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Old photo taken to
a flexible French airship, where it can be seen the great multitude
observing its elevation . |
The flexible airships
and their gradual development .
In the beginnings of
the XX Century there was another type of aerial vehicle that, although
did not acquire the fame of the airplanes ,it was of great value
for certain purposes; this one was the dirigible. The airship is
the natural descendant of the spherical balloon, that was invented
by two Parisian manufacturers of paper Joseph and Etienne Montgolfier,
in 1783. The inventors filled their globes with hot air, which ,
naturally, cannot be used for trips longer than a few minutes of
duration, because the air cools off. Sometime later, in the same
year, the physicist M. Charles corrected this difficulty using hydrogen
content in an envelope of varnished silk, and the form of the spherical
balloon has not varied materially since then until now. It did not
pass a year since then without several tests of construction of
airships done , one of which, provided with great oars and governed
with a rudder was completed successfully in time of calm. This was
the work of the Robert brothers, who introduced a novelty, a characteristic
that later formed a numerous dirigible class. A spherical balloon
immovable respect to the air that surrounds it does not undergo
pressures in the surface that unbalances it, and, by consequence,
it can be left the interior in communication with the atmosphere. |
Nevertheless, when it is wanted to advance
the air resistance to this movement tends to compress the balloon and
it is necessary to resist this tendency, or constructing a rigid frame
within the balloon, or closing the cover and making that the inner pressure
of the balloon is slightly superior to the atmospheric one . To prevent
any gas escape it is introduced in the cover a small globe (ballonet),
or air chamber, and the pressure of the gas is regulated by the introduction
in the ballonet of a greater amount of air or by the extraction of this
gas. This was the artifice invented by the Robert brothers to maintain
the form of their balloon .
In 1852, Enrique Giffard did a successful experiment with an airship,
using a steam engine of three horsepower. It must be noticed that while
in the United Kingdom almost all the inventors made their works on the
dynamic flight, in France it was laid the foundations of the apparatuses
lighter than the air. The following important advance was made by the
captain Renard, whose airship La France, moved by an electrical motor,
made numerous trips in 1884 and 1885, that demonstrated its good conditions
of maneuverability and reached an average speed of 25 kilometers per hour
in its different flights.
| Towards the end of the
XIX Century, the light gasoline motor became practicable for general
use, and provided the same impulse to the airship that it had done
to the airplane. Santos Dumont , the same Brazilian young man who
made in Europe the first flight by airplane, was also the first one
that was completely successful with a balloon equipped with a gasoline
motor. He constructed a great number of airships, overcoming his difficulties
one after one, and finally he won, in 1901, the Deutch prize flying
from the field of the Aero Club of France, then around the Eiffel
tower, and returning to the starting point . His balloons, although
excellent as sport novelties , did not have sufficient force or cargo
capacity to be of great military value, and the inventor returned
to his airplane, having contributed greatly to the world-wide knowledge
of the airship. Later, increases in the size and improvements of detail
were made , specially by the brothers Lebaudy and the commander Parseval
in Germany; but little radically new has been added to the nonrigid
dirigible of Santos Dumont . |
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Photo of the forced landing of the
Zeppelin Z-4 in France.
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The rigid Zeppelin dirigible and its
military "record" .
Let us see now a radically different type of airship : the rigid airship.
This is almost exclusively a fruit of the German works, and it was generally
known by the public by the name "Zeppelin", that was the name
of its German constructor.
The Count Ferdinand von Zeppelin (1838-1917), who was a military attaché
of Germany in the Potomac army in 1863 (Civil War), where he made his
first balloon ascent , was official in the Franco-Prussian war. After
retiring of the active service, he began to be interested much in dirigibles,
and finished the construction of the first devised by him in 1900. This,
as all in the long series that followed it , was a true rigid balloon.
The outer cover was extended on a complicated aluminum alloy frame. Within
the frame there were numerous balloons (up to 17) that contained hydrogen.
Under the frame there was suspended the nacelle that transported the passengers
and motors. This system had the advantage that because of the reinforcement
of the frame in the most demanding points, the balloon could travel to
practically limitless speeds without fear that it would become deformed,
and the subdivision of the gas containers prevented the total destruction
if there was an accident in any compartment. The Zeppelin I had 32 horsepower
and reached a speed of 38 kilometers per hour. It had passed five years
before Zeppelin II was arranged to its tests. This model finished later
with a fast disaster, because it was practically destroyed by a hurricane.
