River Falls journal. [volume] (River Falls, Pierce County, Wis.) 1872-2019, 1914-06-18
MAKING A BIC Gun
One of the Amazing conquests of
Modern Engineering.
WEAPONS WITH SHORT LIVES.

In the manufacture of big guns the
engineer has certainly achieved some
OF his most daring conquests. for it Is
doubtful If there is anything more
wonderfully fashioned or scientifically
constructed than 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 a speed
Of thirty-ive miles a minute. or 2,1O0
miles an hour. These death dealing
missiles may be so designed as to
burst after they have forced their way
through a ships side or Immediately
they strike an object or at some point
during their fight.
The big gun itself consists of sew
eral tubes. or cylinders. slipped over
one another and named after the let
ters OF the alphabet. "A" is inside
and scorcned by the powder gases.
3D. goes over "A" and SO on. the out
side tube 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 a huge solid steel ingOt Is
cast, weighing upward of thirty tons.
The ends having been cut off, the in
got Is mounted in a lathe. and a tube
Iiko t1trona N ming" hOp0P rovnnvoc q long
core from the center. The ingOt is
then dismounted from the lathe and
heated. A long. hollow bar somewhat
smaller than the destined bore of the
gun Is passed through the central hole.
and the ingot Is placed under a $500
ton forging press, which gradually
thins and draws it out along the bar.
which is kept cool by water circulat-
ing through 1t. After being turned
outside and bored inside the tube has
to be tempered. and this is done by
dipping 1t into a tank filed with thou
sands of gallons of cottonseed oil.
As it would be impossible to slip the
"B". and 'C'' tubes over the "A" tube
when cold. this difficulty is got owe by
heating them. The work, however, re-
Quires 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 at the ends first, and the
central part of the tube to cool In a
state of dangerous tension. To avoid
such a thing happening n part is
cooled artificially by means OF water
Jets. while the other portions are heat
ed by gas flames.
We now come to the wiring process.
Layers Of ribbon-like steel wire are
wound outside the innermost cylinder
but one, as metal arranged In this
manner withstands bursting strains
better than anything yet devised. A
twelve inch gun consumes no fewer
than 1910 miles Of wire. one-quarter
inch wide and one-sixteenth Of an inch
thick.
That the she'll may travel business
end" foremost throughout its journey 1t
must be given q twisting motion round
its axis-in other words, be made to
spin. This rotation prevents its turn
ing head over heels, as 1t undoubt-
eddy would do If not spinning, and
makes it travel farther and more ac-
curately. The spinning motion is
brought about by rifing-the cutting
Of spiral grooves In the bore, or In
side Of the gun. This Is done by a
long, hollow steel rod, which carries
three tools at the end and cuts three
grooves at once.
AS the rifing comes so near h
end of the manufacture of a big gun
1t must be conducted with the great
est care. for a single badly cut groove
would spoil the gun. now representing
perhaps $4,000 in work and material.
Indeed. extreme care n accuracy
characterize every process In the q
Ing of heavy ordnance. The steel for
the tubes is made carefully; the ingots
are cast carefully and forged careful
Iy. Every tube Is bored and turned
to the fve-hundredth part OF an fnch.
Though a twelve inch gun Is nearly
twenty inches thick over the powder
chamber, each of it's various jackets
must have its proper tension In order
to receive its fair share Of the shock
Of explosion.
Finally, there is the breechblock-
the door through which the shell is In
serted. 1t moves on a hinge n Is a
very massive affair. weighing about
half a ton. Thanks to the presence OF
certain levers and the perfection OF
the workmanship, any one who a
the knack can move it quite easily. 1t
can be slammed and locked In about
five seconds. The door gives entrance
to the twelve foot chamber where the
shell Is placed.
The active life of a gun is made up
of the total of the very short periods
occupied by the various shells passing
through it's bore. Tie bore of a
twelve inch gun is about forty-fve feet
long. and the average rate at which
the shell travels through it is halfway
ha%Uoon no ponkfnn a. oil oud tho mnZ-