David Schwartz

David Schwarz (Croatian: David Švarc, pronounced [d%C7%8E%CA%8Bit ʃʋârt͡s];[note 1] 20 December 1850 – 13 January 1897)[1][2] was a Croatian-Hungarian aviation pioneer of Jewish descent born in the Austrian Empire. He is known for creating an airship with a rigid envelope made entirely of metal. .[2] Schwarz died only months before the airship was flown. Some sources[3] have claimed that Count Ferdinand Graf von Zeppelin purchased Schwarz's airship patent from his widow, a claim which has been disputed.[4] He was the father of the opera and operetta soprano Vera Schwarz (1888–1964).

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• https://en.wikipedia.org/wiki/David_Schwarz_(aviation_inventor)
• https://en.wikipedia.org/wiki/David_Schwarz

• References
• Bibliography
• External links

Birth date and nationality

Sources for his date of birth vary. The OCLC cites Rotem, Ẓ. giving it as 7 December 1850, while Brockhaus gives it as 20 December 1850[1] The OCLC, as well as Brockhaus, show Schwarz's place of birth as Zalaegerszeg, Ungarn (Hungary).[1][dubious – discuss]

Sources do not agree regarding Schwarz's nationality: while it is not disputed that he was born a subject of the Austrian Empire and later an Austro-Hungarian citizen, there are claims that he was of either Croatian, or Hungarian nationality.

Early life

David Schwarz was born in Keszthely, Kingdom of Hungary, then part of the Austrian Empire, the son of Jewish parents. He was a timber merchant raised in Županja, but he spent most of his life in Agram, formerly also part of the Austrian Empire, then part of the Austro-Hungarian Empire and today's Zagreb, capital of Croatia.

Although Schwarz had no special technical training, he became interested in technology and developed improvements for woodcutting machinery.

First airship thoughts

Schwarz first became interested in airships during the 1880s. This occurred while working away from home supervising the felling of some forest land. As the work took longer than planned, he had his wife send him books to while away the evenings. These included a mechanics textbook. Although Schwarz became excited, it is not certain that 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 proposed aluminium, then a very new material, for construction.

First airship in Russia

Having worked out the design of an all-metal airship, Schwarz then offered his ideas to the Austro-Hungarian war minister. Some 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, where an airship using Schwarz's ideas was built in 1893.[10][11] Schwarz, and later his widow, assumed that test flights would also be made there, but this did not happen. He began construction in late 1892, with the industrialist Carl Berg supplying the aluminium and necessary funding.[12]

Problems arose during gas-filling: on inflation, the framework collapsed.[10] Schwarz apparently intended the metal skin to contain the gas directly without internal gas bags. The Russian engineer Kowanko pointed out that the lack of a ballonet would cause stresses on the skin during ascent and descent.[13] Also, the skin was not airtight,[14]

The first airship's specifications were:

• Power: four cylinder engine weighing 298 kg (657 lb) producing 10 horsepower (7.5 kW) at 480 rpm
• Volume: 3,280 m3 (116,000 cu ft)
• Empty weight: 2,525 kg (5,567 lb)
• Gross lift: 958 kg (2,112 lb)
• Ballast and fuel: 170 kg (370 lb)
• Equipment and three people: 385 kg (849 lb)
• Net lift: 85 kg (187 lb)

The circumstances of Schwarz's return are unclear; there were reports of a hasty departure from Russia.

Second airship in Berlin

In 1894, Carl Berg procured a contract to build an airship for the Royal Prussian government, referring to Schwarz as the originator of the idea.[15][16] Berg already had experience working with the then novel aluminium, and was to later manufacture components for Zeppelin's first airship. With financial and technical help from Berg and his firm, the airship was designed and built.

