IMPROVEMENTS IN SELF- PROPELLING SUBMERGED TORPEDOES." PROPELLING SUBMERGED TORPEDOES
Year: 1871

page_text: LETTERS PATENT to George Wightwick Rendel, of Newcastle-upon-
Tyne, Civil Engineer, for the Invention of "IMPROVEMENTS IN SELF-
PROPELLING SUBMERGED TORPEDOES."
PROPELLING SUBMERGED TORPEDOES."
Sealed the 29th August 1871, and dated the 28th March 1871.
PROVISIONAL SPECIFICATION left by the said George Wightwick
Rendel at the Office of the Commissioners of Patents, with his
Petition, on the 28th March 1871.
I, GEORGE WIGHTWICK RENDEL, of Newcastle-upon-Tyne, Civil
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SELF-PROPELLING SUBMERGED TORPEDOES," to be as
follows:-
According to this Invention in order to cause a self-propelling torpedo
to float at a predetermined depth below the surface an arrangement
analogous to the swimming bladder of a fish. The torpedo contains
a magazine of compressed air, which affords the means of distending
a bag or expanding any suitable vessel when the torpedo sinks below
the required depth. This distension or expansion displaces water from
the body of the torpedo, and by increasing its buoyancy causes the
torpedo to ascend, but in passing the point at which it is intended to

page_text: rest air is let out of the bag or vessel to reverse the effect.
The torpedo
then descends, and finally settles at a point where flotation and gravity
are in equilibrium.
The admission of air to the bag and its escape therefrom are regulated
by the pressure of the external water which opens an admission valve
when the depth attained gives sufficient pressure to overcome the
resistance of a predetermined weight or clastic force, and allows an
escape valve to be opened by the preadjusted force when the external
pressure becomes less than that force.
For a spherical torpedo a single air bag in the centre would be
sufficient, but for a cigar form or any other elongated form favorable
for propulsion and small resistance two air bags with independent
valves and connections will, be required, viz., one on each side of
the centre and in such positions as will cause the torpedo to float
horizontally.
The propelling power is compressed air applied to a screw propeller,
which may either be placed at the head of the torpedo to drag it or at
the stern to push it.
The charge is carried at the forward end, and is fired by a percussive
arrangement which takes effect when the torpedo strikes an object.
The impact also acts upon a valve which admits air from the magazine
nto the bags, and thus brings the torpedo to the surface when it fails to
explode.
In discharging the torpedo at an object the first direction is deter-
mined by placing it in a tube or guide frame, and in order to lessen its
liability to deflection during its course one or more spiral keels or fins
may be fixed to the exterior of the torpedo to make it rotate on its
longitudinal axis in passing through the water.
The accompanying diagram shews a torpedo such as is above
described.
In this diagram A is a reservoir of compressed air; B, ballast;
C, propelling engine; D, charge; E, propeller; F, air cylinder with
elastic diaphragm acted on by the water and controlling the regulating
valve H; G, flotation bags; H, valve for admission or emission of air
to or from flotation bags; J, pipe from valve to compressed air
chamber; K, pipe from valve to flotation bag; L, pipe from valve
to sea

