Evening star., 1925-10-02
LANSD0WNE ASKED
FOR VALVE CHANGE
Warning Was Given Twice by
Aeronautic'S Bureau to
Show Care.
BY the Associated Press.

BY the Associated Press.
LAKEHJRST. n. j.. October 2.-In
approving the gas-valve system change
in the airship Shenandoah the Bureau
Of Aeronautics at Washington warned
those on the ship that the new system
was not as "foolproof' as the original
installation, and that extreme care
should be taken in the operation of
the ship.
This was disclosed today before the
naval court of inquiry here by the
reading into the record of the official
correspondence that passed on the
subject between Comdr. Zachary Lans-
downe, captain of the ship, and the
Bureau of Aeronautics.
Warned of Valves.
Changes in the valve system first
were suggested by Lansdowne as early
as September 16, 1924, but finally Were
not approved by the bureau until May
2S. 1925, and then only with a warning
from Capt. +. S. Land. Construction
Corps, attached to the bureau. This
warning was. renewed on June Is.
1925. in letter signed by Comdr. Fl.
c. Richardson, Construction Corps. by
direction of the chief of the bureau.
This correspondence . shows that
Comdr. Lansdowne not only recon-
mended the change. but that when
there was delay in acting on his recon-
mendation he sent a telegram request
ing telegraphic authorization for
was given by way of experiment.
and it was added that the necessary
precautions should be taken in operat.
ing the ship. p.
On June 13, 1928, Comdr. Richardson
wrote that in view Of the change there
should be use Of the maneuvering
valves to discharge gas whenever that
should become necessary in flight.
Capt. Lands Letter.
Capt Lands letter of May 2s said:
The modified arrangement of
valves proposed for the Shenandoah Is
not as foolproof as the original In
stallation. The proposed arrange
ment imposes an added reason for
cautious operation of the ship near
pressure height. If for any reason
the ship gets out of control and driven
above pressure height consequences
will be serious. However. on the as
sumption that the operating person
mel realizes and accepts the operating
practice which is involved and will
tdhe Ine NECESSARY pIcCdullOlS, lHc
arrangement of gas valves and
trunks as proposed is is~approVed by
way of experiment.
A report after three months ex-
perience with the modified installa
ton was called for.
In his letter of June 8. 1925, Comdr.
Richardson said that calculations In
dicated that the change in the valve
system would cut in half the safe
-l,tr L.
words from 500 to 400 feet minute.
Rate of Ascent Cut.
He added: The bureau notes the
argument that a very small gas valve
capacity was found to be sufficient
on the West coast fight. In this con-
nection the bureau invited attention
to the fact that in that fight no very
rapid ascents above pressure heights
occurred. -. .s
1T is considered that the.naximum
gas capacity Is likely to be required
only in the event of the airsfiip being
suddenly carried upward in vertical
current during a squall. 1t is under
stood that the Shenandoah has never
been subjected to this condition, al
though it quite conceivably may occur,
and the total gas valve capacity must
be sufficient to provide for It.
1T is known the Zeppelins have
occasionally burst gas cells, due to
insufficient valve capacity, when
rising rapidly in thunderstorms. Yep
pelin practice is to provide for rate
Of ascent of at least 3 meters per
second or about 600 feet per minute
- meters per second was preferred.
With the limited automatic gas
valve capacity which will remain
after completion of the changes now
in progress, the rate of ascent in ex-
treme conditions must be carefully
watched and the gas cells relieved of
excessive pressure by opening the
maneuvering valves IL necessary"
Other Type Abandoned.
At the outset there was some dis.
cussion between Comdr. Lansdowne
and the bureau with reference to the
use of a combination automatic and
maneuvering valve to replace the orig
inal system, but after some expert
mentation this type was abandoned.
On December Is, 1924, Comdr. La ms
downe renewed his recommendation
for a change in the valve system. say
ing the German design was based
upon two considerations which do not
obtain at present: operation with
hydrogen gas and operation in time
of war"
With the use of heium, he said. the
use of the internal casing manifold
for equaliZing purposes during flight
provides a means Of keeping all of the
bags at the same pressure. The ideal
scheme, therefore. would be to make
the casing manifold larger and con-
slider 1t as a permanent part of the
gas cell installation. providing an au-
tomato valve on each end Of the mani
fold. These valves would give ample
protection to the gas bags under pres
ent operating conditions. Should con-
ditions so change as to necessitate
faster valving the maneuvering valves
could always be used in an
emergency"
Lands Proposal.
On December 81 Capt. Land pro-
posed for the Bureau of Aerona utics
that the present gas valve system in
the Shenandoah he replaced by
complete installation of combined
automatic and maneuvering valves
along the top of the ship, and at the
same time an enlarged casing mani
fold along the keel be installed and
provided with valve at each end.
I.ansdowne's comments on this were
requested. and on January 9. 1925,
he suggested a slightly modified sys-
tenn.
Again on May ~, 1925, after the
West Coast fight, Lansdowne recon-
mended a new system-that subse-
quently installed. He said this would
effect a saving in weight without
jeopardizing the safety Of the ship
IN any way.
The proposed scheme" he wrote
Sin addition to increasing cruising
radius, will cut down the rate of d!ffu-
sion and the loss of helium through
1eaEv va Ives -