Soon it became evident that an airship of such great dimensions (the Zeppelin
II had 126 meters in length) required mooring facilities like those needed
for a transatlantic
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Image of the armed German Zeppelin . In the image can be seen the nacelles, one of the
two propulsion "protrusions", carrying its motor, machine
gun and dynamo and the machine gun located in the stern. |
The inventor later made diverse improvements
in his apparatus, and in 1908 a military zeppelin made a trip of
432 kilometers at an average speed of 35 kilometers per hour. In
1910 a regular service of passengers between several German cities
was implanted, that worked until exploding the World War I , being
used it the zeppelins. The German government, anticipating the great
military value of the invention supported the Count Zeppelin , who
could follow his experiments, constructing, undoing, and returning
to construct balloon after balloon without the economic difficulties
that he had experienced in the beginnings.
The German authorities trustily waited for great feats of the rigid
airships applied to the war; but these apparatuses had not given
all the awaited results . The zeppelins were able to transport heavy
weights, and had the advantage of being able to locate themselves
on any place; but being so great, they presented an excellent target
to the artillery and had to remain at a considerable height by this
cause. The war incursions on England were not used for any important
military objective, and resulted solely in destruction of private
property and the death of noncombatant.
The development
in Italy of kite balloons and semi-rigid airships
During the World War
I, the tremendous activity in the aeronautics extended to other
countries , and the lighter than the air apparatuses gave origin
to certain number of important inventions. Italy invented a kite
balloon of almost spherical form that completely remained quiet
with moderate winds. These balloons were used primarily for the
observation, mainly for the fire control of artillery. They were
tied to the ground by means of a cable and remained in the air as
a kite.
The Italian engineers specialized during many years in the semi
dirigibles , and is considered that in this specialty they had advanced
more than any other country. It has been seen that these apparatuses
adapted perfectly to the necessities of the Italians during the
war, because they could move to high altitude, although they never
were considered as a particularly fast type of aerial ship. The
unfortunate Rome, bought by the United States in 1921, was the greatest
airship of this type constructed in the world. It had 125 meters
in length, with a capacity of 33,722 cubic meters of hydrogen, and
completely loaded it weighed 38 tons, including ballast, fuel and
provisions. |
The terrible disasters
of the "Rome" and the "ZR-2" and their causes.
The destruction of airship Rome, at the
beginning of 1922, with the death of ten people, happened during its first
trial flight , after the installation of the new Liberty motors that had
replaced the primitively used Italian ones and that had not been satisfactory
for the flight in the United States; and it was due to the inflammation
of hydrogen, when hitting the ship a high tension cable when it was going
to land because of a failure. In its first flights in the United States
the helium was used to fill the "Rome"; but due to the shortage
and difficulty to obtain the gas in sufficient amount to provide the gigantic
airship, it had been replaced by hydrogen. The ZR-2, that was destroyed
in one of the greater disasters ever known in the history of the aeronautics
of beginnings of XX Century, when it made his final trip of test, before
being accepted by the government of the United States, when falling over
Hull, England, in 1920, differed from the "Rome" in that it
had a rigid frame that extended throughout the inferior surface of the
cover , what provided many of the advantages of a rigid airship with smaller
weight. The ZR-2 had 213 meters in length and a capacity of 77,825 cubic
meters of gas.
The catastrophe of the
" Shenandoah " .
The catastrophe in which the Shenandoah
was destroyed the September 3 , 1925, reached even more terrible proportions
. By order of the U.S. Government it was ordered to the airship to make
a trip to visit the fairs of some western States. Near Ava, Ohio, it was
surrounded in a stormy burst, against which it fought laboriously during
several hours, until it was divided in two pieces. The stern of the apparatus
crashed against the ground, perishing the captain and 13 crew members.
The prow, where lieutenant Rosendahl was , floated for a moment and could
land without a loss of lives. Rosendahl later made a dramatic story of
all the process of the catastrophe, that gave place to colonel Guillermo
Mitchell blaming the military department and the Navy of the United States
of "incompetence , criminal negligence and almost treasonous administration".
The Shenandoah had 207.25 meters in length and weighed 37 tons. Its frame
was of made duralumin , it was fed on helium and it was powered by six
machines able to maintain the march of the apparatus during two days and
two nights up to 90 kilometers per hour. It had cost 2,950,000 dollars
and had already made 50,000 kilometers of airship navigation.
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The airship "Shenandoah",
in the heat of flight, before the catastrophe. |
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