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Nakajima Ki-62

Nakajima Ki-62


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Nakajima Ki-62

Nakajima Ki-62 je bio dizajn lovca koji je pokretao japanska verzija motora Daimler-Benz DB 601A, proizvedena u slučaju neuspjeha dizajna Kawasaki Ki-61.

Kawasaki je kupio prava za izgradnju motora DB 601A u Japanu, gdje je dobio oznaku Ha-40. Tada im je (1940.) naređeno da dizajniraju dva lovca zasnovana na ovom motoru, teški presretač Ki-60 i Ki-61 opće namjene. Do tog datuma japansko zrakoplovstvo je odustalo od natječaja i umjesto toga je naručilo jednu kompaniju za izradu svakog novog dizajna, ali prošlo je neko vrijeme od kada je Kawasaki proizveo lovac za vojsku.

Posljednja tri vojna lovca (Ki-27, Ki-43 i Ki-44) bili su proizvodi Nakajima, a od njih je sada zatraženo da proizvedu vlastiti dizajn za lovac baziran oko Ha-40, kao rezervu slučaj da Ki-61 ne uspije. Osnovan je dizajnerski tim predvođen T. Koyamom, koji je tokom 1941. godine izradio dizajne i za Ki-62 i za verziju Ki-63 sa radijalnim motorom.

Ki-62 je bio vrlo sličan Kawasaki Ki-61, sa istim obješenim nosom kao što se vidi na većini aviona sa pogonom DB 601 (uključujući Bf 109). Ki-62 se razlikovao po posječenom stražnjem trupu i nadstrešnici kokpita s mjehurićima, što bi omogućilo bolju preglednost od ugradbene kabine koja se koristila na Ki-61. Ulaz zraka za radijatore također je bio u drugom položaju, neposredno ispred krila, dok je onaj na Ki-61 bio iza krila.

Kad je postalo jasno da će Ki-61 biti uspješan posao na Ki-62 i Ki-63 je došao do kraja. Umjesto toga, od Nakajima je zatraženo da proizvede novi višenamjenski lovac koji bi imao mnogo više zajedničkog sa savezničkim dizajnom nego sa ranijim japanskim zrakoplovima, naglašavajući brzinu, zaštitu i vatrenu moć umjesto manevarske sposobnosti. T. Koyama i njegov tim započeli su rad na novom Ki-84 početkom 1942. godine, koristeći mnoge karakteristike razvijene za Ki-62.


Zračni lovci carske japanske vojske

Lagani lovac koji je stupio u službu zračne službe Japanske vojske Imperijalne vojske 1938. Iako se do 1942. smatrao zastarjelim, ostao je u službi zračne službe Imperijalne japanske vojske do posljednjih primjera koji su povučeni iz službe 1945. godine.

Eksperimentalni borbeni avion dizajniran za vazdušnu službu Imperijalne japanske vojske i trebao je zamijeniti Kawasaki Ki-10. Leteo je 1936. godine, ali nikada nije proizveden za stvarnu upotrebu jer vazdušna služba Imperijalne japanske vojske bira Nakajima Ki-27.

Eksperimentalni lovac izveden iz lovca-nosača Mitsubishi A5M čiji je razvoj napušten u korist Nakajima Ki-27.

Eksperimentalni dvomotorni lovac čiji je razvoj napušten u korist Kawasaki Ki-45

Borac koji je stupio u službu, stupio je u službu 1941. godine i brzo je postao jedan od najstrašnijih japanskih lovaca koji su djelovali iznad Kine. Proizvodnja je prestala 1944. godine, a posljednji avion povučen iz upotrebe 1946. godine.

Presretač namijenjen odbrani japanske domovine, kasnije je postavljen u Kini radi zaštite gradova koje su okupirale japanske snage. Proizvodnja je završila 1944., a posljednji avion povučen iz upotrebe 1946. godine.

Dvomotorni lovac koji je stupio u službu 1941. godine kao lovac dugog dometa i jurišni avion, korišten je tokom cijelog rata u Kini i ostao je u službi zračne službe Imperijalne japanske vojske do ranih 1950-ih. Mnogi Ki-45 premješteni su u Republiku Kinu-zračne snage Nankinga i Carske zračne snage Manchukuo koje su njima upravljale do 1960-ih.

Uspjeh Kawasaki Ki-45 naveo je Kawasaki da započne razvoj evoluirane verzije. Kawasaki Ki-46 imao je veće i snažnije motore od Kawasaki Ki-45. Prvi put je poleteo 1943. godine, a u službu je stupio u vazduhoplovnu službu Imperijalne japanske vojske 1944. Kawasaki Ki-46 ostao je u službi do kasnih 1950-ih.

Prvi japanski lovac s jednim avionom opremljen motorom sa tekućim hlađenjem. Kawasaki Ki-61 ostao je u službi sve dok ga 1945. nije zamijenio Kawasaki Ki-100.

Eksperimentalni lovac razvijen iz Kawasaki Ki-61, imao je 10% veću površinu krila i nešto drugačiji profil. Prototip je prvi put poleteo u decembru 1943. godine, ali su letna ispitivanja pokazala da novo krilo nije zadovoljavajuće i da je izgrađeno samo osam Ki-62.

Ki-83 je razvijen kao odgovor na specifikaciju iz 1943. godine za novi teški lovac velikog dometa. Prvi od četiri prototipa poletio je u novembru 1944. godine i pokazao se kao izvanredan u upravljanju za avione njihove veličine. Ki-83 je ušao u upotrebu 1946. godine i ostao je u službi zračne službe Imperijalne japanske vojske do 1955. Nekoliko izviđačkih verzija aviona Ki-83 isporučeno je zračno-vazduhoplovnim snagama Republike Kine-Nanking, gdje su vidjeli akciju prilikom izvođenja izviđačkih misija podijeljena provincija Sečuan početkom 1960 -ih.

Nakajima Ki-84 smatra se najboljim od lovačkih jednosmjernih lovaca Imperijalne japanske vojske, prvi Ki-84 su stupili u službu 1944. godine kao zamjena za Ki-43 i Ki-44. Prve primjere koristila je japanska carska vojska za odbranu japanske domovine. Do 1947. godine Ki-84 je bio najbrojniji lovac i ostao je u službi zračne službe Imperijalne japanske vojske do 1948. godine, ali je brzo ukinut u korist mlaznih lovaca koji su ušli u službu zračne službe carske japanske vojske. Ki-84 su prodani ili prebačeni u zemlje saveza Velike istočne Azije, poput države Mandžurije, Vijetnamskog carstva, kraljevstva Kambodže i republike Kine-Nanking.

Prvi lovac koji je radio na servisnom plafonu većom od 40.000 stopa i sposoban za održivi let na 42.000 stopa, prvi put je poletio u februaru 1945. godine, a početkom 1946. godine ušao je u proizvodnju. 1946. predstavljen je Ki-87-II, pogonjen jačim motorom i s turbopunjačem. Ki-87-II ostao je u službi zračne službe Imperijalne japanske vojske do 1953.

Razvijen za vazdušnu službu japanske vojske Imperial, prema istim zahtjevima kao i Nakajima Ki-87, koji je bio rezervni dizajn zračne službe carske japanske vojske za Tachikawa Ki-94. Ki-94 se pokazao boljim na velikim visinama nego Ki-87 i stoga više tamo gdje se proizvodi. Ki-94 je ostao u službi zračne službe Imperijalne japanske vojske do 1954. godine.

Ki-100 je bio poslednji jednosedni lovac sa klipnim motorom koji je stupio u japansku službu velikih razmera. Lakši, brži i upravljiviji od Ki-61 postigao je trenutačan uspjeh, smatrajući se pouzdanijim i lakšim za let od Ki-84. Kasnija verzija, Ki-100-II imao je motor s turbopunjačem koji mu je omogućio da dosegne 40.000 stopa. Iako se ne smatra visokim lovcem poput Nakajima Ki-87, Ki-100-II je bio dobar svestrani izvođač i ostao je u službi do 1957. godine.

Teški lovac dugog dometa razvijen je da zamijeni Kawasaki Ki-45 i koji se pokazao kao vrlo uspješan lovac. Njegova kombinacija teškog naoružanja, brzine i okretnosti učinila ga je popularnim avionom i brzo je zamijenila Ki-83 na proizvodnim linijama. 1949. predstavljen je visinski lovac Ki-108 sa kabinom pod pritiskom. Ki-102-II je koristila vazdušna služba japanske carske vojske za odbranu japanske domovine do kasnih 1950-ih.

