AIRSHIP, a power-driven aircraft which is sustained in the air through the agency of the lift of a buoyant gas contained in an outer envelope. The first known flight, however, made by a lighter-than-air balloon was with one filled, not with gas, but with heated air.
Two French brothers, J. M. and J. E. Montgolfier, were the inventors of this embryo airship. Their family owned a paper mill at Annonay where they experimented with large paper en velopes open at the bottom ; under the aperture they burnt more paper; the air inside becoming hotter than the air outside, the envelope rose. Their success so pleased the brothers that they, re peated their experiments throughout 1783, each time on a larger scale, until in April they built a balloon with a capacity of 23,000 cu.ft. In June this balloon made a public ascent from Annonay before astounded onlookers, and, indeed, to the intense wonder ment of the civilized world.
The Montgolfiers built more balloons, one lifting a load of some 400-500 lb. whilst a third made an ascent at Versailles in the presence of Louis XVI. and Marie Antoinette. It landed its passengers, consisting of a cock, a duck and a sheep, safely two miles away.
The first human ascent was made by J. F. P. de Rozier on Oct. 15, 1783, in a captive balloon; i.e., one attached by a rope to the ground. The King, who, like everyone in Paris, was taking an interest in balloons, would not allow his subjects to risk their lives by rising in a free balloon. He conceded that two convicts should be the first aeronauts, and be pardoned if they came down alive. However, this honour was snatched from them by the enthusiastic young Frenchman, de Rozier, who obtained Louis' permission to make an ascent, taking with him as companion his friend the marquis d'Arlandes. , The Montgolfier balloon for this flight was 74ft. high by 48ft. diameter, having a large opening underneath, below which was slung, by iron chains, a brazier.
On Nov. 21, 1783, at 1.54 P.M., after one false start this historic flight started before a vast crowd in the Bois de Boulogne. The balloon rose to 3,000ft. and remained visible to all Paris for some 20 minutes, landing 14m. from the point of departure. The fuel used was straw put into the brazier and stirred by the marquis d'Arlandes, who is referred to in contemporary accounts as the "chauffeur." This was literally an epoch-making flight—a flight which opened men's eyes to the fact that there actually existed a new mode of transport.
All the features of a modern balloon as now used are more or less due to Charles, who invented the valve at the top and sus pended the car from a hoop, which was in turn attached to the balloon by netting.
Free ballooning having started with a dash remained for a century not much more than a desultory sport. Few could afford it as a pastime even after the introduction of coal gas by the English balloonist, Green, in 1821. It, therefore, except in time of war, fell into the hands of professional balloonists who gave exhibitions at fairs and entertainments. From time to time at tempts were made to organize an industry, but without success. The utter helplessness of the pilot to control its direction pre vented the balloon from ever becoming a practical means of trans pert, and since the place of descent might be the sea, as a specu lative amusement it had more than a fair share of danger.
It was not until 6o or 7o years later, in 1851, that the next step was accomplished, when an engineer named Henri Giffard, well known as the inventor of the steam injector, constructed a 5 h.p. steam engine weighing 1 oo lb., or 20 lb. per h.p., which he used as the motive power for an elongated balloon. Giffard cal culated that this engine would give a speed of about 4-5 m.p.h. and such was approximately the result obtained. He constructed several other airships with a certain measure of success, and it is interesting to note that he planned one of 1,97oft. long by 98ft. diameter, with a capacity of 7,800,000 cu.ft. He estimated that the engine would weigh 3o tons and give a speed of 45 m.p.h. The cost was far too great to permit him to carry out this plan.
Among other experimentalists of the second half of the 19th century may be mentioned Charles Renard and Kreb, who created a sensation in 1885 by forming a figure of eight in the air. They drove their airship by means of an electric motor at a speed of about 14 m.p.h. Experiments were also carried out in Germany and Austria.
The year 1898 may be considered the birth year of the modern airship, which the advent of the internal combustion engine, with its more reasonable proportion of weight to horse power, made a practical proposition. A steam engine with its necessary ad juncts of boiler and boiler water was always too heavy, besides which the boiler itself throwing out smouldering sparks was not the best possible companion to an inflammable gas.
