David Schwarz (aviation inventor) : biography
Return to Germany, construction at Tempelhof
In Germany in 1894, the industrialist Carl Berg procured a contract to build an airship for the Royal Prussian Government, citing Schwarz as the provider of the idea. Berg already had experience working with the then new structural material of 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.Dooley, A.187 For a time the Prussian Airship Battalion placed 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.Whale, Dooley, A.184. Accounts vary, George Whale wrote that the Berlin firm of Weisspfennig and Watzesch built it while Sean Dooley cites the U.S. airship historian Douglas Robinson as stating these were Carl Berg’s engineers. A gondola, also of aluminium, was fixed to the framework. Attached to the gondola was a Daimler engine that drove aluminium propellers. One of the propellers was used to steer the craft.
In June 1896 Carl Berg, in Moscow, 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 and tested on 9 October 1896, 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 purity and did not provide sufficient lift. However some sources mention that a test was performed on 8 October 1896. It was determined that gas with a density of 1.15 kg per cubic metre was needed. Gas of that quality could not be obtained until 13 January 1897, the day of Schwarz’s death.
First airship thoughts
Schwarz first became interested in airships during the 1880s. This occurred as he resided in a Croatian log cabin at the start of winter to supervise the treefelling in a newly purchased forest. As the work took longer than planned he had his wife send him literature to while away the evenings. Because the works of Charles Dickens and Victor Hugo did not appeal to him, an assumption arising from one of his wife’s letters, she sent him a work from Aristotle and a mechanics textbook. Although Schwarz became excited, it is not altogether clear this inspired him to build his own airship. His lumber business suffered due to his obsession and, like other aviation pioneers, his project attracted mockery. Nevertheless his wife Melanie supported him. Schwarz began using aluminium for construction, then a very new material.
David Schwarz was the son of Jewish parents. He was a wood merchant raised in Županja, but he spent most of his life in Zagreb, then part of the Austro-Hungarian Empire.
Although Schwarz had no special technical training, he became occupied with technology and developed improvements for woodcutting machinery.German Wikipedia editors
First airship in Russia
David Schwarz worked out the design of an all-metal airship. He then offered his documents to the Austria-Hungary war minister. Interest was shown, but the government was not 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 his widow, assumed that test flights would also be made there, but this did not happen. He began the construction in late 1892, with the industrialist Carl Berg supplying the aluminium and necessary funding.
Sources reported that 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 contain the gas directly without gas bags. Russian engineer Kowanko pointed out that the lack of a ballonet would cause stresses on the skin during ascent and descent. As well, the skin was not airtight, temporary "filling bags" were also not airtight, with Schwarz and the manufacturer both blaming each other. Finally, the airship’s skin imploded after filling.Dooley, A.185-A.186 citing Robinson, pp2-3
The first airship’s specifications were:Dooley, A.185 citing Robinson, pp2-3
- gas volume:
- empty weight: 2525 kg
- gross lift: 958 kg
- power: four cylinder engine weighing 298 kg, at 480 rpm
- ballast and fuel: 170 kg
- equipment and three people: 385 kg
- net lift: 85 kg
The circumstances of Schwarz’s return are unclear; there were reports of a hasty departure from Russia.