Читать книгу Aircraft and Submarines - Willis J. Abbot - Страница 12

Photo by Press Illustrating Service.

A French "Sausage".

Though Count von Zeppelin had begun his experiments in 1873 it was not until 1890 that he actually began the construction of his first airship. The intervening years had been spent in constructing and testing models, in abstruse calculations of the resistance of the air, the lifting power of hydrogen, the comparative rigidity and weight of different woods and various metals, the power and weight of the different makes of motors. In these studies he spent both his time and his money lavishly, with the result that when he had built a model on the lines of which he was willing to risk the construction of an airship of operative size, his private fortune was gone. It is the common lot of inventors. For a time the Count suffered all the mortification and ignominy which the beggar, even in a most worthy cause, must always experience. Hat in hand he approached every possible patron with his story of certain success if only supplied with funds with which to complete his ship. A stock company with a capital of $225,000 of which he contributed one half, soon found its resources exhausted and retired from the speculation. Appeals to the Emperor met with only cold indifference. An American millionaire newspaper owner, resident in Europe, sent contemptuous word by his secretary that he "had no time to bother with crazy inventors." That was indeed the attitude of the business classes at the moment when the inventors of dirigibles were on the very point of conquering the obstacles in the way of making the navigation of air a practical art. A governmental commission at Berlin rejected with contempt the plans which Zeppelin presented in his appeal for support. Members of that commission were forced to an about-face later and became some of the inventor's sturdiest champions. But in his darkest hour the government failed him, and the one friendly hand stretched out in aid was that of the German Engineers' Society which, somewhat doubtfully, advanced some funds to keep the work in operation.

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A British "Blimp".

With this the construction of the first Zeppelin craft was begun. Though there had been built up to the opening of the war twenty-five "Zeps"—nobody knows how many since—the fundamental type was not materially altered in the later ones, and a description of the first will stand for all. In connection with this description may be noted the criticisms of experts some of which proved only too well founded.

The first Zeppelin was polygonal, 450 feet long, 78 broad, and 66 feet high. This colossal bulk, equivalent to that of a 7500-ton ship necessary to supply lifting power for the metallic frame, naturally made her unwieldy to handle, unsafe to leave at rest, outside of a sheltering shed, and a particularly attractive target for artillery in time of war. Actual action indeed proved that to be safe from the shells of anti-aircraft guns, the Zeppelins were forced to fly so high that their own bombs could not be dropped with any degree of accuracy upon a desired target.

The balloon's frame is made of aluminum, the lightest of metals, but not the least costly. A curious disadvantage of this construction was made apparent in the accident which destroyed Zeppelin IV. That was the first of the airships to be equipped with a full wireless outfit which was used freely on its flight. It appeared that the aluminum frame absorbed much of the electricity generated for the purpose of the wireless. The effect of this was two-fold. It limited the radius of operation of the wireless to 150 miles or less, and it made the metal frame a perilous storehouse of electricity. When Zeppelin IV. met with a disaster by a storm which dragged it from its moorings, the stored electricity in her frame was suddenly released by contact with the trees and set fire to the envelope, utterly destroying the ship.

The balloon frame was divided into seventeen compartments, each of which held a ballonet filled with hydrogen gas. The purpose of this was similar to the practice of dividing a ship's hulls into compartments. If one or more of the ballonets, for any reason, were injured the remainder would keep the ship afloat. The space between the ballonets and the outer skin was pumped full of air to keep the latter taut and rigid. Moreover it helped to prevent the radiation of heat to the gas bags from the outer envelope whose huge expanse, presented to the sun, absorbed an immense amount of heat rays.

Two cars were suspended from the frame of the Zeppelin, forward and aft, and a corridor connected them. A sliding weight was employed to raise or depress the bow. In each car of the first Zeppelin was a sixteen-horse-power gasoline motor, each working two screws, with four foot blades, revolving one thousand times a minute. The engines were reversible, thus making it possible to work the propellers against each other and aid materially in steering the ship. Rudders at bow and stern completed the navigating equipment.