Construction began in 1895 at the Tempelhof field in Berlin.[17] For a time the Prussian Airship Battalion placed its grounds and personnel at Schwarz's disposal.[18] The components were produced in Carl Berg's Eveking Westphalia factory and, under the direction of Schwarz, assembled in Berlin.[19] A gondola, also of aluminium, was fixed to the framework. Attached to the gondola was a 12 hp (8.9 kW) Daimler engine that drove aluminium propellers. One of the propellers was used to steer the craft.[10]

In June 1896 Carl Berg sent a card to his stepfather from Moscow apparently indicating that he had searched for information on Schwarz and became cynical of delays and was nearly convinced he had been swindled.[20]

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 delivered by the Vereinigte Chemische Fabriken from Leopoldshall (part of Staßfurt) was not of the required purity and so did not provide enough lift. However, some sources claim that a test was performed on 8 October 1896.[21][22] 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 for some time, and a test flight could not be made until November 1897, roughly ten months after Schwarz's death.[23]

Death and maiden flight

David Schwarz' airship

Schwarz did not live to see his airship fly. Between 1892 and 1896 he traveled frequently, which affected his health. Shortly before his death he received news that his airship was ready to be filled with gas. On 13 January 1897 he collapsed outside the "Zur Linde" restaurant in Vienna, and died minutes later from heart failure, aged 44. Historical sources speak of a blutsturz (a term meaning either hemoptysis or hematemesis).[24]

David Schwarz was buried in Zentralfriedhof, Vienna.[25]

Carl Berg required confirmation of Schwarz's death, suspecting he had fled to sell his secrets.[26] 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.[26]

This second airship had these specifications:[27]

• Volume: 3,250 m3 (114,700 cu ft)
• Length: 47.55 m (56 ft)
• Diameter: 13.49 m (44 ft 3 in)
• Engine: 16 horsepower (12 kW) Daimler
• Four propellers: one of 2.6 m (8 ft 6 in) diameter between the gongal and the envelope, two of 2 m (6 ft 7 in) diameter mounted on brackets either side of the envelope, and a fourth of 2 m (6 ft 7 in) diameter revolving in the horizontal plane mounted below the gondola to drive the craft up or down.
• Envelope: 0.2 mm aluminium plates riveted to framework.

A later structural analysis based on the drawings concluded that it was defective, with the skin taking most of the shear stresses: distortions of the skin can seen in a photo of the craft in flight.[28]

The second airship was tested with partial success at Tempelhof near Berlin, Germany, on 3 November 1897. Airship Battalion mechanic Ernst Jägels[29][30] climbed into the gondola and lifted off at 3 p.m.[29] However, the airship broke free of the ground crew, and because it rose quickly Jägels disengaged the vertical axis 'lift' propeller.[29] At an altitude of about 130 m (430 ft) the drive belt slipped off the left propeller, resulting in the ship "...[turning] broadside to the wind, [and with the result that] the forward tether broke free."[29] As the ship rose to 510 m (1,670 ft) the drive belt slipped off the right propeller, the airship thus losing all propulsion.[29] Jägels then opened the newly fitted gas release valve and landed safely, but the ship turned over and collapsed and was damaged beyond repair.[29]

Legacy

About the time of the trial flight and for decades after, various accounts, sometimes conflicting or misleading, were written of the events. Later, Berg, as well as his son, would write negatively of his experiences with Schwarz.

Some sources[3] state that Count Ferdinand von Zeppelin purchased Schwarz's patent from his widow in 1898, while others claim that the count used the design. However, Hugo Eckener, who worked with Count Zeppelin, dismissed these claims:

"Count Zeppelin negotiated with Herr Berg's firm for the purchase of the aluminium for his own ship. The firm, however, was under contract to supply aluminium for airships exclusively to the Schwarz undertaking. It had to obtain release from this contract by an arrangement with Schwarz' heirs before it could deliver aluminium to Count Zeppelin. That is the origin of the legend."[4]

Cvi Rotem (1903–1980) wrote the only known biography, titled David Schwarz: Tragödie des Erfinders. Zur Geschichte des Luftschiffes.[31] Rotem wrote that both Berg and Schwarz wished to keep their work secret.

