St. Paul daily globe. [volume] (Saint Paul, Minn.) 1884-1896, 1890-12-26
CHIEF OF Dynamite GUNS.
A Terrible Instrument Now Nearly
Finished.

AhoCA AiilCit ~
Finished.
What Is said to be the largest dyna-
mite gun which has yet been made is
now nearly completed at Birmingham.
The following account Of it is printed
in the Birmingham Post:
1.-The explosive contents are made up.
for greater safety, in tiny waXen pellets
and lodged in q shell, the true flight of
which is secured by a tapering tele-
scopic tail; and the gun is to be dis
charged by the expansion of condensed
air at the pressure of 5000 pounds per
square inch, the impulse of which is a
safer pr0pelling energy than the igni-
ton of any kind of powder, because it
does not operate so suddenly as to cause
a danger OF the premature explosion of
the missile. The telescope tail enables
Lieut.. Graydon to shorten his shell by
one-half, and to reduce prOportionately
the length OF the impulse tube or gun
proper; while tie use of a pneumatic
charge makes it possible, without dam
ger, TO construct the she'll more filmSily
than otherwise would be the case.
The contract with MeSsrS. Taunton
u Go. is for a t~ifteen-inch torpedo pro-
Jector which will throw a charge of 600
pounds Of dynamite a distance of three
miles; but it is expected this contract
Va w VI OtNtCto 1Ol SIIIt
larger weapons. As sOOn as the gun now
III hand is delivered there will be a trial
of its powers at Portsmouth against the
ZallnSki gun, not with dummy shells, as
in the case of the American expert
mentS, but with actual charges of dyna-
mite. The noise of the discharge being
small, the prOjectlle might be dropped
into a fort or OH a ship without giving
the besieged any intimation of the
quarter from which the attack came.
| The conclusion when the dynamite eX-
ploded would in all probability be VIC
lent enough to put a large garrison hors
du combat, even if they were not
wounded by the debris; and, truly
aimed, a single shell would destroy an
ironclad.
1.-THE barrel or pneumatic tube of the
gun is of Whitworth forged steel, and
weighs about eleven tons. 1t is sup
ported at the breech end on fixed trun-
mons fifteen inches in diameter, which
are followed for the passage of the COM
pressed air. Toward the muZZle it is
carried on movable %trunnions engaged
with two forged steel arms or levers.
These levers have sliding fulcrums. and
are actuated by a hydraulic plunger for
the purpose of %elevating or depressing
the gun. The breech is closed by means
of a steel screw block with Interrupted
threads, as in heavy service ordnance.
"a peculiar feature of this particular
GraydOn gun is that it can be loaded at
any degree of elevation within it's work.
ing range, Pivoted to the breech trun-
mons there is a loading slide or tray for
the reception of the projectile or tor
pedo, the weight of which is about one
ton. This slide, at all times when the
barrel is elevated above the horizontal
line, rises by hydraulic pressure to re-
ceive the %prOjectile from a tram-trolley.
By opening a valve the slide is then
made to descend with it's load, and be-
comes lineable with the barrel of the
gun.
ION each side of the barrel is fixed a
small double-acting hydraulic cylinder,
the plungerS OF which not only control
the movement of the loading-slide. but
also, by their continued action, draw
the projectile up into the barrel, where
it is held. The breech- closing block,
suspended above the trunnions by
CONFERENCE.-The, then deScendS. and is
also drawn into the breech by the cross
head of the hydraulic plungers and
locked. The u is now ready for dis
charge. The cOmpresSed-air reservoirs,
q complement of which numbers thirty
two, are four feet long, and ten inches
in diameter, are made of metal three
quarters of an inch thick, and are the
invention of Mr.. Lane. They are tested
to a pressure of four tons to the square
inch. They are carried with the gun in
fOur sections OF eight each. two OH each
side of the u carriage. Filled with
air compressed to 5000 pounds per
square inch, or about n three-hun-
bred and fOrtieth OF its original volume,
the capacity of each at the working
pressure is 1900 cubic feet of air,
,,0;rIf,rr 1 1nn ,r-15.h%, -, =
condition.
ANY number out of the four sections
may be discharged, according to the
range desired or the weight Of the pro-
%jectile. The ~diScharging valves are a
peculiar arrangement of the piston
type, and are packed on the hydraulic
system. All valves and pipes, where
not forged, are Of Whitworth cas- steel.
The carriage On which the barrel is
mounted is constructed of heavy steel
steel plates, with massive trunnion
numerous turned bolts. The carriage is
supported on the roller path with con-
ical rollers, geared together and ac-
tuated by a Heenan and Proud spher-
ical engine, the motive power of which
is also compressed air. The roller path.
which will ultimately be imbedded in
| concrete, is made in sections of cast
iron. 1t is twenty-one feet in diameter,
and is planned on its surface. The air
from the compressorS is passed to the
reservoirs on the gun carriage through
a central pivot or swivel tube. The gun
can be loaded, elevated, trained and dis
charged by II person.
with the u there is. of course, a
special air compressor. This is a modi-
fication Of the high-pressure machines
designed by III. Lane (now largely in
use IN this country and adopted by sew
eral foreign governmentS) for oxygen,
hydrogen and carbonic acid. The air is
compressed in four operations, the pis-
tons decreasing in diameter at each
stage. The first. which draws the air
from the atmosphere, is twelve inches
in diameter, and the last, which delivers
it to the reservoirs; is two and a half
inches. After each operation the air is
cooled by a tubular coil surrounded
with water.
1.-The designing and construction of
the pneumatic gun has been carried out
by MIR. Lane, engineer to the company,
under the supervision of the in
ventor, Lieut.. j. w. Graydon, OF
the United States navy, who has been
residing in Birmingham with that ob-
ject. 1t is IN some measure due to him
that the apparatus for throwing highly
explosive shells considerable distances
with accuracy Is at present engaging the
serious attention of all the covers. A
pneumatic gain is now being erected at
Shoeburyness for trial by the British
government, and the Quilted States
government has not only spent already
a great deal of money on this class of
weapon, but has set aside funds for the
purchase of $50 of them. Five Euro
pean governments have sent represent
atives to Birmingham to see and report.
upon the Graydon protector during its
construction. and the Chinese, japan
csc, and South American governments