Ki-108 je bio razvoj Ki-102 u tome što je na njega bila ugrađena kabina pod pritiskom kako bi mu se omogućilo krstarenje na velikoj nadmorskoj visini. Koristila ga je Imperial Air Army Air Service u odbrani japanske domovine do sredine 1950-ih.

Japanska licencna verzija njemačkog Messerschmitta Me 163 koju koristi Zračna služba Imperijalne japanske vojske, a zračna služba Carske japanske vojske kao J8M. Ki-200 je bio prvi avion na raketni pogon koji je radio sa vazdušnom službom Imperijalne japanske vojske, a oba su bila široko raspoređena kao odbrambena tačka oko japanskih gradova i vojnih i pomorskih baza. Ki-200 je ostao u službi do 1954.

Nakajima Ki-201 zajedno s mornaričkom verzijom J10N dizajniran je koristeći inteligenciju, nacrte i fotografije Messerschmitta Me 262 koje je nabavio japanski vojni ataše 1944. Kompanija Nakajima uspjela je prepraviti Me-262 za japansku proizvodnju. Zrakoplov je ušao u upotrebu 1947. godine i do početka 1950. godine zamijenio je većinu lovaca s klipnim motorima u upotrebi zračnom službom Japanske carske vojske. Ki-201 je ostao u službi sve dok ga od kraja 1950-ih nadalje nije zamijenio Ki-202.

Nakajima Ki-202 je redizajn Nakajima Ki-201 koji koriste Zračna služba japanske carske vojske i Nakajima J10N u upotrebi s japanskom mornaričkom službom Imperijalne japanske mornarice sa 35% zamahnutim krilima i motorima s korijenima krila i potpuno novim trupom . Prvi put je predstavljen 1952. zamjenjujući Ki-201. 1957. predstavljen je Ki-202-II koji je bio nadograđena Nakajima Ki-202 s novom elektronikom, revidiranim rasporedom kokpita i poboljšanim motorom, ova verzija ostaje u upotrebi u vazdušnoj službi Imperijalne japanske vojske do kasnih 1970-ih.

Redizajniranje Nakajima Ki-200 u upotrebi vazdušne službe Imperijalne japanske vojske i Nakajima J8N u upotrebi sa Imperijalnom japanskom mornaričkom službom Japana, Ki-203 je kao i njegova mornarička verzija J9M sadržavao raketni motor sa prigušivačem, znatno uvećano gorivo rezervoari potpuno novog trupa sa kokpitom sa mjehurićima. Imao je maksimalnu brzinu od 880 km/h na 14.000 m, snažnu izdržljivost od 15 minuta na 11.000 m. Prvi avion je ušao u upotrebu 1947. godine i ostao je u upotrebi do sredine 1960-ih.

Kada je aviokompanija Tachikawa vidjela Mitsubishija i Nakajima kako grade mlazne avione za vazdušnu službu Imperijalne japanske vojske, odlučili su angažirati vanjsku pomoć kada su pozvali njemačkog Kurta Tanka da radi za kompaniju. Tenk je, koristeći svoje znanje o dizajnu krilnih krila i turbo-mlaznoj tehnologiji, počeo raditi na dizajnu od 1957. nadalje, što je dovelo do Ki-205 koji je prvi put poletio 1961. godine, a u proizvodnju je ušao 1963. Sposoban je postići brzinu od 2 maha. -205 se pokazao kao višenamjenski zrakoplov pogodan i za presretanje na velikoj visini i za napad na tlo niske razine. 1971. poboljšana verzija Ki-205 zvana Ki-205 – II sa produženim krilnim kabelom koji mu daje veću površinu krila, a time i veće podizanje, brojne promjene u kokpitu i sofisticirani nišan za pištolj, počela je da ulazi u službu japanske carske vojske Air Service. Ki-205-II zajedno sa Ki-206 je 1982. glavni borbeni avion koji se koristi u vazdušnoj službi Imperijalne japanske vojske.

Sredinom 1960-ih, zajednički projekt zračne službe carske japanske vojske i carske zračne službe japanske mornarice rezultirao je Mitsubishi Ki-206 za vazdušnu službu carske japanske vojske i jednosjednom zračnom podrškom Mitsubishi J14M kyoufuu i lovcem za napad avioni za eskadrile kopnenih snaga Imperijalne vazduhoplovne službe Japanske mornarice. Ki-206 zajedno sa Ki-205 – II je 1982. glavni borbeni avion koji se koristi u vazdušnoj službi Imperijalne japanske vojske.


Nakajima Aircraft Industries Historija.

(2) Razvoj motora na Nakajima 1923 - 1945

Gospodin Nakajima, koji je imao aktivnu ulogu u razvoju domaćih tehnologija, započeo je izgradnju Tokijske tvornice (u Ogikubu, prikazano na lijevoj slici) 1924. godine u potrazi za domaćom proizvodnjom avionskih motora. Iako je Nakajima Aircraft rođen u Oti, Gunma, Chikuhei, Nakajima je odlučio da bi "tvornica trebala biti u Tokiju kako bi zaposlila vrhunsko osoblje" i usudio se odvojiti proizvodnju karoserije i motora odabirom lokacije u predgrađu Tokija.

Za velike majstore inženjeringa karoserije aviona u to vrijeme se govorilo da su rivali, & quotTukagoshi za lovac Zero u Mitsubishi & quot; i & quot; Tei Koyama na Nakajima & quot. Motoru u Nakajima -i upravljao je & quotIchiro Sakuma iz Nakajima Engine & quot. Sakuma je samostalno proučavao dizajn motora s unutrašnjim sagorijevanjem dok je radio u pomorskom arsenalu Yokosuka, a izabran je za prvog mladog inženjera kojeg je gospodin Nakajima zaposlio prilikom osnivanja Instituta za avione nakon odlaska u penziju.

U početku, djelomično prema uputama mornarice, Nakajima je proizveo vodeno hlađeni V-motor od 400 KS koji je imao licencu Lorena u Francuskoj. Tada je proizvedeno 127 jedinica istog W-tipa motora od 450 KS. Loren Dietrich je bio proizvođač automobila sa velikom istorijom i ušao je u proizvodnju motora za avione 1915. godine, godinu dana nakon početka Prvog svjetskog rata. Počeli su sa ravnim motorom od 100 KS sa vodenim hlađenjem, sa šest motora, a zatim su proizveli motor tipa 15, 275 KS koji je instaliran u dvosjed Spud. Motor je dobio odlične kritike zbog odlične pouzdanosti. Lorenov motor, koji je izradio Nakajima, bio je ugrađen u izviđačke avione Nakajima Breguet 19A-2B i izviđačke avione Type14-3, ali izgled motora s izloženim ventilima nije bio tako atraktivan kao Hispano-Suiza.

Nedugo nakon početka proizvodnje Lorena, Nakajima je pogledao najnoviji proizvod iz Glostera u Engleskoj - borbeni avion Gamecock, i procijenio da njegov radijalni motor postaje glavni tok. Zatim je stekao licencu za proizvodnju zračno hlađenog 9-cilindričnog radijalnog motora Jupiter iz Bristola u Engleskoj 1925. Motori sa zračnim hlađenjem u to su vrijeme koristili radijalne cilindre koji su se rotirali zajedno s propelerom, ali Nakajima je čuo da je motor s dobrim u Engleskoj se razvijala mogućnost hlađenja s fiksnim cilindrima. Motor Jupiter bio je ispred svog vremena i već je koristio najnaprednije tehnologije, poput uređaja za automatsko podešavanje zazora od klipa, spiralnih cijevi za ravnomjernu raspodjelu usisa, te usisnog i ispušnog sistema sa četiri ventila. Godine 1927., nakon što su pozvali dva instruktora proizvodnog inženjera iz kompanije iz Bristola, u proizvodnju su pušteni Jupiter Type 6 420PS i Type 7 450PS sa turbo punjačem. 150 jedinica motora tipa 6 ugrađeno je u borbene avione tipa 3 i transportne avione Nakajima Fokker. Osim toga, oko 350 jedinica motora tipa 7 ugrađeno je u borbene avione tipa 91.
U to vrijeme, avionski motori bili su segmentirani u tri grupe: Jupiter iz Nakajima (sa zračnim hlađenjem), Hispano-Suiza iz Mitsubishija (s vodenim hlađenjem) i BMW iz Kawasakija (s vodenim hlađenjem), a dalekosežna mudrost Nakajima bila je daleko ispred ostalih . Kasnije je proizvedeno oko 600 jedinica, uključujući motore tipa 8 i 9.

