 |
AEROPLANES AND DIRIGIBLES OF WAR
By Frederick A. Talbot
PREFACE
Ever since the earliest days of the great conquest of the air, first by the dirigible balloon and then by the aeroplane, their use in time of war has been a fruitful theme for discussion. But their arrival was of too recent a date, their many utilities too unexplored to provide anything other than theories, many obviously untenable, others avowedly problematical.
Yet the part airships have played in the Greatest War has come as a surprise even to their most convinced advocates. For every expectation shattered, they have shown a more than compensating possibility of usefulness.
In this volume an endeavour has been made to record their achievements, under the stern test of trial, as an axiom of war, and to explain, in untechnical language, the many services to which they have been and may be applied.
In the preparation of the work I have received assistance from many sources—British, French, Russian and German—from official reports and from men who have played a part in the War in the Air. The information concerning German military aircraft has been obtained from Government documents, most of which were placed at my disposal before the outbreak of war.
The use of aircraft has changed the whole art and science of warfare. With its disabilities well in hand, with its strength but half revealed, the aerial service has revolutionised strategy and shorn the unexpected attack of half its terrors. The Fourth Arm is now an invaluable part of the complex military machine.
F. A. TALBOT.
CONTENTS CHAPTER
I. The introduction of aircraft into military operations II. The military uses of the captive balloon III. Germany's rise to military airship supremacy IV. Airships of war V. Germany's aerial dreadnought fleet VI. The military value of Germany's aerial fleet VII. Aeroplanes of war VIII. Scouting from the skies IX. The airman and artillery X. Bomb-throwing from air-craft XI. Armoured aeroplanes XII. Battles in the air XIII. Tricks and ruses to baffle the airman XIV. Anti-aircraft guns. Mobile weapons XV. Anti-aircraft guns. Immobile weapons XVI. Mining the air XVII. Wireless in aviation XVIII. Aircraft and naval operations XIX. The navies of the air
CHAPTER I. THE INTRODUCTION OF AIRCRAFT INTO MILITARY OPERATIONS
It is a curious circumstance that an invention, which is hailed as being one of the greatest achievements ever recorded in the march of civilisation, should be devoted essentially to the maiming of humanity and the destruction of property. In no other trend of human endeavour is this factor so potently demonstrated as in connection with Man's Conquest of the Air.
The dogged struggle against the blind forces of Nature was waged tenaciously and perseveringly for centuries. But the measure of success recorded from time to time was so disappointing as to convey the impression, except in a limited circle, that the problem was impossible of solution. In the meantime wondrous changes had taken place in the methods of transportation by land and sea. The steam and electric railway, steam propulsion of vessels, and mechanical movement along the highroads had been evolved and advanced to a high standard of perfection, to the untold advantage of the community. Consequently it was argued, if only a system of travel along the aerial highways could be established, then all other methods of mechanical transportation would be rendered, if not entirely obsolete, at least antiquated.
At last man triumphed over Nature—at least to such a degree as to inspire the confidence of the world at large, and to bring aerial travel and transportation within range of realisation. But what has been the result? The discovery is not devoted to the interests of peace and economic development, but to extermination and destruction.
At the same time this development may be explained. The airship and aeroplane in the present stage of evolution possess no economic value. True, cross-country cruises by airship have been inaugurated, and, up to a point, have proved popularly, if not commercially, successful, while tentative efforts have been made to utilise the aeroplane as a mail-carrier. Still, from the view-point of the community at large aerial travel is as remote as it was centuries ago.
It is somewhat interesting to observe how history is repeating itself. When the Montgolfiers succeeded in lifting themselves into the air by means of a vessel inflated with hot air, the new vehicle was hailed not so much as one possessed of commercial possibilities, but as an engine of war! When the indomitable courage and perseverance of Count von Zeppelin in the face of discouraging disasters and flagrant failures, at last commanded the attention of the German Emperor, the latter regarded the Zeppelin craft, not from the interests of peace, but as a military weapon, and the whole of the subsequent efforts of the Imperial admirer were devoted to the perfection of the airship in this one direction.
Other nations, when they embarked on an identical line of development, considered the airship from a similar point of view. In fact, outside Germany, there was very little private initiative in this field. Experiments and developments were undertaken by the military or naval, and in some instances by both branches, of the respective Powers. Consequently the aerial craft, whether it be a dirigible airship, or an aeroplane, can only be regarded from the military point of view.
Despite the achievements which have been recorded by human endeavour in the field of aerial travel, the balloon per se has by no means been superseded. It still remains an invaluable adjunct to the fighting machine. In Great Britain its value in this direction has never been ignored: of late, indeed, it has rather been developed. The captive balloon is regarded as an indispensable unit to both field and sea operations. This fact was emphasised very strongly in connection with the British naval attacks upon the German forces in Flanders, and it contributed to the discomfiture of the German hordes in a very emphatic manner.
The captive balloon may be operated from any spot where facilities exist for anchoring the paying out cable together with winding facilities for the latter. Consequently, if exigencies demand, it maybe operated from the deck of a warship so long as the latter is stationary, or even from an automobile. It is of small cubic capacity, inasmuch as it is only necessary for the bag to contain sufficient gas to lift one or two men to a height of about 500 or 600 feet.
When used in the field the balloon is generally inflated at the base, to be towed or carried forward by a squad of men while floating in the air, perhaps at a height of 10 feet. A dozen men will suffice for this duty as a rule, and in calm weather little difficulty is encountered in moving from point to point. This method possesses many advantages. The balloon can be inflated with greater ease at the base, where it is immune from interference by hostile fire. Moreover, the facilities for obtaining the requisite inflating agent—hydrogen or coal gas—are more convenient at such a point. If the base be far removed from the spot at which it is desired to operate the balloon, the latter is inflated at a convenient point nearer the requisite position, advantage being taken of the protective covering offered by a copse or other natural obstacle.
As is well known, balloons played an important part during the siege of Paris in 1870-1, not only in connection with daring attempts to communicate with the outer world, but in reconnoitring the German positions around the beleaguered city. But this was not the first military application of the aerial vessel; it was used by the French against the Austrians in the battle of Fleurus, and also during the American Civil War. These operations, however, were of a sporadic character; they were not part and parcel of an organised military section.
It is not generally known that the British War office virtually pioneered the military use of balloons, and subsequently the methods perfected in Britain became recognised as a kind of "standard" and were adopted generally by the Powers with such modifications as local exigencies seemed to demand.
The British military balloon department was inaugurated at Chatham under Captain Templer in 1879. It was devoted essentially to the employment of captive balloons in war, and in 1880 a company of the Royal Engineers was detailed to the care of this work in the field. Six years previously the French military department had adopted the captive balloon under Colonel Laussedat, who was assisted among others by the well-known Captain Renard. Germany was somewhat later in the field; the military value of captive balloons was not appreciated and taken into serious consideration here until 1884. But although British efforts were preceded by the French the latter did not develop the idea upon accepted military lines.
The British authorities were confronted with many searching problems. One of the earliest and greatest difficulties encountered was in connection with the gas for inflation. Coal gas was not always readily available, so that hydrogen had to be depended upon for the most part. But then another difficulty arose. This was the manufacture of the requisite gas. Various methods were tested, such as the electrolytic decomposition of water, the decomposition of sulphuric acid by means of iron, the reaction between slaked lime and zinc, and so forth.
But the drawbacks to every process, especially upon the field of battle, when operations have to be conducted under extreme difficulties and at high pressure, were speedily recognised. While other nations concentrated their energies upon the simplification of hydrogen-manufacturing apparatus for use upon the battle-field, Great Britain abandoned all such processes in toto. Our military organisation preferred to carry out the production of the necessary gas at a convenient manufacturing centre and to transport it, stored in steel cylinders under pressure, to the actual scene of operations. The method proved a great success, and in this way it was found possible to inflate a military balloon in the short space of 20 minutes, whereas, under the conditions of making gas upon the spot, a period of four hours or more was necessary, owing to the fact that the manufacturing process is relatively slow and intricate. The practicability of the British idea and its perfection served to establish the captive balloon as a military unit.
The British military ballooning department has always ranked as the foremost of its type among the Powers, although its work has been carried out so unostentatiously that the outside world has gleaned very little information concerning its operations. Captain Templer was an indefatigable worker and he brought the ballooning section to a high degree of efficiency from the military point of view.
