CHAPTER XIII
THE COMMERCIAL ZEPPELIN
THE AMBITION OF THE AGES REALIZED—A GIANT GERMAN DIRIGIBLE—ZEPPELIN ACCOMPLISHMENTS—HIGH COST OF ZEPPELINS—SAFETY OF TRAVEL—SOME BRITISH PREDICTIONS—THE FUTURE OF HELIUM—THE LIFE-BLOOD OF COMMERCE
Almostdaily during the winter of 1918-1919 reports were coming out of Europe to the effect that Zeppelins were being converted into aerial merchantmen to fly regularly between New York and Hamburg.
Because these gigantic lighter-than-air machines, measuring more than 700 feet in length, 70 feet in diameter, buoyed up by more than 2,000,000 cubic feet of hydrogen gas, and driven by six Maybach-Mercedes engines, generating a total of 1,400 horse-power, had carried, in all kinds of weather and under adverse circumstances of war, a crew of forty-eight men and a useful load of four tons from Germany over the British fleet and the North Sea and the anti-aircraft guns and by hostile fleets of Allied aeroplanes, and had successfully raided England and Scotland more than a score of times, returning safely to their home ports, often having flown a total distance of approximately 800 miles—the eyes of the aeronautical world, like search-lights in the night, were sweepingthe heavens over the Atlantic seaboard to discover whether these leviathans of the air or the little dragon-flies of aeroplanes were to be the first to appear in the firmament, aerially transnavigating the 1,195 miles of water that separates the Old World from the New.
Indeed, ever since man has learned to fly he has become such an exalted creature that he has ceased to regard any mechanical feat as impossible. This is, in a measure at least, pardonable when we stop to consider that ever since man got up off his hands and learned to walk upright he has longed to be able to fly as a bird through the heavens in any direction he chose, without let or hindrance, boundary or border. Though he expended every effort to accomplish this feat, and often lost his life in the attempt, for countless ages the privilege to soar aloft was denied him.
In point of time it was, as we have seen, September, 1783, before the Montgolfier brothers succeeded in sending up even a paper bag inflated with hot air, and it was November of the same year before two Frenchmen, the Marquis d’Arlandes and Pilâtre de Roziers, made the world’s first trip in any kind of aerial vehicle—namely, a free balloon.
But these and most of the attempts to navigate the air in the next century were unsuccessful, primarily due to the lack of power adaptable to propelling a gas-bag through the air. In 1852. Henri Gifford, another Frenchman, made the first successful directed flight in a dirigible 143 feet long and 39 feet in diameter. It was inflated with hydrogen and driven by a three-horse-powersteam-engine, an eleven-foot screw propeller, and it made six miles an hour relative to the wind. Owing to the fuel, fire, and weight problems the steam-engine was then impractical as a means of propulsion for lighter-than-air machines.
In 1884 Captain Charles Renard went a step farther in the right direction by installing a 200-pound electric motor, generating nine horse-power. The battery, composed of chlorochromic salts, delivered one shaft horse-power for each eighty-eight pounds of weight, but in spite of such a handicap he flew over Paris at fourteen and a half miles an hour. Nevertheless, the electric motor was also impractical, even for a rigid dirigible. As a matter of fact, every gas-bag was at the mercy of the winds, and could not steer a direct course, until the gasoline motor was invented and developed to generate more than a dozen horse-power.
The first man to build a rigid dirigible with an aluminum framework and drive it with a gasoline motor was an Austrian named Schwartz, but the first man to build, equip, and perform the necessary evolutions with a rigid dirigible was Santos-Dumont, the famous Brazilian. He accomplished this feat in September, 1898, when he set out from the Zoological Gardens at Paris and in the face of a gentle wind steered his airship in nearly every point of the compass. In 1901 he circumnavigated the Eiffel Tower, thus demonstrating the feasibility of the lighter-than-air ship as a practical means of locomotion through the air.
The world’s first successful flight in a man-carrying heavier-than-air machine, made by the Wright brothers two years later at Kitty Hawk, North Carolina, only went further to confirm man’s belief that the conquest of the air and the age of aerial navigation were at hand.
