AN IMPROVED MORTAR for BOAT SERVICE
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I WALTER CHIDIOCK NANGLE H.M. Gun Wharf, Portsmouth Co Hants Dep.
Comssy Gen of Ordnance and Senior Ordnance Store Officer for the Southern
District on the Staff of Gen! H.S. Highness Prince Edward of Saxe Weimar do
hereby declare the nature of my Invention for AN IMPROVED MORTAR for
BOAT SERVICE to be as follows:-
A tube of some metal open at each end, fashioned like a gun so as to well resist
the discharge of the cartridgo. It has about half submerged in water. This half
is a little smaller in diameter than the upper part of the tube, the former sloping
off gently into the latter, at this point (when loading) is placed a wad, or plug, of
suitable material and shape about 3in thick, over this is placed the cartridge, then
the projectile, so that on the discharge taking place, it is the forcing of the plug
through the length of narrow diameter of the tube and against the water, which
acts as the resisting power to the explosion at the time the projectile is projected.
This arrangement passed through the bottom of even a common row boat would
enable a bombardment &c. to be carried out from heretofore unpracticable and
unnavigable streams or waters, owing to its small weight.
WALTER CHIDIOCK NANGLE,
Portsmouth.

page_text: COMPLETE SPECIFICATION.
I, WALTER CHIDIOCK NANGLE late of the Royal Artillery now Deputy
Commissary General of Ordnance and Senior Ordnance Store Officer of the
Southern District (address at H.M. Gunwharf, Portsmouth do hereby declare the
nature of my Invention for ENABLING A MORTAR OR GUN TO BE FIRED OFF
WITHOUT A BREECH and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement, and in
conjunction with the accompanying Drawings :-
The mortar is a tube of metal open at both extremities and the diameter of the
lower half of this tube is slightly less than that of the upper half, theso differences
of diameter do not however form a shoulder but slope gently off, one into the other
see Fig. 1. e df g. This lower portion of the tube or mortar is submerged before
the piece is fired off, the water passing up the bore, up to about where the lesser
diameter begins to enlarge (observe the line wl Fig. 2).
Now on loading the mortar, a plug is first passed down the bore it is of wood or
rope or other suitable material and is about 4 thick see of h c, Fig. 1. it fits into
and is a little longer than that part of the bore which unites, or connects, the
greater with the lesser diameter of the bore, the plug cannot therefore fall out
through the lower end of the mortar. After this plug is inserted the cartridge P,
Fig. 1 (waterproof) then the projectile (a smooth bore is represented in this case).
Now on the discharge taking place, the plug is forced right out of the bore, that
is to say through the lower half of the mortar, which half is, as already stated, of
a little less diameter than the plug itself is, it has also to overcome the pressure,
and resistance, of the water below, and which penetrates up the lower half of the
mortars bore, so that before this plug is forced out, the projecting of the shell from
the upper part of the mortar has been fully accomplished.
By this construction and by reason of the comparatively little weight of the
piece (owing to the small strain by the explosion on the metal) as well as absence
of recoil, I am enabled to mount and carry a mortar of large calibre in an ordinary
cutter or rowing boat, or to sling, carry, or balance the same between two boats, or
rafts, or on a raft, or in any manner most desired, provided the lower half or
extremity of the mortar be submerged, consequently I can take the boat, with such
a mortar, into such shallow waters as would be unnavigable to a mortar vessel as
now used. Thus to adapt the mortar to a boat, I contrive an aperture, or hole, xy,
Fig. 2, in the bottom of the boat, and into this hole I fit a ball b Fig. 2 & 3 of
wood or other suitable material, either hollow or solid, it is contained by the
socket 88, packing or india-rubber, or other means, being used to keep the water
from entering between the two. Through this ball 6 the mortar is passed, into the
water (mn), it can thus be moved to any point of the compass, its upper part
resting on the racer r, see Fig. 2 & 3. Also a clamp is fixed to the pieco or under
the racer, so as to secure the piece in any position.
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,-
The construction of breechless gun or mortar for use in boats in which the
lower portion thereof is submerged and the column of water entering the same is
employed in place of the breech as set forth.
Dated thin Camonth donos
Anot 1001