But the British Government was peculiarly favoured, if such a term may be used. Our little wars in various parts of the world contributed valuable information and experience which was fully turned to account. Captive balloons for reconnoitring purposes were used by the British army for the first time at Suakim in 1885, and the section established its value very convincingly. The French military balloon department gained its first experience in this field in the previous year, a balloon detachment having been dispatched to Tonkin in 1884. In both the Tonkin and Soudan campaigns, invaluable work was accomplished by the balloon sections, with the result that this aerial vehicle has come to be regarded as an indispensable military adjunct. Indeed the activity of the German military ballooning section was directly attributable to the Anglo-French achievements therewith.
In this work, however, the British force speedily displayed its superiority and initiative. The use of compressed hydrogen was adopted, and within the course of a few years the other Powers, realising the advantages which the British department had thus obtained, decided to follow its example. The gas is stored in cylinders under a pressure varying from six to ten or more atmospheres; in other words from about 80 to 140 or more pounds per square inch. Special military wagons have been designed for the transport of these cylinders, and they are attached to the balloon train.
The balloon itself is light, and made of such materials as to reduce the weight thereof to the minimum. The British balloons are probably the smallest used by any of the Powers, but at the same time they are the most expensive. They are made of goldbeater's skin, and range in capacity from 7,000 to 10,000 cubic feet, the majority being of the former capacity. The French balloon on the other hand has a capacity exceeding 18,000 cubic feet, although a smaller vessel of 9,000 cubic feet capacity, known as an auxiliary, and carrying a single observer, is used.
The Germans, on the other hand, with their Teutonic love of the immense, favour far larger vessels. At the same time the military balloon section of the German Army eclipses that of any other nations is attached to the Intelligence Department, and is under the direct control of the General Staff. Balloon stations are dotted all over the country, including Heligoland and Kiel, while regular sections are attached to the Navy for operating captive balloons from warships. Although the Zeppelin and aeroplane forces have come to the front in Germany, and have relegated the captive balloon somewhat to the limbo of things that were, the latter section has never been disbanded; in fact, during the present campaign it has undergone a somewhat spirited revival.
The South African campaign emphasised the value of the British balloon section of the Army, and revealed services to which it was specially adapted, but which had previously more or less been ignored. The British Army possessed indifferent maps of the Orange Free State and the Transvaal. This lamentable deficiency was remedied in great measure by recourse to topographical photographs taken from the captive balloons. The guides thus obtained were found to be of extreme value.
During the early stages of the war the hydrogen was shipped in cylinders from the homeland, but subsequently a manufacturing plant of such capacity as to meet all requirements was established in South Africa. The cylinders were charged at this point and dispatched to the scene of action, so that it became unnecessary to transport the commodity from Britain. The captive balloon revealed the impregnability of Spion Kop, enabled Lord Roberts to ascertain the position of the Boer guns at the Battle of Paardeburg, and proved of invaluable assistance to the forces of General White during the siege of Ladysmith.
CHAPTER II. THE MILITARY USES of THE CAPTIVE BALLOON
Although the captive balloon is recognised as indispensable in military operations, its uses are somewhat limited. It can be employed only in comparatively still weather. The reason is obvious. It is essential that the balloon should assume a vertical line in relation to its winding plant upon the ground beneath, so that it may attain the maximum elevation possible: in other words, the balloon should be directly above the station below, so that if 100 yards of cable are paid out the aerostat may be 100 yards above the ground. If a wind is blowing, the helpless craft is certain to be caught thereby and driven forwards or backwards, so that it assumes an angle to its station. If this become acute the vessel will be tilted, rendering the position of the observers somewhat precarious, and at the same time observing efficiency will be impaired.
This point may be appreciated more easily by reference to the accompanying diagram. A represents the ground station and B the position of the captive balloon when sent aloft in calm weather, 300 feet of cable being paid out. A wind arises and blows the vessel forward to the position C. At this point the height of the craft in relation to the ground has been reduced, and the reduction must increase proportionately as the strength of the wind increases and forces the balloon still more towards the ground. At the same time, owing to the tilt given to the car, observation is rendered more difficult and eventually becomes extremely dangerous.
A wind, if of appreciable strength, develops another and graver danger. Greater strain will be imposed upon the cable, while if the wind be gusty, there is the risk that the vessel will be torn away from its anchoring rope and possibly lost. Thus it will be seen that the effective utilisation of a captive balloon is completely governed by meteorological conditions, and often it is impossible to use it in weather which exercises but little influence upon dirigibles or aeroplanes.
The captive balloon equipment comprises the balloon, together with the observer's basket, the wire-cable whereby it is anchored and controlled, and the winding apparatus. Formerly a steam engine was necessary for the paying in and out of the cable, but nowadays this is accomplished by means of a petrol-driven motor, an oil-engine, or even by the engine of an automobile. The length of cable varies according to the capacity of the balloon and the maximum operating height.
The average British balloon is able to lift about 290 or 300 pounds, which may be taken to represent the weight of two observers. On the other hand, the French and German balloons are able to carry four times this weight, with the exception of the French auxiliaries, which are designed to lift one observer only. The balloons of the two latter Powers have also a greater maximum altitude; it is possible to ascend to a height of some 2,000 feet in one of these.
The observing station is connected with the winding crew below either by a telephone, or some other signalling system, the method practised varying according to circumstances. In turn the winding station is connected with the officer in charge of the artillery, the fire of which the captive balloon is directing. The balloon observer is generally equipped with various instruments, such as telescope, photographic cameras, and so forth, so as to be able, if necessary, to prepare a topographical survey of the country below. By this means the absence of reliable maps may be remedied, or if not regarded, as sufficiently correct they may be checked and counter-checked by the data gained aloft.
Seeing that the gas has to be transported in cylinders, which are weighty, it is incumbent that the waste of this commodity should be reduced to the minimum. The balloon cannot be deflated at night and re-inflated in the morning—it must be maintained in the inflated condition the whole time it is required for operation.
There are various methods of consummating this end. One method is to haul in the balloon and to peg it down on all sides, completing the anchorage by the attachment of bags filled with earth to the network. While this process is satisfactory in calm weather, it is impracticable in heavy winds, which are likely to spring up suddenly. Consequently a second method is practised. This is to dig a pit into the ground of sufficient size to receive the balloon. When the latter is hauled in it is lowered into this pit and there pegged down and anchored. Thus it is perfectly safe during the roughest weather, as none of its bulk is exposed above the ground level. Furthermore it is not a conspicuous object for the concentration of hostile fire.
In some instances, and where the military department is possessed of an elaborate equipment such as characterises the German army, when reconnaissance is completed and the balloon is to be removed to another point, the gas is pumped back into the cylinders for further use. Such an economical proceeding is pretty and well adapted to manoeuvres, but it is scarcely feasible in actual warfare, for the simple reason that the pumping takes time. Consequently the general procedure, when the balloon has completed its work, is to permit the gas to escape into the air in the usual manner, and to draw a fresh supply of gas from further cylinders when the occasion arises for re-inflation.
Although the familiar spherical balloon has proved perfectly adequate for reconnoitring in the British and French armies, the German authorities maintained that it was not satisfactory in anything but calm weather. Accordingly scientific initiative was stimulated with a view to the evolution of a superior vessel. These endeavours culminated in the Parseval-Siegsfeld captive balloon, which has a quaint appearance. It has the form of a bulky cylinder with hemispherical extremities. At one end of the balloon there is a surrounding outer bag, reminiscent of a cancerous growth. The lower end of this is open. This attachment serves the purpose of a ballonet. The wind blowing against the opening, which faces it, charges the ballonet with air. This action, it is claimed, serves to steady the main vessel, somewhat in the manner of the tail of a kite, thereby enabling observations to be made as easily and correctly in rough as in calm weather. The appearance of the balloon while aloft is certainly curious. It appears to be rearing up on end, as if the extremity saddled with the ballonet were weighted.
British and French captive balloon authorities are disposed to discount the steadying effect of this attachment, and, indeed, to maintain that it is a distinct disadvantage. It may hold the vessel steadier for the purpose of observation, but at the same time it renders the balloon a steadier target for hostile fire. On the other hand, the swaying of a spherical balloon with the wind materially contributes to its safety. A moving object, particularly when its oscillations are irregular and incalculable, is an extremely difficult object at which to take effective aim.
Seeing that even a small captive balloon is of appreciable dimensions—from 25 to 33 feet or more in diameter—one might consider it an easy object to hit. But experience has proved otherwise. In the first place the colour of the balloon is distinctly protective. The golden or yellowish tinge harmonises well with the daylight, even in gloomy weather, while at night-time it blends excellently with the moonlight. For effective observations a high altitude is undesirable. At a height of 600 feet the horizon is about 28 miles from the observer, as compared with the 3 miles constituting the range of vision from the ground over perfectly flat country. Thus it will be seen that the "spotter" up aloft has the command of a considerable tract.
