Mines for Land Service.
Year: 1886

page_text: Date of Application, 6th May, 1886.
Complete Left, 3rd Feb., 1887.
Complete Accepted, 4th Mar., 1887.
Mines for Land Service.
We JOHN TOWNSEND BUCKNILL, Major in H.M. Corps of Royal Engineers and of
Thornfield in the County of Southampton and WILLIAM OLIVER SMITH of Westbury,
Holly Park, Crouch Hill in the County of Middlesex Telegraphic Engineer do hereby
declare the nature of this invention to be as follows:--
This Invention has for its object an improved firing apparatus for torpedoes or
mechanical mines for land service.
The improved firing apparatus consists of a metal tube which can be fixed in a vertical
position into the top of the case in which the explosive is contained.
Within the said tube there is a piston with a rod or stem projecting upwards and.
passing out of the tube by a hole provided for it in an end piece which closes the
upper extremity of the tube.
The lower end of the tube is also closed by an end piece and this is perforated and
on its inner side carries a nipple which receives a percussion cap. When this cap is
fired by a blow struck by the piston upon it the torpedo or mine goes off. When the
explosive employed requires the use of a detonator this is applied beneath the cap.
Around the rod or stem of the piston there is a coiled spring; it abuts at its lower
end on the piston and at its upper end on a metal fork.
This metal fork has two prongs and these enter two notches or slots cut for them
through the tube one on either side.
The fork embraces the tube between its prongs and is slidden in its place in a
direction at right angles to the length of the tube-the prongs project partly through
the notches in the tube and they form the abutment for the spring.
The spring is held compressed between the piston and this abutment by a copper
wire inserted into a hole bored through the piston rod or stem and through the upper
end piece of the tube.
For further security the piston rod or stem is retained until the torpedo or mine is
laid by another fork embracing the rod immediately over the upper end piece; the
prongs of this fork enter notches filed to receive them on either side of the piston rod
or stem.

page_text: When the torpedo or mine is laid a deck of wood triangular in shape and about
18 inches long covers the mine; one corner presses on the top of the piston rod or
stem and the other two corners are supported upon a step cut in the slightly excavated
ground. Or a plank of wood about 3 feet long may be used instead of the triangular
deck, one end of the plank resting on a step cut in the ground and the other end
resting on the top of the piston rod of the torpedo. The deck or the plank is then
covered with grass, soil etc to represent the surrounding ground.
A wire is attached to the fork which embraces the piston rod or stem and by pulling
this wire from a distance the torpedo or mine is rendered active and the fork coming
to the hand of the operator shows him that the torpedo or mine is in the active
condition. A sufficient weight now coming on the hidden deck or plank will cause
the mine to explode. The sensitivity of the mine to such action can be adjusted as
desired by using a copper wire of any desired strength to resist the shearing force
applied. No. 19 B.W.G. soft copper wire is found to give satisfactory results.
In order to render the mine safe for recovery a second pull line is provided and is
connected to the fork which forms the abutment for the spring of the apparatus, and
this line can also be attached to the deck or plank over the apparatus. On pulling
this line both the deck or plank and the abutment fork are withdrawn, and the latter
coming to hand shows that the torpedo or mine may be approached with safety.
The safety of the apparatus is so fully ensured by the withdrawal of the abutment
fork, that it may be considered unnecessary to withdraw the deck or plank also, which
arrangement has the defect that in frosty weather it might he very difficult to draw
away the plank or deck.
A tin cylinder is generally used for the charge case.
A group of mines is conveniently laid in the following manner :-
Two pickets are driven into the ground to mark an alignment.
On the alignment a series of labels or indicators one for each mine of the group is
placed.
The mines are laid directly in front of the labels or indicators and on each of the
latter the distance from its mine is written.
The recovery line of each mine passes back to its label or indicator.
The lines to render the mines active pass back a short distance only.
To render the mines active a pull wire is employed it is attached in turn to each
of the last mentioned lines and by means of it the safety forks are successively
withdrawn.
To recover the mines the other lines are pulled from the alignment until the
abutment forks are brought to hand.
MAEL & Co.,
Agents for the Applicants.

page_text: An Improved Firing Apparatus for Torpedoes or Mechanical
Mines for Land Service.
We, JOHN TOWNSEND BUCKNILL Major in H.M. Corps of Royal Engineers and of
Thornfield in the County of Southampton and WILLIAM OLIVER SMITH of Westbury
Holly Park, Crouch Hill in the County of Middlesex, Telegraphic 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 an improved firing apparatus for torpedoes or
mechanical mines for land service.
The improved firing apparatus consists of a metal tube which can be fixed in a
vertical position into the top of the case in which the explosive is contained.
Within the said tube there is a piston with a rod or stem projecting upwards and
passing out of the tube by a hole provided for it in an end piece which closes the
upper extremity of the tube.
The lower end of the tube is also closed by an end piece and this is perforated and
on its inner side carries a nipple which receives a percussion cap. When this cap is
fired by a blow struck by the piston upon it the torpedo or mine goes off. When the
explosive employed requires the use of a detonator this is applied beneath the cap.
Around the rod or stem of the piston there is a coiled spring, it abuts at its lower
end on the piston and at its upper end on a metal fork.
This metal fork has two prongs and these enter two notches or slots cut for them
through the tube one on either side.
The fork embraces the tube between its prongs and is slidden in its place in a
direction at right angles to the length of the tube, the prongs project partly through
the notches in the tube and they form the abutment for the spring.
The spring is held compressed between the piston and this abutment by a copper
wire, inserted into a hole bored through the piston rod or stem and through the upper
end piece of the tube.
For further security the piston rod or stem is retained until the torpedo or mine is
laid by another fork embracing the rod immediately over the upper end piece, the
prongs of this fork enter notches filed to receive them on either side of the piston rod
or stem.
When the torpedo or mine is laid a deck of wood triangular in shape and about
18 inches long covers the mine, one corner presses on the top of the piston rod or stem
and the other two corners are supported upon a step cut in the slightly excavated
ground. Or a plank of wood about 3 feet long may be used instead of the triangular
deck, one end of the plank resting on a step cut in the ground and the other end
resting on the top of the piston rod of the torpedo. The deck or the plank is then
covered with grass, soil, etc., to represent the surrounding ground.

page_text: passive by withdrawing the second fork and thereby depriving the spring f of its
abutment.
Having now particularly described and ascertained the nature of our said invention,
and in what manner the same is to be performed we declare that what we claim is :-
1. Firing apparatus for land torpedoes or mechanical mines in which the mine is
rendered active, after being safely laid, (and so retained) by the withdrawal of a slide
that holds the piston rod substantially as described.
2. Firing apparatus for land torpedoes or mechanical mines in which the mine
is rendered passive to be safely recovered by the withdrawal of the abutment of the
firing spring thereby liberating the said spring substantially as described.
3. Firing apparatus substantially as described for torpedoes or mechanical mines for
land service.
CARPMAEL & Co.,
Agents for the Applicants.