New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1891-08-15
TERRIFIC WAR WEAPONS.
SHELLS THROWN MILES INTO THE AIR.
WHAT THE TwELvEIxcH MoRrARs WHICH WILL
DEFEND NEw-YoRK HARBoR CAN DO.


DEFEND NETWORK HARBoR CAN DO.
Four Of the twelve-inch rifed mortars intended to
form part of the for the defences of New
York City have been received at the Sandy Hook
Proving Ground. These mOrtars consist essentially Of
cast iron body. forced the rear portion by
two OF steel hoops. The weight of one Of these
breech-loadng mortars is fourteen and half tons.
and It's total length is ten and three-quarter feet.
The maximum charge Of powder IS eighty pounds.
and the weight Of the shell Is $50 pounds The shell
will contain a Bursting charge Of forty pounds of
powder or some other explosive.
With the maximum charge. and angle Of elevar
ton of forty-fve degrees given TO the mortar,
range Of six miles is attained The great accuracy
OF the fire IS shown by the following figures taken
from the report Of the trials Of of the mortars.
At a range of five and half miles. ten shots all fell
within space 1876 l-3 yards long and eight aud
half yards wide or about the same space as that
occupied by one of the large transatlantic steamers.
Fired at an angle OF elevation of so degrees, and
with a reduced charge Of powder, ten consecutive
shots at Iange of two and a half miles, all fell
within rectangle sxtysix yards long and nineteen
yards wide
As these mortars are to be placed In batteries Of
sixteen consisting Of four groups with four mortars
in each group the eject of vOlY Of sixteen shells,
Weighing ten thousand pounds In the aggregate
and filed with explosive charges may be partially
IMAGINED should the fire be directed on the channel
The maximum range (stN miles, of the mortar Is
obtained when il is placed with angle OF elevation
Of forty five degrees The shell rises mile and
half to attain this range The mortar was also hred
at an angle Of elevation of sixty degrees and charged
with tmrty-three pounds OF powder. In this case
range Of 1905 yards reached, and the shell rose
one mile I'm the air before descending. one mile and
mile and a half may appear fairly high. But mnch
greater heights have been attained by these great
masses OF metal shell fired with the mortar at
an angle Of elevation OF seventy degrees, with
charge Of sxty-fve pounds behind It, travelled 4153
yards and actually climbed three miles in the air be-
fore began its gracefully curving descent toward the
EARTH To accomplish the entire journey. the scream
ing shell required only minute and two and onehaf
seconds Imagination can only family grasp the
probable result of one OF these ponderous bodies loaded
with destruction, dropping from above on any part
Of a manof war.
But the protective deck plates have in Of the
later warshlps been increased 10 thickness Of four
to four and onehaf inches TO resist this form Of at
tack and there may be doubt to whether
these casiron, steelhOoped mortars formidable they
are have any surplus Of power in attacking these
heavy armOred deck plates. To overcome this in
creased resistance Of deck in recent warshps the
aIsteel breechoading tweveinch mortar has been
built. This type Of mortar is now at the United
States Army Ordnance Proving Ground. awaiting test
With the castirOn seelhOOped mOrars the castron Is
the limiting factOr In the strength and the pressure
of the powder gases in the chamber is kept down to
a maximum Of % 900 pounds per square Inch Eighty
pounds Of prismatic powder and 6OO-pound shell
are employed
These composite mOrtars are highly trustworthy as
IS shown by the fact that Of them has been used
for firing about $50 rounds castron mortar with
out the steel hopping burst into many fragments at
the twentieth round, under pressure Of 1900
mounds per square inch. The value of steel hopping
in rendering such structure trustworthy was clearly
demonstrated But safe though it may be- within the
required limits Of pressure the power Of such mortar
is much less than that OF the steel mortar, when
weighs a ton less and is foot longer The powder
charge has been increased from eighty to 100 pounds,
and the shell of the asteel mortar weighs 800 pounds
II is possible that a 900 pound shell may be used
The aIlstee mortar Is composed Of an Inner tube,
jacket the breech end Of the tube, with single
row Il twelve hoops surrounding the jacket.
All the parts are forged Of steel The breech
mechanism Of the twelye-inch breech loading
steel mortar is similar to that Of the
other modern steel guns. 1t Is expected that the nl-
tal velocity Of the proecie Will be 115O feet per
second and the muzze energy 1884 fOottonS. against
5795 fooons in the castrOn, steel hooped mOrtas.
The I2inch rhed mOrtars In service will be employed
with several types of carriages. one type ALREADY
tested and OF which about a dozen carriages are now
being manufactured Is KNOWN as The hasAdkOH hi0''
Its main feature is that it permits recoil Of the
] ~.
rear al an angle Of sixty degrees, the ecOil being
checked pnrtly By two courses Of Beeville springs
pIaced arallel TO the slides. but mainly by TWO ny
drauc cylinders. The mortar descends about thirty
inches and after the reco the reaction OF the springs
raises the mortar the firing position. Stee plates OF
3 II ana inches thickness, strongly backed with
oak and representing a section Of ship decking, nave
been set up at the proving ground about fifty Yards
from twelveinch mortar These will be fired at WIN
reduced charges 10 assmllate the striking velocity AT
hattie ranges From the results Of these experiment.
Il will be determined what character Of mortar smell
will be suitable. ...,
II Is expected that thirty OF these modern mortaTs
will be completed before August OF next year.