Various ways and means of finding the range of a captive balloon have been prepared, and tables innumerable are available for committal to memory, while those weapons especially designed for aerial targets are fitted with excellent range-finders and other instruments. The Germans, with characteristic thoroughness, have devoted considerable attention to this subject, but from the results which they have achieved up to the present this guiding knowledge appears to be more spectacular and impressive than effective.
To put a captive balloon out of action one must either riddle the envelope, causing it to leak like a sieve, blow the vessel to pieces, or ignite the highly inflammable gas with which it is inflated. Individual rifle fire will inflict no tangible damage. A bullet, if it finds its billet, will merely pass through the envelope and leave two small punctures. True, these vents will allow the gas to escape, but this action will proceed so slowly as to permit the vessel to remain aloft long enough to enable the observer to complete his work. A lucky rifle volley, or the stream of bullets from a machine gun may riddle the envelope, precipitating a hurried descent, owing to the greater number of perforations through which the gas is able to escape, but as a rule the observer will be able to land safely.
Consequently the general practice is to shatter the aerostat, and to this end either shrapnel, high explosive, or incendiary shells will be used. The former must explode quite close to the balloon in order to achieve the desired end, while the incendiary shell must actually strike it, so as to fire the gas. The high explosive shell may explode effectually some feet away from the vessel, inasmuch as in this instance dependence is placed upon the terrific concussion produced by the explosion which, acting upon the fragile fabric of the balloon, brings about a complete collapse of the envelope. If a shrapnel is well placed and explodes immediately above the balloon, the envelope will be torn to shreds and a violent explosion of the gas will be precipitated. But as a matter of fact, it is extremely difficult to place a shrapnel shell so as to consummate this end. The range is not picked up easily, while the timing of the fuse to bring about the explosion of the shell at the critical moment is invariably a complex problem.
One favourite method of finding the range of a balloon is shown in the accompanying diagrams. The artillery battery is at B and the captive balloon, C, is anchored at A. On either side of B and at a specified distance, observers O1 and O2 respectively are stationed. First a shell is fired at "long" range, possibly the maximum range of the gun. It bursts at D. As it has burst immediately in the line of sight of B, but with the smoke obscured by the figure of the balloon C, it is obvious to B that the explosion has occurred behind the objective, but at what distance he cannot tell. To O1 and O2, however, it is seen to have burst at a considerable distance behind C though to the former it appears to have burst to the left and to the second observer to the right of the target.
Another shell, at "short" range, is now fired, and it bursts at E. The explosion takes place in the line of sight of B, who knows that he has fired short of the balloon because the latter is eclipsed by the smoke. But the two observers see that it is very short, and here again the explosion appears to O1 to have occurred to the right of the target, while to O2 it has evidently burst to the left of the aerostat, as revealed by the relation of the position of the balloon to the bursting of the shell shown in Fig. 3.
A third round is fired, and the shell explodes at F. In this instance the explosion takes place below the balloon. Both the observers and the artillery man concur in their deductions upon the point at which the shell burst. But the shell must explode above the balloon, and accordingly a fourth round is discharged and the shell bursts at G.
This appears to be above the balloon, inasmuch as the lines of sight of the two observers and B converge at this point. But whether the explosion occurs immediately above the vessel as is desired, it is impossible to say definitely, because it may explode too far behind to be effective. Consequently, if this shell should prove abortive, the practice is to decrease the range gradually with each succeeding round until the explosion occurs at the critical point, when, of course, the balloon is destroyed. An interesting idea of the difficulty of picking up the range of a captive balloon may be gathered from the fact that some ten minutes are required to complete the operation.
But success is due more to luck than judgment. In the foregoing explanation it is premised that the aerial vessel remains stationary, which is an extremely unlikely contingency. While those upon the ground are striving to pick up the range, the observer is equally active in his efforts to baffle his opponents. The observer follows each successive, round with keen interest, and when the shells appear to be bursting at uncomfortably close quarters naturally he intimates to his colleagues below that he desires his position to be changed, either by ascending to a higher point or descending. In fact, he may be content to come to the ground. Nor must the fact be overlooked that while the enemy is trying to place the observer hors de combat, he is revealing the position of his artillery, and the observer is equally industrious in picking up the range of the hostile guns for the benefit of his friends below.
When the captive balloon is aloft in a wind the chances of the enemy picking up the range thereof are extremely slender, as it is continually swinging to and fro. While there is always the possibility of a shell bursting at such a lucky moment as to demolish the aerial target, it is generally conceded to be impossible to induce a shell to burst within 100 yards of a balloon, no matter how skilfully the hostile battery may be operated.
The value of the captive balloon has been demonstrated very strikingly throughout the attack upon the entrenched German positions in Flanders. Owing to the undulating character of the dunes the "spotters" upon the British monitors and battle ships are unable to obtain a sweeping view of the country. Accordingly captive balloons are sent aloft in some cases from the deck of the monitors, and in others from a suitable point upon the beach itself. The aerial observer from his point of vantage is able to pick up the positions of the German forces and artillery with ease and to communicate the data thus gained to the British vessels, although subjected to heavy and continuous hostile fire. The difficulty of hitting a captive balloon has been graphically emphasised, inasmuch as the German artillerists have failed to bring down a solitary balloon. On the other hand the observer in the air is able to signal the results of each salvo fired from the British battleships as they manoeuvre at full speed up and down the coastline, while he keeps the fire of the monitors concentrated upon the German positions until the latter have been rendered untenable or demolished. The accuracy of the British gun-fire has astonished even the Germans, but it has been directly attributable to the rangefinder perched in the car of the captive balloon and his rapid transmission of information to the vessels below.
The enthusiastic supporters of aerial navigation maintained that the dirigible and the aeroplane would supersede the captive balloon completely. But as a matter of fact the present conflict has established the value of this factor more firmly than ever. There is not the slightest possibility that the captive balloon sections of the belligerents will be disbanded, especially those which have the fruits of experience to guide them. The airship and the aeroplane have accomplished wonders, but despite their achievements the captive balloon has fully substantiated its value as a military unit in its particular field of operations.
CHAPTER III. GERMANY'S RISE TO MILITARY AIRSHIP SUPREMACY
Two incidents in the history of aviation stand out with exceptional prominence. The one is the evolution of the Zeppelin airship—a story teeming with romance and affording striking and illuminating glimpses of dogged perseverance, grim determination in the face of repeated disasters, and the blind courageous faith of the inventor in the creation of his own brain. The second is the remarkable growth of Germany's military airship organisation, which has been so rapid and complete as to enable her to assume supremacy in this field, and that within the short span of a single decade.
The Zeppelin has always aroused the world's attention, although this interest has fluctuated. Regarded at first as a wonderful achievement of genius, afterwards as a freak, then as the ready butt for universal ridicule, and finally with awe, if not with absolute terror—such in brief is the history of this craft of the air.
Count von Zeppelin can scarcely be regarded as an ordinary man. He took up the subject of flight at an age which the majority of individuals regard as the opportune moment for retirement from activity, and, knowing nothing about mechanical engineering, he concentrated his energies upon the study of this science to enable him to master the difficulties of a mechanical character incidental to the realisation of his grand idea. His energy and indomitable perseverance are equalled by his ardent patriotism, because, although the Fatherland discounted his idea when other Powers were ready to consider it, and indeed made him tempting offers for the acquisition of his handiwork, he stoutly declined all such solicitations, declaring that his invention, if such it may be termed, was for his own country and none other.
Count von Zeppelin developed his line of study and thought for one reason only. As an old campaigner and a student of military affairs he realised the shortcomings of the existing methods of scouting and reconnoitring. He appreciated more than any other man of the day perhaps, that if the commander-in-chief of an army were provided with facilities for gazing down upon the scene of operations, and were able to take advantage of all the information accruing to the man above who sees all, he would hold a superior position, and be able to dispose his forces and to arrange his plan of campaign to the most decisive advantage. In other words, Zeppelin conceived and developed his airship for one field of application and that alone-military operations. Although it has achieved certain successes in other directions these have been subsidiary to the primary intention, and have merely served to emphasise its military value.
Von Zeppelin was handicapped in his line of thought and investigation from the very first. He dreamed big things upon a big scale. The colossal always makes a peculiar and irresistible appeal to the Teutonic nature. So he contemplated the perfection of a big dirigible, eclipsing in every respect anything ever attempted or likely to be attempted by rival countries. Unfortunately, the realisation of the "colossal" entails an equally colossal financial reserve, and the creator of this form of airship for years suffered from financial cramp in its worst manifestation. Probably it was to the benefit of the world at large that Fortune played him such sorry tricks. It retarded the growth of German ambitions in one direction very effectively.
