David Schwarz
David Schwarz (December 20, 1852, Keszthely, Hungary – January 13, 1897, Vienna) was a Croatian aviation pioneer.
Schwarz created the first flyable rigid airship. It was also the first airship with an external hull made entirely of metal. He died before he could see it finally fly.
David Schwarz was a wood merchant born in Županja, but he spent most of his life in Zagreb, then part of the Kingdom of Croatia-Slavonia, Austro-Hungarian Empire.
Although Schwarz had no special technical training, he busied himself with technology and developed improvements for woodcutting machinery.
Schwarz first interested himself with airships in the 1880s. This occurred as he stayed in a Croatian log cabin at the start of winter to supervise the treefelling in a newly purchased forest.
David Schwarz worked out the construction of an all-metal airship. He then offered his documents to the Austria-Hungary war minister. Great interest was shown, but no one was ready to provide financial support.
The Russian military attaché, a technically educated man, advised Schwarz to demonstrate his airship in St. Petersburg. There, an airship following Schwarz's idea was built in 1893.
Schwarz and later also his widow assumed that test flights would also be made there, but this did not happen. He began construction late 1892, with industrialist Carl Berg supplying the aluminium and necessary funding. Sources report problems arose during gas-filling. George Whale wrote that on "inflation, the framework collapsed". Dooley cites Robinson's detailed dimensions, weights and engine performance, and reports several deficiencies in the design: Schwarz apparently intended the metal skin to hold the gas directly without gas bags; Russian engineer Kowanko pointed out the lack of a ballonet would cause stresses on the skin during ascent and descent; the skin was not airtight; temporary "filling bags" were also not airtight, Schwarz and the manufacturer both blaming each other; and finally the skin imploded after filling directly and waiting.
In Germany in 1894, Carl Berg procured a contract to build an airship for Royal Prussian Government, citing Schwarz as idea-provider. Carl Berg had already experience in working and developing the then new aluminium, and was to later deliver parts for Zeppelin's first airship. With financial and technical help from Berg and his firm, the airship was designed and built.
The construction began in 1895 at the Tempelhof field in Berlin. For a time the Prussian Airship Battalion put its grounds and personnel at Schwarz's disposal. The pieces were produced in Carl Berg's Eveking Westphalia factory and under the direction of Schwarz, assembled in Berlin. A gondola, also of aluminium, was fixed to the framework. Attached to the gondola was a 12 horsepower Daimler engine that drove aluminium propellers. One of the propellers was used to steer the craft.
In 1896 June Carl Berg was in Moscow and sent a card to his stepfather, apparently indicating that he had searched for information on Schwarz and became cynical of delays and was nearly convinced he had been swindled.
Due to delays, the airship was first filled with gas on 1896-10-09 and tested, but the results were not satisfactory because the hydrogen gas delivered by the Vereinigten Chemischen Fabriken from Leopoldshall (part of Staßfurt) was not of the required quality and did not provide sufficient lift. (Some sources mention a test was done on October 8, 1896. It was reckoned that gas with a density of 1.15 kg per cubic metre was needed. Gas with that quality could not be produced until 1897, the year of Schwarz's death.
Schwarz did not live to see the maiden flight of his airship. Between 1892 until 1896 he was often traveling, which had affected his health. In 1897-01-13 he collapsed in the street in Vienna by the restaurant "Zur Linde" and died minutes later in a hallway from heart failure.
The city of Vienna honoured David Schwarz with an Ehrengrab (a memorial grave) and with a Grabmal (a kind of tomb) at the Zentralfriedhof.
Carl required confirmation of Schwarz's death, suspecting he had fled to sell his secrets. Nevertheless, Berg resumed the work with Melanie, Schwarz's widow and together with the Airship Battalion they completed the airship with the addition of a gas relief valve.
This second airship had a gas volume of 4,610 cubic metres and a length of 38.32 metres
The second airship tested with partial success at Tempelhof near Berlin, Germany, on 3 November 1897. Battalion mechanic Ernst Jägels climbed into the gondola and lifted off at 15:00. The ship broke free of the ground crew, and because it rose too fast Jägels disengaged the horizontal propeller. At about 130 metre altitude the driving belt slipped off the left propeller, causing partial loss of steering, the ship "turned broadside to the wind, and the forward tether broke free." As the ship drifted up to 510 metres the belt slipped off the right propeller, thus losing all steering. Jägels then opened the newly fitted gas release valve and landed safely, but the ship turned over and collapsed.
Starting around the time of the trial flight crash, and for decades after, various reports were written, some often conflicting and misleading.
Later, Berg, and also his son would write negatively of his experiences with Schwarz.
Some sources say Count Ferdinand von Zeppelin purchased the patent from his widow in 1898, others claim he used the design.
See Also
Sources of Information
- [1] Wikipedia