Improvements in Submerged Mines and in Apparatus for Operating or Controlling the same.
Year: 1887

page_text: Date of Application, 21st May, 1887
Complete Left, 15th Feb., 1888
Complete Accepted, 16th Mar., 1888
Improvements in Submerged Mines and in Apparatus for Operating
or Controlling the same.
I, FRANTS ALBERT VELSCHOW, Civil Engineer of 2 Euston Square in the County
of Middlesex do hereby declare the nature of this invention to be as follows:-
--
This Invention has for its object improvements in submerged mines and in apparatus
for operating or controlling the same.
According to my invention I attach mines to a submerged rope or cable and on
shore I provide a capstan or windlass round which the rope or cablo is led. The rope
or cable also passes around a pulley also submerged and it is then led back to the
windlass. The mines which are lighter than the water which they displace, are
connected with the rope or cable by short lines which when all is arranged hold them
at such a distance below the surface of the water that a vessel passing over may strike
against one or other of the mines and thereby cause it to explode. The distance below
the surface at which the mines are so moored is regulated by applying a greater or
less tension to the rope or cable to which they are attached, and an indicator is provided
on shore, which indicates constantly the tension of the rope or cable.
Each mine is of a fish-like form and it is connected with the rope or cable in such a
manner as to keep the mine steady whilst it is drawn through the water by means of
the rope or cable or against the current. The mine when drawn through the water by
the rope or cable tends to rise to the surface and all risk of its fouling the bottom is
avoided. The mine is also furnished with directing blades to cause it to travel steadily
through the water.
The operation of attaching the mines to the rope or cable is performed on shore and
then the rope or cable is wound forward by means of the windlass until the mines
attached to it are brought to the position in which they are required to operate. In a
similar manner the mines when no longer required are removed or sunk to the bottom
by the weight of the cable and this is an operation which can be rapidly performed, so
that the channel may be cleared from mines to allow a friendly vessel to pass, and then
the mines may be replaced to again bar the channel.

page_text: In order that these operations may be performed in safety I employ a fuse of such
a nature that when the mine is out of the water or floating on the surface the fuze
is inoperative whilst it becomes operative when the mine is submerged at a suitable
depth in consequence of the pressure of the water then acting thereon. The fuze is
provided with a pin or striker which in order to fire the charge requires to be driven
inwards either by direct collision with a ship or floating body or otherwise. In the
path of this pin I provide a bolt and the bolt has a hole or recess in it, by which the
firing pin has to pass before it can ignite the charge. The bolt is connected with a
flexible diaphragm supported by a light spring which normally holds the bolt in such
a position that the pin cannot pass. When however the mine is submerged the pressure
of the water against the flexible diaphragm compresses the spring and moves the bolt
to a position such that the firing pin is then able to pass freely. Mines armed with
this fuze may be safely handled when on shore or when floating on the surface of the
water. But when they are drawn down beneath the surface and submerged to a
sufficient depth the fuze becomes operative and then a collision of a vessel with the
mine will cause it to explode but it is not to be exploded by the concussion of explosions
in its neighbourhood, such as countermining.