As is well known Zeppelin evolved what may be termed an individual line of thought in connection with his airship activities. He adopted what is known as the indeformable airship: that is to say the rigid, as opposed to the semi-rigid and flexible craft. As a result of patient experiment and continued researches he came to the conclusion that a huge outer envelope taking the form of a polygonal cylinder with hemispherical ends, constructed upon substantial lines with a metallic skeleton encased within an impermeable skin, and charged with a number of smaller balloon-shaped vessels containing the lifting agent—hydrogen gas—would fulfil his requirements to the greatest advantage. Model after model was built upon these lines. Each was subjected to searching tests with the invariable result attending such work with models. Some fulfilled the expectations of the inventor, others resolutely declined to illustrate his reasonings in any direction.
The inevitable happened. When a promising model was completed finally the inventor learned to his sorrow what every inventor realises in time. His fortune and the resources of others had been poured down the sink of experiment. To carry the idea from the model to the practical stage required more money, and it was not forthcoming. The inventor sought to enlist the practical sympathy of his country, only to learn that in Germany, as in other lands, the axiom concerning the prophet, honour, and country prevails. No exuberant inventor received such a cold douche from a Government as did Count Zeppelin from the Prussian authorities. For two years further work was brought practically to a standstill: nothing could be done unless the sinews of war were forthcoming. His friends, who had assisted him financially with his models, now concluded that their aid had been misplaced.
The inventor, though disappointed, was by no means cast down. He clung tenaciously to his pet scheme and to such effect that in 1896 a German Engineering Society advanced him some funds to continue his researches. This support sufficed to keep things going for another two years, during which time a full-sized vessel was built. The grand idea began to crystallise rapidly, with the result that when a public company was formed in 1898, sufficient funds were rendered available to enable the first craft to be constructed. It aroused considerable attention, as well it might, seeing that it eclipsed anything which had previously been attempted in connection with dirigibles. It was no less than 420 feet in length, by 38 feet in diameter, and was fitted with two cars, each of which carried a sixteen horse-power motor driving independent propellers rigidly attached to the body of the vessel. The propellers were both vertical and horizontal, for the purpose of driving the ship in the two planes—vertical and horizontal respectively.
The vessel was of great scientific interest, owing to the ingenuity of its design and construction. The metallic skeleton was built up from aluminium and over this was stretched the fabric of the envelope, care being observed to reduce skin friction, as well as to achieve impermeability. But it was the internal arrangement of the gas-lifting balloons which provoked the greatest concern. The hull was divided into compartments, each complete in itself, and each containing a small balloon inflated with hydrogen. It was sub-division as practised in connection with vessels ploughing the water applied to aerial craft, the purpose being somewhat the same. As a ship of the seas will keep afloat so long as a certain number of its subdivisions remain watertight, so would the Zeppelin keep aloft if a certain number of the gas compartments retained their charges of hydrogen. There were no fewer than seventeen of these gas-balloons arranged in a single line within the envelope. Beneath the hull and extending the full length of the latter was a passage which not only served as a corridor for communication between the cars, but also to receive a weight attached to a cable worked by a winch. By the movement of this weight the bow or stem of the vessel could be tilted to assist ascent and descent.
The construction of the vessel subsequently proved to be the easiest and most straightforward part of the whole undertaking. There were other and more serious problems to be solved. How would such a monster craft come to earth? How could she be manipulated upon the ground? How could she be docked? Upon these three points previous experience was silent. One German inventor who likewise had dreamed big things, and had carried them into execution, paid for his temerity and ambitions with his life, while his craft was reduced to a mass of twisted and torn metal. Under these circumstances Count Zeppelin decided to carry out his flights over the waters of the Bodensee and to house his craft within a floating dock. In this manner two uncertain factors might be effectively subjugated.
Another problem had been ingeniously overcome. The outer envelope presented an immense surface to the atmosphere, while temperature was certain to play an uncertain part in the behaviour of the craft. The question was to reduce to the minimum the radiation of heat and cold to the bags containing the gas. This end was achieved by leaving a slight air space between the inflated gas balloons and the inner surface of the hull.
The first ascent was made on July 2nd, 1900, but was disappointing, several breakdowns of the mechanism occurring while the vessel was in mid-air, which rendered it unmanageable, although a short flight was made which sufficed to show that an independent speed of 13 feet per second could be attained. The vessel descended and was made fast in her dock, the descent being effected safely, while manoeuvring into dock was successful. At least three points about which the inventor had been in doubt appeared to be solved—his airship could be driven through the air and could be steered; it could be brought to earth safely; and it could be docked.
The repairs to the mechanism were carried out and on October 17th and 21st of the same year further flights were made. By this time certain influential Teuton aeronautical experts who had previously ridiculed Zeppelin's idea had made a perfect volte-face. They became staunch admirers of the system, while other meteorological savants participated in the trials for the express purpose of ascertaining just what the ship could do. As a result of elaborate trigonometrical calculations it was ascertained that the airship attained an independent speed of 30 feet per second, which exceeded anything previously achieved. The craft proved to be perfectly manageable in the air, and answered her helm, thus complying with the terms of dirigibility. The creator was flushed with his triumph, but at the same time was doomed to experience misfortune. In its descent the airship came to "earth" with such a shock that it was extensively damaged. The cost of repairing the vessel was so heavy that the company declined to shoulder the liability, and as the Count was unable to defray the expense the wreck was abandoned.
Although a certain meed of success had been achieved the outlook seemed very black for the inventor. No one had any faith in his idea. He made imploring appeals for further money, embarked upon lecturing campaigns, wrote aviation articles for the Press, and canvassed possible supporters in the effort to raise funds for his next enterprise. Two years passed, but the fruits of the propaganda were meagre. It was at this juncture, when everything appeared to be impossible, that Count Zeppelin discovered his greatest friend. The German Emperor, with an eye ever fixed upon new developments, had followed Zeppelin's uphill struggle, and at last, in 1902, came to his aid by writing a letter which ran:—
"Since your varied flights have been reported to me it is a great pleasure to me to express my acknowledgment of your patience and your labours, and the endurance with which you have pressed on through manifold hindrances till success was near. The advantages of your system have given your ship the greatest attainable speed and dirigibility, and the important results you have obtained have produced an epoch-making step forward in the construction of airships and leave laid down a valuable basis for future experiments."
This Imperial appreciation of what had been accomplished proved to be the turning point in the inventor's fortunes. It stimulated financial support, and the second airship was taken in hand. But misfortune still pursued him. Accidents were of almost daily occurrence. Defects were revealed here and weaknesses somewhere else. So soon as one trouble was overcome another made itself manifest. The result was that the whole of the money collected by his hard work was expended before the ship could take to the air. A further crash and blasting of cherished hopes appeared imminent, but at this moment another Royal personage came to the inventor's aid.
The King of Wurtemberg took a personal interest in his subject's uphill struggle, and the Wurtemberg Government granted him the proceeds of a lottery. With this money, and with what he succeeded in raising by hook and by crook, and by mortgaging his remaining property, a round L20,000 was obtained. With this capital a third ship was taken in hand, and in 1905 it was launched. It was a distinct improvement upon its predecessors. The airship was 414 feet in length by 38 feet in diameter, was equipped with 17 gas balloons having an aggregate capacity of 367,000 cubic feet of hydrogen, was equipped with two 85 horse-power motors driving four propellers, and displaced 9 tons. All the imperfections incidental to the previous craft had been eliminated, while the ship followed improved lines in its mechanical and structural details.
The trials with this vessel commenced on November 30th, 1905, but ill-luck had not been eluded. The airship was moored upon a raft which was to be towed out into the lake to enable the dirigible to ascend. But something went wrong with the arrangements. A strong wind caught the ungainly airship, she dipped her nose into the water, and as the motor was set going she was driven deeper into the lake, the vessel only being saved by hurried deflation.
Six weeks were occupied in repairs, but another ascent was made on January 17th, 1906. The trials were fairly satisfactory, but inconclusive. One of the motors went wrong, and the longitudinal stability was found to be indifferent. The vessel was brought down, and was to be anchored, but the Fates ruled otherwise. A strong wind caught her during the night and she was speedily reduced to indistinguishable scrap.
