wire and to the
speed of the boat. These coils and wire are fixed to a table with other coils, equal
to the above, forming part of the unknown arm of the bridge; the remainder of the
unknown arm is equal in resistance to the lengths of wire, above mentioned
and is joined in loops to the insulated pieces of platinum on the sight bar:
Above the wires and coils stand three theodolites, two of which may be
sighted by .one operator, the third by a second operator, all the theodolites
are free to move independently in vertical planes. The first two are con
nected at their eye pieces, the connection giving a fixed base to a right
angle triangle the hypotenuse being the prolongation of the axis of the first
theodolite, this instrument being free to move in a horizontal plane. The third
theodolite is connected to the second in such a manner that, at whatever distance
it may be moved, it still remains parallel to the one to which it is connected.
Number one and number three theodolite carry sliding pieces, making contacts, on
the adjustable arm of the bridge. Number two and number three theodolite have
cach in front of their object glasses, two shutters of mica, which shutters are auto-

page_text: matically brought up in front, alternately, at any desired interval of time, but when
up still leaving a narrow vertical slit, in the centre of which slit is the vertical hair
of the theodolite. The motions of the shutters are caused by electro-magnets,
whose circuits are closed by different contacts resting on a uniformly and rapidly
moving contact wheel.
The coils in series with the table wires and their equals in the unknown arm of
the bridge are, as stated, proportioned to the speed of the torpedo boat; and
the wires between the contacts of number one and number two theodolite
proportional to the distance of the enemy; and the wire between two and three
theodolite proportional to the speed of the enemy; this speed being given by the
time that occurs between the closing up of the shutters: further the resistance
of the table coils is varied by the movement of the theodolite system about a center,
so that it may be proportional to the angular speed of the boat. The table coil
which is active is in the adjustable arm or unknown arm according to whether
the torpedo boat is going in the same or the opposite direction to the enemy.
In guns firing projectiles of high velocity, the third theodolite and the time
shutters are not used, the elevation of the sight, or the gun, being given by the
inclination of the axes of the two theodolites; the angle of the gun, or its sight,
being given by the movement of the theodolite system about a center, the contacts
of a second bridge being affected by this motion and thus causing a second motor to
operate in moving the sight, or the gun, about a center.
When the guns are moved directly, on shipboard, the time of firing is then
determined by a pendulum making an electrical contact at the moment that the ship
is level.
It is evident that if the contacts of the theodolite system bear on many
Wheatstone bridge arrangements, that many guns may be simultaneously trained on
the same object by the same operator. The operators may be quite sheltered from
adverse fire by making the theodolites with two rectangular bends with a prism in
each bend.
The gyroscope in the torpedo is supported in gymbals, which allow of its keeping
its position by the expenditure of an extremely minute amount of work, however
the torpedo might roll or turn. Motion is given to the gyroscope by a wire coiled
on a fusee, one end of which wire passes out through a valve in the skin of the
torpedo and is attached to the torpedo tube, the other end passes through a loose
collar on the axis of the fusee; one pivot of the fusec is prolonged to pass through
Jugs in the gymbals and on the spindle of the fusee is fixed a gear wheel, gearing
with a similar wheel on the axis of the gyroscope, thus holding the gyroscope
rigidly in its position. When the torpedo is fired the wire rotates the fusee and
thus the gyroscope, with an increasing velocity, finally, when the end of the wire is
drawn free, from the loose collar, the fusee falls to a lower position withdrawing its
pivot, disengaging the wheels and leaving the gyroscope freely revolving on its
horizontal axis.
If the torpedo is deflected, on first striking the water, no similar deflection is
given to the gyroscope, but contact points, which are carried on one gymbal, close
electric circuits varying, in effect, with the deflection. A contact table which is
concentric to the gymbal allows of similar contacts being made when the torpedo is
rolling. The electric circuits, closed, energise magnets which move the tiller
directly, or air pistons which cause the movement of the tiller.
The steering gear for controlling the torpedo in the horizontal plane, that is its
vertical movements, is similar to the above mentioned, but the contacts are made
by contact points fixed at the base of a pendulum. A contact table concentric to
the axis of the pendulum is movable about this axis to a limited extent, the amount
being determined by the movement of a plate of metal, connected by a diaphragm
to one of the bulkheads in the torpedo, the surface of the. plate remote from the
table being exposed to the external pressure of the water.
In torpedoes, which it is desirable to control, the gyroscope contact table is made
movable about a vertical axis to definite positions, this movement being caused, at

page_text: will, by a step by step magnetic apparatus, the magnets being energised by a current
passing from the shore, or torpedo boat to the torpedo through a small insulated
wire, or cable.