page_text: COMPLETE SPECIFICATION.
Improvements in Submerged Mines and in Apparatus for Operating
or Controlling the same.
I, FRANTS ALBERT VELSCHOW Civil Engineer of 2 Euston Square 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 :-
This invention has for its object improvements in submerged mines and in apparatus
for operating or controlling the same.
According to my invention I attach mines to a submerged rope or cable and on
shore I provide a capstan or windlass round which the rope or cable is led. The ropo
or cable also passes around pulley also submerged and it is then led back to the
windlass. The mines which are lighter than the water which they displaco are
connected with the rope or cable by short lines which when all is arranged hold them
at such a distance below the surface of the water that a vessel passing over may strike
against one or other of the mines and thereby cause it to explode. The distance below
the surface at which the mines are so moored is regulated by applying a greater or
less tension to the rope or cable to which they are attached, and an indicator is provided
on shore, which indicates constantly the tension of the rope or cable.
Each mine is of a fish like form and it is connected with the rope or cable in such a
manner as to keep the mine steady whilst it is drawn through the water by means of
the rope or cable or against the current. The mine when drawn through the water
by the rope or cable tends to rise to the surface and all risk of its fouling the bottom
is avoided. The mine is also furnished with directing blades to cause it to travel
steadily through the water.
The operation of attaching the mines to the rope or cable is performed on shore and
then the rope or cable is wound forward by means of the windlass until the mines
attached to it are brought to the position in which they are required to operate. In a
similar manner the mines when no longer required are removed or sunk to the bottom
by the weight of the cable and this is an operation which can be rapidly performed,
so that the channel may be cleared from mines to allow a friendly vessel to pass, and
then the mines may be replaced to again bar the channel.
In order that these operations may be performed in safety I employ a fuse of such
a nature that when the mine is out of the water or floating on the surface the fuze is
inoperative whilst it becomes operative when the mine is submerged at a suitable depth
in consequence of the pressure of the water then acting thereon. The fuze is provided
with a pin or striker which in order to fire the charge requires to be driven inwards
either by direct collision with a ship or floating body or otherwise. In the path of
this pin 1 provide a bolt and the bolt has a hole or recess in it, by which the firing pin
has to pass before it can ignite the charge. The bolt is connected with a flexible

page_text: diaphragm supported by a light spring which normally holds the bolt in such a position
that the pin cannot pass. When however the mine is submerged the pressure of the
water against the flexible diaphragın compresses the spring and moves the bolt to a
position such that the firing pin is then able to pass freely. Mines armed with this
fuze may be safely handled when on shore or when floating on the surface of the water.
But when they are drawn down beneath the surface and submerged to a sufficient
depth the fuze becomes operative and then a collision of a vessel with the mine will
cause it to explode but it is not to be exploded by the concussion of explosions in its
neighbourhood, such as countermining.
Figure 1 represents the ordinary case of closing a channel half a mile or two thirds
of a mile wide. The water to the left of this channel is supposed to be not deep
enough for an enemy's vessels to pass. A ship is shown crossing the line of mines.
a are the mines, 6 is a capstan on shore. This base of operation is supposed to be
sheltered and concealed behind works of fortification, not shewn in the figure.
The wooden raft c, carrying a pulley d, having been securely moored by a sufficient
number of strong anchors, will float on the surface until the cable has been led round
the pulley, when it is pulled down under the surface by the weight of the cable. The
cable is led from the capstan on shore across the channel, round the pulley and back
again to the shore, being in the meantime supported by a sufficient number of buoys.
The ends of the cable are then spliced or linked together. By cutting off the supporting
buoys the cable is finally sunk to its proper position. When the depth, to which the
cable is sunk has to be adjusted according to the changing tide arrangements are
made for the capstan to slide backwards and forwards or the ends of the cable are left
free, being both led round the capstan or links are added to or taken out of the endless
cable.
If there was no current in the channel no great strength of cable would be necessary,
as the buoyancy of the mines could be adjusted, so as to carry the whole weight of the
cable or nearly so, and the cable could so far be suspended across any reasonable
distance.
It is to resist the force of the current that the cable wants strength, and it has been
found, that, for a span of two thirds of a mile, with 30 mines attached to the cable,
each carrying 200 lbs. of the explosive; with a dip of the cable not less than 1-60,
and with a maxima current of 3 knots an hour-a three-tons cable of best stranded
steel-wire answers the purpose well.
When cables, in such a number as deemed sufficient to close the channel in question,
have been fixed in their proper positions, everything is arranged for the reception of
the enemy, without preventing the channel from being used for ordinary traffic,-the
loaded mines being kept in readiness for immediate use in a suitable place of shelter
on shore. The loaded imines are kept ready in rows on the carriages of a small line
of rails leading to the base of operations on the beach, or they are brought thither
by boat.
The operators, while moving the cable outwards with the capstan or windlass, fix
the mines on to the cable one by one in their proper distance from each other, and the
weight of the cable draws them below the surface. The fastening of the mines goes
very quickly in the following manner :-The cable, see figure 9, is marked every four
fathoms. At such places the mines are attached, at distances from each other;as
required in each special situation, by means of a thin endless steel chain about one
yard long. The chain is slung round the cable and bites on to it, when hauled tight.
A spring-hook attached to the end of the wire from the nine is next hooked on to the
chain.
By this arrangement the cable, with the mines attached, can, as is sometimes
required, pass round the pullies without getting entangled with these.
A counting apparatus in connection with the winding-gear on shore shows the
operator at any moment the exact position of all and any of the mines attached to his
cable.
By reversing the motion of the gear, the mines are brought to the shore. As they
appear one by one on the surface, they may be handled with perfect safety, as the lock