Since then in a heavier-than-air machine man has climbed to 30,500 feet and has flown 920 miles without stopping. In a free balloon man has drifted 1,503 miles through the air—from Paris to Kharkoff, Russia—and to an altitude of over 38,000 feet. In a rigid dirigible the Germans have transported machinery for making munitions all the way from Austria-Hungary over Bulgaria—while that country was still neutral—to Constantinople, a distance of 500 miles; within a radius of 350 miles of Germany, despite all military and naval opposition on land and sea, the Huns have flown with tons of high explosives and dropped them on London, Paris, and Bucharest. In the last days of the war a super-Zeppelin flew from Jamboli, in Bulgaria, to Khartum, in Egypt, and back, a distance of more than 6,000 miles each way, carrying a crew of twenty-two men and twenty-five tons of medicine and munitions. It was intended to transport the supplies to General Lettow-Vorbeck in German East Africa, but a wireless received when the Zeppelin was over Khartum notified its commander to return, for Lettow-Vorbeck had been captured.
On March 22, 1919, the British Government officially announced that the US-11, a non-rigid type of dirigible,had flown 1,285 miles over the North Sea without stopping, the actual flying time being forty and a half hours. The voyage took the form of a circuit, embracing the coast of Denmark, Schleswig-Holstein, Heligoland, North Germany, and Holland.
The trip was characterized by extremely unfavorable weather, and therefore is regarded as ranking as perhaps the most notable flight of the kind ever undertaken. The airship started from the Firth of Forth, laying a straight course toward Denmark. There was a northwest wind of fifteen to twenty miles an hour, and the night was dark, but the airship was only a mile from her course when she passed the Dogger Bank Lighthouse. After passing the lighthouse the velocity of the wind increased, and calcium flares were dropped into the sea frequently to determine the location.
The airship’s troubles began on the return journey. The wind became stronger and more tempestuous. At midnight one engine became useless and the ship was forced a considerable distance to leeward.
The captain contemplated landing in France, but finally decided to hold on in the hope that the wind would abate. The wind abating somewhat, a “land fall” was made at North Forel. At this time the gasoline supply was running low.
In two radically different types of flying-machines man has in the last decade aerially transnavigated great natural and geographic barriers in the form of the Alps, the Pyrenees, and the Taurus Mountains,and the North, the Baltic, the Adriatic, and the Mediterranean Seas. He has made these flights in all kinds of winds, weather, and atmospheric and polemic conditions.
At last he has ascended higher than the lark and flown faster than the eagle and farther than the mightiest bird of prey. Small wonder then that he should consider the flight across the Atlantic by either the aeroplane or the Zeppelin as nothing but a question of time.
As a matter of fact, man does not doubt that eventually not only the Atlantic, the Pacific, and the Seven Seas, but even the globe itself will be aerially transnavigated. His only concern is how soon these feats will be accomplished facts.
Several preparations—but only one real attempt—to fly across the Atlantic had been made up to January, 1919. The first effort to cross the ocean from America to Europe by air was made by Walter Wellman and a crew of five men in the dirigibleAmericaon October 15, 1910. The airship measured 228 feet in length and 52 feet in diameter, with a lifting capacity of twelve tons. The envelope carrying the gas weighed approximately two tons. Attached to the bag was a car 156 feet long. The nine thousand pounds of gasoline necessary for the trip were stored under the floor of the car. TheAmericacarried three eighty horse-power gasoline engines, one of which was a donkey, the two others being used to drive the propellers. Beneath the car hung a 27-foot lifeboat thatwas to be used in case they had to abandon the airship. A 330-foot equilibrator, consisting of a long steel cable on which were strung thirty spool-like steel tanks each carrying 75 pounds of gasoline, and forty wooden blocks, trailed from the cabin. The blocks were about twenty inches long.
The object of the equilibrator was to eliminate ballast. It was intended that the balloon should sail along at a height of about two hundred feet; if it settled close to the water the wooden blocks and the tanks would float on the water and relieve it of some of its weight. TheAmericawas also equipped with sextants, compasses, and other instruments for locating its position, the same as an ocean-liner.
