The morning news. [volume] (Savannah, Ga.) 1887-1900, 1891-12-04
BIGGEST LATHE IN THE woELp.
It VIII Be 1 81 Feet Long and VIII Be
Used IN Turning Big Guns.


From the Philadelphia Record
The largest, heaviest and most powerful
gun lathe in the world is now being built
for the naval gun shops at Washington by
William Sellers & Co Of this city. The
contract for this stupendous instrument was
awarded Dec. S, 1880. and the company has
been working steadily upon it ever since,
VITO the prospect Of completing IL by JAM
uary.
This lathe, which will be constructed Of
bronze, steel and cast-iron, will weigh 5OO,-
QUO pounds and will be 1873 feet in length.
It's greatest hight will be II feet. its great
est width 10 feet 6 inches and its boring
capacity 10 inches. The largest guns that
the naval shops can now construct are u
IU-lncn bore, and these are also the largest
employed 10 the service. When the nevg
lathe is completed, however, the navy will
be equipped with 16-inch-bore shooting
irons, more than One-third as big again as
the guns now in use.
As soon as the lathe, which will cost S76,-
UOO, Is completed the company will begin
operations upon seven others. These will be
only slightly smaller than the former, and
Will be Of l4-inch bore. They will be built
at cost. in round numbers, of $3.50, 900.
and will be employed for boring and turn
ing the gun tubes and jackets.
One Of the greatest features Of the 16-iuch
lathe VIII be Its face plate. This portion of
the lathe Is now almost completed; IL is con-
struoted throughout Of cast-steel and weighs
10000 ponds 1t is provided with four
adjustable steel jaws and gear wheel,
which has seventy-fve teeth Of 3-inch piGch
and lO19-inch face. Skilled workmen have
been employed day and night for
three weeks In cutting these teeth,
aud the operation is not yet finished. Four
teen speeds, ranging by exact geometrical
progression from O. 4 revelation to T. revo-
lutions per minute, will be obtained with a
cutting pressure on 50-inch diameter of
l4O 900 pounds on the slowest speed. This
plate is said to be one of the most perfect
and costly steel structures that has ever
been built by machinists.
The bed of the lathe is now lying in the
company's shops, and 1t, too, is almost fin
ished. This is built Of cast-iron, and is 10
feet l01 inches long, with a width Of 8 feet.
The wide part, or main bed, has four WAYS.
two Of which carry the tool carriage on one
side, while the other two serve to hold the
steady rests and tail stock on the other.
The middle ways are formed in one section
of metal
Inc boring arrangement Is provided with
a 6'inch steel screw, which is sixty~two
feet in length. This screw receives both
slow and quick motion from a short-gear
shaft, connecting it with the proper train
OF gears on the side of the boring bench.
All the parts Of the lathe, which include
head stock, tool carriages, rests, tail stock,
boring arrangement and counters, are
built on the same enormous scale, and are
perfect examples of the machinist's art.
The l4inch lathes will be constructed
upon the same model as the 16-inch instru-
ment, but will be slightly smaller through
out. Each bed will be sixty-five feet In
length, and the other parts will be built
upon a similar scale They will be pushed
to completion as soon as possible, bat the
exact time this will require is uncertain.