page_text: In place of using one receiver A both to drive the engine and to
work the equilibrium arrangement F, G, two receivers may be used,
one for each purpose.
Before starting air will have been forced into the cylinders F at the
pressure due to that of the intended depth of flotation, and when the
torpedo enters the water the elastic diaphragms will be curved outwards
and will rest against stops. The valve will then be open for the emission
of the air from the air bags to the sea, and there will be springs to keep
the bags closed.
The weight of the torpedo will be slightly greater than the displace-
ment when the bags are collapsed. The torpedo will therefore at first
descend, and when it attains the required depth the elastic diaphragms
will become straight, and in assuming this form will close the valves
which will remain closed if the torpedo remains at the right depth. If,
however, it continues to descend the diaphragms will curve inwards, and
in doing so will open a communication between the compressed air
chamber and the air bags; the torpedo will then rise, and after oscil-
lation will finally continue to travel at the required depth, the exact
quantity of air having been admitted into the bags.
For further controlling the motion of the torpedo at a uniform level
below the surface I propose to use fins or steering blades placed
externally and horizontally, and acted on by the apparatus F in a
similar arrangement, so that when the torpedo descends below the level
at which the elastic diaphragm is in equilibrium the blades may be
caused to incline in a direction to reverse its motion and make it
ascend, and vice versa.
When such steering blades are used the spiral fins already described
would not be used. Such blades may also be used alone for retaining
the torpedo at a uniform depth below the surface, care being taken that
the displacement of the whole torpedo in that case is made equal to its
weight, or the blades may be used in conjunction with the apparatus
previously described.
To adjust the torpedo so that the centre of gravity in a vertical
direction shall coincide with the centre of displacement I employ a
weight capable of being moved longitudinally along the torpedo, and of
being fixed at any desired point.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Wightwick Rendel in the Great Seal
Patent Office on the 28th September 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WIGHTWICK RENDEL, of Newcastle-upon-Tyne, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of March, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George Wightwick Rendel, Her
special license that I, the said George Wightwick Rendel, my.executors,
administrators, and assigns, or such others as I, the said George
Wightwick Rendel, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make, usc," exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN SELF-PROPELLING SUBMERGED TORPEDOES,"
upon the condition (amongst others) that I, the said George Wightwick
Rendel, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Scal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Wightwick Rendel, 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 thereof, that is to say :—
According to this Invention, in order to cause a self-propelling
torpedo to float at a predetermined depth below the surface, an arrange-
ment analagous to the swimming bladder of a fish is employed. The
torpedo contains a magazine of compressed air which affords the means
of distending a bag or expanding any suitable vessel when the torpedo
sinks below the required depth. This distension or expansion displaces
water from the body of the torpedo, and by increasing its buoyancy

page_text: causes the torpedo to ascend, but in passing the point at which it is
intended to rest air is let out of the bag or vessel to reverse the effect.
The torpedo then descends and finally settles at a point where flotation
and gravity are in equilibrium.
The admission of air to the bag and its escape therefrom are regulated
by the pressure of the external water which opens an admission valve
when the depth attained gives sufficient pressure to overcome the
resistance of a predetermined weight or elastic force, and allows an
escape valve to be opened by the preadjusted force when the external
pressure becomes less than that force.
For a spherical torpedo a single air bag in the centre would be
sufficient, but for a cigar form or any other elongated form favorable
for propulsion and small resistance two air bags with independent valves
and connections will be required, viz., one on each side of the centre,
and in such positions as will cause the torpedo to float horizontally.
The propelling power is compressed air applied to a screw propeller,
which may either be placed at the head of the torpedo to drag it or at
the stern to push it.
The charge is carried at the forward end, and is fired by a percussive
arrangement which takes effect when the torpedo strikes an object, the
impact also acts upon a valve which admits air from the magazine into
the bags, and thus brings the torpedo to the surface when it fails to
explode.
In discharging the torpedo at an object the first direction is deter-
mined by placing it in a tube or guide frame, and in order to lessen its
liability to deflection during its course one or more spiral keels or fins.
may be fixed to the exterior of the torpedo to make it rotate on its
longitudinal axis in passing through the water.
Figure 1 of the Drawings hereunto annexed shews a torpedo such as
is above described.
In this Figure A is a reservoir of compressed air; B, ballast; C, pro-
pelling engine; D, charge; E, propeller; F, air cylinders with elastic
diaphragm acted on by the water and controlling the regulating
valve H; G, flotation bags; H, valve for admission or emission of air.
to or from flotation bags; J, pipe from valve to compressed air chamber;
K, pipe from valve to flotation bag; L, pipe from valve to sea. The
spaces between the bulkheads X, Y, are open to the sea.