Besides Walter Wellman, the explorer and writer, were Melvin Vaniman, chief engineer; F. Murray Vaniman, navigator of airships; J. K. Irwin, wireless operator; Albert L. Loud and John Aubert, assistant engineers.
They left Atlantic City in a dead calm and were towed out to sea by a motor-boat. Three days later, on October 18, after many vicissitudes the engines broke down and the huge gas-bag was at the mercy of the winds. Wellman and his crew were picked up by the steamerTrent375 miles east of Cape Hatteras. The dirigible had been carried out of its course because of insufficient power to navigate against the winds and had to be abandoned, a total loss.
A year later, financed by the Chamber of Commerce of Akron, Ohio, and one of the large rubber companies,a balloon called theAkron, 268 feet long and 47 feet in diameter, with a gas capacity of 350,000 cubic feet, was built to be flown across the Atlantic by Melvin Vaniman. It had two 105 horse-power engines.
Unfortunately, on July 2, 1912, while making a trial flight over Absecon Inlet, near Atlantic City, the balloon took fire and exploded, killing Melvin Vaniman and the four members of his crew. This disaster put an end to building dirigibles in this country for transatlantic flight.
The preparation for another attempt to cross the Atlantic was made by Glenn H. Curtiss through the generosity of Rodman Wanamaker, who financed the building of the flying-boatAmerica. Owing to the breaking out of the war this project was abandoned.
Neither of these two American-built lighter-than-air ships could be compared in size, engine power, lifting capacity, or flying radius with the dirigibles constructed by the German Government and people under the direction of Count Ferdinand von Zeppelin. Indeed, his first airship, constructed in 1900, measured 410 feet and contained 400,000 cubic feet of hydrogen, whereas the super-Zeppelins were many times larger than either Wellman’s or Vaniman’s airship.
A description of the giant dirigible brought down in the summer of 1916 in Essex, England, will give an excellent idea of the gigantic proportions, the buoyancy, the engine power, and the accommodations of these leviathans of the air.
The airship measured 650 feet to 680 feet in lengthand 72 feet in diameter. The vessel was of cigar-shaped stream-line form, with a blunt rounded nose and a tail that tapered off to a sharp point. The framework was made of longitudinal latticework girders, connected together at intervals by circumferential latticework tires, all made of aluminum alloy resembling duraluminum. The whole was braced and stiffened by a system of wires. The weight of the framework was about nine tons, or barely a fifth of the total of fifty tons attributed to the airship complete with engines, fuel, guns, and crew. There were twenty-four balloonets arranged within the framework, and the hydrogen capacity was 2,000,000 cubic feet.
A cat walk—an arched passage with a footway nine inches wide—running along the keel enabled the crew, which consisted of twenty-two men, to move about the ship and get from one gondola to another. The gondolas, made of aluminum alloy, were four in number: one was placed forward on the centre line; two were amidships, one on each side, and the fourth was aft, again on the centre line.
The vessel was propelled at 60 miles an hour in still air—by means of six Maybach-Mercedes gasoline engines of 240 horse-power each, or 1,440 horse-power in all. Each had six vertical cylinders with overhead valves and water cooling, and weighed about a thousand pounds. They were connected each to a propeller shaft and also to a dynamo used either in lighting or for furnishing power to the wireless installation. One of these engines with its propeller was placed at theback of the large forward gondola; two were in the amidships gondolas, and three were in the after gondola. In the last case one of the propellers was in the centre line of the ship, and the shafts of the two others were stayed out, one on either side. The gasoline-tanks had a capacity of two thousand gallons, and the propeller shafts were carried in ball bearings.
Forward of the engine-room of the front gondola, but separated from it by a small air space, was first the wireless-operator’s cabin and then the commander’s room. The latter was the navigating platform, and in it were concentrated the controls of the elevators and rudder at the stern, the arrangement for equalizing the levels in the gasoline and water tanks, the engine-room telegraphs, and the switchboards of electrical gear for releasing the bombs. Nine machine-guns were carried. Two of these, of half-inch bore, were mounted on the top of the vessel, and six of small caliber were placed in the gondolas—two in the forward, one each in the amidships ones, and two in the aft one. The ninth was carried in the tail.