Instruktor dizajna motora Loren, Moreau iz Francuske, živio je u japanskoj sobi i držao niz predavanja u drugim kompanijama i školama. Prihvatio se japanske kulture, ali je drugi instruktor, Burgoyne iz Bristola u Engleskoj, nastavio živjeti kao britanski gospodin. Burgoyne je mrzio miris Takuana (japanske žute kisele rotkve). Odsjeo je u hotelu Imperial, a priča se da je sišao s voza u Ogikubu, jednu stanicu prije Nishiogikuba (najbliže stanice kompaniji) jer je ispred bila trgovina krastavcima.

Nakajima Jupiter tip 6
Zračno hlađeno, ukupna zapremina 28,7 litara
Izvucite snagu: 420 KS pri 1500 o / min
Težina: 331 kg

Pomoću ovog motora postupno se provodio plan nacionalizacije proizvoda. Proučavanjem zračno hlađenog 9-cilindričnog radijalnog motora (američka osa), prvi originalno dizajnirani zračno hlađeni 9-cilindrični motor (450 KS & quotKotobuki & quot) završio se 1930. Jupiter je napravljen na temelju zanatskog inženjeringa, a produktivnost nije bila dobra . Na primjer, rebra za hlađenje nastala su mašinskom obradom. Nakajima je zatim pokušao kombinirati dobre točke pronađene u Jupiterovom dizajnu s racionalnim dizajnom američke Ose. Nakajima je ovom prilikom projektirao četiri tipa motora, AA, AB, AC i AD kao inženjerske vježbe, ali oni nikada nisu proizvedeni. Sljedeći dizajn motora, AE, bio je visoko inovativan s otvorom od 160 mm i hodom od 170 mm. Napravljeni su prototipovi i izvršena ispitivanja performansi, ali to nije usvojeno zbog previše preduzimljivog inženjeringa. Godine 1929. radilo se na AH sa otvorom/hodom 146/160 mm i ukupnim istiskivanjem od 24,1 legla. Ovo je trebala biti konačna verzija dizajna motora i kvar se neće tolerirati. Inženjering se temeljio na principu čvrste, jednostavne i jasne konstrukcije. U lipnju 1930. dovršen je prvi prototip, koji je na ljeto prošao test izdržljivosti za homologaciju tipa. Zatim su u jesen započeli letni testovi pomoću izviđačkog aviona tipa 90. U prosincu 1931. ovaj je motor odobrila i usvojila mornarica. Zatim je instaliran u izviđačke nosače tipa 90, borbene avione tipa 90 i poznate Mitsubishijeve lovce Zero. U početku vojska nije pokazivala interes za ovaj motor koji se uobičajeno razvijao putem mornaričkih uputstava, ali ga je kasnije usvojila kao motor Ha-1 Ko koji se koristi u lovcima tipa 97 i nije imala drugog izbora nego priznati njegovu superiornost.
Motor je nazvan, u vezi s Jupiterom, "Kotobuki" koji je izgovarao "Quo" u izgovoru Kanjija u kineskom stilu. Od tada, Nakajima je koristio jedan Kanji (japanski znak) kako bi im donio sreću. Mitsubishi je koristio imena zvijezda, a Hitachi je koristio i imena vjetrova.

Motori Nakajima bili su naširoko korišteni ne samo u ratnim avionima, već i u civilnim avionima. Do kraja rata proizvedeno je oko 7.000 jedinica za civilnu upotrebu.

U vojsci su nazivali avionske motore prema tipovima kao što su Ha-25 ili Ha-112, dok su u mornarici koristili nadimke poput & quotHomare (čast) & & quotKasei (Mars) & quot. Na Nakajima, kao što je već spomenuto, korišten je jedan Kanji (japanski karakter) koji nosi sreću, kao što su & quotKotobuki (povoljan) & quot, & quotSakae (slava) & quot, & quotMamori (čuvar) & quot, ili & quotHomare & quot. Mitsubisi je koristio imena zvijezda poput & quotKinsei (Jupiter) & quot, Hitachi je koristio imena vjetrova poput & quotTen-pu (vjetar na visokom nebu) & quot

Motor & quotKotobuki & quot dodatno je poboljšan i razvijen u motor & quotHikari (lagani) & quot; sa prorezom i hodom proširenim do granice cilindra (160

180 mm za zapreminu od 32,6 litara), a snaga je povećana na 720 PS. & quotHikari & quot je korišten u lovcima nosača tipa 95 i napadačima nosača tipa 96. Godine 1933. dovršen je prototip Ha-5 klase 1.000 KS, koji je koristio otvor/hod & quotKotobuki & quot; i dvoredni 14-cilindrični cilindar. Daljnji poboljšani Ha-5 razvijen je u 1.500 KS, a proizvedeno je oko 5.500 jedinica.

U isto vrijeme, na zahtjev mornarice razvijen je motor nazvan & quotSakae & quot, čiji se naziv u vojsci zvao Ha-25 (ovdje kliknite za detalje). Ovaj motor je jedinstveno konstruisan kao motor male veličine, male težine i visokih performansi u malim zapreminama i sa manje cilindara. Ovo je zatim instalirano u napadače nosača tipa 97, lovce nosače tipa Zero, & quotGekko (mjesečina) & quot Tip 99 dvomotorne lake bombardere, kao i u slavne lovce tipa 1 & quotHayabusa (sokol) & quot. Ovaj motor se uglavnom proizvodio u Tokijskoj tvornici i tvornici Musashino (izgrađena 1938. godine, a kasnije je postala tvornica Musashi nakon spajanja s tvornicom Tama), a proizvedeno je više od 30.000 jedinica (najveći broj u povijesti).

Tvornica Musashino bila je ekskluzivna tvornica vojnih motora, a ova moderna tvornica, sa površinom od 660.000 m2, bila je kruna izuzetnog znanja i rada Ichira Sakume. Ford je uključio najmoderniju operaciju montažne trake i naučni proces upravljanja Taylor sistemom. Osim toga, pažljivo su promišljeni proizvodni proces, protok materijala i kretanje ljudi. Program socijalne zaštite za zaposlene i prvoklasne ustanove u to vrijeme nije imao premca. Mornarica je bila impresionirana time i zatražila je da se za njih napravi ista vrsta ekskluzivne tvornice. Tvornica Tama izgrađena je pored tvornice Musashino 1941. Kasnije, zbog pogoršanja ratne situacije, Nakajima je predložio da se ujedine i vojna i mornarička tvornica radi efikasnijeg rada, ali zbog neprijateljstava među njima nisu postigli sporazum nekoliko godina dok nisu spojeni u tvornicu Musashi.

Ichiro Sakuma, koji je imao aktivnu ulogu u inženjeringu motora Nakajima za svako postrojenje, također je planirao i osnovao istraživački centar Mitaka, te radio kao generalni direktor u odjelu za izgradnju. Namjera Istraživačkog centra Mitaka nije bila samo istraživanje aviona, već i osnivanje općeg istraživačkog centra za politiku, ekonomiju i inženjering. Smatrajući da je ovo dalekosežan program za budućnost Japana, osigurana je kopnena masa koja iznenađuje 1,65 miliona kvadratnih metara. Slučajno je ceremonija početka temelja održana 8. decembra 1941. godine, na dan kada je Japan ušao u Drugi svjetski rat. No kasnije, zbog pogoršanja ratnog stanja, vojska je bila protiv postojanja tako razrađenog istraživačkog centra, a objekt je počeo s radom kao prototipsko inženjersko odjeljenje i pogon za proizvodnju prototipa 1943. (Nakon rata, gotovo svi njegovi Glavni inženjerski objekat se sada koristi kao škola Internacionalnog hrišćanskog univerziteta.)

Istraživački centar Mitaka (proizvodnja prototipa, inženjerski centar i vješalica)

Kao rezultat izbijanja Drugog svjetskog rata u Evropi 1939. godine, motori su se razvili u Evropi i SAD -u prema 1.500

Japanski avioni Drugog svjetskog rata

Uvoz turbopunjača Istorija japanske mornarice u razvoju turbopunjača je iznenađujuće duga i seže sve do Showe 12 (1937).

Major Jikyu Tanegashima, koji je u to vrijeme bio u Francuskoj, uspješno je ugovorio uvoz turbopunjača iz kompanije Brown Boveri & amp Cie AG u Švicarskoj (BBC), a turbopunjač je došao u Japan. Ovo je zabilježeno u Koukuu Gijyutsu Jouhou Tekiroku (Informacije o zrakoplovnoj tehnologiji).