This year saw two men of widely different character, with dif ferent ends in view, commence a series of interesting trials with airships, one Alberto Santos Dumont, a young Brazilian, in France, the other, in Germany, an elderly German, Count Ferdinand von Zeppelin.
Count F. von Zeppelin.—Count von Zeppelin, a retired Ger man Army officer, started work in 1898 on the construction of a dirigible which was not only the largest balloon yet built but different from all previous ships in that it possessed a rigid frame work. It was 42oft. long, 38ft. in diameter and had a capacity of 400,000 cu.ft. The framework was of aluminium, which was covered with specially treated linen and silk. The hydrogen was contained in special compartments or gasbags inside. The en gines were two 16 h.p. motors, each on a separate car. He also adopted the same idea as Santos Dumont of having a sliding weight with which to raise or lower the nose. The first successful trial flight of Zeppelin's craft was made on Oct. 21, 1900, when a speed of nearly 20 m.p.h. was attained.
Zeppelin at first found considerable difficulty in raising funds. However, by 19o5, he had collected enough to build an improved model very slightly smaller than "No. 1" but with two 85h.p. motors which were actually lighter than the 16h.p. of the former —the whole airship weighing 9 tons or a ton less than its predeces sor. After two unimpressive trial flights, a strong wind so damaged it while at anchor that it was dismantled. Zeppelin then started work on "No. 3," an airship which in 1906 justified his faith. German patriotism and enthusiasm were now roused ; subscrip tions were started and a quarter of a million pounds quickly raised. The Kaiser decorated Count Zeppelin with the Order of the Black Eagle, and shortly afterwards issued orders that "No. 3" should be known as "S.M.S. Zeppelin No. 1." Development of Airships by Nations Since 1859, when Count Zeppelin flew his first semi-rigid craft, about 15o dirigibles have been built, but more than half of them have met with disaster. Several nations, including England, the United States, France, Italy, and notably Germany have experi mented with their development, but only Germany has shown any record of consistent performance in the bigger type of ships.
Germany.—A German zeppelin company, formed by Count Zeppelin, between 1910 and 1914 built a succession of rigid air ships, which as commercial craft carried during these years more than 17,000 passengers and flew ioo,000 miles without one fatality. Chiefly because of its pre-World War background in airship experi mentation and construction, this country from 1914 to 1918 readily built a large number of dirigibles. Many of these were destroyed during the great conflict, and those that remained were either dismantled under the Treaty of Versailles or delivered to the Allies as war indemnity.
One impressive wartime zeppelin performance was given in 1917 in the flight of the German "L-57" from Jamboli, Bulgaria to the Daka Oasis in East Africa and return without landing, a flight of 4,20o miles in 96 hours. Strategic Allied centres were sub ject to German zeppelin raids during the war, particularly Lon don, although these raids were fraught with exceeding danger to the raiding ships because of the anti-aircraft defense which the Allies developed against attack from the skies. At the same time, however, the zeppelins struck with considerable effect, particu larly against the morale of the Allied homelands. (See AIR RAIDS.) Ten years after the Armistice the "LZ-12 7," named the Graf Zeppelin in memory of Count Zeppelin, was completed at Fried richshafen as a peacetime commercial vessel, and began immedi ately to be the greatest lighter-than-air demonstrator since the early years of airship building. Shortly after its test flights in Europe, the "Graf Zeppelin" made a voyage to the United States, covering nearly 6,30o miles, remaining aloft 112 hours, during which it circumnavigated many storm areas, despite a badly dam aged stabilizing fin for a portion of the voyage over the Atlantic. The ship carried 20 passengers, freight, mail and a crew of 4o.
In the first eight years of its career, the "Graf Zeppelin" made more than Soo trips, covering 775,00o miles in a flight time of 12,50o hours. She carried 12,50o passengers, averaging 25 per trip, which, with her crew, means that about 65 persons were aboard each time she went aloft. In addition to the passenger list, she carried about 85,00o pounds of mail and io5,000 pounds of freight in her wanderings over the North and South Atlantic, one trip across the Pacific and over the Arctic Circle. Her aver age speed for all these operations was 62 miles an hour, which, while slower than estimates for the performance of her successor, the "LZ-129," is none the less impressive, considering the "Graf Zeppelin's" earlier date of construction and her consistent flying.