From 3 December 2000 to 20 April 2001 the Museen der Stadt Lüdenscheid held an exhibition which covered Berg, Schwarz and Zeppelin history from 1892 to 1932, with displays of documents, photographs and airship remnants.[30][32][33]

David Schwarz (Kesthely, Mađarska, 20. prosinca 1850. - Beč, 13. siječnja 1897.), trgovac i izumitelj židovsko-mađarskog podrijetla.

Tvorac prvoga upravljivog aluminijskog zračnog broda s benzinskim motorom. S trinaest godina nastanio se s majkom u Županji. Svršivši trgovački zanat, postao je trgovcem brašnom u Zagrebi 1890. Kako bi mogao dalje razvijati svoj naum, otišao je u Njemačku te zainteresirao tvorničara aluminija Carla Berga za izradbu letjelica. Pridobivši zanimanje ruskoga vojnog atašea, Schwarz je u Sankt Peterburgu 1893. izgradio zračni brod. No optužen za špijunažu u korist Austrije, uništio ga je dan uoči predstavljanja javnosti i pobjegao u Zagreb, odakle je nastavio tražiti potporu za ostvarivanje svoje zamisli. Na kraju su mu ju pružili njemački car Vilim II., Carl Berg i balonar Bartsch von Siegeld, dodijelivši mu 1895. na raspolaganje vojno uzletište Tempelhof pokraj Berlina. Ondje je od aluminija izgradio zračni brod oblika topovske granate, ispunjen vodikom, dugačak 48 metara, promjera 12 metara, mase 3 560 kilograma, obujma 3 697 m3; pokretao ga je benzinski motor snage 11,76 kW. Brod je prvi put uspješno iskušao 8. listopada 1896., kada se zbog slabe kvalitete plina podignuo samo jedan metar. Prvi službeni let zakazan za 15. siječnja 1897. Schwarz nije dočekao. Ipak, let je obavljen 3. studenog 1897., kada se brod srušio zbog pada remenja s propelera, a pilot se spasio iskakanjem iz letjelice. Potaknut Schwarzovom idejom, grof Ferdinand von Zeppelin od Schwarzove udovice za 15 000 njemačkih maraka otkupio je projekt s nacrtima, na osnovi kojih je 1900. izradio svoj brod (cepelin), i njime nezasluženo stekao slavu tvorca prvoga zračnoga broda.

Životopis

Živio je u Županji od svoje trinaeste godine. Upisuje obrtnu školu te izučava trgovački zanat. Bio je trgovac brašnom. U Županji provodi veći dio svoga života te upoznaje svoju suprugu Melani. Svjestan nepotpunih i opasnih rješenja na balonima, želi napraviti upravljivu zračnu letjelicu. Na svoj prototip drugi od izumitelja ugrađuje benzinski motor (prvi je bio Hermann Wölfert 1888.). U Petrogradu pod pokroviteljstvom cara Aleksandra III. gradi prvi metalni zračni brod na svijetu. Nakon optužbi da je austrijski špijun uništava svoju konstrukciju i bježi u Njemačku gdje uz potporu vojske na polju Tempelhof kraj Berlina ponovno gradi zračni brod. Načinio je zračni brod duljine 48 m, promjera 12 m, širine 13,5 m. Prvi neslužbeni let bio je izveden 1896., kada se brod podigao tek jedan metar. Prvi službeni let bio je predviđen za 15. siječnja 1897. no dva dana ranije dok se očekivao Schwarzov dolazak u Berlin, on u Beču umire od posljedica moždanog udara. Nakon njegove smrti mehaničar Ernest Jagels 3. studenog 1897. uzdiže Schwarzov brod na 464 metara gdje se dešava nezgoda uslijed ispadanja remena s remenice za pogon bočnih elisa. Nacrte od Schwarzove udovice Melanie Schwarz kasnije kupuje njemački general, grof Ferdinand von Zeppelin, za 15 000 maraka.