Despite catastrophe the inventor wrestled gamely with his project. The lessons taught by one disaster were taken to heart, and arrangements to prevent the recurrence thereof incorporated in the succeeding craft. Unfortunately, however, as soon as one defect was remedied another asserted itself. It was this persistent revelation of the unexpected which caused another period of indifference towards his invention. Probably nothing more would have been heard of the Zeppelin after this last accident had it not been for the intervention of the Prussian Government at the direct instigation of the Kaiser, who had now taken Count Zeppelin under his wing. A State lottery was inaugurated, the proceeds of which were handed over to the indefatigable inventor, together with an assurance that if he could keep aloft 24 hours without coming to earth in the meantime, and could cover 450 miles within this period, the Government would repay the whole of the money he had lavished upon his idea, and liquidate all the debts he had incurred in connection therewith.
Another craft was built, larger than its predecessors, and equipped with two motors developing 170 horse-power. Upon completion it was submitted to several preliminary flights, which were so eminently successful that the inventor decided to make a trial trip under conditions closely analogous to those imposed for the Government test. On June 20th, 1908, at 8:26 a.m. the craft ascended and remained aloft for 12 hours, during which time it made an encouraging circular tour. Flushed with this success, the Count considered that the official award was within reach, and that all his previous disasters and misfortunes were on the eve of redemption.
The crucial test was essayed on August 5th, 1908. Accompanied by twelve observers the vessel ascended and travelled without incident for eight hours. Then a slight mishap demanded attention, but was speedily repaired, and was ignored officially as being too trivial to influence the main issue. Victory appeared within measurable distance: the arduous toil of many patient years was about to be rewarded. The airship was within sight of home when it had to descend owing to the development of another motor fault. But as it approached the ground, Nature, as if infuriated at the conquest, rose up in rebellion. A sudden squall struck the unwieldy monster. Within a few moments it became unmanageable, and through some inscrutable cause, it caught fire, with the result that within a few moments it was reduced to a tangled mass of metallic framework.
It was a catastrophe that would have completely vanquished many an inventor, but the Count was saved the gall of defeat. His flight, which was remarkable, inasmuch as he had covered 380 miles within 24 hours, including two unavoidable descents, struck the Teuton imagination. The seeds so carefully planted by the "Most High of Prussia" now bore fruit. The German nation sympathised with the indomitable inventor, appreciated his genius, and promptly poured forth a stream of subscriptions to enable him to build another vessel. The intimation that other Powers had approached the Count for the acquisition of his idea became known far and wide, together with the circumstance that he had unequivocally refused all offers. He was striving for the Fatherland, and his unselfish patriotism appealed to one and all. Such an attitude deserved hearty national appreciation, and the members of the great German public emptied their pockets to such a degree that within a few weeks a sum of L300,000 or $1,500,000 was voluntarily subscribed.
All financial embarrassments and distresses were now completely removed from the Count's mind. He could forge ahead untrammelled by anxiety and worry. Another Zeppelin was built and it created a world's record. It remained aloft for 38 hours, during which time it covered 690 miles, and, although it came to grief upon alighting, by colliding with a tree, the final incident passed unnoticed. Germany was in advance of the world. It had an airship which could go anywhere, irrespective of climatic conditions, and in true Teuton perspective the craft was viewed from the military standpoint. Here was a means of obtaining the mastery of the air: a formidable engine of invasion and aerial attack had been perfected. Consequently the Grand Idea must be supported with unbounded enthusiasm. The Count was hailed by his august master as "The greatest German of the twentieth century," and in this appreciation the populace wholeheartedly concurred. Whether such a panegyric from such an auspicious quarter is praise indeed or the equivalent of complete condemnation, history alone will be able to judge, but when one reflects, at this moment, upon the achievements of this aircraft during the present conflagration, the unprejudiced will be rather inclined to hazard the opinion that Imperial Teuton praise is a synonym for damnation.
Although the Zeppelin was accepted as a perfect machine it has never been possible to disperse the atmosphere of disaster with which it has been enveloped from the first. Vessel after vessel has gone up in smoke and flame: few craft of this type have enjoyed more than an evanescent existence; and each successive catastrophe has proved more terrible than its predecessor. But the Teutonic nation has been induced to pin its whole faith on this airship, notwithstanding that the more levelheaded engineers of other countries have always maintained the craft to be a "mechanical monstrosity" condemned from its design and principles of construction to disaster. Unshaken by this adverse criticism, Germany rests assured that by means of its Zeppelins it will achieve that universal supremacy which it is convinced is its Destiny.
This blind child-like faith has been responsible for the establishment and development of the Zeppelin factories. At Friedrichshafen the facilities are adequate to produce two of these vessels per month, while another factory of a similar capacity has been established at Berlin. Unfortunately such big craft demand large docks to accommodate them, and in turn a large structure of this character constitutes an easy mark for hostile attack, as the raiding airmen of the Allies have proved very convincingly.
But the Zeppelin must not be under-rated. Magnificent performances have been recorded by these vessels, such as the round 1,000 miles' trip in 1909, and several other equally brilliant feats since that date. It is quite true that each astounding achievement has been attended by an equally stupendous accident, but that is accepted as a mere incidental detail by the faithful Teutonic nation. Many vivid prophecies of the forthcoming flights by Zeppelin have been uttered, and it is quite probable that more than one will be fulfilled, but success will be attributable rather to accident than design.
Although the Zeppelin is the main stake of the German people in matters pertaining to aerial conquest, other types of airships have not been ignored, as related in another chapter. They have been fostered upon a smaller but equally effective scale. The semi-rigid Parseval and Gross craft have met with whole-hearted support, since they have established their value as vessels of the air, which is tantamount to the acceptance of their military value.
The Parseval is pronounced by experts to be the finest expression of aeronautical engineering so far as Teuton effort is concerned. Certainly it has placed many notable flights to its credit. The Gross airship is an equally serviceable craft, its lines of design and construction closely following those of the early French supple airships. There are several other craft which have become more or less recognised by the German nation as substantial units of war, such as the Ruthemberg, Siemens-Schukert, and so forth, all of which have proved their serviceability more or less conclusively. But in the somewhat constricted Teuton mind the Zeppelin and the Zeppelin only represents the ultima Thule of aerial navigation and the means for asserting the universal character of Pan-Germanism as well as "Kultur."
CHAPTER IV. AIRSHIPS OF WAR
So much has been said and written concerning the Zeppelin airship, particularly in its military aspect, that all other developments in this field have sunk into insignificance so far as the general public is concerned. The Zeppelin dirigible has come to be generally regarded as the one and only form of practical lighter-than-air type of aircraft. Moreover, the name has been driven home with such effect that it is regarded as the generic term for all German airships.
These are grievous fallacies. The Zeppelin is merely one of a variety of types, even in Germany, although at the moment it probably ranks as the solitary survivor of the rigid system of construction. At one time, owing to the earnestness with which the advantages of this form of design were discussed, and in view of the fact that the Zeppelin certainly appeared to triumph when all other designs failed, Great Britain was tempted to embrace the rigid form of construction. The building of an immense vessel of this class was actively supported and it was aptly christened the "May-fly." Opponents of the movement tempered their emphatic condemnatory criticism so far as to remark that it MAY FLY, but as events proved it never did. The colossal craft broke its back before it ever ventured into the air, and this solitary experience proving so disastrous, the rigid form of construction was abandoned once and for all. The venture was not in vain; it brought home to the British authorities more convincingly than anything else that the Zeppelin was a mechanical monstrosity. The French never even contemplated the construction of such a craft at that time, estimating it at its true value, and the British failure certainly served to support French antagonism to the idea. Subsequently, however, an attempt at rigid construction was made in France with the "Spiess" airship, mainly as a concession to public clamour.
Even in Germany itself the defects of the Zeppelin were recognised and a decided effort to eliminate them was made by Professor Schutte in co-operation with a manufacturer of Mannheim named Lanz. The joint product of their ambitions, the Schutte-Lanz, is declared to be superior to the Zeppelin, but so far it has failed to justify any of the claims of its designers. This vessel, which also favours the colossal, is likewise of the rigid type, but realising the inherent dangers accruing from the employment of metal for the framework, its constructors have used wood, reinforced and strengthened where necessary by metallic angle-iron, plates, and bracing; this utilisation of metal is, however, carried out very sparingly. The first vessel of this class was a huge failure, while subsequent craft have not proved much more successful.