The "LZ-128," while designed, never went far beyond the blue print stage, and the "LZ-129" became the next German airship of importance. Considered to sustain the lighter-than-air prestige so ably built up by the "Graf Zeppelin" but so badly damaged by accidents to airships of other countries, the "LZ-129" was de signed as the biggest airship built up to its time. Its plans included accommodations for 5o passengers, aside from com modious space for crew and cargo. Specifications called for a length of 813 feet, diameter of 135 feet, and gas (helium) capacity of 6,720,00o cubic feet. The performance figures included an 8,000 mile range at 8o m.p.h. cruising speed, and a North Atlantic schedule of 4o to 42 hours eastbound (with prevailing winds) and 6o to 65 hours westbound.
The "LZ-129" frame was built of longitudinal and transverse girders of duralumin, including 15 main support polygon rings of 36 angles each, spaced 44 feet apart fore and aft of the hull, and 32 auxiliary rings, the hull containing 16 compartments for as many lifting gas cells. Power of the "LZ-129" was designed to come from four diesel engines, totalling 4,40o horsepower, each engine gondola being a unit in itself and accessible from the in side hull gangways to permit work upon the motors while the airship was in flight. Storage for crude oil for the diesel engines was built into the keel of the ship, fuel capacity amounting to 130,000 lbs. (See Arts ROUTES.) Great Britaincannot be said to have contributed in any degree to the development of airships prior to the World War and the whole history of British airship activity has been one of private individuals urging the Government to stimulate and encourage their development. As a result of persistent advocacy by Mr. Coswell the British War Office was induced to form a balloon de partment under Captain Templar in 1879. This corps served in Suakin in 1885 and in the Boer War, but it was not until after private individuals, such as Dr. Barton in 1900 and Mr. Willows in 1904, had constructed and demonstrated small non-rigid air ships that the War Office were prevailed upon to start work upon a few small airships at the Government balloon factory in 1907. Although, as it will be remembered, Zeppelin had achieved a de cided success with his fourth airship by this date, the British Government factory proceeded to construct a succession of five small non-rigid vessels of from 21,00o to 7 7, 50o ft. No novel feature was introduced and the vessels, because of their small size, were below the standard of contemporary foreign vessels.
By 1909, British public opinion had become alarmed at the dis parity of achievement between Germany and England, and the Admiralty was authorized to construct England's first rigid air ship, named the "Mayfly." This craft, of 800,000 cubic feet gas capacity, was larger than any such vessel previously built, but the vessel was wrecked in September of 1911 while being removed from her shed, and even before she ever took the air.
No lives were lost in the "Mayfly" accident, but the disaster caused suspension of airship development in England until the end of 1913 when an airship section of the Royal Naval Air Serv ice was set up by the Admiralty. Under this new department, another rigid airship of approximately 800,000 cubic feet was or dered from Messrs. Vickers, Ltd. Construction was commenced in the early part of 1914, but after the outbreak of the World War the Admiralty countermanded the order and all work was suspended in March of 1915, it being thought that the vessel would not be completed before the war ended. A few months later, however, the German zeppelin air raids induced a reversal of position, and not only was the ship, the "R-9," ordered finished, but orders were given for further craft. The "R-9" was completed in April of 1917. She had a speed of 45 m.p.h. but her useful lift was very small and on that account had limited endurance, which rendered her of little value except for training purposes, although she carried out several patrols in the North Sea. No new feature of importance was embodied and she compared un favourably with contemporary German vessels, Germany by the outbreak of the war having had the experience of construction of more than 3o zeppelins.