Djela

• Cvi Rotem: David Schwarz, Tragödie des Erfinders; Manuskript (1983.)
• Eckhard Trox(Hrsg.): Der Traum vom Fliegen. Carl Berg und die Luftschiffidee von Lüdenscheid bis Lakehurst. (Forschungen zur Geschichte Preußens im südlichen Westfalen, Bd. 4., Lüdenscheid, 2000.)
• G. Bresonik: David Schwarz - Carl Berg - Graf Zeppelin, Ein Beitrag zur Frühgeschichte des Starrluftschiffes, (in: Zeppelin und Frankreich. Szenen einer Hassliebe (Hrsg. W. Meighörner), Friedrichshafen 1998., 42.-57.)

SCHWARZ, David (Schwartz), izumitelj (Keszthely, 7. XII. 1850 — Beč, 13. I. 1897). U rodnom gradu završio židovsku osnovnu školu, a u Županji, kamo se doselio na poč. 1860-ih, izučio za trgovca. Od kraja 1870-ih živio u Osijeku, u drugoj pol. 1880-ih s obitelji se nastanio u Zagrebu. Bavio se trgovinom drvenom građom te kraj Našica podignuo pilanu. U strojarstvu samouk; za duljega oporavka nakon ozljede u požaru u drugoj pol. 1880-ih upoznao se s tehničkom literaturom, što ga je navelo na zamisao o upravljivoj aerostatičkoj letjelici čvrste konstrukcije s motornim pogonom i kruto ovješenom gondolom mjesto balonske košare. Napustivši trgovanje, posvetio se konstruiranju zračnoga broda, u izradbi nacrta kojega mu je pomagao šumarski inženjer J. Pfister. Prvotni planovi vjerojatno su predviđali drveni kostur, no kad je 1889. na Svjetskoj izložbi u Parizu predstavljen aluminij, uočio je njegovu primjenjivost u zrakoplovnoj tehnici te pošao upoznati tehnologiju proizvodnje u pogonima tvorničara C. Berga u Lüdenscheidu i Evekingu, napose u svezi s mogućnostima povećanja čvrstoće aluminijskih slitina te spajanja dijelova zakivanjem i lemljenjem. Na poč. 1892. projekt letjelice u Beču je neuspjelo ponudio austrougarskomu Ministarstvu rata, potom ruskomu veleposlanstvu, na preporuku kojega je uz vojnu potporu potkraj godine u Sankt Peterburgu započeo gradnju. S tim u svezi u kolovozu 1892. s Bergom je sklopio ugovor o djelomičnom zajmovnom financiranju, tehničkoj izvedbi i dostavi dijelova, obvezavši se prinijeti idejni nacrt te nadzirati sklapanje i pokusne letove. Pod njegovim je vodstvom u ljeto 1894. dovršen prvi metalni zračni brod duljine 31 m, mase 2530 kg i obujma 3284 m³, no pokusni let u rujnu nije uspio jer je pri punjenju vodikom došlo do pucanja unutarnjih radijalnih nosača te djelomične implozije i propuštanja vanjske aluminijske stijenke, nakon čega je u nerazjašnjenim okolnostima (navodno pod sumnjom na špijunažu) napustio Rusiju, a brod je proglašen neuporabivim te rastavljen. U prosincu 1894. sklopio je novi ugovor – u njem je istaknut kao izumitelj – u kojem je Berga ovlastio za gradnju zračnih brodova za prusku odn. njemačku vladu, ali isključivo pod njegovim tehničkim vodstvom i uz diobu dobiti, što se odnosilo i na nasljednike. Nakon što je 1895. pothvat zadobio potporu oblasti, vojni i Bergovi inženjeri prema njegovim su naputcima izradili nacrte te sastavne dijelove, montirane na berlinskom vojnom vježbalištu Tempelhofu 1896, u čem je sudjelovalo ljudstvo Odreda zračnih brodova. I drugi brod bio je gotovo u cijelosti izgrađen od aluminija, aerodinamičnoga cilindričnoga oblika sa stožastim prednjim