THE DIRIGIBLE BALLOON

New Zealand Tablet, 10 December 1914, Page 11

THE DIRIGIBLE BALLOON

ITS USE IN WAR.

Military aircraft have certainly not revolutionised warfare, nor have they done the tremendous amount of damage to life and property which some impressionable civilians fear (says the Outlook Nevertheless, they have played a more successful and useful (if that word may be employed in connection with instruments of destruction) part in the European war than the newspaper correspondents have credited them with. While the French have devoted themselves largely to the heavier-than-air flying-machines, the Germans have pinned their faith to the gas-filled balloon. In this respect the Germans, with their characteristic efficiency, are following the experimental history of a century. When the Frenchman, Montgolfier, with his balloon filled with hot air rose for the first time in 1785, it was assumed that this great problem was solved .and the possibility of navigation of the air was secured. Even then aeronauts tried to make such spherical balloons dirigible by providing them with sails and rudders. The trials were failures and cost many lives. The fundamental laws were not sufficiently known, and the experiments were given up. A century later the problem was attacked again. Krebs, a Frenchman ; Schwarz, an Austrian, and others tried to ' move their balloons by mechanical power, but their engines were by far too heavy for their po\yer. The weight of their engines probably was at least 50 pounds per horsepower, far too much for the capacity of their balloons even in quiet air. The first to succeed was Santos Dumont, the Brazilian, at the end of the nineteenth century. Like some of his predecessors, he used cylindrical, cigar-shaped balloons, from which the hulls or carriers were suspended. Success came with the use of gasoline motors, as used in automobiles, because of, the much lower comparative weight of the engines and fuel. Dumont’s balloons were all of the flexible kind, without any metallic stiffening, and -the hull or carrier hung from a netting covering the balloon.

The Three Types of Dirigibles: The Parseval.

The progress above described did not suffice to make the balloon a practical means of travelling and transportation. It took years before this was accomplished. Three types of systems were developed : flexible, halfrigid, and rigid balloons were built. s Many different constructions appeared, especially from ' workshops of inventors and navigators. In Germany ‘these three types were introduced by three men, all) military officers Major Parseval, Major Gross, and General Count Zeppelin. Parseval’s flexible balloon, in order to keep its shape even after great loss of gas,, contains two airbags near its ends which are filled by a ventilator,!)and are thus kept more or less inflated according to - necessity. This arrangement is most ingenious, as simple as it is effective. It enables the navigator to steer the balloon vertically by filling or emptying the ballonets, as these air-bags are called, at one end or the other, thereby lifting or lowering one end or the other of the balloon. Another great advantage is the facility with which balloons of this kind are launched or landed—an essential for safety where there are no sheds or hangars. In cases of unexpected landing the flexible balloons present