page_text: In place of using one receiver A both to drive the engine and to work
the equilibrium arrangement F, G, two receivers may be used, one for
cach purpose.
Before starting air will have been forced into the cylinders Fat the
pressure due to that of the intended depth of flotation, and when the
torpedo enters the water the elastic diaphragms will be curved outwards,
and will rest against stops, the valves will then be open for the emission
of the air from the air bags G, and there will be springs to keep the
bags closed.
The weight of the torpedo will be adjusted so as to be slightly greater
than the displacement when the bags are collapsed. The torpedo will
therefore at first descend, and when it attains the required depth the
clastic diaphragms will become straight, the pressure being the same on
both sides, and in assuming this position the diaphragms will close the
valves, which will remain closed if the torpedo remains at the right
depth. If, however, it continues to descend, the diaphragms will curve
inwards, and in doing so will immediately open a communication
between the compressed air chamber and the air bags. The torpedo
will then rise, and after oscillation will finally continue to travel at the
required depth, the exact quantity of air having been admitted into
the bags.
To adjust the torpedo so that the centre of gravity in a vertical
direction shall coincide with the centre of displacement a weight
capable of being moved longitudinally along the torpedo and of being
fixed at any desired point may be employed.
Figures 2 of the Drawings shew the arrangement for keeping the
torpedo at the required depth by self-acting steering blades instead of by
a self-acting alteration of displacement as previously described. In this
arrangement the elastic diaphragm ƒ of the closed vessel F instead of
acting upon a valve, as in the case previously described, acts upon a
lever M by a rod N to turn the steering blades O, O, up or down.
When the required depth is exceeded the diaphragm f being unduly
depressed by the pressure of the external water carries with it the
lever M. and moves the steering blades O, O, in such a direction as to
turn the torpedo and cause it to direct its motion upwards. Similarly
when the torpedo is at less than the desired depth the pressure of air
in the closed vessel F being not completely balanced by the pressure
of the water outside expands the diaphragm f and moves the rudders

page_text: in a direction to turn the torpedo downward.
In this arrangement
also the weight of the torpedo must be adjusted so as to nearly equal
the displacement, but it may be made a little more or a little less
according as it is desired that the torpedo should sink or rise when
its forward motion ceases. The keels P, P, are provided so that the
axis of the steering blades may be constantly in a horizontal plane.
I prefer to make the upper one of wood or some other light material,
or hollow, and the lower one weighty but of the same section and
external form as the upper one so as to bring the centre of gravity of.
the whole torpedo below the centre of displacement. Two screws
revolving in opposite directions may also be used instead of a single
screw so as to obviate the tendency to rotate under the propelling forces.
The propellers may be either at one end or other, or both ends of the
torpedo.
Figure 3 shews one method of arranging the apparatus for igniting
the charge of the torpedo. In this arrangement a trigger Q retains a
bolt R acted upon by a spiral spring S. In coming in contact the
trigger is sprung and the bolt released when it strikes a cap T and fires
the charge. For greater security in handling and launching the torpedo
a safety bolt U is provided preventing the trigger from being sprung.
This safety bolt is acted upon by a rod V and spring W, which presses
the rod against the surface of a recessed wheel a. When the engine
is started the recessed wheel a being connected with it commences
slowly to revolve and after making nearly a full turn brings a notch b
in its projecting rim opposite a tooth d on the rod V and allows it
to spring forward drawing the safety bolt and thus leaving the trigger
free to act. I do not however limit myself to this method of igniting
the charge, which may be fired by the momentum of a free weight
acting in contact or by other simple means.
In order to equalize the pressure of the compressed air in the reservoir
A so as to cause it to drive the engine at an uniform speed, I employ a
valve of the general description shewn in Figure 4. This valve consists
of a plug and piston (e) moving in a tube (g). The compressed air
from the reservoir is admitted to the tube above. the piston e by the
5 groove and otherwise presses upon the piston and compresses the
spiral spring i. k is the orifice by which the air presses to the propelling
engine. The cylindrical plug e opposite this orifice is tapered off so
that when the spring is fully compressed the small end of the taper

page_text: passes below the orifice and it is closed. On the other hand when the
spiral spring is freely expanded the large end of the taper is opposite
the orifice and the air passes freely into the engine. In intermediate
positions of the plug the air passage is more or less throttled. The
strength of the spring i is, adjusted so as to allow a sufficient quantity
of air to pass to the engine when the pressure is at a maximum.
As the pressure is reduced the spring expands and increases the aperture.
Having thus described the nature of my Invention and the manner
in which I prefer to carry the same into effect, I would have it
understood that what I claim as my improvements in self-propelling
submerged torpedoes is,-
1. The employment of expansible bags substantially as herein.
described to keep such torpedoes at the required depth below the
surface.
2. The employment of steering blades substantially as herein
described to keep such torpedoes at the required depth below the
surface.
In witness whereof, 1, the said George Wightwick Rendel, have
hereunto set my hand and seal, this Twenty-fifth day of
September, in the year of our Lord One thousand eight hundred
and seventy-one.
TTY
DOVANE