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Italian Dirigibile

Unlike most of the other countries who were flying airships, the Italians preferred to make use of semi-rigid designs. During World War I, they had operated seven larger ships, and 12 smaller designs. After the war the surviving airships were redesigned for passenger service. Experiments using mooring masts were carried out, and several small and medium-sized models were built for foreign customers, including Japan.

Dirigibles are divided into three general classes-rigid, semirigid, and nonrigid. Count von Zeppelin, despite anything which may be said to the contrary, may be regarded as the inventor, pioneer, and only successful exponent of the rigid type of airship. Imitators have striven to eclipse his achievements, but have only met with exasperating failure and disappointment. The nonrigid dirigible is represented by several well-known types, such as the Parseval, Clement-Bayard, Astra-Torres, Zodiac, and Lebaudy. This type is a large gas bag, from which is suspended the car or gondola containing the motors, fuel tanks, instruments, guns, etc. The suspension of the gondola is by means of ropes or pliable bands. The whole structure, except the gondolas themselves, was nonrigid.

The semirigid type is one in which there is one large gas bag connected to a keel-like structure, which is rigid. The Forlanini type, manufactured in Italy, is an example of this kind of dirigible. The semi-rigid is a compromise, sharing some advantages and some disadvantages of both battleship and scout. It has a rigid keel, within which the car is built. It has less head-resistance and dead-weight to carry than the rigid; but is less safe than the other types, and, with its cumbrous keel, is harder to transport than the easily deflated non-rigid.

Besides turning out a large number of skillful and daring pilots, Italy produced some remarkable innovations both in dirigibles, airplanes, machinery and appliances Senator Enrico Forlanini (1848-1930) held as high a reputation in airship construction as Count Zeppelin. The Italian inventor began his airship experimenting and dreaming many years before his German competitor. Forlanini's first airship the Leonardo da Vinci, was begun in 1901 and completed in 1910.

He constructed a second and improved dirigible by 1912, called Citia de Milano. The circumstances attending the loss of the Forlanini airship Citta da Milano showed what great risks were run by any gas-supported aerostat in close proximity to even the glowing ends of cigars or cigarettes. The career of this vessel had, up to the time of the mishap which destroyed it, been singularly free from accident, and this fact and the equally successful career of its predecessor, the Leonardo da Vinci, tend to show that under normal circumstances the Forlanini is an excellent and safe type, and well worth further experiment, inasmuch as the design of the airship had nothing whatever to do with the disaster, whereas in the case of the last Zeppelin destroyed by fire in peace time, the accident was, as far as we know, entirely due to the design, which permitted an accumulation of gas from leakage in close proximity to the engines.

The loss of the Citta da Milano on 09 April 1914 was due simply and solely to the crass stupidity of the peasants and others who assembled to watch the proceedings when, in order to repair a leaky valve, it was brought to the ground in the course of a cruise, in charge of a perfectly competent crew, the well-known Major Del Fabbro, of the Italian Airservice, being also on board. The vessel was moored to the ground and to some trees with both hemp and steel ropes, the crew being assisted by men belonging to a farm near which the descent had been made, and expert assistance was sent for. Before the necessary repairs could be made to the valve, the ropes gave way and the airship was driven for about 170 yards against some mulberry trees. She was again moored, and the commanding officer decided to deflate the bag. A crowd of peasants gathered to watch the operations. The soldiers could not drive them back. Indeed, they could not be even made to give up smoking. As the deflated bag fell over towards the crowd on the left side, several explosions followed hard on one another. A great blast of blue flame shot out from the airship, and passing away left behind nothing but a twisted mass of framework and a struggling body of human beings. About eighty people were more or less seriously injured.

The reliability of his construction became recognized by the Italian government, which ordered one for the navy, the F-3. From that time he turned out an airship almost every year, each one an improvement on its predecessors. These dirigibles were of the semi-rigid type, and differed considerably from the Zeppelin rigid form; they are lighter and can rise to great heights less time. Another important point of differene was that Forlanini built his cars close to and into tbe rigid keel instead of suspending them underneath. Like Zeppelin, he also experienced disasters and aerial shipwrecks.