page_text: is then in safe-position, or locked. However, to give further moral security to the
operator, ho may now insert a safety-pin or screw on the cover for the lock, before
carrying the mine on shore.
is
The system permits any ordinary shape of mine to be used.
As however the system is particularly adaptable for use in places, where the current
very heavy, a special fish-like-shaped mine has been constructed.
This mine is represented in figures 7, 8, 9 and 10.
Figure 7 is a side elevation, Figure 8 is a horizontal section, Figure 9 is a longi-
tudinal vertical section and Figure 10 a transverse vertical section. It gives the least
resistance to the current, so as not to overstrain the cable, and moves steadily through
the water, always current-right.
There are four contacts, one in front, one aft, and one on each of the rounded sides
of the mine.
One of the two first inentioned contacts will therefore always face the approaching
enemy, whether he is coming against or with the current.
Either of the other two contacts will, in case either of the first should miss, be
sure to strike fire, when the mine is scouring along the side of the hull of the
vessel.
The mines may be exploded by any of the systems in use: by electricity, electric
contact or ordinary contact.
The safety-lock is shown in figures 11, 12, 13 and 14. Figures 11 and 12 are
longitudinal sections, figure 13 is a side elevation of one half, and figure 14 is a plan.
Figures 11 and 12 show the two positions of the plunger: e, figure 11, in safe-
position and figure 12 pressed down against the spring e' into the chamber prepared
for the chemical fuse.
The lock is divided into two halves and g the half containing the plunger being
scen in front in figure 13. is the safety bolt of steel, h¹ its spring and the flexible
diaphragmn.
Particular precaution is taken against the plunger being pressed down by the
concussion froin explosions in the neighbourhood of the mine; the plunger is of steel,
so as to combine strength with the least possible sectional area, it being on this area,
that the pressure from concussions will work and the water from outside the mine is
led into the chamber, in which the upper thicker portion of the plunger moves.
the water in this chamber will have to be removed, when the plunger is to go down,
it will act as a cushion.
As
The instantaneous shock from countermining can therefore not fire off the mine by
pressing down the plunger.
The diaphragm k is protected from being destroyed by concussions, as it rests
with its entire surface against the cup-shaped head of the bolt h when the bolt is
pressed in.
Where the water is unclean, the hole, through which the water enters the lock is
covered with a small linen bag, or a flexible through-holed diaphragm, so as to prevent
sand or other particles from entering the lock.
Water is prevented from entering the bolt-chamber along the steel plunger by an
india rubber ring on the top of which rests a plate of leather m with the edge turned
up. Both are kept down by the spring resting against them.
As however a few drops of water, by entering the bolt-chamber would bring the
lock out of working order, a small outlet n is provided leading from the bolt-chamber
into the inside of the mine. A small india rubber bag o is attached to this outlet,
that the explosives may not be damaged by the few drops of water, which might
enter.
The system being mainly intended to be used as a means of defence, manual labour
or animal power is generally sufficient to work the cables.
However it is sometime of advantage to propel the cables with an accelerated speed,
and then hydraulic power or electric power on the storage system is found most suitable.
Steam power might also be used, but as the smoke might be a guide for the enemy, as
to where the mines are lodged, it is better not to use steam.