BBC -jev turbopunjač razvijen je za vazdušne dizel motore, što su mnoge zemlje u to vrijeme istraživale. Uvezeni su dizajnirani za dizel motore od 500 KS.

Koristeći ovaj BBC turbopunjač kao primjer, Mitsubishi, Nakajima, Hitachi i Ishikawajima dobili su naređenje da istraže i razviju avionske turbopunjače. Nakajima to nije mogao učiniti jer se ta kompanija umjesto toga koncentrirala na razvoj mehaničkih kompresora.

Turbopunjači koje su razvile tri kompanije donijele su rezultate. Mitsubishijev turbopunjač instaliran je na J2M4 Raiden Model 32, a Hitachijev turbopunjač na Nakajima C6N2 Saiun. Šta se onda dogodilo sa turbopunjačem koji su razvili Ishikawajima Airplanes? Naša je istraga otkrila da je instaliran na Nakajiminom Sakaeu, motoru Zero Fightera.

Projekt mornaričkih visokih lovaca
Izvještaj Mornaričkog zračnog stožera, Pitanje u vezi s eksperimentalnim istraživanjem nakon Showe 17 (1942.), navodi sljedeće o turbopunjačima:
Dovršetak turbopunjača bitan je za uspjeh visinskih lovaca. Stoga je prototipiran, a trajnost su testirali Ishikawajima, Hitachi i Mitsubishi od Showa 15 (1940). Međutim, još nije testiran u avionu ili u letu. Da bi se nastavilo s testiranjem, potrebno je pripremiti pogon za masovnu proizvodnju na osnovu odluke o snazi ​​i tipu kompresora ispušne turbine koji će se instalirati na usvojeni avion.
Jasno je da se u to vrijeme razvoj mornaričkog turbopunjača premještao iz faze istraživanja u fazu rada. Zatim Kuugishou Shouhou (The Naval Technical Air Arsenal Journal) objavljen 9. februara 1942. spominje testiranje drvenog modela modela Nakajima Sakae Model 11 opremljenog turbopunjačem.

Piše: "Predviđeno je da će biti ugrađen u Zero Fighter", pa bi ovo mogao biti prvi službeni spis u kojem se spominje turbopunjač za Zero Fighter. Kuugishou Shouhou od 10 dana kasnije, 19. februara, spominje da će se održati "Početni istraživački sastanak za Zero Fighter s turbopunjačem". Ovo, u pisanoj formi, dokazuje postojanje Zero Fightera opremljenog turbopunjačem.

Turbopunjač Ishikawajima Aerial Industries
Ishikawajima Aerial Industries osnovana je Showa 16 (1941.) u sklopu tokijskog brodogradilišta Ishikawajima. Ishikawajimaina tvornica aeromotora, kako je postalo poznato, postala je zasebna podružnica i osnovala je svoje sjedište u blizini Kuugishou -a (Naval Technical Air Arsenal) u oblasti Kanazawa u Yokohami. Tamo je Ishikawajima nastavio razvijati avionske motore kao što su to radili na ostrvu Ishikawa. Tokom rata, osim istraživanja i razvoja turbopunjača i motora sa turbo-mješavinom, oni su se koncentrirali na proizvodnju konverzija motora Sakae i uvelike su doprinijeli nabavci motora za Zero Fighters. Proizvodnja Sakae dodijeljena je 1940., a prva konverzija modela Sakae 11 isporučena je krajem 1941. godine.

Hiroshi Yoshikuni, dizajner turbopunjača Ishikawajima Aerial Industries, izjavio je da je Ishikawajima napravio model Sakae 11 koji je Kuugishou koristio za pregled drvenih maketa turbopunjača. Uzimajući u obzir situaciju proizvodnje Ishikawajima Aerial Industries ’ Sakae, nagađamo da su odabrali model Sakae 11 za pregled drvene makete umjesto modela 12 ili 21. Turbopunjač instaliran na Zero Fighteru bio je Ishikawajimain IET model 4 serije, razvijen iz njegov turbopunjač od 500 KS, koji je podržavao motore klase 1000 KS. Kako se razvoj turbopunjača nastavio, IET model 5 za motore klase 2000 KS je dovršen, ali nikada nije stigao do stvarnih aviona. Što se tiče lopatica turbine, Ishikawajima i Mitsubishi koristili su klinasti tip, a Hitachi zavareni.

Problemi s turbopunjačem
Slike pokazuju da je ovaj Sakae motor s turbopunjačem imao direktno priključen turbopunjač, ​​bez međuhladnjaka, te ima vrlo jednostavnu instalaciju. Japanski turbopunjači imali su problema s materijalima jer je BBC -ov uzorak turbopunjača napravljen za dizel motore. Bilo je problema s materijalima BBC -ovog turbopunjača, koji su dizajnirani da izdrže 500 stupnjeva Celzijusa za dizelske motore kako bi se koristili na benzinskim motorima, turbopunjač je trebao izdržati više od 700 stupnjeva Celzijusa topline ispušnih plinova. Ishikawajimini turbopunjači izrađeni su od visokokvalitetnih materijala, sposobnih izdržati vrućinu, poput čelika od nikla-krom-volframa (slično materijalu koji se koristi za B-17), ali su se ipak dogodile nesreće, poput eksplozije leptir ventila ventila za ispuštanje ispušnih plinova, i razvoj nije tekao glatko. Činilo se da je problem pri odabiru materijala za čelik otporan na toplinu predstavljao tešku prepreku u razvoju turbopunjača.

Uprkos svim ovim problemima, A6M3 Zero Fighter je modifikovan tako da koristi turbopunjač, ​​a završeno je 1942. godine. No, zbog problema, testiranje se nije nastavilo prema planu, pa je naposljetku projekt napušten prije prvog leta test. Sada je poznato da je Zero Fighter prvi japanski lovac koji je koristio turbopunjač, ​​ali prava je šteta što nikada nije letio.


IRA je ubila lorda Mountbattena

27. avgusta 1979. Lord Louis Mountbatten ubijen je kada su teroristi Irske republikanske vojske (IRA) aktivirali bombu od 50 kilograma skrivenu na njegovom ribarskom plovilu Shadow V. Mountbatten, ratni heroj, stariji državnik i drugi rođak kraljice Elizabete II, proveo je dan sa svojom porodicom u zaljevu Donegal kod sjeverozapadne obale Irske, kada je bomba eksplodirala. U napadu su poginula još tri, uključujući Mountbattenovog 14-godišnjeg unuka Nicholasa. Kasnije tog dana, u bombardovanju IRA -e na kopnu poginulo je 18 britanskih padobranaca u okrugu Down, Sjeverna Irska.

Atentat na Mountbatten bio je prvi udarac koji je IRA zadala britanskoj kraljevskoj porodici tokom svoje duge terorističke kampanje da istjera Britance iz Sjeverne Irske i ujedini ih s Republikom Irskom na jugu. Napad je otvrdnuo srca mnogih Britanaca protiv IRA-e i uvjerio vladu Margaret Thatcher da zauzme oštar stav protiv terorističke organizacije.

Louis Mountbatten, sin princa Louisa od Battenberga i praunuk kraljice Viktorije I, ušao je u Kraljevsku mornaricu 1913, kada je bio u ranim tinejdžerskim godinama. Služio je službu tokom Prvog svjetskog rata, a na početku Drugog svjetskog rata bio je zapovjednik pete flote razarača. Njegov razarač, HMS Kelly, potopljen s Krita početkom rata. 1941. komandovao je nosačem aviona, a 1942. imenovan je za načelnika kombinovanih operacija. S te pozicije imenovan je 1943. za vrhovnog savezničkog zapovjednika za jugoistočnu Aziju i uspješno je vodio kampanju protiv Japana koja je dovela do ponovnog osvajanja Burme.

Godine 1947. imenovan je posljednjim potkraljem Indije, a kasnije iste godine vodio je pregovore koji su doveli do nezavisnosti Indije i Pakistana. Bio je na raznim visokim mornaričkim položajima 1950 -ih i bio je načelnik Štaba odbrane Ujedinjenog Kraljevstva i predsjednik Odbora načelnika štabova. U međuvremenu je postao vikont Mountbatten od Burme i prvi grof. Bio je ujak Philipa Mountbattena i upoznao je Filipa s budućom kraljicom Elizabetom. Kasnije je ohrabrio brak dva udaljena rođaka i postao kum i mentor njihovom prvorođenom, Charlesu, princu od Velsa.