In the first Zeppelins, the corridor connecting the two cars was wholly outside the frame and envelope of the car. Later the perilous experiment was tried of putting it within the envelope. This resulted in one of the most shocking of the many Zeppelin disasters. In the case of the ship L-II., built in 1912, the corridor became filled with gas that had oozed out of the ballonets. At one end or the other of the corridor this gas, then mixed with air, came in contact with fire—perhaps the exhaust of the engines—a violent explosion followed while the ship was some nine hundred feet aloft, and the mass of twisted and broken metal, with the flaming envelope, fell to the ground carrying twenty-eight men, including members of the Admiralty Board, to a horrible death.

But to return to the first Zeppelin. Her trial was set for July 2, 1900, and though the immediate vicinity of the floating hangar was barred to the public by the military authorities, the shores and surface of the lake were black with people eager to witness the test. Boats pulled out of the wide portal the huge cigar-shaped structure, floating on small rafts, its polished surface of pegamoid glittering in the sun. As large as a fair-sized ocean steamship, it looked, on that little lake dotted with pleasure craft, like a leviathan. Men were busy in the cars, fore and aft. The mooring ropes were cast off as the vessel gained an offing, and ballast being thrown out she began to rise slowly. The propellers began to whir, and the great craft swung around breasting the breeze and moved slowly up the lake. The crowd cheered. Count von Zeppelin, tense with excitement, alert for every sign of weakness watched his monster creation with mingled pride and apprehension. Two points were set at rest in the first two minutes—the lifting power was great enough to carry the heaviest load ever imposed upon a balloon and the motive power was sufficient to propel her against an ordinary breeze. But she was hardly in mid-air when defects became apparent. The apparatus for controlling the balancing weight got out of order. The steering lines became entangled so that the ship was first obliged to stop, then by reversing the engines to proceed backwards. This was, however, a favourable evidence of her handiness under untoward circumstances. After she had been in the air nearly an hour and had covered four or five miles, a landing was ordered and she dropped to the surface of the lake with perfect ease. Before reaching her shed, however, she collided with a pile—an accident in no way attributable to her design—and seriously bent her frame.

The story told thus baldly does not sound like a record of glorious success. Nevertheless not Count Zeppelin alone but all Germany was wild with jubilation. Zeppelin I. had demonstrated a principle; all that remained was to develop and apply this principle and Germany would have a fleet of aërial dreadnoughts that would force any hostile nation to subjection. There was little or no discussion of the application of the principle to the ends of peace. It was as an engine of war alone that the airship appealed to the popular fancy.

But at the time that fancy proved fickle. With a few repairs the airship was brought out for another test. In the air it did all that was asked for it, but it came to earth—or rather to the surface of the lake—with a shock that put it out of commission. When Count Zeppelin's company estimated the cost of further repairs it gave a sigh and abandoned the wreck. Thereupon the pertinacious inventor laid aside his tools, got into his old uniform, and went out again on the dreary task of begging for further funds.

It was two years before he could take up again the work of construction. He lectured, wrote magazine articles, begged, cajoled, and pleaded for money. At last he made an impression upon the Emperor who, indeed, with a keen eye for all that makes for military advantage, should have given heed to his efforts long before. Merely a letter of approval from the all-powerful Kaiser was needed to turn the scale and in 1902 this was forthcoming. The factories of the empire agreed to furnish materials at cost price, and sufficient money was soon forthcoming to build a second ship. This ship took more than two years to build, was tested in January, 1906, made a creditable flight, and was dashed to pieces by a gale the same night!

The wearisome work of begging began again. But this time the Kaiser's aid was even more effectively given and in nine months Zeppelin III. was in the air. More powerful than its predecessors it met with a greater measure of success. On one of its trials a propeller blade flew off and penetrated the envelope, but the ship returned to earth in safety. In October, 1906, the Minister of War reported that the airship was extremely stable, responded readily to her helm, had carried eleven persons sixty-seven miles in two hours and seventeen minutes, and had made its landing in ease and safety. Accepted by the government "No. III." passed into military service and Zeppelin, now the idol of the German people, began the construction of "No. IV."