The gyroscope, for the torpedo boat, sighting table, is rotated by an electric
motor connected to the vertical axis of the gyroscope; the magnets, of the motor,
are supported by its bearings on the axis of the gyroscope, and are attached to the
boat by lengths of steel wire sufficient to resist the torsion and yet admit of the
The sighting
free movement of the entire system about its supporting point.
table is supported on the gyroscope by gymbals so that it always remains quite
level.
Improvements in Apparatus for Directing Torpedo Tubes and
Ordnance, and for Steering Torpedoes.
I, MARK HENRY HURRELL, of Fair View, Dartmouth, in the County of Devon.
late of 42, Myddleton Road, Hornsey, in the County of Middlesex, Electrical
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 improvements in apparatus for directing torpedo
tubes and ordnance and for steering torpedoes.
The direction which should be given to a torpedo tube or the angle which the
axis of the tube should make with the line of sight or direction of the target ship
depends on several conditions: It depends on the speed of the target ship across
the line of fire; also on the distance of the target ship for the speed at which the
torpedo travels is not uniform throughout the range; also (if the torpedo tube be
on ship board) it depends on the speed of the torpedo vessel; and it depends on the
direction in which the torpedo vessel is travelling.
According to my invention.
(1) represent each of these conditions by an electrical resistance which can be
independently varied.
(2) I include these resistances in a Wheatstone bridge.
(3) include also in the Wheatstone bridge a resistance which is varied by the
movement of the sight and so made to balance the other resistances.
(4) I provide a motor geared with the sight and I control this motor by means
of the bridge galvanometer so that the motor traverses the sight in one direction or
the other when a current is passing either way through the galvanometer and the
motor and the sight remain at rest when no current is passing through the bridge
galvanometer.
(5) I measure the speed of the target ship across the line of sight by means of
two telescopes which are set parallel the one with the other and they always so
remain but the distance between them can be varied. I provide in connection with
the two telescopes, shutters or like instruments visible in the telescopes and which
by a movement mark definite instants of time.
I so arrange that the shutters or signalling instruments in connection with the
two telescopes move the one after the other with a known small interval of time
(say a quarter of a second) between the two signals.
In the use of this speed measuring apparatus the telescopes are moved to such a
distance apart that each at the instant when the time signal is visible in it bears on
the same point in the target ship. Then the lateral distance between the two
telescopes is known to be the distance across the line of sight travelled over by the
target ship during the time interval.
(6) I arrange the moveable telescope of the pair above mentioned to carry with

page_text: it a sliding contact maker and to slide it over electrical contacts connected with a
series of electrical resistances. The position of the telescope thus automatically
determines how many of the resistances of this series are in circuit.
(7) To make the adjustment dependent upon the distance of the target
ship I provide a third telescope which does not remain parallel to the other
telescopes but can be inclined at a small angle so that although at a little distance
off from the companion telescope it can be brought to bear on the same point. The
angle between the direction of the two telescopes when set depends on the distance
of the target ship.
This third telescope as it is caused to incline also moves a slider over electrical
contacts in the manner already described and so it varies the number of resistances
in circuit in another series provided to effect the adjustment dependent on length
of range:
(8) To make the adjustment required for variations in the speed of the torpedo
vessel or ship carrying the torpedo tube I provide several series of resistances;
these are all kept plugged and out of use except the one required ciz:; the one
which corresponds to the known speed of the torpedo vessel. These resistances are
supplied in duplicate and are used in one or other side of the Wheatstone bridge
according as the movements of the torpedo vessel and the target ship are in similar
or opposite directions.
(9) The compensation to be made for the speed of the torpedo vessel will vary in
amount according to the directions in which the torpedo vessel is heading it is obvious
that if the target vessel is directly ahead or astern no compensation is required and
the maximum compensation is required when the target ship is broad on the beam:
this adjustment is made in the following manner: the resistances mentioned in the
preceding paragraph are connected with contacts over which a slider is caused to
move by means which I shall proceed to explain. The whole of the sighting
apparatus above described and their contacts also are mounted upon a table carried
upon a steady platform which if necessary is maintained at rest notwithstanding the
movement of the ship by gyroscopic apparatus which forms no part of the present
invention.
The table is turned by suitable gear so that the telescope which is fixed upon it
is brought to bear on a point on the target ship.
There is a finger or arm however so connected that it maintains at all times a
fore and aft position and this is connected with the slider and holds it stationary
whilst the table revolves and whilst the contacts which are arranged in ares about
the axis of the table pass beneath it. Consequently the number of these resistances
which remain in circuit is dependent on the position of the table in relation to the
finger or arm above mentioned.