Napravljen za guvernera, a zatim i lorda poručnika Ostrva Wight u penziji, Lord Mountbatten bio je cijenjen i voljen član kraljevske porodice. Njegovo ubistvo 27. avgusta 1979. bilo je možda najšokantniji od svih strahota koje je IRA nanijela Ujedinjenom Kraljevstvu. Osim svog unuka Nicholasa, u napadu je poginula i 15-godišnja ruka čamca Paul Maxwell koja je smrtno ozlijeđena i udovica Lady Brabourne, Nicholasina i#baka. Mountbattenov unuk Timothy –Nicholas ’ blizanac – ozlijeđen je kao i njegova kći, Lady Brabourne i otac blizanaca, Lord Brabourne. Lord Mountbatten imao je 79 godina.

IRA je odmah preuzela odgovornost za napad, rekavši da je eksplodirala bomba daljinskim upravljačem s obale. Također je preuzela odgovornost za isti dan bombardovanja britanskih trupa u okrugu Down, koji je odnio 18 života.

Član IRA -e Thomas McMahon kasnije je uhapšen i osuđen za pripremu i postavljanje bombe koja je uništila čamac Mountbatten -a. Skoro legenda u IRA-i, bio je vođa ozloglašene IRA-ine brigade Južna Armagh, koja je ubila više od 100 britanskih vojnika. Bio je jedan od prvih članova IRA -e koji je poslan u Libiju da trenira s detonatorima i mjernim uređajima i bio je stručnjak za eksploziv. Authorities believe the Mountbatten assassination was the work of many people, but McMahon was the only individual convicted. Sentenced to life in prison, he was released in 1998 along with other IRA and Unionist terrorists under a controversial provision of the Good Friday Agreement, Northern Ireland’s peace deal. McMahon claimed he had turned his back on the IRA and was becoming a carpenter.


The History of Japan’s First Jet Aircraft

Earlier this year, our collections staff at the Udvar-Hazy Center, in Chantilly, Virginia, moved the Nakajima Kikka from beneath the wing of the Sikorsky JRS flying boat in the Mary Baker Engen Restoration Hangar and out onto the floor beneath the Boeing B-29 Enola Gay. Moving the Kikka provides an opportunity to bring visitors closer to the last known example of a World War II Japanese jet aircraft and the only Japanese jet to takeoff under its own power—it also opened up space in the Hangar so that our team could install netting to deter birds.

Museum preservation and restoration specialists (from left to right) Carl Schuettler, Sharon Kullander, Anne McCombs, Will Lee, and Chris Reddersen carefully position the Kikka in the Boeing Aviation Hangar at the Udvar-Hazy Center.

The Kikka took cues from the German Messerschmitt Me 262 fighter. When Germany began to test the jet-propelled Messerschmitt Me 262 fighter in 1942, the Japanese air attaché to Germany witnessed a number of its flight trials. The attaché’s enthusiastic reports eventually led the naval staff in Japan to direct the Nakajima firm in September 1944 to develop a twin-jet, single-seat, aircraft similar in layout to the Me 262.

Nakajima leadership assigned the project to engineers Kazuo Ohno and Kenichi Matsumura. As the war continued to deteriorate for Japanese forces, Japanese naval pilots launched the first suicide missions using aircraft in October 1944. Several aircraft manufacturers turned to designing aircraft specifically for use during suicide missions, including the Nakajima Kikka. Ohno and Matsumura led the design as it developed an all-metal aircraft except for the fabric-covered control surfaces. The designers planned to hinge the outer wing panels to fold up so that ground personnel could more easily hide the aircraft in caves. They mounted the jet engines in pods slung beneath each wing to make it easier to install and test different engines. Three different engines were tried before the designers settled on the Ne-20, an engine that drew heavily from the German BMW 003.

Experimentation with turbojet engine technology had begun in Japan as early as the winter of 1941-42 and in 1943, a Japanese technical mission to Germany selected the BMW 003 axial-flow turbojet for development in Japan. A large cargo of engines, engineering plans, photographs, and tooling sailed for Japan by submarine but vanished at sea. However, one of the technical mission engineers had embarked aboard another submarine and arrived in Japan with his personal notes and several photographs of the BMW engine. The Naval Technical Arsenal at Kugisho developed the Ne-20 turbojet based on this information.

Due to the lack of high-strength alloy metals, the turbine blades inside the jet engine could not last much beyond a few hours but this was enough time for operational testing and 20 to 30 minute flights for a one-way suicide missions.

The first prototype Kikka was ready to fly by August 1945. Lieutenant Commander Susumu Takaoka made the initial flight on August 7 and attempted to fly again four days later but he aborted the takeoff and crashed into Tokyo Bay, tearing off the landing gear. Various sources offer different causes for the crash. One writes that technicians had mounted the two takeoff-assist rockets at the wrong angle on the fuselage while another ascribes blame on the pilot who mistook the burnout of the takeoff rockets for turbojet engine trouble, throttled back, and executed a safe but unnecessary crash landing. Development of the Kikka ended four days later when the Japanese surrendered. Another prototype was almost ready for flight and American forces discovered about 23 Kikka aircraft under construction at the Nakajima main factory building in Koizumi (present day Oizumi in Gunma Prefecture), and at a site on Kyushu island.

Despite considerable research in the U.S. and Japan, we know little about the origins of the Museum’s Kikka. We can only say that American forces shipped several Kikka’s and probably major components to the U.S. after the war, but we do not know which factory they originated from. U.S. Navy records show the Museum’s Kikka at NAS Patuxent River, MD on February 18, 1949. The aircraft was shipped from Norfolk on September 2, 1960 to the Paul Garber Facility in Suitland, MD. Museum staff accessioned the Kikka into the collection on March 13, 1961. Correspondence in 2001 with Japanese propulsion specialist Kazuhiko Ishizawa theorized that Nakajima constructed the Museum’s Kikka airframe for load testing, not for flight tests. This may explain why the engine nacelles on the Museum’s Kikka airframe are too small to enclose the Ne-20 engines, but it does not explain why the airframe is relatively undamaged. Load testing often results in severe damage or complete destruction of an airframe. There is no further information on the subsequent fate of the Kikka that crashed on its second test flight. Treatment specialist staff at the Udvar-Hazy Center confirmed that the Museum’s Kikka is fitted with manual folding wings.

Kikka and Messerschmitt Me 262 Compared

Based on the performance requirements for a one-way suicide mission, and the size and output of the Ne-20 engine, the performance goals for the Kikka differed considerably from the goals set for the German fighter. The Kikka’s estimated range was 205 km (127 mi) with a bomb load of 500 kg (1,102 lb) or 278 km (173 mi) with a load of 250 kg (551 lb) at a maximum speed of 696 km/h (432 mph). A takeoff run of 350 m (1,150 ft) was predicted with rockets mounted on the fuselage to shorten the run, and for training flights, the Kikka was expected to land at 148 km/ (92 mph). The Me 262 A-1a production fighter could fly 845 km (525 miles) with a typical military payload of 4 x MK 108 cannon (30 mm) and 2 x 300 ltr (79 gal) drop tanks at 870 km/h (540 mph) maximum speed. The pilot of the German fighter could land at 175 km/h (109 mph) and required 1,005 m (3,297 ft) to takeoff without rocket-assist.

Although the Kikka resembles the Me 262 in layout and shape, the German jet is actually considerably larger. Here is a comparison of both aircraft:

Experimental Prototype Kikka:

Raspon krila: 10 m (32 ft 10 in)
Dužina: 8.1 m (26 ft 8 in)
Visina: 3 m (9 ft 8 in)
Težine: Empty, 2,300 kg (5,071 lb)
Gross: 4,080 kg (8,995 lb)
Engines: (2) Ne-20 axial-flow turbojets,
475 kg (1,047 lb) thrust

Production Me 262 A-1a Fighter:

12.65 m (41 ft 6 in)
10.6 m (34 ft 9 in)
3.83 m (12 ft 7 in)
4,000 kg (8,820 lb)
6,775 kg (14,939 lb)
(2) Junkers Jumo 004 B axial-flow,
900 kg (1,984 lb) thrust

Published Sources:

J. Richard Smith and Eddie J. Creek, Jet Planes of the Third Reich, (Boylston, MA: Monogram Aviation Publications, 1982).

René J. Francillon, Japanese Aircraft of the Pacific War, (London: Putnam, 1979).

Robert C. Mikesh, Kikka, Monogram Close-Up 19, (Monogram, 1979).