In fact, one of the largest German airships ever designed, L4, is, or rather was, a Schutte-Lanz, with a capacity of 918,000 cubic feet, but over 6,000 pounds lighter than a Zeppelin of almost similar dimensions. I say "was" since L4 is no more. The pride of its creators evinced a stronger preference for Davy Jones' Locker than its designed realm. Yet several craft of this type have been built and have been mistaken for Zeppelins owing to the similarity of the broad principles of design and their huge dimensions. In one vital respect they are decidedly inferior to their contemporary—they are not so speedy.
The most successful of the German lighter-than-air machines are those known respectively as the semi rigid and non-rigid types, the best examples of which are the Gross and Parseval craft. Virtually they are Teutonic editions of the successful French craft of identical design by which they were anticipated. The Lebaudy is possibly the most famous of the French efforts in this direction. The gas-bag has an asymmetrical shape, and is pointed at both ends, although the prow is blunter or rounder than the stem. The gas-bag comprises a single chamber for the inflating agent, the distended shape of the envelope being sustained by means of an air-ballonet. By varying the contents of the latter through the agency of a pump the tension of the gas in the lifting envelope can be maintained, and the shape of the inflated balloon preserved under all conditions.
Beneath the gas-bag is a long strengthened girder, and from this in turn the car is suspended. It is the introduction of this rigid girder which is responsible for the descriptive generic term of "semi-rigid." On the other hand the "non-rigid" type may be roughly described as a pisciform balloon fitted with propelling machinery, inasmuch as the car containing the driving machinery is suspended from the balloon in the manner of the car in the ordinary drifting vessel. So far as the French effort is concerned the Bayard-Clement type is the best example of the non-rigid system; it is represented in Germany by the Parseval class.
The Gross airship has been definitely adopted as a military machine by the German authorities, and figures in the "M" class. The "M-IV" completed in 1913 is the largest of this type, and differs from its prototypes in that it carries two cars, each fitted with motors, whereas the earlier machines were equipped with a single gondola after the French pattern. This vessel measures 320 feet in length, has a maximum diameter of 44 1/2 feet, displaces 13 tons, and is fitted with motors developing 450 horse-power, which is sufficient to give it a speed of 47 miles per hour. This vessel represents a huge advance upon its predecessors of this design, inasmuch as the latter were about 245 feet in length by 36 1/4 feet in diameter, and displaced only six tons, while the single car was provided with a motor developing only 150 horse-power, the speed being 28 miles per hour. Thus it will be seen that a huge development has suddenly taken place, a result due no doubt to the co-operation of the well-known engineer Basenach. The "M-IV" is essentially an experiment and great secrecy has been maintained in regard to the trials which have been carried out therewith, the authorities merely vouchsafing the fact that the airship has proved completely successful in every respect; conclusive testimony of this is offered by the inclusion of the vessel in the active aerial fleet of Germany.
But it is the Parseval which is regarded as the finest type of airship flying the German flag. This vessel is the product of slow evolution, for it is admitted to be a power-driven balloon. Even the broad lines of the latter are preserved, the shape being that of a cylinder with rounded ends. It is the direct outcome of the "Drachen-Balloon," perfected by Parseval and Siegsfeld, the captive balloon which is an indispensable part of the German military equipment.
The complete success of the suspension system in this captive balloon prompted Parseval to continue his researches and experiments in regard to the application of power to the vessel, so as to induce it to move independently of the wind. The suspension system and the car are the outstanding features of the craft. It is non-rigid in the strictest interpretation of the term, although, owing to the incorporation of the steadying hollow "mattress" (as it is called by its inventor), the strength of the suspension system, and the substantial character of the car, it conveys an impression of great solidity. The thinnest rope, both manilla and steel, in the suspension system is as thick as a man's finger, while the car, measuring 30 feet in length by 6 feet in width, carried out in wood, is a striking example of the maximum of strength with the minimum of weight, being as steady and as solid as a boat's deck. The propellers are collapsible, although in the latest craft of this class they are semi-rigid.
The mechanical equipment is also interesting. There are two propellers, and two motors, each nominally driving one propeller. But should one motor break down, or motives of economy, such as husbanding of fuel, render it advisable to run upon one engine, then the two propellers may be driven by either of the motors.
The inventor has perfected an ingenious, simple, and highly efficient coupling device to attain this end, but to ensure that the propeller output is of the maximum efficiency in relation to the engine, the pitch of the propellers may be altered and even reversed while the engine is running. When one motor only is being used, the pitch is lowered until the propellers revolve at the speed which they would attain if both engines were in operation. This adjustment of the propeller pitch to the most economical engine revolutions is a distinctive characteristic, and contributes to the efficiency and reliability of the Parseval dirigible to a very pronounced degree.
Steering in the vertical plane is also carried out upon distinctive lines. There are no planes for vertical steering, but movement is accomplished by tilting the craft and thus driving the gas from one end of the balloon to the other. This is effected by the manipulation of the air-ballonets, one of which is placed at the prow and stem of the gas bag respectively. If it is desired to descend the gas is driven from the forward to the after end of the envelope, merely by inflating the bow ballonet with air by means of a pump placed in the car. If ascent is required, the after-ballonet is inflated, thereby driving the gas to the forward end of the balloon, the buoyancy of which is thus increased. The outstanding feature of the "Drachen-Balloon" is incorporated in the airship. This is the automatic operation of the safety valve on the gas-bag directly by the air ballonets. If these ballonets empty owing to the pressure of the gas within the envelope, a rope system disposed within the balloon and connecting the ballonets and the gas-valve at the top is stretched taut, thereby opening the gas-valve. In this manner the gas-pressure becomes reduced until the ballonets are enabled to exercise their intended function. This is a safety precaution of inestimable value.
The Parseval is probably the easiest dirigible to handle, inasmuch as it involves no more skill or knowledge than that required for an ordinary free balloon. Its movements in the vertical plane are not dissimilar to those of the aeroplane, inasmuch as ascent and descent are normally conducted in a "screwing" manner, the only exception being of course in abrupt descent caused by the ripping of the emergency-valve. On one occasion, it is stated, one of the latest machines of this type, when conducting experimental flights, absolutely refused to descend, producing infinite amusement both among the crowd and those on board.
The development of the Parseval is directly attributable to the influence and intimate interest of the Kaiser, and undoubtedly this represents the wisest step he ever made in the realm of aeronautics. It certainly has enabled the German military machine to become possessed of a significant fleet of what may be described as a really efficient and reliable type of dirigible. The exact number of military Parsevals in commission is unknown, but there are several classes thereof, in the nature of aerial cruisers and vedettes.
The largest and most powerful class are those known as the B type, measuring about 240 feet in length by 40 feet maximum diameter, of 223,000 cubic feet capacity, and fitted with two motorsand two propellers. This vessel carries about 10 passengers, can climb to a maximum height of approximately 8,500 feet, and is capable of remaining in the air for twenty hours upon a single fuel charge. While this is the largest and most serviceable type of Parseval designed for military duties, there is another, the A class, 200 feet in length with accommodation for six passengers in addition to the crew of three, which is capable of attaining a maximum altitude of 6,700 feet, and has an endurance capacity of 15 hours. This class also is fitted with twin propellers and motors. In addition there are the C and E classes, carrying from four to eight passengers, while the vedettes are represented by the D and F classes, which have a maximum altitude of 2,000 feet and can remain aloft for only five hours upon a single fuel charge. These smaller vessels, however, have the advantage of requiring only one or two men to handle them. The present military Parseval dirigible is made in one of these five standardised classes, experience having established their efficiency for the specified military services for which they are built. In point of speed they compare favourably with the latest types of Zeppelin, the speeds of the larger types ranging from 32 to 48 miles per hour with a motor effort of 360 to 400 horse-power.
So far as the French airships of war are concerned, the fleet is somewhat heterogeneous, although the non-rigid type prevails. The French aerial navy is represented by the Bayard-Clement, Astra, Zodiac, and the Government-built machines. Although the rigid type never has met with favour in France, there is yet a solitary example of this system of construction—the Spiess, which is 460 feet in length by 47 feet in diameter and has a displacement of 20 tons. The semi-rigid craft are represented by the Lebaudy type, the largest of which measures 293 feet in length by 51 feet in diameter, and has a displacement of 10 tons.
One may feel disposed to wonder why the French should be apparently backward in this form of aerial craft, but this may be explained by the fact that the era of experiment had not been concluded at the time war was declared, with the result that it has been somewhat difficult to determine which type would meet the military requirements of the country to the best advantage. Moreover, the French military authorities evinced a certain disposition to relegate the dirigible to a minor position, convinced that it had been superseded by the heavier-than-air machine. Taken on the whole, the French airship fleet is inferior to the German in point of speed, if not numerically, but this deficiency is more than counterbalanced by the skill and ability of the men manning their craft, who certainly are superior to their contemporaries in Germany, combined with the proved character of such craft as are in service.