That ship was larger than her predecessors and carried a third cabin for passengers suspended amidships. Marked increase in the size of the steering and stabling planes characterized the appearance of the ship when compared with earlier types. She was at the outset a lucky ship. She cruised through Alpine passes into Switzerland, and made a circular voyage carrying eleven passengers and flying from Friedrichshaven to Mayence and back via Basle, Strassburg, Mannheim, and Stuttgart. The voyage occupied twenty-one hours—a world's record. The performance of the ship on both voyages was perfection. Even in the tortuous Alpine passes which she was forced to navigate on her trip to Lucerne she moved with the steadiness and certainty of a great ship at sea. The rarification of the air at high altitudes, the extreme and sudden variations in temperature, the gusts of wind that poured from the ice-bound peaks down through the narrow canyons affected her not at all. When to this experience was added the triumphant tour of the six German cities, Count von Zeppelin might well have thought his triumph was complete.

But once again the cup of victory was dashed from his lips. After his landing a violent wind beat upon the ship. An army of men strove to hold her fast, while an effort was made to reduce her bulk by deflation. That effort, which would have been entirely successful in the case of a non-rigid balloon, was obviously futile in that of a Zeppelin. Not the gas in the ballonets, but the great rigid frame covered with water-proofed cloth constituted the huge bulk that made her the plaything of the winds. In a trice she was snatched from the hands of her crew and hurled against the trees in a neighbouring grove. There was a sudden and utterly unexpected explosion and the whole fabric was in flames. The precise cause of the explosion will always be in doubt, but, as already pointed out, many scientists believe that the great volume of electricity accumulated in the metallic frame was suddenly released in a mighty spark which set fire to the stores of gasoline on board.

With this disaster the iron nerve of the inventor was for the first time broken. It followed so fast upon what appeared to be a complete triumph that the shock was peculiarly hard to bear. It is said that he broke down and wept, and that but for the loving courage and earnest entreaties of his wife and daughter he would then have abandoned the hope and ambition of his life. But after all it was but that darkest hour which comes just before the dawn. The demolition of "No. IV." had been no accident which reflected at all upon the plan or construction of the craft—unless the great bulk of the ship be considered a fundamental defect. What it did demonstrate was that the Zeppelin, like the one-thousand-foot ocean liner, must have adequate harbour and docking facilities wherever it is to land. The one cannot safely drop down in any convenient meadow, any more than the other can put into any little fishing port. Germany has learned this lesson well enough and since the opening of the Great War her territory is plentifully provided with Zeppelin shelters at all strategic points.

Photo by Paul Thompson.

The Death of a Zeppelin.

Fortunately for the Count the German people judged his latest reverse more justly than he did. They saw the completeness of the triumph which had preceded the disaster and recognized that the latter was one easily guarded against in future. Enthusiasm ran high all over the land. Begging was no longer necessary. The Emperor, who had heretofore expressed rather guarded approval of the enterprise, now flung himself into it with that enthusiasm for which he is notable. He bestowed upon the Count the Order of the Black Eagle, embraced him in public three times, and called aloud that all might hear, "Long life to his Excellency, Count Zeppelin, the Conqueror of the Air." He never wearied of assuring his hearers that the Count was the "greatest German of the century." With such august patronage the Count became the rage. Next to the Kaiser's the face best known to the people of Germany, through pictures and statues, was that of the inventor of the Zeppelin. The pleasing practice of showing affection for a public man by driving nails into his wooden effigy had not then been invented by the poetic Teutons, else von Zeppelin would have outdone von Hindenburg in weight of metal.

The story that Zeppelin had refused repeated offers from other governments was widely published and evoked patriotic enthusiasm. With it went shrewd hints that in these powerful aircraft lay the way to overcome the hated English navy, and even to carry war to the very soil of England. It was then eight years before the greatest war of history was to break out, but even at that date hatred of England was being sedulously cultivated among the German people by those in authority.