Non-rigid Airships.—As a result of the Government's vacillat ing policy in regard to rigid airships, the war found both the Brit ish Admiralty and the War Office unprepared in this direction, and in the first few months efforts were concentrated upon the small non-rigid airship for coast patrol and the kite balloon for Army observation work. The first of the small airships, named officially the "S.S." type (Sea Scout) but more popularly called Blimp, was completed by Feb. 1915 and in 1916 a more developed type called the "S.S.Z." was produced. These were followed a year later by the "S.S.T." type (Sea Scout Twin) and in each case an increase of size, speed and range was involved. The "S.S.T." had a speed of 5o m.p.h. and could patrol for 5o hours at a stretch.
These vessels were supplemented by larger vessels of the sane type, the most notable being the "N.S." (North Sea) type of 36o, 00o cu.ft. displacement, with a maximum speed of S5 m.p.h. These vessels did remarkably good work and in 1918 there were only nine days in which British airships did not fly, and in that year up to the time of the armistice they had completed over 50,00o flying hours.
Other Rigid Airships.—Other rigid airships ordered after the contract for the "R-9" had been reinstated in 1915 were known as the "R-23" class, and although they were an improvement on the "R-9," they still did not match the German ships of the time, but in 1916 the German zeppelin"L-33"was brought down in good con dition at Colchester and served as a model from which the and "R-34" were built. These vessels, which were not completed until after the war, were a marked improvement on any vessel that had been constructed previously in England ; the "R-34" in 919 made the first trans-Atlantic dirigible flight, but was destroyed in January of 1921. No lives were lost in the accident, which oc curred at Howden where high winds tore her to pieces while she was at her mooring.
In 1917, another vessel of 1,250,00o cu.ft. was ordered from Messrs. Vickers, Ltd. This vessel, called the "R.8o," was the first rigid airship built in England that embodied any new feature other than those of minor constructional importance. The departure from contemporary practice consisted in building the hull of a good streamline form without any parallel portion. Unfortunately the performance of this vessel was not great, chiefly because of poor engine equipment. Completed in 192o, she was inferior to the German-built "Bodensee," a vessel of approximately the same size, and completed about a year earlier. This latter vessel was used upon a regular service in 1919 between Friedrichshafen and Berlin, and made Io3 voyages carrying 2,43o passengers without mishap. The high speed of 81 m.p.h. has been claimed for her.
In August 1918, the design of a new vessel, the "R.38" (2,7oo, 00o cu.ft. capacity), was begun at the Government airship works at Cardington. In Oct. 1919, all airship work was transferred from the Admiralty to the Air Ministry. In 1920, the "R.38" was sold by the British to the American Government for $5oo,000, the ship to be delivered to the United States by air. Three test flights re vealed structural and control weaknesses, however, and on the fourth flight, Aug. 23, 1921, the ship broke in two, killing 44 British and American officers and men.
As a result of this disaster the airship department of the Air Ministry was closed down and all airships, airship bases and ma terial turned over to the Disposals Board for sale.
After the destruction of the"R-38," there was no airship activity in England until 1924 when a contract was placed with the Air ship Guarantee Company for a 5,000,000 cubic f t. ship, called the "R-Ioo," and in 1925 under a new policy of the Government the Air Ministry was authorized to build the "R-Ioi," also of 5, 000,000 cubic feet. Orders for both ships called for a speed of 7o m.p.h. and accommodations for ioo passengers. When the new vessels were ordered, the British and Dominion Governments de cided to proceed with the erection of mooring mast bases in Canada, South Africa, Egypt, India and Australia in anticipation of vast operations through the empire.
The "R-i oo" made its first important flight in July of 193o, going from Cardington to Montreal in 79 hours and returning in 57 hours. On October 5th of the same year, however, the "R.-1cm" was destroyed as she crashed on a hilltop near Beauvais, France, and burst into flames, killing 46 persons, including Lord Thomson, Air Minister. The seven who survived were badly injured. After this disaster, the "R-Ioo" was scrapped, bases were no longer maintained and lighter-than-air activity ceased again.