dijelom, duljine 38,32 m, promjera 12 m, mase 3560 kg i obujma 3697 m³. Rešetkasti nosači i uzdužni profili tvorili su kostur konstrukcije presvučene aluminijskom ljuskom debljine 0,2 mm, a uz donji dio trupa bila je pričvršćena gondola. Četverocilindrični benzinski motor tipa Daimler od 12,9 konjskih snaga trebao je sustavom prijenosnih remena pokretati četiri propelera (dva bočna i stražnji za potisak i usmjerivanje te jedan između trupa i gondole za dodatni uzgon), a proračunata nosivost broda bila je 240 kg (osoba i 130 kg balasta). Pokusno polijetanje u listopadu 1896. nije uspjelo zbog vodika nedostatne čistoće. Kad je zadovoljavajući vodik na poč. 1897. proizveden, Schwarz je iznenada umro te je sporazumno s Bergom njegov udio u poslovnom pothvatu preuzela udovica mu Melanija rođ. Kaufmann, po čijem je nalogu prvi javni let izveden 3. XI. 1897. Angažiran mjesto djelatnih letača Odreda zračnih brodova, bivši dočasnik zemaljskoga osoblja strojobravar E. Jagels uzletio je isključivši uzgonski propeler; brod je isprva svladavao protuvjetar od približno 25 km/h, no pod snažnim opterećenjem skliznuli su pogonski remeni pa se Jagels, izgubivši nadzor nad smjerom kretanja, nadomak četvrti Wilmersdorf odlučio na žurno slijetanje naglim ispuštanjem vodika (prema instrumentima, dosegnuta je visina od približno 460 m, na kojoj je brzina vjetra bila 45 km/h). Brod je pritom uništen, a on se spasio iskakanjem na maloj visini. Ocjene o uspjehu leta bile su podijeljene pa pruske odn. njemačke oblasti nisu naručile proizvodnju, već ju je Berg – potaknut i neuspjehom patentne zaštite – 1898. ugovorio s F. von Zeppelinom i njegovim Društvom za promicanje zrakoplovstva (na temelju stečenih iskustava poletio je 1900. zračni brod LZ 1). S tim u svezi udovici je prema ugovorima s Bergom i Zeppelinom isplaćena naknada. Navodi o dijelu Schwarzovih životopisnih podataka i postignuća nepouzdani su, pa i proturječni, no kao idejnomu tvorcu i voditelju izradbe prve upravljive aerostatičke letjelice krute konstrukcije nedvojbeno mu pripada istaknuto mjesto u povijesti razvoja zrakoplovne tehnike. — Propeler broda iz 1896. te dio dokumenata vezanih uza suradnju s Bergom (nacrti, ugovori, korespondencija) u Njemačkom su prirodoslovnom i tehničkom muzeju u Münchenu. U Mađarskoj su izdane poštanske marke (1948, 1977) i medalje (Z. Képíró, 1975) s njegovim likom te 1967. u Prometnom muzeju u Budimpešti (u kojem je u parku skulptura od 1968. i njegovo poprsje, rad I. J. Nagya) priređena memorijalna izložba, u Lüdenscheidu je 2000. u Povijesnom muzeju (u stalnom postavu kojega je motor broda iz 1896) također priređena izložba, a ispred Tehničkoga muzeja u Zagrebu postavljen mu je 2001. portret u bronci (S. Gračan). God. 1991. i Kuba je izdala poštansku marku s njegovim likom, a izrađena je i brončana plaketa (A. Shagin). LIT.: Das Schwarz’sches Luftschiff. Agramer Tagblatt, 11(1896) 12. IX, str. 4. — Ein kroatischer Erfinder. Agramer Zeitung, 71(1896) 10. IX, str. 4. — Das lenkbare Luftschiff. Slavonische Presse, 13(1897) 16. XI, str. 3. — (Nekrolog). Hrvatsko pravo, 3(1897) 14. I, str. 2. — W. L. Moedebeck: Die militärische Bedeutung