less danger than other types, and, in fact, no losses r of Parseval airships from this cause have ever occurred. A ~ Parseval balloon can be landed •' and • dismantled in . about an hour. It can be transported in three heavy freight carts. The suspending lines for the hull are run over pulleys and ingeniously arranged so that it will remain level even when the balloon itself is tilted up or down at a decided angle. The stability of the Parseval type has been conclusively demonstrated. Airships 9f this type are manufactured by a German stock company, the LuftfahrzeugGesellschaft in Berlin, which up to last year had built more than twenty dirigibles of different sizes, not only for the German Government, but for'Austria, Italy, Russia, England, Japan, and Turkey. The first ones built had a capacity of 1500 to 2000 cubic meters (about 55,000 to 73,000 cubic feet), and their speed was ,40 to 50 kilometers (25 to 32 miles) per hour! They are now built with 8800 to 10,000 cubic meters (about 300,000 to 360,000 cubic feet) capacity, and capable of a speed of 70 to 80 kilometers (about 40 to 50 miles) 'per hour. The Half -Rigid Type. A second class of dirigible air-ships are those built by the German Government after the plans of Major Gross. These are of the half-rigid type. Major Gross’s air-ships have a metallic keel, above which the balloon is fastened and from which is hung the carrier. The keel, by giving a certain stiffness to the air-ship, guarantees its dirigibility. In a French experiment with an air-ship of a similar type the rigid part was bent and broken by the pressure of the wind, the balloon torn open, and a terrible accident was the result. The Gross dirigibles have special devices to provide against just such accidents. The vertical steering is chiefly done by movable weights running on rails along the keel. The stability of these balloons lengthwise as well as laterally is perfect. The defects of both the Parseval and Gross systems are that dirigibles of these types are limited in carrying capacity, in radius of action, and in speed. High speed is a source of safety in bad weather and against head winds and gales. Their usefulness in warfare is therefore questionable. Their destructability by shrapnel is also a great military defect. The Zeppelin. Count Zeppelin began his experiments pn quite different principles. He proposed to create an air-ship to be sailed and controlled in the air as the giant ships are navigated on the ocean. He desired to transport a number of passengers and considerable freight without danger even in heavy weather. Greater carrying capacity, speed, and radius of action were his goal. So he gave his balloon a rigid skeleton made of rings and angles of aluminum, and covered it with impregnated cloth. Inside he put the real lifting power a row of gas-filled ballonets. In his first experimental balloon, in 1902, he had nine ballonets. His first engines were two Maybach motors of 75 to 100 horse-power each. He could carry over two tons, and had a speed of 60 kilometers (about 40 miles) an hour. The dirigibility of. his ship was perfect from the beginning. In spite of a number of serious accidents, and after sacrificing his fortune, Zeppelin at last conquered public opinion, obtained the support financially of the German people and Government, and went on improving and enlarging his balloons, and making them suitable for service in peace and war. A modern war Zeppelin may be described as follows; Capacity, 30,000 to 35,000 cubic meters (1,100,000 to 1,300,000 cubic feet) speed, 100 kilometers per hour (62 miles) ; radius of action, 36 to 40 hours in the air at full speed'; height of Rising, 3000 to 3500 meters (10,000 to 12,000 feet) ; propelling power, four motors of 125 to 150 horse-power each, connected by belts with the propellers. • The two hulls carry two propellers each. A third hull is provided for commander and pilot. . An . open air-shaft in the centre of the balloon affords free vision to the sky. The vertical steering is done mainly

by dynamical apparatus, but also by throwing out ballast. Ample provision is made against loss of gas. The gas, when heated by radiation of the sun, is cooled by strong ventilation. The surface of the balloon case is painted with aluminum paint, which keeps it from oyer-heating. The number of gas-filled ballonets inside is from 15 to 17, of which 5 to 7 may be hit by bullets and emptied of their gas without destroying the buoyancy of the whole. The Zeppelin in War, For military service a Zeppelin may be arxnfed with one or two machine guns, with one or two light rapidfire guns, and with machinery • for dropping bombs. It can carry about a ton and a half of ammunition and explosives. It is fitted out with a wireless telegraph apparatus with a radius of about two hundred miles. The Zeppelin air cruiser is well suited for its purpose. While its speed is somewhat less than that of aeroplanes, it can rise very much more quickly. Its main advantage lies in its great radius of action, which enables it to make long scouting flights. Even in cases when it has been brought down by the enemy, the results of its expedition are not lost because of its wireless communication.

In the hulls a number of officers are conveniently and safely carried to make observations, take photographs, and plot maps. German military authorities express satisfaction with the efficiency of the Zeppelins in the present European war. Some of them are built so that they can be. propelled on the surface of the water. The Zeppelin Hensa has successfully descended from the air to the surface of the water and risen again; and great sheds or hangars are maintained at Cuxhaven and Heligoland as a basis for both sea-going and land-scouting. Zeppelins. At the beginning of the. war Germany possessed ten or twelve war Zeppelins ready for active service in her army and navy. There are two great yards for building air-ships, at Friedrichshaven and Potsdam, in each of which five dirigibles can be under construction at the same time. It takes from two to three months under present circumstances to build a Zeppelin, and before long Germany will have fifty such air-vessels at her command. While Germany has given her attention chiefly to the development and building of dirigibles of the Zeppelin type, she has not wholly neglected the construction and use of aeroplanes, and many monoplanes and biplanes are employed for scouting duties by the different German armies, each of which has its own ‘ Flieger Corps.’ But the building of flying-machines or aeroplanes, as contrasted with the dirigibles, is believed by the Germans to be still in its infancy.