The foregoing description is illustrated by the drawings Figures 1, 2 and 3.
Figure 1 is a diagram of the parts carried upon the table.
Figure 2 is a diagram of the sight upon the torpedo tube.
Figure 3 is a diagram of the Wheatstone bridge arrangement so arranged that
the connection may be more readily followed than they can be in Figure 1.
a is a table mounted upon a steady platform and capable of being revolved about
a central pivot. b is a telescope carried upon this table and which is brought to
bear on the object by the rotation of the table. This telescope is furnished with a
semi transparent shutter, it may be of talc, which by the operation of an electro
magnet and clockwork is suddenly closed and opened again every few seconds.
The observer at this telescope notes the exact point on the target ship marked by
wires in the eye piece when the shutter closes or when any like time signal
is given. c is another telescope like the telescope b but its shutter closes a
fraction of a second later or earlier; it is always parallel to the telescope b but can
be slidden sideways; its extreme positions are marked at c' c². It is the duty of
the observer at the telescope c so to place it that at the instant marked by the
closing of the shutter the wires in its eye piece mark the same point on the target
ship as are marked under like circumstances by the wires of the telescope b. It is

page_text: not necessary that there should be two observers as by the use of reflectors in a
well known way the two images may be brought into the same field of view. The
observer or observers when satisfied that the telescope c is properly set presses on a
finger key in a circuit which when closed indicates that the torpedo is to be ejected
or which by automatic mechanism causes it to be so. There are several finger keys
in this circuit which I may call the firing circuit and they must all be depressed
simultaneously to complete the circuit. d is a series of contact pieces insulated the
one from the other except that they are connected by wire coils of suitable resistance.
A battery e is connected with one end of the series and a conductor is led away
from the other end. The telescope c moves a slider along the series d but for this
slider the battery current would have to pass and repass the full length of the series
but the slider wherever it may happen to be placed, enables the current to cut
across and return without reaching the further end of the series. is another
telescope at some distance from the telescope but capable of inclining so that it
can he brought to bear simultaneously on the same mark as the telescope b. These
telescopes b and ƒ may be so arranged that they may be used by the same observer:
it is not necessary to make use of the telescope at the same instant as the
telescope c. The telescope as it is brought to bear moves a slider along the series
of contacts g which are arranged in the manner already described. The observer
at the telescope when satisfied with the adjustment presses a key in the firing
circuit. and are other series of resistances, as many as may be considered
necessary, one only is used at a time and this is selected according to the speed of
the torpedo vessel and whether running in the same direction as the target ship or
in the opposite direction. If in the same direction some of the resistances are
employed; if in the opposite direction then one or other of the series marked h¹.
i and are other resistances which are not varied whilst in use. I is the bridge
galvanometer m is the rear sight on the torpedo tube it is formed in connection
with a slider which works over a series of contacts n and as in the other cases it
allows, according to its position, a number more or less of the resistance coils of this
series to be in circuit. o is an electro motor geared with the rear sight m. This
motor is of such construction that it runs in one direction or the other according
to the direction of the current passing through it and accordingly it traverses the
sight and the slider along the contacts n. p is a battery which supplies current to
the motor, its two extremities are connected say with the two upper stops of the
bridge galvanometer whilst the motor terminals are connected the one with the
centre of the battery and the other with the two lower stops of the galvanometer.
Consequently when the needle of the bridge galvanometer is deflected current flows
through the motor and it runs in one way or the other according to the direction of
the deflection. When the galvanometer needle leaves the stops the motor ceases to
run. The bridge connections are clearly seen in Figure 3; one side of the bridge
comprises the resistances d, g and h another side the resistances h' and n whilst the
remaining sides consist of the invariable resistances i and . The galvanometer I is
connected across the bridge in the usual way.
In some cases and for some purposes parts of the mechanism above described may
be dispensed with; thus for elevating the sight of a gun the optical distance
measurer with its contacts g may alone be employed to vary the resistance in
one side of a Wheatstone bridge, whilst that in another side is varied by the move-
ment of the sight m over contacts n such movement being automatically produced
by a motor o controlled by the bridge galvanometer l. In other cases other parts of
the mechanism or even the whole of the observing apparatus may be dispensed with
the judgment of an operator being relied on to place the several sliders in
appropriate positions. Even this partial use of my invention will have great
advantages as in a very convenient way it permits of the several adjustments
required being separately provided for and afterwards the joint effect being obtained
without mental effort. Again by providing a sufficiently powerful motor the
torpedo tube or the gun itself may at once be directed as required in place of leaving
this to be done by an operator by the aid of the sights. Or again in place of

page_text: moving the sight by the automatic mechanism an indicator may be moved and the
sight may then be set in accordance with the indication so given.