The same criticism may be said to apply to Great Britain. That country was backward in matters pertaining to the airship, because its experiments were carried out spasmodically while dependence was reposed somewhat too much upon foreign effort. The British airships are small and of low speed comparatively speaking. Here again it was the advance of the aeroplane which was responsible for the manifestation of a somewhat indifferent if not lethargic feeling towards the airship. Undoubtedly the experiments carried out in Great Britain were somewhat disappointing. The one and only attempt to out-Zeppelin the Zeppelin resulted in disaster to the craft before she took to the air, while the smaller craft carried out upon far less ambitious lines were not inspiritingly successful. Latterly the non-rigid system has been embraced exclusively, the craft being virtually mechanically driven balloons. They have proved efficient and reliable so far as they go, but it is the personal element in this instance also which has contributed so materially to any successes achieved with them.
But although Great Britain and France apparently lagged behind the Germans, appreciable enterprise was manifested in another direction. The airship was not absolutely abandoned: vigilance was maintained for a superior type of craft. It was an instance of weighing the advantages against the disadvantages of the existing types and then evolving for a design which should possess the former without any of the latter. This end appears to be achieved with the Astra type of dirigible, the story of the development of which offers an interesting chapter in the annals of aeronautics.
In all lighter-than-air machines the resistance to the air offered by the suspension ropes is considerable, and the reduction of this resistance has proved one of the most perplexing problems in the evolution of the dirigible. The air is broken up in such a manner by the ropes that it is converted into a brake or drag with the inevitable result that the speed undergoes a severe diminution. A full-rigged airship such as the Parseval, for instance, may present a picturesque appearance, but it is severely unscientific, inasmuch as if it were possible to eliminateor to reduce the air-resistance offered by the ropes, the speed efficiency might be raised by some sixty per cent and that without any augmentation of the propelling effort. As a matter of fact Zeppelin solved this vexatious problem unconsciously. In his monster craft the resistance to the air is reduced to a remarkable degree, which explains why these vessels, despite all their other defects are able to show such a turn of speed.
It was this feature of the Zeppelin which induced Great Britain to build the May-fly and which likewise induced the French Government to stimulate dirigible design and construction among native manufacturers, at the same time, however, insisting that such craft should be equal at least in speed to the Zeppelins. The response to this invitation was the Spiess, which with its speed of 45 miles per hour ranked, until 1914, as one of the fastest dirigibles in the French service.
In the meantime a Spanish engineer, Senor Torres, had been quietly working out a new idea. He realised the shortcomings of the prevailing types of airships some eleven years ago, and unostentatiously and painstakingly set out to eliminate them by the perfection of a new type of craft. He perfected his idea, which was certainly novel, and then sought the assistance of the Spanish Government. But his fatherland was not adapted to the prosecution of the project. He strove to induce the authorities to permit even a small vessel to be built, but in vain. He then approached the French Astra Company. His ambition was to build a vessel as large as the current Zeppelin, merely to emphasise the value of his improvement upon a sufficiently large scale, and to enable comparative data concerning the two designs to be obtained. But the bogey of expense at first proved insuperable. However, the French company, decided to give the invention a trial, and to this end a small "vedette" of about 53,000 cubic feet displacement was built.
Although an unpretentious little vessel, it certainly served to emphasise the importance of the Torres idea. It was pitted against the "Colonel Renard," the finest ship at that time in the French aerial service, which had proved the fastest airship in commission, and which also was a product of the Astra Company. But this fine craft was completely outclassed by the puny Astra-Torres.
The builders and the inventor were now additionally anxious to illustrate more emphatically the features of this design and to build a far larger vessel. The opportunity was offered by the British Government, which had been following the experiments with the small Astra-Torres in France. An order was given for a vessel of 282,500 cubic feet displacement; in this instance it was ranged against another formidable rival—the Parseval. But the latter also failed to hold its own against the Spanish invention, inasmuch as the Astra-Torres built for the British authorities exceeded a speed of 50 miles per hour in the official tests. This vessel is still doing valuable duty, being attached to the British air-service in France.
The achievements of the British vessel were not lost upon the French Government, which forthwith placed an order for a huge vessel of 812,200 cubic feet capacity, equipped with motors developing 1,000 horse-power, which it was confidently expected would enable a speed of 60 miles per hour to be attained. Thus France would be able to meet the Germans upon fairly level terms, inasmuch as the speed of the latest Zeppelins does not exceed 60 miles per hour. So confident were the authorities that a second order for an even larger vessel was placed before the first large craft was completed.
This latter vessel is larger than any Zeppelin yet built, seeing that it displaces 38 tons, and is fitted with motors developing 1,000 horse-power. It has recently been completed, and although the results of the trials, as well as the dimensions of the craft have not been published, it is well known that the speed has exceeded 60 miles per hour, so that France now possesses the speediest dirigible in the world.
The Torres invention has been described as wonderful, scientifically perfect and extremely simple. The vessel belongs to the non-rigid class, but the whole of the suspension system is placed within the gas-bag, so that the air-resistance offered by ropes is virtually eliminated in its entirety, for the simple reason that practically no ropes are placed outside the envelope. The general principle of design may be gathered from the accompanying diagram. It is as if three sausage-shaped balloons were disposed pyramidally—two lying side by side with one super-imposed, with the bags connected at the points where the circular sections come into contact. Thus the external appearance of the envelope is decidedly unusual, comprising three symmetrical ridges. At the points where the three bags come into contact cloth bands are stretched across the arcs, thereby forming a cord. The suspension system is attached to the upper corners of the inverted triangle thus formed, and converges in straight lines through the gas space. The bracing terminates in collecting rings from which a short vertical cable extends downwards through a special accordion sleeve to pass through the lower wall of the envelope. These sleeves are of special design, the idea being to permit the gas to escape under pressure arising from expansion and at the same time to provide ample play for the cable which is necessary in a flexible airship.
This cable emerges from the envelope only at the point or points where the car or cars is or are placed. In the British airship of this type there is only one car, but the larger French vessels are equipped with two cars placed tandem-wise. The vertical cable, after extending downwards a certain distance, is divided, one rope being attached to one, and the second to the other side of the car. The two-bladed propellers are disposed on either side of the car, in each of which a 500 horse-power motor is placed.
The Astra-Torres type of dirigible may be said to represent the latest expression in airship design and construction. The invention has given complete satisfaction, and has proved strikingly successful. The French Government has completed arrangements for the acquisition of larger and more powerful vessels of this design, being now in the position to contest every step that is made by Germany in this field. The type has also been embraced by the Russian military authorities. The Astra-Torres airship has a rakish appearance, and although the lines of the gas-bag are admitted to increase frictional resistance, this is regarded as a minor defect, especially when the many advantages of the invention are taken into consideration.
CHAPTER V. GERMANY'S AERIAL DREADNOUGHT FLEET
Although Germany, as compared with France, was relatively slow to recognise the immense possibilities of aircraft, particularly dirigibles, in the military sense, once the Zeppelin had received the well-wishes of the Emperor William, Teuton activities were so pronounced as to enable the leeway to be made up within a very short while. While the Zeppelin commanded the greatest attention owing to the interesting co-operation of the German Emperor, the other types met with official and royal recognition and encouragement as already mentioned. France, which had held premier position in regard to the aerial fleet of dirigibles for so long, was completely out-classed, not only in dimensions but also in speed, as well as radius of action and strategical distribution of the aerial forces.
The German nation forged ahead at a great pace and was able to establish a distinct supremacy, at least on paper. In the light of recent events it is apparent that the German military authorities realised that the dawn of "The Day" was approaching rapidly, and that it behoved them to be as fully prepared in the air as upon the land. It was immaterial that the Zeppelin was the synonym for disaster. By standardisation its cost could be reduced while construction could be expedited. Furthermore, when the matter was regarded in its broadest aspect, the fact was appreciated that forty Zeppelins could be built at the cost of one super-Dreadnought, so that adequate allowance could be made for accidents now and then, since a Zeppelin catastrophe, no matter how complete it may be, is regarded by the Teuton as a mere incident inseparable from progressive development.
At the beginning of the year 1914 France relied upon being strengthened by a round dozen new dirigibles. Seven of these were to be of 20,000 cubic metres' capacity and possessed of a speed of 47 miles per hour. While the existing fleet was numerically strong, this strength was more apparent than real, for the simple reason that a large number of craft were in dry-dock undergoing repair or overhaul while many of the units were merely under test and could not be regarded therefore as in the effective fleet. True, there were a certain number of private craft which were liable to be commandeered when the occasion arose, but they could not be considered as decided acquisitions for the simple reason that many were purely experimental units.