The Italians, even before the European War, exhibited originality by enclosing the stiffening member or frame in the gas bag itself. This frame is not rigid, but composed of articulated panels, thus accommodating itself to the variations of form of the envelope. The car of the P class (containing dirigibles of smallest volume) is of steel and water-tight, so that in case of need it may float on the surface of the water. In the M class (M = mean, between the smallest class, P, and the largest, G) the car is of steel and completely closed, and thus shelters the crew from wind and weather and at high altitudes. These are real military qualities, for they permit the balloon to go out under unfavorable climatic and weather conditions. In the G class the car forms an integral part of the balloon body.

The dirigible was already under heavy fire in the Turko-Italian [1911-12] and the Balkan wars [1912-13]. In the first, Italian airships, at a position 6000 feet above Turkish artillery, were almost omniscient so far as the enemy on the ground was concerned, and quite safe as well. The field-guns, though their tails were planted in the sides of sandhills to give a nearly vertical aim, were wholly inefficient in shooting up-as indeed all artillery rapidly tends to become when fired upward. Realization of Germany's true vision of air-empire came to the nations of Europe with the Turko-Italian war. It was appallingly clear from the damage done by small Italian airships what havoc the big Zeppelins might work. There could be no clinging to faith in the dreadnought or the aeroplane as a match for the dirigible.

At the beginning of the Great War, Italy had six non-rigid dirigibles and two Forlanini semi-dirigibles. By late 1917 the latest type of dirigible invented by the Italian Forlanini - the F3 - was said to possess so many distinctly new features that it placed the Forlanini design in a class of its own, and materially broadened the field of the dirigible balloon. This design can rise to great heights in perfect safety. During trials it ascended to an altitude of 17,500 feet, which is a world's record for dirigible airships. It made a journey of 8 hours' duration at an elevation of 13,000 feet. The Zeppelin type can attain only 12,000 feet after every possible object that can be dispensed with is thrown overboard. Furthermore the Forlanini airship has an excellent chance of escaping hostile airplanes because it can climb 3300 feet every four minutes. The best of airplane climbers can rise 1000 feet per minute up to 10,000 feet when the rate drops rapidly.

For bombing operations the Forlanini design was said to approach the ideal. It can remain 40 hours in the air, covering a distance of 2000 miles. With a useful load of 6000 pounds it can rise to 13,000 feet; with less load it can rise to 20,000 feet. Because of its ability to rise quickly to great heights it should prove immune from anti-aircraft defenses.

The Forlanini airship had a double envelope: an inner or gas envelope and an outer one completely surrounding the former. A continuous and entirely free air space is left between the two envelopes. The gas envelope is fitted with transverse and longitudinal diaphragms. A rigid truss girder runs from the bow to the stern, thus stiffening the entire structure. The girder is axially suspended from the gas envelope. The car or nacelle is arranged close to the envelope and is rigidly suspended from the truss. For steering purposes flexible surfaces of grate-like construction are used. The propelling apparatus is split up into independent sets. The screw propellers are arranged for adjustable and reversible pitch, which enables the airship to reverse on its course. An upper platform is provided on top of the gas bag, and is connected to the car by means of a ladder passing thru the well. These improvements serve to lower the resistance to flight, to maintain stability during the descent from high altitudes, and to maintain the regular external form of the dirigible.

Italy received her share of the Zeppelins and on June 3, 1920, the Zeppelin-built LZ-120 "Bodensee" (Lake Constance) was turned over to the Italians as war reparations from the German government. This airship was the first "streamlined" zeppelin. It was built for the specific purpose of small-scale passenger operations, and it was hoped that operations would provide needed publicity for future undertakings. Construction was begun in January 1919, and the first flight was on August 20, 1919. On 19 November 1920 the "L-120" left her station at Scerappen, Koenigsberg, for Stolpe in Pomerania, where she was turned over to representatives of Italy. The hangar at Seerappen also was assigned to Italy; to be taken down, transported to Milan, and reelected there to house the "L-120." A duration record of 105 hours was claimed for this airship. Renamed "Esperia", this airship was based at Ciampino (an airfield near Rome), and was used by the military, although it was ocassionaly flown as a passenger ship until it was broken up for scrap in July, 1928.

Italy also secured from Germany the "L-61" and it was reported that previous o making the voyage to Italy, the "L-61" carried 85 passengers during a trial trip lasting 10 hours at a height of 2500 meters. The journey from Friedrichshafen to Rome took 12 hours, and to cross the Alps the airship had to rise to 3500 meters. On arrival at Rome it was found that the shed provided was only 15.4 inches higher than the airship, hut the vessel was docked without mishap.

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