As a result of this national attitude Count Zeppelin's enterprise was speedily put on a sound financial footing. Though "No. IV." had been destroyed by an accident it had been the purpose of the government to buy her, and $125,000 of the purchase price was now put at the disposal of the Count von Zeppelin. A popular Zeppelin fund of $1,500,000 was raised and expended in building great works. Thenceforward there was no lack of money for furthering what had truly become a great national interest.

But the progress of the construction of Zeppelins for the next few years was curiously compounded of success and failure. Fate seemed to have decreed to every Zeppelin triumph a disaster. Each mischance was attributed to exceptional conditions which never could happen again, but either they did occur, or some new but equally effective accident did. Outside of Germany, where the public mind had become set in an almost idolatrous confidence in Zeppelin, the great airships were becoming a jest and a byword notwithstanding their unquestioned accomplishments. Indeed when the record was made up just before the declaration of war in 1914 it was found that of twenty-five Zeppelins thus far constructed only twelve were available. Thirteen had been destroyed by accident—two of them modern naval airships only completed in 1913. The record was not one to inspire confidence.

In 1909, during a voyage in which he made nine hundred miles in thirty-eight hours, the rumour was spread that von Zeppelin would continue it to Berlin. Some joker sent a forged telegram to the Kaiser to that effect signed "Zeppelin." It was expected to be the first appearance of one of the great ships at the capital, and the Emperor hastened to prepare a suitable welcome. A great crowd assembled at the Templehoff Parade Ground. The Berlin Airship Battalion was under orders to assist in the landing. The Kaiser himself was ready to hasten to the spot should the ship be sighted. But she never appeared. If von Zeppelin knew of the exploit which rumour had assigned to him—which is doubtful—he could not have carried it out. His ship collided with a tree—an accident singularly frequent in the Zeppelin records—so disabling it that it could only limp home under half power. A rather curt telegram from his Imperial master is said to have been Count von Zeppelin's first intimation that he had broken an engagement.

However, he kept it two months later, flying to Berlin, a distance of 475 miles. He was greeted with mad enthusiasm and among the crowd to welcome him was Orville Wright the American aviator. It is a curious coincidence that on the day the writer pens these words the New York newspapers contain accounts of Mr. Wright's proffer of his services, and aeronautical facilities, to the President in case an existing diplomatic break with Germany should reach the point of actual war. Mr. Wright accompanied his proffer by an appeal for a tremendous aviation force, "but," said he, "I strongly advise against spending any money whatsoever on dirigible balloons of any sort."

Thereafter the progress of Count von Zeppelin was without interruption for any lack of financial strength. His great works at Friedrichshaven expanded until they were capable of putting out a complete ship in eight weeks. He was building, of course, primarily for war, and never concealed the fact that the enemy he expected to be the target of his bomb throwers was England. What the airships accomplished in this direction, how greatly they were developed, and the strength and weakness of the German air fleet, will be dwelt upon in another chapter.

But, though building primarily for military purposes, Zeppelin did not wholly neglect the possibilities of his ship for non-military service. He built one which made more than thirty trips between Munich and Berlin, carrying passengers who paid a heavy fee for the privilege of enjoying this novel form of travel. The car was fitted up like our most up-to-date Pullmans, with comfortable seats, bright lights, and a kitchen from which excellent meals were served to the passengers. The service was not continued long enough to determine whether it could ever be made commercially profitable, but as an aid to firing the Teutonic heart and an assistance in selling stock it was well worth while. The spectacle of one of these great cars, six hundred or more feet long, floating grandly on even keel and with a steady course above one of the compact little towns of South Germany, was one to thrill the pulses.

