The river press. [volume] (Fort Benton, Mont.) 1880-current, 1914-09-30
MAKING A BIG Gun
One of the Amazing Conquests of
Modern Engineering.
WEAPONS WITH SHORT LIVES.
rhc Monster Twelve Inch Rifles Are
Useless After Firing a Hundred
Rounds, and That In Actual Time Of
She'll Passage Means Three Seconds.

Shell Passage Means Three Seconds.
In the manufacture Of big guns the
engineer has certainly achieved some
of his most daring c%onquests. for it Is
doubtful if there is anything more
wonderfully fashioned or scientifically
constructed thar the monster weapons
found ON the latest battleships and in
large forts.
From their muZZles they are capable
OF launching into space shells weigh
ing as much as half a ton at Il speed
IT %thirty-tve miles Il minute. or 2,1OO
nileS an hour. These death dealing
missiles may be so designed as to
burst after they have forced their way
through IL ships side or Immediately
they strike an object or at some point
during their flight.
The big gun itself consists of sew
pi:li tubes. or cylinders, slipped V
one another and named after the let
trrS of the alphabet. "A" is inside
and Scorchel by the powder gases.
- goes over "A" and so on. the out
side ube of all being known as the
Jacket.
Each separate tube. or cylinder. is
fashioned in much the same way. In
the case Of the "A" tube for a twelve
inch gun n huge solid steel ingOt is
east. weighing upward O. thirty tons.
The ends having been cut off. the in
got Is mounted in a lathe. and Il tube
like "~trepannjny" borrr removes a long
core from the center. The incot Is
then diSmounted from the lathe and
heated. 4 long. hollow bar somewhat
smaller than the destined bore Of the
gun is passed through the central hole.
and the in.ot is placed under Il $500
ton forging press. which gradually
Trims and draws it out along the bar.
which is kept cool by water circulat-
in= through it. After being turned
outside and bored inside the tube has
10 he tempered. and this is done by
dipping 1t into a tank filed with thou
sands Of gallons of c%ottonseed oil.
As it would be impossible to slip the
II" and &c" tubes over the "a" tube
when cold. this difficulty is got over by
hpnting them. The work. however. re-
uuires great care and constant atten-
ton. The heated cylinder. Of course.
decreases in length as well as in diam.
eter as it cOols. and. unless great pre-
cautions are taken. it would naturally
cool ut the ends first. and u the
central part Of the tube to cool In Il
state Of dangerous tension. To avoid
such Il thing happening one part Is
FOOLED artificially by means Of water
jets. while the other portions are heat
ell by gas flames.
We now come to the wiring process.
Layers of ribbon-like steel wire are
wound outside the innermost cylinder
l,ut one. as metal arranged in this
| manner withstandS bursting strains
better than anything yet devised. a
twelve inch gun consumes no fewer
;,nn 100 miles Of wire. one-uuartcr
| inch wide and on%e-siNteenth Of an inch
thick.
That the she'll may travel "bu>iness
nd" foremost throughout its journey 1t
mrSt be given a twisting motion round
IT'S axiS-in other words. be made tn
spin. This rotation prevents its turn
'ny head owe heels. rs it undoubt.
ul!y would do il not spinning. and
makes it travel farther and more ac-
rnrately. The spinning motion is
nruught about by r~itling-the cutting
of spiral grooves in the bore. or in
side uf the gun. This is done by Il
nny. hollow steel rod. which carries
three tools ut the end and cuts three
grooves ut once
As the ritliny comes so near the
end of the manufacture of IL big CUR
it must be conducted with the great
est care. for II single badly cut groove
would spoil the gun now representing
perhaps $4,000 in work and material
Indeed. extreme care and accurac!
characterize every process in the max
ing Of heavy ordnance. The steel fol
the tubes is made carefully: the inSots
are cast carefully and forged careful
~. Every tube is bored and turne(
to the tive-hundredth part OF an inch
Though a twelve inch gun Is nrarl!
twenty inches thick over the powder
chamDer. each of its various jacket:
must have its proper tension In ordel
to receive it's fair share Of the shOcl
nf explosion.
!, Finally, there Is the breechblock-
, the door through which the shell is in
serted. 1t moves on Il hinge and is
very massive affair. weighing abOu
half Il ton. Thanks to the presence o
certain levers and the perfection o
| the. workmanship. any II who ha'
! the knack can move it quite easily. |
! IAN be slammed and locked in ahou
1--WE seconds. The door gives entranc,
l to the twelve foot chamber where TIN
shell is placed.
The active life Of Il gun is made III
Of the total of the very short period
occupied by the various shells paS>in'
: through its bore. The bore Of
twelve inch gun is about forty.tive fee
, long. and the average rate ut which
the shell travels through it is halfwa.