The separate gas-bags were a decided advantage over the free balloon and earlier airships, which carried all the gas in one compartment; for if the latter sprung a leak for any reason it had to descend, whereas the Zeppelin could keep afloat with several of the separate compartments in a complete state of collapse.
Since the Zeppelin, like all airships, is buoyed up by hydrogen gas—which weighs one and one-tenth pounds per two hundred cubic feet as compared with sixteenpounds which the same amount of air weighs—the dirigible is sent up by the simple expedient of increasing the volume of gas in the envelopes until the vessel rises. This was done by releasing the gas for storage-tanks into the gas-bags. In order to head the nose up, air was kept in certain of the rear bags, thus making the tail heavier than the forward part, which naturally rose first. Steering was done by means of rudder or the engines, or both, and the airship was kept on an even keel by use of lateral planes. The airship could be brought down by forcing the gas out of the bags into the gas-tanks, thus decreasing the volume, and by increasing the air in the various compartments.
This airship had a flying radius of 800 miles, could climb to 12,000 feet, could carry a useful load of 30 tons, and could remain in the air for 50 hours.
Because so many Zeppelins were lost to Germany and because so much time and money were necessary to construct the enormous airships, many people have jumped to the conclusion that the rigid dirigible was an absolute failure even as an offensive war weapon. Yet despite its bulk and the fact that it could not fly faster than seventy miles an hour, and though more than a hundred Zeppelins raided England at some time or another during the war, only two were shot down by aeroplanes and only a few by antiaircraft guns. Most of them were destroyed because they ran out of fuel and consequently became unmanageable and were blown out of their course and forced toland or had to descend so low that they came within easy range of aircraft guns of the land batteries or the naval guns.
This record is truly surprising when we stop to consider that the Zeppelin had to navigate entirely by compass and mostly at night over hundreds of miles of hostile sea and land, opposed by the guns of a huge Allied fleet and thousands of antiaircraft guns, without lights or landmarks to aid them and often with untrained and inexperienced pilots to guide them! No wonder that some of these airships met disaster—like the L-49, which had to land in France; or the L-20, which was forced to land on the Norwegian coast near Stavanger; or others, which came down so low over the North Sea that they became easy targets for the British torpedo-boat guns.
But this is judging the Zeppelins purely as offensive weapons of war. Even as such they forced the British Empire to maintain a large standing army and a huge armament of guns and aeroplanes in England by threatening to land a mammoth army of invasion there from Belgium. What they did to spread terror in Belgium and to keep the German army informed by wireless of the conditions behind the British and French and Belgian lines in the first advance to the Marne is a matter of history. Also what they performed in disorganizing the armies and in disconcerting the people of Antwerp and Bucharest, not to mention many Russian cities and Paris itself, during the Hun advance against those cities, is almost too horribleto relate. Over the Rumanian capital alone they descended so low—because there were no antiaircraft guns to defend the city—that they scarcely flew clear of the buildings as they rained down hundreds of tons of high explosives on the frightened inhabitants, and even bombed a part of the imperial palace, where the Queen was nursing the Crown Prince.
This unlawful use of these giant aircraft does not detract from what they demonstrated could be done in the way of aerial navigation and transportation under the frightful opposition of war, and it is only an augury of what will be accomplished when the same vessels of the air will be put to carrying man up and down the aerial highways of the heavens, which know no barriers, obstructions, or hostile opposition.
Their greatest service to the Germans was as aerial scouts rather than as ethereal battleships or cruisers; and if these rigid dirigibles had performed no other feats for the Huns, from the Teutonic point of view at least, their work in planning and directing every move of the German high-seas fleet in the great naval battle off Jutland amply repaid Germany for the time and money and effort expended in building those air cruisers.
On May 30 in the first stage of that battle it will be recalled that Admiral Sir David Beatty was cruising with his scout fleet looking for the Germans several hundred miles east of the British grand fleet, which was under Admiral Sir John Jellicoe, somewhere off the Orkney Islands. Flying out under the protection of afog-bank that was moving down over the North Sea a German naval Zeppelin discovered the isolated position of Admiral Beatty’s scout fleet and sent a wireless message to the German high-seas fleet, which came out under Admiral Von Scheer with the sole object of cutting off and destroying Admiral Beatty’s fleet before it could unite with the British grand fleet. Undoubtedly, had it not been for a seaplane launched from the mother shipEngadineand flown by Flight Lieutenant Frederick J. Rutland, who discovered the entire German navy coming out, the British scout fleet might have been cut off and completely destroyed before Admiral Jellicoe could come to the rescue.