des Versuchs mit dem Metallballon System Schwarz. Kriegstechnische Zeitschrift (Berlin), 1(1898) br. 2. — Das Luftschiff »System Zeppellin–Schwarz«. Agramer Tagblatt, 15(1900) 5. VII, str. 1. — Graf Zeppelin und David Schwarz. Agramer Zeitung, 83(1908) 29. VIII, str. 5. — A. Gelber: Erinnerungen an David Schwarz. Die Drau, 41(1908) 6. VI, str. 14–15. — L. Šik (L. Schick): David Schwarz. Agramer Tagblatt, 27(1912) 25. IV, str. 5–6. — K. Berg: David Schwarz, Carl Berg, Graf Zeppelin. Ein Beitrag zur Geschichte der Luftfahrt. München 1926. — Zeppelin – naš domaći zagrebački izum. Novosti, 22(1928) 19. XI, str. 7. — B. Prodanović: Zagrepčanin David Švarc odista je prvi izmislio cepelin. Politika (Beograd), 25(1928) 20. X, str. 7–8. — J. Bobek: Eine Lanze für David Schwarz. Morgenblatt, 46(1931) 12. VII, str. 3–4. — L. Šik: Zagrepčanin David Schwarz – izumitelj zrakoplova. Jevrejski narodni kalendar, 2(1936–37) str. 33–50. — Ž. Harambašić (ž. h-ć.): Upravljivi zrakoplov završio je katastrofom zbog naručene sabotaže! Večer, 18(1937) 20. II, str. 9. — D. Pejnović (D. P-ć.): Crtica iz povjesti zrakoplovstva. Priroda, 39(1952) 9, str. 350–352. — J. Modly: Aeronautika … san i stvarnost. Zagreb 1960, 16–18. — F. Jelinčić: Leteća cigara. Arena, 13(1971) 544, str. 28–29. — P. Rév: Schwarz Dávid léohajóépítő tevékenysége oroszorszában. A Közlekedési múzeum évkönyve (Budapest), 1971, 1, str. 265–279. — B. Puhlovski: Ne Cepelin nego Švarcoplan. Večernji list, 20(1976) 6–20. XII. — C. Rotem: David Schwarz. Tragödie des Erfinders. Bloomington 1983. — J. F. Jahn: Von der Montgolfiere zum Riesen-Luftschiff. Kultur & Technik (München), 8(1984) 3, str. 140–143. — S. Szabó: Schwarz Dávid a kormányozható léghajó feltalálója. Keszthely 1991. — B. Puhlovski: (Podlistak o D. Schwarzu). Hrvatski vojnik, 3(1993) 44, str. 102–105; 46, str. 101–104; 48, str. 102–105; 50, str. 101–103. — Isti: David Schwarz. U: Znanost u Hrvata (katalog izložbe), 2. Zagreb 1996, 406. — V. Muljević: David Schwarz i njegov zračni brod. Hrvatski glasnik intelektualnog vlasništva, 4(1997) 2, str. 683–686. — C. Mentschl: David Schwarz. Österreichisches biographisches Lexikon 1815–1950, 54. Wien 1999. — N. Staklarević: David Schwarz, izumitelj upravljivog aluminijskog zračnog broda 1850–1897. Zagreb 2000. — E. Trox i dr.: Der Traum vom Fliegen (katalog izložbe). Lüdenscheid 2000. — Z. Bödők: Magyar feltalálók a repülés történetében. Dunaszerdahely 2002, 26–31. — S. Dooley: The Development of Material-Adapted Structural Form – Part II: Appendices (disertacija). École polytechnique fédérale de Lausanne, 2004, 166, 182–187, 189–196, 231–232. — E. Molnár: A magyar közlekedés nagyjai érmeken és plaketteken a Közlekedési múzeum gyűjteményében. A Közlekedési múzeum évkönyve, 2005, 14, str. 105. — Z. Benčić: Kultura pamćenja. Strojarstvo, 51(2009) 6, str. 679. — L. Eleršek: David Schwarz – nezasluženo u sjeni Zeppelina. Hrvatski vojnik, 6(2009) 224, str. 26–27; 225, str. 26–27.

Mladena Tkalčević, Robert Krog i Filip Hameršak (2016)

• Izvor / Source: http://hbl.lzmk.hr/clanak.aspx?id=11921 , Hrvatski biografski leksikon, Leksikografski Zavod "Miroslav Krleža"