After the United States entered the war, British experience of rigid airships was placed at their disposal, and, in 1918, work was started by the United States naval authorities upon the designs of a rigid vessel about the same size as the British "R.33." This vessel, subsequently called the "Shenandoah" (2,148,000 cu. ft.), was completed in 1923, and made her first flight in September of that year. Two developments were made in this vessel, (I) she was designed to be about 3o% stronger than contemporary vessels of the same size; and (2) helium was employed as a lifting gas in stead of hydrogen. After carrying out a large number of flights and experimental trials at mooring masts the Shenandoah was destroyed in Sept. 1925 on encountering a line squall when over Ohio. The violent vertical gusts generated in this line squall broke the ship into three portions and, unfortunately, the captain and several of the crew were killed.
While the "Shenandoah" was being built, the Italian-built air ship "Roma" arrived in the United States, but this craft crashed to earth at Hampton Roads, Virginia, on Feb. 21, 1922, bringing death to 34 men. She was making a flight to test out new Ameri can motors which had replaced her Italian-built power plant, when a rubber cable snapped and she plunged to earth, striking some high-tension electric wires which ignited the hydrogen in her gas bags.
The United States next acquired the naval dirigible "Los Angeles," a ship of 2,5oo,000 cubic feet which had been built as the "ZR-3" in Germany and delivered to the United States in con formity with the reparations arrangements. The vessel was flown from Friedrichshafen to Lakehurst, N. J. in November of 1924, a distance of 5,000 miles in 81 hours, and was turned over to the Navy for operation. For ten years, the "Los Angeles" served as a training and experimental craft, including demonstrations of picking up and dropping aeroplanes while both were in flight. At the end of ten years new and bigger craft were authorized, and the "Los Angeles" was moored to a mast at the Naval Air Station at Lakehurst, there ostensibly to ride out her life equipped with scientific instruments for the measurement of mooring stresses.
The new ships were the "Akron" and "Macon," built for the Navy with a Government appropriation of $4,000,000 each, and on their completion were considered the last word in dirigible con struction, especially for service purposes. They were both of 6,5oo,000 cubic feet gas volume and had an over-all length of 785 feet and a maximum diameter of 133 feet. Their cruising range was o,58o miles, and in their hulls was hangar space for aero planes. After 1,5oo flight hours, however, the "Akron" crashed into the sea during a storm off the New Jersey coast on April 4, 1933, causing the loss of the lives of 73 officers and men, including Rear Admiral William A. Moffett, chief of the Naval Bureau of Aeronautics. The "Macon," which was completed subsequent to the "Akron," was flown across the United States to its base at Sunnyvale, California, and while there performed considerable scouting work with the surface fleet, but on Feb. 12, 1935 she went down in the Pacific not far off the California coast. Inquiry developed that structural failure during a training flight had thrown the ship out of control. The loss of life in this accident was small, but the loss of the craft was sufficient to intensify the sentiment against lighter-than-air ships and, as in England, dirigible construction in the United States came to a halt.
In the field of smaller lighter-than-air craft the United States has been more fortunate. The Army and the Navy have used blimps to considerable advantage in training and patrol work, and the Goodyear Zeppelin Corporation for many years has main tained a fleet of small ships for advertising, passenger carrying, student training and research.
France.—Airshipdevelopment in France subsequent to Santos Dumont did not justify the hopes encouraged by that country's early contribution to aeronautics. Three commercial companies built a succession of non-rigid and semi-rigid vessels, ranging in size from oo,000 to 800,000 cubic feet, for the French and foreign Governments, and a fourth company built a rigid airship, the "Spiess," of 575,000 cubic feet, in 1912-13, but this vessel had a wooden structure and was unsatisfactory. In 1923, France lost the dirigible "Dixmude" on a flight over the Mediterranean, and the only clue to her fate was the finding of the body of her commander. Fifty men lost their lives in her destruction.
Italy.—Italy built the airship "Roma" which came to disaster in the United States, but also constructed the semi-rigid "Norge," with which in May of 1926, Captain Roald Amundsen's expedi tion flew from Spitzbergen to Alaska, crossing the North Pole and 3,000 miles of the Arctic in 71 hours. Three years later, how ever, the "Italia" with General Umberto Nobile's expedition blew up in the Arctic. General Nobile was rescued, but eight of his men lost their lives. See also TRANS-OCEANIC AND TRANS-CON TINENTAL FLIGHTS.