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Title (Dublin Core)
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How the failure of dirigibiles during World War I led to the construction of the largest bombing plane
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Article Title and/or Image Caption (Dublin Core)
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Title: Exit the Zeppelin Airship: Entering the Zeppelin Flier
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Subtitle: Out of failure of the dirigibiles grew the largest of airplanes
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extracted text (Extract Text)
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BOMBING planes are primarily
weight-carriers. They must be
able to fly for hours, which means
that they must be able to carry much
fuel; they must be able to do much
damage, which means that they must
be able to transport heavy bombs. It
is fortunate that the weight of the
crew does not increase proportionately
with the size of the machine. The four
men of a Handley-Page, for instance,
could navigate a much larger craft.
It is easier to state the principle than
to carry it out. There is no more
difficult engineering task than the
construction of a huge biplane. The
British deserve the credit of having
developed the first big bombing plane
—the Handley-Page. To be sure, the
Russian Sikorsky —a machine even
larger than the Handley-Page—was
built before the war, but it failed to
meet the test of war because the struc-
tural problem had not been solved.
Curtiss, in the United States, had also
‘made experiments with large machines.
But the fact remains that the British
evolved thefirst practical giant bomber.
Bombing Zeppelins Abandoned
‘When we consider the difficulty of
building a huge bombing biplane, and
the failures that greeted pre-war at-
tempts with the Sikorsky and other
big machines, it is no wonder that,
when Germany determined to intimi-
date England by bombing London
and other British towns from the air,
she rejoiced in her Zeppelins. Their
radius of action was well-nigh bound-
less; they could elude early air defense
artillery with ease.
There was a rude awakening when,
later in the war, one great dirigible
after another became literally a flam-
ing altar on which a score of lives were
sacrificed. German officers at last
saw the truth. The Zeppelin was a
good naval scout, but a vulnerable
bomber. When it became apparent
that the Zeppelin airship must be
abandoned for bombing raids over Eng-
land, the Germans copied the Handley-
Page and produced their first Gotha.
But Gothas did not take the place
of Zeppelins; and the Germans gave
orders for ,the construction of air-
planes of startling dimensions. Aided
by the Albatros works, the Zeppelin
Company produced a giant bird which
marks a distinct advance in the
development of the long-range
bombing airplane. The new
craft's load of bombs is two
tons, as against the Handley-
Page's half a ton. The span Is 4
135 feet, as against the Handley-
Page's 98; the length 94 feet, as
against 65; horsepower 1200, as against
740. The speed remains what it was
in the Zeppelin dirigible—75 miles an
hour—against the Handley-Page’s 85.
It is the general practice in large
bombing planes to balance the eleva-
tor and the ailerons, by which latter
side-to-side balance is preserved. In
other words, there is usually a_bal-
ancing surface in front of the pivot-
shat, the object being to make the
operation of the control surfaces as
easy as possible. In the Zeppelin
bomber there is no such attempt at
balancing. The conclusion is inevita-
ble that there must have been auxiliary
engines (probably electric motors) to
operate ailerons and elevator, although
French engineers who reconstructed a
wrecked machine are silent on that
point.
Inside of the wings is an intricate
filigree-like wooden lattice-work which
is designed to secure great strength
with little weight or air resistance,
and which reminds one of the be-
wildering framing of a Zeppelin dirigi-
ble's envelope. The spars are of hol-
low girders. All the other framing is
of steel tubing. Wherever the tubes
are exposed, so that they must be
driven through the air (struts, etc),
they are encased in thin wooden shells
admirably stream-lined. The tail-
framing, however, is of aluminum, for
the reason that the tail, being farthest
from the center of gravity, must be
extraordinarily responsive.
How the Zeppelin Was Copied
It will be remembered that in the
latest Zeppelin dirigibles the May-
bach engines were enclosed in egg-
shaped cars so as to reduce head-on
resistance. In the biplane we find
similar “eggs” in which the engines
(Maybachs, of course) are housed,
while the crew sits in a separate cen-
tral car. But in the biplane each
“egg” contains two 300-horsepower
engines, one behind the other.
Examine the illustration on the op-
posite page and you will see that there
are both pusher and tractor screws in
tandem. This is indeed a bold de-
parture from long accepted doctrines.
Why did the Germans violate the rule?
Because it was areal advantage to have
four separate engines and four seperate
propellers and only two engine-rooms.
The air resistance of the engines is
obviously reduced by half, and the
weight of the engines can be brought
nearer the center of the machine.
Landing Twelve Tons at High Speed
The greatest problem that confronts
the designer of mammoth bombing
biplanes is the provision of an adequate
landing gear. Here, for instance, is a
machine that weighs twelve tons, and
that lands at a speed scarcely less
than forty miles an hour. Imagine
what that means. The Zeppelin
biplane’s most meritorious feature is its
landing gear. Look at the picture op-
posite. Note how low, sturdy, light,
and devoid of drag is its extraordinarily
simple framing. Note the wheels ar-
ranged in groups of four. This mass of
pneumatic tires efficiently supplement
the shock-absorbers.
Tn a small machine 2 tail-plane such
as that on the Zeppelin flier might
lead to stalling. But a mammoth
‘machine is free from any such danger
because of its momentum and its
multiple engines. Without the pecu-
liar tail the main landing gear would
have to be very much higher, air-
resisting, and ponderous. Because
the landing gear is low it becomes neces-
sary to usefour propellersof small diam-
eter in place of the two large propellers
of the Handley-Page. These make it
possible to lower the landing gear.
Clearly, landing on such a gear offers
anew problem. Unless the pilot comes
down on nearly an even keel, the ma-
chine’s nose strikes the ground at
such an angle that the strain would
be more than the front wheels could
withstand. This difficulty has been
met by the ingenious arrangement of
the tail, in which the French engineers
who reconstructed the machine before
mentioned failed to see anything but
a puzzle.
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Contributor (Dublin Core)
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Carl Dienstbach (Article writer)
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Language (Dublin Core)
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eng
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Date Issued (Dublin Core)
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1919-01
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pages (Bibliographic Ontology)
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74
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Rights (Dublin Core)
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Public domain (Google digitized)
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Archived by (Dublin Core)
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Davide Donà
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Marco Bortolami (editor)
Popular Science Monthly, v. 94, n. 1, 1919
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