Airships

As Europe's industrial revolution progressed during the Nineteenth Century, inventors attempted to harness new power sources to the old hydrogen balloon, to create an 'Air Ship' that was steerable (dirigible in French). By using a steam engine or electric batteries to turn a propeller, it was hoped that aerial navigation could at last become independent of the wind, and that man would sail through the air as easily as he navigated the seas. The first steam balloon was constructed by Frenchman Henri Giffard in 1852, and produced promising results. His second machine, tested in 1855, was unstable, however, and crash-landed on its first flight. It was not until 1872 that anyone was able to produce a full-scale machine that improved on Giffard's design. In that year German Paul Haenlein tested a large dirigible powered by a 3 h.p. gas motor in Austria. Again, the results were promising, but Haenlein ran out of money and had to halt his work. Electric power was tried by the Tissandier brothers in 1883, but they abandoned their experiments when they heard of the success of the France the following year. This large airship was sponsored by the French army, and on 9 August 1884 it finally achieved what was the 'holy grail' of aviation at the time - a deliberate circle through the air. It's 8 h.p. electric motor turned a single propeller at the front of the giant 165 ft. long ship.

As with heavier-than-air aviation, it was the invention of the petrol engine which proved to be the huge spur to lighter-than-air experiments. The honour of first using a petrol motor to power an aircraft (of any sort) fell to a German, Dr Karl Wolfert. In 1896 he constructed a dirigible pointedly named the Deutschland. The gondola was in direct contact with the 28,000 cu. ft. capacity envelope and carried an 8 h.p. Daimler engine. Dr Wolfert made ascents from Templehof in Berlin, on 28 and 29 August 1896 and on 6 March 1897, but did not have a great deal of success in navigation. Tragically, on 14 June 1897 he and his mechanic were killed when the Deutschland caught fire and crashed a few minutes after take off. Escaping hydrogen from the envelope had probably come into contact with the hot exhaust gases from the engine. They were the first victims of power-driven aviation. Future designers would avoid placing the petrol engine so near the flammable hydrogen balloon.

At the same time, Austrian engineer David Schwarz was also attempting to harness the petrol engine to dirigible flight. His airship was highly unusual (and ahead of its time) in being made of sheet aluminium, an eight thousandth of an inch thick, which was supported internally by an aluminium frame braced with wires. The large craft was 156 ft. long and had a capacity of 130,000 cu. ft. Power was provided by a 12 h.p. Daimler engine, driving four propellers, two of which were for steering and two for propulsion. Schwarz's mechanic had the dubious honour of testing his employer's novel brainchild. The airship made its maiden voyage from Templehof, Berlin, on 3 November 1897. It made several successful circles, but then started to descend rapidly before it struck the ground and broke up. This time however the pilot was able to walk away, unhurt.

Alberto Santos-Dumont

Whilst Wolfert and Schwarz were conducting their experiments in Germany, they were eagerly followed by a young Brazilian living in Paris - Alberto Santos-Dumont. After the Wright brothers, Santos-Dumont deserves to be recognized as one of the outstanding figures in early aviation history. He had come to France from South America in the 1890s precisely to investigate the problems of flight. His success must have surpassed even his highest hopes. His achievement was twofold - not only did he introduce Europe to heavier-than-air flight by aeroplane (see Europe's First Flight), but first he also played the leading role in developing the airship into a practical craft. 

After some brief experiments with free balloons he constructed his first dirigible in 1898, the year after Schwarz's crash. He christened it the Santos-Dumont No.1. It was made of lightweight Japanese silk, had a capacity of 6,350 cu.ft. and was powered by a 3 h.p. electric motor. In common with many other quirky Santos-Dumont designs, the No.1 was no bigger than was strictly necessary to lift its pilot. Santos-Dumont did not even have room to sit down in the tiny wicker basket. A successful take off was made on 20 September 1898 from the Jardin d'Acclimatation, a botanical garden to the west of Paris, and the Brazilian rose to 1,300 ft. But on the descent the gas in the long cylindrical envelope lost pressure and it began to collapse. Fortunately, the little Brazilian was not badly hurt. The airship had been built with two gas compartments: one for hydrogen, and another smaller one for air. The idea was that air could be pumped into the smaller compensating balloon in order to keep the main envelope fully inflated as hydrogen leaked out. Unfortunately, the pump fitted had not been powerful enough and so the main envelope had lost its shape. Writing later, Santos-Dumont expressed his disapproval of any aviator who foolishly insisted "on rising to these altitudes without adequate purpose in the early stages of their experience with dirigible balloons!" Had the pump failed altogether, Santos-Dumont could have been killed.