But the ill luck which pursued Count von Zeppelin even in what seemed to be his moments of assured success was remorseless. In 1912 he produced the monster L-I, 525 feet long, 50 feet in diameter, of 776,900 cubic feet capacity, and equipped with three sets of motors, giving it a speed of fifty-two miles an hour. This ship was designed for naval use and after several successful cross-country voyages she was ordered to Heligoland, to participate in naval manœuvres with the fleet there stationed. One day, caught by a sudden gust of wind such as are common enough on the North Sea, she proved utterly helpless. Why no man could tell, her commander being drowned, but in the face of the gale she lost all control, was buffeted by the elements at their will, and dropped into the sea where she was a total loss. Fifteen of her twenty-two officers and men were drowned. The accident was the more inexplicable because the craft had been flying steadily overland for nearly twelve months and had covered more miles than any ship of Zeppelin construction. It was reported that her captain had said she was overloaded and that he feared that she would be helpless in a gale. But after the disaster his mouth was stopped by the waters of the North Sea.

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A German Dirigible, Hansa Type.

This calamity was not permitted long to stand alone. Indeed one of the most curious facts about the Zeppelin record is the regular, periodical recurrence of fatal accidents at almost equal intervals and apparently wholly unaffected by the growing perfection of the airships. While L-I was making her successful cross-country flights, L-II was reaching completion at Friedrichshaven. She was shorter but bulkier than her immediate predecessor and carried engines giving her nine hundred horse power, or four hundred more than L-I. On its first official trip this ship exploded a thousand feet in air, killing twenty-eight officers and men aboard, including all the officials who were conducting the trials. The calamity, as explained on an earlier page, was due to the accumulation of gas in the communicating passage between the three cars.

Photo by Press Illustrating Service.

A Wrecked Zeppelin at Salonika.

This new disaster left the faith and loyalty of the German people unshaken. But it did decidedly estrange the scientific world from Count von Zeppelin and all his works. It was pointed out, with truth, that the accident paralleled precisely one which had demolished the Severo Pax airship ten years earlier, and which had caused French inventors to establish a hard and fast rule against incorporating in an airship's design any inclosed space in which waste gas might gather. This rule and its reason were known to Count von Zeppelin and by ignoring both he lent new colour to the charge, already current in scientific circles, that he was loath to profit by the experiences of other inventors.

Whether this feeling spread to the German Government it is impossible to say. Nor it is easy to estimate how much official confidence was shaken by it. The government, even before the war, was singularly reticent about the Zeppelins, their numbers and plans. It is certain that orders were not withheld from the Count. Great numbers of his machines were built, especially after the war was entered upon. But he was not permitted longer to have a monopoly of government aid for manufacturers of dirigibles. Other types sprung up, notably the Schutte-Lanz, the Gross, and the Parseval. But being first in the field the Zeppelin came to give its name to all the dirigibles of German make and many of the famous—or infamous—exploits credited to it during the war may in fact have been performed by one of its rivals.

It would be futile to attempt to enumerate all these rivals here. Among them are the semi-rigid Parseval and Gross types which found great favour among the military authorities during the war. The latter is merely an adaptation of the highly successful French ship the Lebaudy, but the Parseval is the result of a slow evolution from an ordinary balloon. It is wholly German, in conception and development, and it is reported that the Kaiser, secretly disgusted that the Zeppelins, to the advancement of which he had given such powerful aid, should have recorded so many disasters, quietly transferred his interest to the new and simpler model. Despite the hope of a more efficient craft, however, both the Gross and the Parseval failed in their first official trials, though later they made good.

The latter ship was absolutely without any wooden or metallic structure to give her rigidity. Two air ballonets were contained in the envelope at bow and stern and the ascent and descent of the ship was regulated by the quantity of air pumped into these. A most curious device was the utilization of heavy cloth for the propeller blades. Limp and flaccid when at rest, heavy weights in the hem of the cloth caused these blades to stand out stiff and rigid as the result of the centrifugal force created by their rapid revolution. One great military advantage of the Parseval was that she could be quickly deflated in the presence of danger at her moorings, and wholly knocked down and packed in small compass for shipment by rail in case of need. To neither of these models did there ever come such a succession of disasters as befell the earlier Zeppelins. It is fair to say however that prior to the war not many of them had been built, and that both their builders and navigators had opportunity to learn from Count von Zeppelin's errors.