No
Another part of my invention relates to the automatic steering of a torpedo
whilst it is running its course. For this purpose I employ a gyroscope
within the torpedo. The gyroscope consists as is usual of a wheel and axle
carried in a gymbal frame. The pivots of the outer hoop of the frame are
vertical and the frame carries arms which move over an arc of electric.
contacts which is fixed within the torpedo. The arms of the gyroscope
point constantly in the same direction and if the torpedo deviates from its course
the contact pieces on one side or the other are moved towards the arms until the
circuit of a battery within the torpedo is closed. A magnet or motor is thus brought
into operation which acts upon the rudder in the way required to correct the
deviation. In order to avoid friction against the arms of the gyroscope,
which would be liable to interfere with its action, the electrical contacts may
be periodically moved by the propelling mechanism or otherwise, so as to bring
them within reach of the arms of the gyroscope and then again withdrawn.
Figure 4 illustrates this part of my invention, r is the wheel of the gyroscope,
is the axis of the wheels is the hoop or frame in which the axis r' is carried, t is
the outer frame to which the frames is connected by horizontal pivots at right
angles to the axis. ' ' are the vertical pivots of the frame they are received into
bearings which are fixed within the torpedo. 1212 are electrical contact arms on the
frame t. is an arc of corresponding contacts insulated the one from the other and
on which the arms 2 bear by preference intermittently as above explained.
electric circuit is closed by the operation of the parts t² and u so long as
these parts retain the relative positions which they occupy at the instant
when the torpedo is released; but if the torpedo deviates from its course
the change which results in the relative positions of the arc u and arms t
causes one or other of two battery circuits to be closed and the steering
mechanism to be brought into operation to correct the deviation. v is an axis
which serves to drive the wheel r and to cause it to rotate at a high speed before
the torpedo leaves its tube. The axis is carried in stationary bearings v¹ v² fixed
within the torpedo and it has upon it a spur wheel the teeth of which engage.
with those of a pinion on the axis r¹. The axis serves also as a bolt, it passes
through slots formed to receive it in arms projecting from the gymbal frames & and
and this bolt so long as it is in place serves to lock the frames s and
within the torpedo. is a fusee barrel fast upon the axis and is a sleeve
capable of sliding upon it, this sleeve enters the bearing v. e is a coiled spring
held compressed between the bearing 2 and a flange on the sleeve v. x is a wire
wound upon the fusee and its end is inserted into a hole in the sleeve and in the
axis and it serves to pin the two together. The other end of the wire passes out
from the torpedo and it is made fast in rear of the torpedo tube. To moderate
the strain on this wire this connection may be made through the medium of a
spring.
fast
When the torpedo is released the wire is drawn from the fusee and the axis vis
rapidly rotated. The end of the wire is then drawn out of the hole, the sleeve v³ is
driven by the spring out of the bearing v3 and the bearing being open at the
bottom, the axis falls out of the bearing and out of the notches in the arms on the
frames s and leaving the gyroscope free to act as already explained.
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 means and apparatus herein described for directing torpedo tubes or guns
viz. by the use of a Wheatstone bridge with resistances in one of its sides which
are varied by alteration in the position of the sight of the tube or gun; and with
other resistances in another side which can be separately adjusted to the several
conditions which govern the direction which should be given to the tube or gun and

page_text: with a bridge galvanometer indicating when the sight has been moved to the position
which the conditions taken collectively demand.
2. In combination with the mechanism referred to in the preceding claim a motor
which automatically moves the sight to the required position and which is controlled
by the bridge galvanometer.
3. In combination with the mechanism referred to in the preceding claims optical
speed measuring apparatus and distance measuring apparatus with contacts so
arranged that by directing the said optical measuring apparatus upon the mark the
necessary adjustment of the electrical resistance is automatically made.
4. The means and apparatus referred to in the preceding claims but so arranged
that the resistance in one of the sides of the Wheatstone bridge is varied not by the
movement of the sight but by the movement of the torpedo tube or of the gun or of
an indicator which shows the direction which is to be given to the tube or to
the gun.
5. The means and apparatus for measuring the speed of the target ship across the
line of sight viz.: by the use of two parallel telescopes and time signalling apparatus
in connection therewith so arranged that the telescopes may be set at such a distance
from each other as to bear on the same mark on a moving target at the commence-
ment and the end of a short measured period of time.
6. The combination with a torpedo of a gyroscope and means for driving and
freeing the same at the time required and electrical contact parts controlled by the
gyroscope and governing the position of the rudder of the torpedo.
Datad this day of Dacombor 1900