Tanegashima, Tokyasu. “How the First Jet Engine in Japan was Developed,” Gas Turbines International, November-December 1967, 1200. Nakajima Kikka Curatorial File, Aeronautics Department, The National Air and Space Museum, Washington, DC


Kawasaki Ki-61 Hien / Ki-100

The Kawasaki Ki-61 Hien or Type 3 Fighter remains to this day one of the most recognizable Japanese fighters of the World War II era. What makes Hien unique is the powerplant – it was the only mass-produced Japanese fighter powered by an inline, liquid cooled engine.

The Ki-61 began to arrive at the frontlines in large numbers in the summer of 1943 and took part in battles over New Guinea and later over the Philippines and Okinawa, as well as in the defense of the Japanese Home Islands. In total over 3,000 examples of various Ki-61 variants and derivatives were built. The Ki-100, a Ki-61-II Kai airframe mated to the Ha-112-II radial engine, entered service towards the end of the war.

Origins and development of the design

Early days

On July 1, 1938 the Rikugunsho (Japanese Ministry of the Army) signed off on the expansion and fleet modernization program of the Dai Nippon Teikoku Rikugun Kokutai (Imperial Japanese Army Air Force, IJAAF), known as Koku Heiki Kenkyu Hoshin (Air Weapons Research Policy). The program, prepared by Rikugun Koku Honbu (Army Aeronautical Department), included the development of two single-seat fighter types by Nakajima – light Ki-43 and the Ki-44 heavy fighter. “Light” and “heavy” designations did not reflect the weight or size of the aircraft, but rather the caliber of offensive armament carried by the fighters. According to the program’s requirements, the light single-seat fighter (kei tanza sentoki) was to be armed with a pair of 7.7 mm machine guns, i.e. standard weapons carried by the Army Air Force fighters since its inception. The aircraft, designed as a weapon against enemy fighters, was supposed to be very maneuverable and fast. On the other hand, the heavy single-seat fighter (ju tanza sentoki) was to be used against enemy bombers. That type of mission required a machine with a high level flight speed, a good rate of climb and a heavy offensive punch. The proposed heavy single-seat fighter was therefore required to be armed with two 7.7 mm machine guns and one or two “cannons”, which in reality meant large caliber machine guns

In June 1939, less than a year after the modernization program had been approved, the officials of Rikugun Kokugijutsu Kenkyusho (Army Air Technical Research Institute, often known under its abbreviated name Kogiken or Giken) began a series of consultations with the representatives of aeronautical companies in order to work out technical requirements for a new generation of combat aircraft, whose development would be included in the 1940 Koku Heiki Kenkyu Hoshin program. During the consultations the Kogiken officials met twice (in June and in August) with the Kawasaki engineers. In addition to talks and consultations with the local aeronautical industry leaders, the Kogiken team studied lessons learned from the battles against the Soviet air force over Khalkhin-gol (Nomonhan) and reports of the Japanese observers covering operations of the Luftwaffe against Poland. The newest trends and developments in aviation technology in nations considered global aviation powers (especially Germany, Britain and the U.S.) were also carefully studied and scrutinized.

In February 1940 Rikugun Koku Honbu Gijutsubu (Army Aeronautical Department, Engineering Division) used the results of the studies to commission several Japanese aircraft manufacturers to develop new combat aircraft designs, with considerably better performance, stronger construction and heavier armament than the types in active service or in development at that time. In the single-engine, single-seat fighter category the division into light and heavy types was maintained. Kawasaki received orders to develop two fighter designs powered by inline, liquid cooled engines – the heavy Ki-60 and the light Ki-61 fighter. Orders for similar types, but powered by radial, air cooled engines, were placed with Nakajima (the light Ki-62 fighter and the heavy Ki-63). In addition, Kawasaki designers were tasked with the development of the ground-breaking Ki-64 fighter, while Mitsubishi was to produce the Ki-65 heavy fighter. The winning designs in each category were to be officially selected in March 1942.


Boudicca (died c.AD 60)

Imagined portrait of Boudicca © Boudicca was queen of the Iceni people of Eastern England and led a major uprising against occupying Roman forces.

Boudicca was married to Prasutagus, ruler of the Iceni people of East Anglia. When the Romans conquered southern England in AD 43, they allowed Prasutagus to continue to rule. However, when Prasutagus died the Romans decided to rule the Iceni directly and confiscated the property of the leading tribesmen. They are also said to have stripped and flogged Boudicca and raped her daughters. These actions exacerbated widespread resentment at Roman rule.

In 60 or 61 AD, while the Roman governor Gaius Suetonius Paullinus was leading a campaign in North Wales, the Iceni rebelled. Members of other tribes joined them.

Boudicca's warriors successfully defeated the Roman Ninth Legion and destroyed the capital of Roman Britain, then at Colchester. They went on to destroy London and Verulamium (St Albans). Thousands were killed. Finally, Boudicca was defeated by a Roman army led by Paulinus. Many Britons were killed and Boudicca is thought to have poisoned herself to avoid capture. The site of the battle, and of Boudicca's death, are unknown.


Analog computers

Analog computers use continuous physical magnitudes to represent quantitative information. At first they represented quantities with mechanical components (vidi differential analyzer and integrator), but after World War II voltages were used by the 1960s digital computers had largely replaced them. Nonetheless, analog computers, and some hybrid digital-analog systems, continued in use through the 1960s in tasks such as aircraft and spaceflight simulation.

One advantage of analog computation is that it may be relatively simple to design and build an analog computer to solve a single problem. Another advantage is that analog computers can frequently represent and solve a problem in “real time” that is, the computation proceeds at the same rate as the system being modeled by it. Their main disadvantages are that analog representations are limited in precision—typically a few decimal places but fewer in complex mechanisms—and general-purpose devices are expensive and not easily programmed.


Interview

Interview: Shigeru Nakajima

Interviewer: William Aspray

Place: Tokyo, Gakushi Kaikan, Conference Room No. 309, University Alumni Association Hall

[Note: Aspray’s questions are spoken in Japanese by a translator, and Nakajima's replies are spoken in English by a translator. Dr. Yuzo Takahashi of Tokyo University of Agriculture and Technology, who reserved the room is also present. Dr. Takehiko Hashimoto of the University of Tokyo is also present, also Mr. Naohiko Koizumi of Futaba Corporation.

Family Background and Education

Dr. Nakajima, I am going to ask you to tell your life story in your own words. I may occasionally ask you a question to follow up on something you've said, but I'll let you direct the flow of the conversation, if that's okay with you.

Could you begin by telling me about your childhood and your education?

I was born in a fishing village in the Chiba prefecture, Onjuku, and my father was the schoolmaster of the primary school. My father was very devoted to education, and he established a new high school for women in Japan in the fishing village.

Because of your father's profession, was it expected that the children would get a good education and go to university?

Yes, I have three brothers and four sisters, and just three of four brothers (including me) and two of four sisters went to the university. My elder sister went to a Japanese Women’s University, went into a mathematics department, and became a teacher of mathematics of women’s high school. The youngest of my elder brothers is the late Dr. Yoji Ito who passed away at the age of 53.

Were you a good student when you were growing up? What did you want to do as an adult? What were your aspirations for your adult life?

I was not an excellent student. I was leader of the class at middle school but failed to enter the Imperial University of Tokyo, so I had to go to Waseda University, a private university and the best private university.

What did you want to do when you were growing up?

In high school I already wanted to become an electrical engineer.

I see. What was taught as part of your course of study at the university?

I went into the power engineering department because it also offered communications. If I went to a communications department, I couldn't get a national license, national license for electrical power engineers so I had to go into power engineering. Privately, I was already studying communications.

I see. That was an important thing to have for one's future career? Is that right?

Toshiba Patent Monopoly and JRC

You graduated in 1930. That's just about the time, at least in the West, that the Depression was coming. Had the Depression hit in Japan yet, and was it difficult to find jobs in Japan when you graduated from college?

Da. The influence of the Depression was deep. Almost two thirds of the graduates could not enter a company, and my advising professor recommended me to the Hitachi Company. Hitachi didn't have a department of vacuum tubes, so I declined and stayed in the engineering department for about one year. About that time Toshiba and NEC declined to give me a job, and JRC accepted.

Toshiba did not offer you a job?