page_text: It may in special cases be of greatest advantage to direct an attack against the
enemy by hurling the whole column of mines attached to a cable against a vessel
crossing the cable.
Nothing could be more detrimental to the enemy than such an attack, when the
mines, following each other with hardly an interval of a few seconds, all explode in
the same spot. Protecting nettings would be of no avail, as the destruction caused by
the first, or the few first mines, would leave an opening to allow the rest of the mines
to come in contact with the hull of the vessel itself.
The mines being all on the spot when the enemy comes up, the attack would possess
of a certainty independent of a changing current etc. of successfully destroying
the enemy, with which no known system of self-movable mines or torpedoes can
compare.
The cable has only to be given the rapid motion the very moment, or a few seconds
before, the enemy actually crosses the line of mines.
Figuro 5 shows a special way of rigging the mines intended to be used in such an
attack. Each mine is attached to the propelling cable by two lines instead of one,
these forming an angle with each other. When namely one line only is used and the
cable is rapidly propelled, the mine does not answer the pull instantaneously, but is
drawn down towards the cable, the angle the wire forms with the perpendicular being
proportioned to the speed. But by placing the two wires, used for each cable under
such an angle with the perpendicular, as the single line would adopt for the required
speed, it is secured, that the mine will answer the pull instantaneously and keep at a
uniform distance from the cable during the whole motion of the cable.
In Figure 2 is shown, how the cable may be worked in two sections, one from each
shore, in case the channel is too wide, or the current is too strong to allow the cablo
to be worked in one span.
The two rafts with their pullies are supported by a submerged buoy in the centre of
the channel.
.
The arrangement in Figure 3 is used in still wider channels.
Four sections of cable-line are used here.
The two outer ones of these are worked from capstans on shore.
The two central cables are worked from capstans, placed on a moored subinergel
vessel in the centre of the channel.
The chain or cable, which keeps the vessel below the water, passes round a moored
wheel or pulley and is given sufficient length to be anchored, up current or down, at
a. considerable distance from the line of mines.
When this anchoring is taken up either, by divers or otherwise, the submerged ship
comes to the surface, and the mines, which are kept in readiness in a boat, are now
to be sent out on the cables in the centre, by manipulating the capstans on the ship.
This done, the vessel is again submerged to its former position, by pulling the anchor-
chain with a powerful steam-tug.
Figuro 4. This arrangement is found useful, when the channel has no shores; or,
when there is shoal water at a considerable distance out from shore, so that the
suspended cable could not be kept above ground.
The raft to the left in the Figure is supported by a buoy and the capstan to the
right is placed on a submerged vessel similar to that in Figure 3.
Figure 6 shows a part of a channel seen from above. This channel is elosed by four
lines of cables.
The two upper cables in Figure indicate how it can be done to arrange the
mines, necessary to form one line of defence, on two cables, each carrying half of the
mines.
This method is used in case the channel is only to be worked from one shore, and
the current is too heavy or the channel too wide to allow the mines to be placed all
on one cable.
The cable below in Figure 6 passes round two pullies, moored at a considerable
distance from each other. The two branches of the cable, being thereby kept apart,
may both be availed of to carry mines, one cable thus forming two lines of defence.
י

page_text: The system of cables is protected against being interfered with by the enemy, by
grappling &c.
1. By the mines attached to them.
2. By mines anchored in the neighbourhood.
3. By modern guns on shore.
4. By the use of electric search lights at night.
5. By the use of picket boats.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The submerged rope or cable from the shore and passing round a pulley whereby
the mines can be placed in position and brought back to shore substantially as
described.
2. A fuse which is inoperative when the mine is out of water or near the surface
whilst it becomes operative when submerged to a certain depth substantially as
described.
3. The combination in a fuse of a plunger and a bolt operated by the pressure of
the water substantially as described.
4. My improvements in submerged mines and in apparatus for operating or
controlling the same substantially as described.
Dated this 9th day of February 1888.