Aerial vessels, like their consorts upon the water, have been divided into distinctive classes. Thus there are the aerial cruisers comprising vessels exceeding 282,000 cubic feet in capacity; scouts which include those varying between 176,600 and 282,000 cubic feet capacity; and vedettes, which take in all the small or mosquito craft. At the end of 1913, France possessed only four of the first-named craft in actual commission and thus immediately available for war, these being the Adjutant Vincenot, Adjutant Reau, Dupuy de Lome, and the Transaerien. The first three are of 197,800 cubic feet. All, however, were privately owned.
On the other hand, Germany had no fewer than ten huge vessels, ranging from 353,000 to 776,900 cubic feet capacity, three of which, the Victoria Luise, Suchard, and Hansa, though owned privately, were immediately available for war. Of these the largest was the Zeppelin naval vessel "L-1" 525 feet in length, by 50 feet diameter, of 776,900 cubic feet capacity, equipped with engines developing 510 horse-power, and with a speed of 51.8 miles per hour.
At the end of 1913 the effective aerial fleet of Germany comprised twenty large craft, so far in advance of the French aerial cruisers as to be worthy of the name bestowed upon them—"Aerial Dreadnoughts." This merely represented the fleet available for immediate use and did not include the four gigantic Suchard-Schutte craft, each of 847,500 cubic feet, which were under construction, and which were being hurried forward to come into commission early in 1914.
But the most interesting factor, apart from the possession of such a huge fleet of dirigible air-craft, was their distribution at strategical points throughout the Empire as if in readiness for the coming combat. They were literally dotted about the country. Adequate harbouring facilities had been provided at Konigsberg, Berlin, Posen, Breslau, Kiel, Hamburg, Wilhelmshaven, Dusseldorf, Cologne, Frankfort, Metz, Mannheim, Strasburg, and other places, with elaborate headquarters, of course, at Friedrichshafen upon Lake Constance. The Zeppelin workshops, harbouring facilities, and testing grounds at the latter point had undergone complete remodelling, while tools of the latest type had been provided to facilitate the rapid construction and overhaul of the monster Zeppelin dirigibles. Nothing had been left to chance; not an item was perfunctorily completed. The whole organisation was perfect, both in equipment and operation. Each of the above stations possessed provision for an aerial Dreadnought as well as one or more aerial cruisers, in addition to scouts or vedettes.
Upon the outbreak of hostilities Germany's dirigible fleet was in a condition of complete preparedness, was better organised, and better equipped than that of any of her rivals. At the same time it constituted more of a paper than a fighting array for reasons which I will explain later. But there was another point which had escaped general observation. Standardisation of parts and the installation of the desired machinery had accomplished one greatly desired end—the construction of new craft had been accelerated. Before the war an interesting experiment was carried out to determine how speedily a vessel could be built. The result proved that a dirigible of the most powerful type could be completed within eight weeks and forthwith the various constructional establishments were brought into line so as to maintain this rate of building.
The growth of the Zeppelin, although built upon disaster, has been amazing. The craft of 1906 had a capacity of 430,000 cubic feet and a speed of 36 miles per hour. In 1911 the creator of this type launched a huge craft having a capacity of 627,000 cubic feet. In the meantime speed had likewise been augmented by the use of more powerful motors until 52 miles an hour was attained. But this by no means represented the limit. The foregoing vessels had been designed for land service purely and simply, but now the German authorities demanded similar craft for naval use, possessed of high speed and greater radius of action. Count Zeppelin rose to the occasion, and on October 7th, 1912, launched at Friedrichshafen the monster craft "L-I," 525 feet in length, 50 feet in diameter, of 776,900 cubic feet capacity, a displacement of 22 tons and equipped with three sets of motors aggregating more than 500 horse-power, and capable of imparting a speed of 52 miles per hour.
The appearance of this craft was hailed with intense delight by the German nation, while the naval department considered her to be a wonderful acquisition, especially after the searching reliability trial. In charge of Count Zeppelin and manned by a crew of 22 officers and men together with nearly three tons of fuel—the fuel capacity conveys some idea of her possible radius of action—she travelled from Friedrichshafen to Johannisthal in 32 hours. On this remarkable journey another point was established which was of far-reaching significance. The vessel was equipped with wireless telegraphy and therewith she kept in touch with the earth below throughout the journey, dropping and picking up wireless stations as she progressed with complete facility. This was a distinct achievement, inasmuch as the vessel having been constructed especially for naval operations she would be able to keep in touch with the warships below, guiding them unerringly during their movement.
The cross-country trip having proved so completely successful the authorities were induced to believe that travelling over water would be equally satisfactory. Accordingly the "L-I" was dispatched to the island of Heligoland, the intention being to participate in naval manoeuvres in order to provide some reliable data as to the value of these craft operating in conjunction with warships. But in these tests German ambition and pride received a check. The huge Zeppelin was manoeuvring over the North Sea within easy reach of Heligoland, when she was caught by one of those sudden storms peculiar to that stretch of salt water. In a moment she was stricken helpless; her motive power was overwhelmed by the blind forces of Nature. The wind caught her as it would a soap-bubble and hurled her into the sea, precipitating the most disastrous calamity in the annals of aeronautics, since not only was the ship lost, but fifteen of her crew of 22 officers and men were drowned.
The catastrophe created consternation in German aeronautical circles. A searching inquiry was held to explain the disaster, but as usual it failed to yield much material information. It is a curious circumstance, but every successive Zeppelin disaster, and their number is legion, has been attributable to a new cause. In this instance the accident was additionally disturbing, inasmuch as the ship had been flying across country continuously for about twelve months and had covered more miles than any preceding craft of her type. No scientific explanation for the disaster was forthcoming, but the commander of the vessel, who sank with his ship, had previously ventured his personal opinion that the vessel was over-loaded to meet the calls of ambition, was by no means seaworthy, and that sooner or later she would be caught by a heavy broadside wind and rendered helpless, or that she would make a headlong dive to destruction. It is a significant fact that he never had any faith in the airship, at least for sea duty, though in response to official command he carried out his duties faithfully and with a blind resignation to Fate.
Meantime, owing to the success of the "L-I" in cross-country operations, another and more powerful craft, the "L-II" had been taken in hand, and this was constructed also for naval use. While shorter than her consort, being only 487 feet over all, this vessel had a greater beam—55 feet. This latter increase was decided because it was conceded to be an easier matter to provide for greater beam than enhanced length in the existing air-ship harbours. The "L-II" displaced 27 tons—five tons in excess of her predecessor. In this vessel many innovations were introduced, such as the provision of the passage-way connecting the cars within the hull, instead of outside the latter as had hitherto been the practice, while the three cars were placed more closely together than formerly. The motors were of an improved type, giving an aggregate output of 900 horse-power, and were divided into four separate units, housed in two engine-rooms, the front car being a replica in every detail of the navigating bridge of a warship.
This vessel was regarded as a distinct improvement upon the "L-I," although the latter could boast some great achievements. But her glory was short-lived. In the course of the Government trials, while some 900 feet aloft, the huge vessel suddenly exploded and was burned in the air, a mass of broken and twisted metal-work falling to the ground. Of the 28 officers and men, including members of the Admiralty Board who were conducting the official trials, all but one were killed outright, and the solitary exception was so terribly burned as to survive the fall for only a few hours.
The accident was remarkable and demonstrated very convincingly that although Count Zeppelin apparently had made huge strides in aerial navigation through the passage of years, yet in reality he had made no progress at all. He committed the identical error that characterised the effort of Severo Pax ten years previously, and the disaster was directly attributable to the self-same cause as that which overwhelmed the Severo airship. The gas, escaping from the balloons housed in the hull, collected in the confined passage-way communicating with the cars, came into contact with a naked light, possibly the exhaust from the motors, and instantly detonated with terrific force, blowing the airship to fragments and setting fire to all the inflammable materials.
In this airship Zeppelin committed an unpardonable blunder. He had ignored the factor of "internal safety," and had deliberately flown in the face of the official rule which had been laid down in France after the Severo disaster, which absolutely forbade the inclusion of such confined spaces as Zeppelin had incorporated. This catastrophe coming so closely as it did upon the preceding disaster to the pride of the German aerial fleet somewhat shook public confidence in these craft, while aeronautical authorities of other countries described the Zeppelin more vehemently than ever as a "mechanical monstrosity" and a "scientific curiosity." |
|