In the meantime another Zeppelin was hovering over the British grand fleet far to the north and was keeping the German Admiral Von Scheer fully informed by wireless of every ship in the squadron. It was this Zeppelin which finally warned the German admiral to return to the protection of secure fortresses and defenses of the great German naval base of Helgoland. By thus saving the Hun fleet from annihilation in this naval encounter it was possible for the Germans to hold a complete, continuous, and dangerous threat that their navy might again come out to attack England or France and cut off English troops from the Continent. This possibility alone compelled the Allies to maintain, until the close of the war, an enormous fleet at all times in the North Sea.
There is no gainsaying that in time of war the aeroplane has many advantages over the Zeppelin. Theheavier-than-air machine can be produced in quantity much more readily than the lighter-than-air craft. Exact figures on the cost of Zeppelins are not available. W. L. Marsh, in the British publicationAeronautics, gives half a million dollars as the estimated cost of a superdirigible of sixty tons, having a lift of thirty-eight tons. This high cost is due, among other things, to the enormous building in which the airship must be constructed, for it must be borne in mind that one of these dinosaurs of the air extends its bulk along the ground farther than the Woolworth Building towers in the air. Indeed, it could not descend in an ordinary city street because of its bulk, and if it did it would extend more than three city blocks of two hundred feet frontage! Moreover, the plant necessary to generate the hydrogen gas sufficient to inflate a bag of two million cubic feet capacity would cost fifty thousand dollars alone. The amount of aluminum in the L-49, forced to land in France in the spring of 1918, would make a foot-bridge over the East River as long as the famous Brooklyn Bridge!
To land and house such an elusive and buoyant monster requires many winches and some two hundred men. Even then some have been known to run away. This happened in the winter of 1907, when thePatrie, a French semirigid dirigible, which was only a third as large as the German super-Zeppelins, was caught in a gale of wind near Verdun and in spite of the two hundred soldiers who held her in leash she broke her moorings and, flying over France, England,Wales, Ireland, shedding a few fragments on the way, finally disappeared into the sky above the North Atlantic.
On the other hand, a six-ton aeroplane can carry a useful load of two tons and does not cost more than $50,000. Also the wing spread of 150 feet of the largest aeroplane is small compared to a 700-foot Zeppelin. Consequently, aeroplanes can be more readily produced in quantity, can be housed, and require only a half-dozen men to take care of them.
Because of the small size of the scout machine—with only a 26-foot wing spread—and its speed of more than a hundred miles an hour—compared to the Zeppelin speed of 60 or 70 miles—the aeroplane was invaluable for scouting over short distances, for duels in the air, for directing artillery-fire, for contact patrol; and the larger aeroplanes were useful for bombing in huge fleets.
In all other purposes of war the Zeppelin is far superior to the aeroplane. Even the contention that the aeroplanes stopped the Zeppelin raids on England is absurd. It is true that two Zeppelins were brought down over England by aeroplane, but it was September 3, 1916, two years after the breaking out of the war, when young Leefe Robinson brought down the first Hun dirigible over London. It was June 3, 1915, when a Canadian sublieutenant, R. A. J. Warneford, flying a Morane monoplane for the Royal Naval Air Service, got above a dirigible returning to its aerodrome in Belgium from a raid on England and droppeda bomb upon the gigantic gas-bag, blowing it up and killing the crew; but before that came to pass thirteen Zeppelin raids had already been visited upon England, 408 bombs had been dropped, twenty-one persons had been killed and a thousand injured. In both this case and in the case of Lieutenant Robinson, more than a year later, the aeroplanes happened to be in the air above the Zeppelins before they came along, and the aeroplanes in both instances were blown completely upside down by the force of the explosion. Needless to say, a moment later Lieutenant Robinson looped the loop for joy when he saw what destruction he had wrought.