Among the chief German rivals to the Zeppelin is the Schutte-Lanz, of the rigid type, broader but not so long as the Zeppelin, framed of wood bound with wire and planned to carry a load of five or six tons, or as many as thirty passengers. No. I of this type met its fate as did so many Zeppelins by encountering a storm while improperly moored. Called to earth to replenish its supply of gas it was moored to an anchor sunk six feet in the ground, and as an additional precaution three hundred soldiers were called from a neighbouring barracks to handle it. It seems to have been one of the advantages of Germany as a place in which to manœuvre dirigibles, that, even in time of peace, there were always several hundred soldiers available wherever a ship might land. But this force was inadequate. A violent gust tore the ship from their hands. One poor fellow instinctively clung to his rope until one thousand feet in the air when he let go. The ship itself hovered over the town for an hour or more, then descended and was dashed to pieces against trees and stone walls.

The danger which was always attached to the landing of airships has led some to suggest that they should never be brought to earth, but moored in mid-air as large ships anchor in midstream. It is suggested that tall towers be built to the top of which the ship be attached by a cable, so arranged that she will always float to the leeward of the tower. The passengers would be landed by gangplanks, and taken up and down the towers in elevators. Kipling suggests this expedient in his prophetic sketch With the Night Mail. The airship would only return to earth—as a ship goes into dry dock—when in need of repairs.

A curious mishap that threatened for a time to wreck the peace of the world, occurred in April, 1913, when a German Zeppelin was forced out of its course and over French territory. The right of alien machines to pass over their territory is jealously guarded by European nations, and during the progress of the Great War the Dutch repeatedly protested against the violation of their atmosphere by German aviators. At the time of this mischance, however, France and Germany were at peace—or as nearly so as racial and historic antipathies would permit. Accordingly when officers of a brigade of French cavalry engaged in manœuvring near the great fortress of Luneville saw a shadow moving across the field and looking up saw a huge Zeppelin betwixt themselves and the sun they were astonished and alarmed. Signs and faint shouts from the aeronauts appeared to indicate that their errand was at least friendly, if not involuntary. The soldiers stopped their drill; the townspeople trooped out to the Champs de Mars where the phenomenon was exhibited and began excitedly discussing this suspicious invasion. Word was speedily sent to military headquarters asking whether to welcome or to repel the foe.

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British Aviators about to Ascend. Note position of gunner on lower seat.

Meantime the great ship was drifting perilously near the housetops, and the uniformed officers in the cars began making signals to the soldiers below. Ropes were thrown out, seized by willing hands and made fast. The crew of Germans descended to find themselves prisoners. The international law was clear enough. The ship was a military engine of the German army. Its officers, all in uniform, had deliberately steered her into the very heart of a French fortress. Though the countries were at peace the act was technically one of war—an armed invasion by the enemy. Diplomacy of course settled the issue peacefully but not before the French had made careful drawings of all the essential features of the Zeppelin, and taken copies of its log. As Germany had theretofore kept a rigid secrecy about all the details of Zeppelin construction and operation this angered the military authorities beyond measure. The unlucky officers who had shared in the accident were savagely told that they should have blown the ship up in mid-air and perished with it rather than to have weakly submitted it to French inspection. They suffered court-martial but escaped with severe reprimands.

The story of the dirigibles of France and Germany is practically the whole story of the development to a reasonable degree of perfection of the lighter-than-air machine. Other nations experimented somewhat, but in the main lagged behind these pioneers. Out of Spain indeed came a most efficient craft—the Astra-Torres, of which the British Government had the best example prior to the war, while both France and Russia placed large orders with the builders. How many finally went into service and what may have been their record are facts veiled in the secrecy of wartime. Belgium and Italy both produced dirigibles of distinctive character. The United States is alone at the present moment in having contributed nothing to the improvement of the dirigible balloon.