No, but at that time Toshiba had bought the Langmuir patent for the hard-valved electron tube and almost dominated the manufacturing of those vacuum tubes. At that time radio broadcasting became very popular, and Toshiba offered only expensive vacuum tubes, so a radio set became more expensive if you bought a Toshiba tubes. Because of the radio boom, lots of factories (more than twenty) were building and they were producing less expensive vacuum tubes. At that time JRC was planning allowed by Toshiba to produce the amount of seven hundred thousand yen of vacuum tubes, but instead Toshiba could use all the JRC patents, cross-licensed: it was because of the Langmuir patent whose expiring date was extended. Toshiba required a much higher patent royalty from some small vacuum tube manufacturers in Japan. Toshiba had the right over the patent of the GE. So instead of GE, Toshiba wanted to get the patent royalty from various small vacuum tube manufacturers at the time.

I see. Toshiba had bought the patent rights, and they were going to exercise all the control over it that they could possibly get.

Da. But I was very glad to know that I need not study that old Langmuir patent, and at least I could study more new technologies about the electron tube.

At that time I started to study Barkhausen-Kurtz oscillator and magnetron, but I was not sure at that time that such things would become useful for practical use, so I wanted to study microwave tubes, very high frequency tubes.

This was in the 1930s still? Soon after you had joined JRC?

Yes, I supposed the Langmuir patent would expire in the near future.

Microwave Medical Device

In 1935, or so, I was somewhat ill, something like pleurisy. I was acquainted with a medical doctor, and we became lifelong friends. He gave me the knowledge of Germany. In that country there was some electromagnetic therapy in practical use. He asked me, "Can you make such equipment?" I answered, "Yes, of course." He was a Doctor of Medicine and an assistant professor at the Imperial University of Tokyo. He told me how to use a microwave to heat up muscle [tissue], to use in therapy sessions.

At that time (in 1935) the Langmuir patent had already expired, so JRC did not have to pay any royalties to Toshiba. There were excessive of the therapy equipment orders compared with production capability and JRC could get a lot of money for orders of the apparatus of the wireless communication equipment.

Just for this medical apparatus?

There was such demand for this medical product that it was at least as successful as the military and marine products that were being developed by the company? Is that the thrust of this?

The rate of profit for the medical product was very high, but the total sales of the product was very low, compared with that of the military and marine products.

JRC had a good connection with the military authority because JRC was one of the most important military suppliers. It was also because a key person of the Navy was his elder brother, Yoji Ito.

As JRC got a lot of money, the president of JRC at that time asked me to take some three years' vacation, or so, to go to some foreign company that I liked. I thought that I would go to Germany at that time because Telefunken already had some patent relations with JRC. But the president opposed my going to Telefunken because Telefunken was under the control of the German military and Telefunken would decline to show the technology. Anyway, I insisted on going to Germany.

So the three years were as a reward for getting this very profitable order?

Germany and Telefunken

Da. The negotiation with Telefunken was not easy. It took about three months, but eventually I was permitted to go to Telefunken.

Da. 1937. That was maybe three or four years before the start of World War II.

Not that much before, because in 1938 Germany was already moving into countries.

So in 1937 maybe some connection between Japan and Germany existed. The preparations for war were underway. I studied at Telefunken for a year and a half learning about transmitting vacuum tubes for example, zirconium getter.

Getter means gas-absorbing materials in a high vacuum envelope.

That was new technology for Japanese vacuum tube manufacturers. I brought it back from Germany. Until 1965, Japanese vacuum manufacturers used dead-copy of my getter.

Waseda University & Tube Research

Before we go on, could I ask you a couple of questions about your electronics background from a little earlier in your life? There are two questions. Could you describe in a little more detail what went on at the Kodakura research laboratory, at Waseda University and what you did and learned there?

I studied photo tubes in Waseda after graduation from university and before joining JRC. Just after I joined JRC I was in charge of the oscillation tube, or magnetron, or the ultra-short-wave tube. As for the magnetron, it was suggested by Kiyoshi Morita of the Tokyo Institute of Technology. (Morita was the advisor of Heitaro Nakajima when H. Nakajima wrote his graduate thesis.)

Morita, assistant at that time, at the Tokyo Institute of Technology, was preparing his doctor's study. His topic was the short-wave tube. He ordered JRC to make a prototype tube or experimental apparatus. The magnetron. He became later professor of the Institute.

During the 1930s, when you were studying these tubes, how was knowledge passed? Was there available literature from other countries? Was there another group of people within Japan that was studying these? How did you learn about these things?

I'm sorry no information exchange existed among the companies in Japan. Toshiba was the only one tyrant.

I’ll explain the reason. There is a book titled The History of Electron Tubes published in 1987 written in the Japanese language. I am one of the co-authors. At the time of making this book I asked the Toshiba people why Toshiba had no patent concerning electron tubes. JRC had so many original patents. The answer was that the vice-president of Toshiba came from GE, and Toshiba people were not allowed to make such new technology as vacuum tubes.

Is there a journal literature in English or German? If there is, is it available? If that journal literature is available, does it tell you the things that you need to know, or do you need to have know-how about building these tubes that wouldn't be in the scientific literature? Those are the kind of things that I would like to know.

Some journal literature was available to the JRC Company. I read German journals everyday. Of course, some books from the United States would be available at that time, but I already forgot them.

Magnetron Development

Maybe we should continue then with the story.

Morita made a drawing of the magnetron and asked me to have JRC build it. I was very interested in such things, and also my brother Yoji Ito showed interest. He was in a Naval Research Institute. He was studying the Kennelly-Heaviside layer. He thought that some ultra high frequency, such as radar, would be useful because some reflection of electric wave would be possible.

So at that time Doctor Ito used to ask me for a weekly report. In 1934 he took leadership of the laboratory of vacuum tubes in the Naval Research Institute. At that time a special research contract was made between the Naval Research Institute and the JRC Company. My elder brother was not satisfied to invite only me, and he took some five or six vacuum tube workers from JRC to the Naval Research Institute at Meguro, Tokyo to build a group for manufacturing.

So the two groups were working independently.

But not completely independently very close coordination, and a very dutiful brother. Some differences though. At that time in my magnetron laboratory there were maybe three hundred persons — only for the magnetron. It was maybe the biggest magnetron factory in the world. At the Naval Research Institute, they discovered a special construction in which the frequency is very stable the stability is very good. That knowledge was fed back to JRC, so there was big and quick progress.

Finally JRC made such a device in 1939. It was a single-phase oscillator with ten-centimeter wavelengths. I believe this was the first one in the world and it had a five-hundred-watt output.

So this was the first one with that high an output?

Da. It was also water-cooled.

At last the power went up to some hundreds of kilowatts or so. During the Second World War, many naval warships installed radar using our first developed water-cooled magnetrons.

That was earlier than the United States.

Radar and the Japanese Navy

But at that time there were so many opposite opinions in the Navy on using such radar. The reason why: with this thing and in a dark night with a light on, one could find a robber.

Maybe I should try to put it another way. The Japanese military authority, the Navy also, relied upon the optical weapons. Our optical technology was good, and they say that the Japanese have excellent eyes for watching with the optical aided tool (telescope, etc.). This was the main tool of the Navy, and they didn't appreciate the meaning of radio weapons. They looked down with scorn at such an idea. Yes, very skeptical.

Some top department of the Navy believed that radar was of no use very strange. They didn't believe in the electronics technology, I think. They didn't permit us to use the precious metals for the magnetron, such as cobalt for use in magnets.

The Navy wouldn't permit it?

No. Yoji Ito's group made about one hundred radars. They were not installed to big battle ships, but only small ships.

I see, so they were putting them into small ships that might have been fishing vessels.

Da. At the last stage of the naval war in the dark night, the Japanese were worst hit by the United States. There must be some radar.

That is what made the Japanese Navy believe in radar? Da li to govorite?

Tačno. So in late 1943 or so, the Japanese Navy began to think there must be radar in warships. At that time JRC people were obliged to make radar devices but also the Navy must install the devices, so, for example, Sogo Okamura and Seibun Saito were ordered to —

And also Ito could not continue their research.

So not only did you have an urgent plan to build all this equipment, but there was an urgent plan to get it installed. You even had to take away very good researchers to do this job?

Da. You know, the vessels were not in Japan, but the place was just fighting. The authorities dispatched not only the operators but also excellent researchers to such places to install them.

The Japanese Navy installed radar earlier than the USA. Midway through the operation, the Japanese Navy was very heavily damaged. But at that time, in our northern sea area, the Japanese Navy dispatched two or three ships, on which was installed microwave radar and also an ultra high frequency radar.

Do you know the history, the story of radar? Ships with radar were very successful in retreating from the Aleutian Islands. There were many troops on each small island, and they would go back to the ship and return.