In other words, because the Zeppelins could put out their lights, shut off their motors, and drift through clouds unheard in the night at two thousand feet altitude, and because the dropping of the bombs, like the throwing out of ballast, allowed the dirigibles to jump suddenly up to much higher altitudes, they were as a rule far too elusive for the aeroplanes to get near enough even to shoot incendiary bullets into them.
In point of flying comforts and safety, time that can be spent in the air, flying distances and useful load carried, the Zeppelin is far in advance of any kind of heavier-than-air machine ever built.
Before the war the passenger-carrying ZeppelinsSchwabenandVictoria Louisewere equipped with cabins for the accommodation of twenty-four passengers and crew. Meals were served à la carte; two rows of easy-chairs were arranged before the windows,with a passageway between; and there was a wash-room with water-faucets; which will give an idea of the completeness of the appointments for the comfort of passengers. In the super-Zeppelins constructed since then, and now being fitted to fly the Atlantic, there is ample room for a promenade of four to five hundred feet in the keel. Moreover, there is even a greater opportunity for the giant sky-liners to provide luxurious cabins and other comforts for the travellers, such as of course cannot possibly be supplied on a heavier-than-air machine, where even the chief engineer cannot so much as leave his seat to examine the engine once the machine is in flight!
The ability of the airship to cruise at low heights is another comfort the dirigible enjoys over the aeroplane, which, to insure a safe landing in event of engine trouble, usually navigates across country at five thousand feet altitude or more. The most pleasurable height for air cruising is between five hundred and one thousand feet, for from there the perspective of the countryside is not too diminutive.
As regards the safety of travel in lighter-than-air machines, naturally there have been several disasters such as are inevitable in perfecting a new science. The disasters that occur in the air are closely analogous to those of the sea. The greatest dangers to the airship are the wind, storms, and fire. Of these the last is the most dangerous, because hydrogen gas is so highly explosive. That was what caused the destruction of theAkron, with Vaniman and his companions. Whatcaused the explosion that annihilated the crew of twenty-five of the L-11 in September, 1913, is not known. Perhaps the absorption of the rays of the sun caused the gas to expand, bursting the gas-bags. Glossed surfaces now deflect the rays and help to avoid that danger.
The extraordinary point in the long experimentation with Zeppelins was the immunity of the actual crews of the airships from death, until the thirteenth year of the Zeppelin’s existence. Despite the ever-recurring accidents and the frequent loss of life and serious injury among landing parties and the workshop hands, not a single fatality occurred to any of the navigators until September, 1913, when naval Zeppelin L-1, which was actually the fourteenth Zeppelin to be constructed, was wrecked in the North Sea by a squall, her crew of thirteen being drowned.
Most of the minor accidents to Zeppelins were due to poor landings and high winds. At first this was not to be avoided, because of the huge bulk of these air-liners and their great buoyancy and the ease with which the wind could blow them against their moorings. With experience, though, this was eliminated. Indeed, the officers of the passenger-carryingSchwabennever bothered about the weather, and went out when aeroplanes would not dare go up. TheParseval VImade 224 trips about Berlin within two years’ time, remained in the air a total of 342 hours, carried 2,286 passengers, and travelled a distance of 15,000 miles.
To compare this record with the long list of thosewho have lost their lives in aeroplane flying and experimentation is impossible and of no avail. The radical differences of construction make it much easier for the balloon to avoid disaster than the aeroplane.
Whenever a wing breaks on an aeroplane or whenever the engine on a single-motored machine stops, the aeroplane must fall down or glide to a landing. These defects will undoubtedly be greatly overcome with standardized construction of aircraft and the establishment of proper landing-fields. The hazard, nevertheless, will always be there in some degree.
Such an accident is not frequent with a lighter-than-air machine, which does not depend on its motor but upon gas to keep it afloat. Indeed, an airship may drift hundreds of miles with the wind with all its motors completely shut off—which, by the way, is another reason why the transatlantic fight with the air-currents, which move from America to Europe, seems to be a very feasible possibility for the lighter-than-air craft. The conservation of fuel under such a condition is tremendous.