The year 1898 also saw the German Count von Zeppelin file a patent for his giant airship design. The contrast between Santos-Dumont's small-scale approach in France and the giant German concept could not have been more marked. Throughout the early 1900s, while the Brazilian was building his little airships in and around Paris, von Zeppelin was conducting his parallel experiments in Germany.

The determined Brazilian modified his design so that envelope failure should be impossible. This time a long sausage shape was rejected in favour of an elliptical envelope, similar to the one Giffard had used. Since it was thickest in the middle it should be unable to fold up on itself. The Santos-Dumont No.3 first flew on 13 November 1899. It solved the problem, but the other problems of aerial navigation remained. No.3 never managed to return to its starting point - the acid test for a true dirigible.

The Deutsch Prize

At this point, a new incentive to airship development was announced by a wealthy member of the French Aero Club, Henri Deutsch de la Meurthe. He would stake a prize of 100,000 francs for the first airship to complete the journey from the Aero Club's Parc d'Aerostation at Saint-Cloud to the Eiffel Tower and back again in under thirty minutes. The distance was 11 km (6.8 miles), which meant an average speed of 14 mph would be required. Santos-Dumont took up the challenge and that year built himself a hanger at Saint-Cloud, from which most of his future experiments were conducted. Santos-Dumont No.4 was constructed there before the end of 1900. It had a long thin envelope (of 14,800 cu.ft.), which supported just a single spar in place of a gondola. To this pole were attached a tractor propellor, a 9 h.p. petrol engine, fuel, ballast and a bicycle seat for the pilot! The design made many test flights before it was transformed into Santos-Dumont No.5 in the summer of 1901. The pole gave way to a lattice-work girder made of wood in triangular cross-sections, while the engine was up-rated to a 16 h.p. Buchet motor weighing 215 lb. The traditional wicker basket reappeared as pilot's accommodation. The No.5 was also notable in its use of piano wire to connect gondola to envelope. This was the first time that the material had been used in aviation, but it's drag-reducing properties meant it would soon become universal.

The inventor at the controls of a typical Santos-Dumont airship. Sandbags are located on the transverse wooden pole in front of the 
pilot so that they can be adjusted to aid balance. The engine is connected to the pusher propeller by a long metal shaft.

With No.4/5 now in the form he wanted, Santos-Dumont felt it was time to head out over Paris and see just how long it would take to reach the Eiffel Tower. On 12 July 1901 he made three flights over the city and on the last one he reached the Tower and rounded it. However, he was forced to land in gardens near the Trocadero area in order to make adjustments to the rudder. The next day Santos-Dumont succeeded in making the round trip from Saint-Cloud to the Eiffel Tower and back again. It had taken forty minutes; just ten minutes longer than allowed. 

On 8 August 1901 he tried again. He had reached the Tower successfully and was round it when a bad hydrogen leak began to force him down rapidly. He was unable to steer for open space and was forced to crash land on the Trocadero Restaurant. The airship's envelope was ripped to shreds and the framework was left dangling precariously from the walls of the building several stories up. Somehow the framework was steady enough for the shaken pilot to climb to safety, aided by the Paris fire brigade!

Undaunted, Santos-Dumont immediately began to construct a replacement. Santos-Dumont No.6 had a capacity of 22,239 cu.ft. and was 108 ft. in length. She was ready by 6 September 1901, just 22 days after the loss of No.5. However, another attempt on the Deutsch Prize could not take place until nearly a month later owing to handling problems discovered during trials. Unsurprisingly, Santos-Dumont was not keen to risk his neck a second time with a hasty attempt at the prize on an untested machine. The problems were finally ironed out, and the weather was suitable again, by 19 October 1901.

At 2:42 p.m. Santos-Dumont left Saint-Cloud and headed out over Paris once more. With a following wind measured at 20 feet per second he reached the Eiffel Tower just nine minutes later at 2:51 p.m. Slightly miscalculating the turn, he narrowly missed colliding with it! However, he succeeded in getting No.6 back under control and pointing back to his base. The return leg in the face of the wind was always going to be a near thing, and technically Santos-Dumont did not make it. He crossed the finishing line at exactly 3:12 and 40 seconds. However, despite some mean spirited complaints, the judges awarded him the 100,000 franc prize and overlooked the odd 40 seconds. Santos-Dumont clearly deserved as much for all his efforts. He also received a similar sum from the Brazilian Government for his exploits. Most of the money was given away to Parisian charities by Santos-Dumont, greatly endearing him to the city.

Alberto Santos-Dumont had graphically demonstrated that the airship was now (thanks largely to his own experimental efforts) a practical vehicle. Moreover, in 1901, two years before the Wright brothers flew, and seven before Europe acknowledged their achievement, the airship seemed like the best answer to the problem of powered flight. However, it would not all be 'plain sailing' for the airship in the years to come.