Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-02-09
GIANT MASTER RING
RAISING TO Be SOON
Work on Navy DirigibIe ZRS-4
ContinueS-Hangar NearS
Completion.

Raising of the giant master ring Of
the Navy dirigible zRS-4, now under
construction at Akron, Ohio, will take
place soon, according to information
received here by the Navy Department
from Goodyear engineers, who are in
charge of the construction work. The
master ring. which is equivalent to the
keel of a battleship forms the maxi
mum girth of the airship, which Is 10
be nearly twice the size of the Graf
Zeppelin.
Rear Admiral William A. Moffett,
chief of the Navy Bureau of Aeronau-
tics, drove golden rivet in the master
ring at impressive ceremonies last No.
Vember, ofhcially inaugurating the con-
struction of the dirigible. Raising of
the great aluminium ring into position
without straining of the unsupported
material Is expected to be one of the
most striking engineering jobs in con-
nection with the construction.
The master ring and two intermedi-
ate rings are almost completed, the
Navy Department has been informed.
They are laid out on horizontal forms
for building, but are to be raised to
the perpendicular when completed
Within each main ring will be q net
work OF wires resembling piano wire,
which VIII stand a tension of more
than 200 pounds. This wire will form
q bulkhead separating the gas cells and
will also serve as additional bracinS
for the main rings.
There are to be 10 main rings Of TIL
angular croSS-Section and one main
ring following the curved profile Of the
nose. These main rings will be placed
approximately "a feet apart and be-
tween each pair will be three interme-
- I'D
struction. All the rings will be con-
nected by horizontal Orders, covered
and braced by network Of wires which
not only will shape the outer fabric
cover but which also will hold the lift
ing gas cells.
The airship dock in which the zRS-4
Is being constructed now Is nearing
completion. 1t is the largest building
OF its kind In the world and is equipped
with numerous unique mechanical de-
vices, which are being used to facilitate
assembly.
Cranes run lengthwiSe through the
dock at various elevations, and because
OF the curvature of the roof and sides
OF the building many of them had tc
be supported at an angle of As degrees
One side OF these travelling cranes l.
supported from rail near the very tor
OF the structure and the second rail is
on level 20 feet lower.
Sturdy cables from these unusual
lifts are attached to the four corners
OF platforms approximately IS feet
square. Men working upon the sides Of
the ship when the rings are hoiste6
into the perpendicular will be lifted tC
desired heights on these platforms
standing on them as they work.
Near the center of the building Is ar
elevator for taking workmen to the va.
riouS cat-walk levels which traverse the
dock. Unlike any other elevator, how.
ever, this strange lifting device de.
ecribes an arc In its ascent and descent
One elevator is installed on each side
OF the building, directly opposite. They
operate much in the manner Of an in.
cline railway-aS one car goes up the
other goes down, the weight OF each
being used to counterbalance the other
The elevator equipment was especially
designed for use In the dock, and 81
far as Is known there is no duplicate
Of it.
The dock in itself is a marvel Of en-
gineering, being l ,100 feet long, 325 fee
wide and 211 feet high. The IRIS.
and its sister ship, the ZRS-5, which
will be built upon completion of thu
former, will be 765 feet long and Is:
feet In diameter 1t will have capacit,
for 100000 cubic feet of helium, a
compared with the Graf Zeppelin's ca
pacity Of 1900 900 cubic feet.