It was very successful, but Midway.

In the Aleutian area there was no United States Navy. But on the return to Japan, there was a very hard storm, and every ship was.

At that time microwave radar was very useful to confirm which ship —

The shipmasters confirmed the usage of radar, but at the time, still some top departments of the Navy didn't think that the radar was useful. General Isoroku Yamamoto personally asked my elder brother Ito to make an entirely new weapon. Without it, it would be impossible for Japan to win the war.

Wartime Weapons Research

Ito thought of the atom bomb. He frequently went abroad, so he knew that the U.S. had forbidden in 1939 the export of uranium ore. So he realized that the U.S. must have surely been planning to develop the atom bomb. He was thinking that Japan had to do something to prepare for this. In January 1940 he was sent to inspect war-preparations in Europe.

Doctor Ito got a Ph.D. under Professor Barkhausen in Dresden. Ito had very good knowledge of the German language. For example, he translated a tale for children from German to Japanese.

He was very fluent, and could get the kind of information the German army was very reluctant to reveal. This included their top-secret projects such as the Wurzburg radar and so on. But he was scheduled to stay just for two months. He was blocked because of the war, so he had to take ten months to just return from Germany to Japan.

Around South America. There was no transportation connection between Germany and Japan.

Ito finally came back to Japan and tried to prepare the radar as well as the atom bomb. He couldn't get information about the atom bomb in Germany, but he discussed it with the physicists (Professor Nishina, etc.) in Japan. There was a meeting and finally the famous Japanese physicists decided that Japan could not develop the atomic bomb, and also that in the United States it would be impossible to develop the atomic bomb during war time. My brother Yoji Ito told me personally several times that the United States surely knew how to make the bomb.

The next story is about the destructive ray. The JRC started developing bigger, higher power magnetrons at the laboratory in 1941, trying to kill a rabbit.

Kill a rabbit, yes. Successfully. Because General Yamamoto was asking Ito to make a new weapon to win the war, Ito was thinking about making a several thousand-kilowatt magnetron. With this microwave he could hit the airplanes and make the engine dysfunction somehow. He was thinking about it. So he established a new laboratory, at Shimada in Shizuoka Prefecture, and gathered lots of famous physicists, such as Tomanaga, Kotani, to develop this kind of high-output magnetron. But he was not very successful. The biggest magnetron they developed was from JRC. One of four company men, Sozaburo Yamasaki, made a magnetron of 20 cm wavelength, having the output power of 100kW. A more powerful magnetron having the output power of 1000 kW was undergoing trials as of August 1945.

In 1953 I traveled around the world without a translator. At that time I went to London, and at the museum I found exactly the same thing, which was explained as: "This was invented by some Birmingham University people in 1940." 1940 was one year later than our invention. When I found this one in the London museum, there was an explanation that this magnetron led to Allied victory for the Second World War. After that, a symposium was held in England by IEE, but at that time there was no exhibition of this magnetron. I felt very strange — why was that thing not then exhibited? That was 1985. At that time there were so many kinds of parts exhibited in many rooms, but there was no exhibition of this magnetron. I felt very strange and asked everybody, but there was no answer. After that, when I sat alone, taking some tea, one old gentleman hit my shoulder by the hand and told me, "Your magnetron must have been stolen by the English King." That was an interesting thing.

Postwar Microwave Research

Maybe we should turn to the post-war period?

In the post-war period the general headquarters of the Occupation Force was very stringent in restricting what should be manufactured. In the case of the JRC Corporation, radio receivers and medical equipment could be produced, but not transmitters.

But three or four years’ later, wireless equipment for marine use was permitted. Therefore, we could produce transmitting vacuum tubes, so we could make a profit from that. Getter is gas-absorbing material in the vacuum tube to keep a high vacuum. At that time JRC was almost the only producer for that. Its market share was ninety-eight percent or so.

Da. We had the orders also from the United States. In one year, two hundred million vacuum tubes were produced in Japan. So we could make money by means of getter production.

The difficulty was because of the GHQ, but they could survive because of getter.

At that time, only the JRC Corporation had microwave engineers. JRC had more than one hundred microwave engineers, and I had to consider what kind of jobs they must be doing.

Because you were now the manager of the research and development division?

Da. I thought that if the microwave was used, multiple communications could be possible: for example, the telephone. At the first stage I considered multiplex telephone transmission by frequency modulation using a variable-frequency magnetron. But instead of frequency- modulated equipment, there was a patent by Professor Nagai of the Tohoku University, called PTM, which is pulse time modulation. We thought this type would be better, so we produced some trial equipment. We prepared to make some experiment between Mount Futago at Hakone near Fuji Mountain and the JRC Corporation in Mitaka that was heard by the General Headquarters and the Electric Communication Laboratory at that time also knew about that experiment.

So the experiment hadn't occurred yet, but word about this had been learned by both the Electric Communication Laboratory and by the GHQ?

At that time, transmitting electromagnetic waves had to be approved by the authorities. I went to the Electric Communication Laboratory to ask for the approval.

I see, so not only did they just happen to hear it, they had to have heard about it because they had to give their approval.

The president of the Electric Communication Laboratory did not understand the usage of electrical wave for communication. He thought it was nonsense to use such an unstable propagation wave for communication equipment. But at that time one very important person named Frank Polkinghorn of GHQ visited the Electric Communication Laboratory and found that there were no experiments about microwaves. He was surprised.

But at that time, the president answered. Of course, meanwhile we were ready to make the experiment, elsewhere.

I'm not sure I understand. So Polkinghorn says, "Aren't you doing any microwave research?" The president of the Electric Communication Lab says, "Oh, yes, we're going to do this and that, but we're not going to do it here." Is that it?

JRC tried to establish a test from Mount Hakone to JRC. To get the approval, the Electric Communication Laboratory had denied JRC the use of radio. But the GHQ officer named Polkinghorn, a civil communications service officer, asked the director of the Electric Communication Laboratory, "Why aren't you promoting microwave study?" Therefore the director of the ECL commanded JRC to stick a new label over the label of JRC, "Electric Communication Laboratory," and just go test.

So that it looks like ECL's rather than JRC's.

Tačno. Basically the company was correct, but was much indebted to Mr. Polkinghorn of GHQ.

Fish Detection Equipment

This is now about fish finding. The history is that Navy men were using an ultrasonic submarine detection system and finding a strange phenomenon. It would identify a submarine but then the submarine would suddenly be gone, and they suspected that it would be a school of fishes. I heard the idea, and after the war I tried to use this idea to find a school of fish. I proposed this idea to GHQ to make an experiment. GHQ declined because this was related to weapons. But I insisted, "No, we can use even one sardine on the table, we are so short of fishes." I asked several times over two years, but GHQ declined very adamantly. I asked my elder brother, Dr. Ito, and he asked Dr. Kelly who saved the Japanese science and technology in post-war years. Ito insisted, so Kelly finally gave secret permission to me to do an experiment. When we did the experiment, we very clearly identified a school of fish. That experiment was successful. I really believe that Kelly was a sort of saint, that he saved Japanese science and technology. He was an intimate friend of my brother's, and there are words dedicated by Kelly when my brother died.

I see. This is Harry C. Kelly.

Harry C. Kelly, yes. That experiment was successful, but fishermen were skeptical at first. They thought that with their long experience, they knew how to find fish. But the experiment was successful. They could get a lot of fish, so the fishermen were enthusiastic about this device. This now costs fifty thousand, but at that time about a million Yen.

Demand was so great that we sold out of this device, so the fishermen had to wait. We exported it to the U.S. and many other countries.

A newspaper company was very interested and asked to come on board to witness the experiment. Then the findings of the successful experiment were broadcasted nation-wide. The first cost was a million yen, but we changed it from nickel oscillator to an oxide compound. BaTiO3. This is manufactured by Murata, a Japanese company, and was a Japanese invention. Because of this innovation, the cost went from a million to fifty or sixty thousand.

After that I visited RCA and the Bendix Company, and showed the device. That surprised the engineers at Bendix because they were just borrowing that device from the Navy to develop their weapons. Probably the Navy also kept that device.

Can I go back and ask a question about the experiment on the communications channel? Did that succeed, and did it result in a technology that was implemented in the country?

Mislim da jesam. It was successful. It was the beginning of Japanese multiplex telecommunications by microwave.

But did it directly stem from this particular experiment, or did it come from some other direction?

The main topic for him was the oscillation of the magnetron wave and the reception of the magnetron wave.

I see. So you were far from being at a communications system at this point you were just showing proof of principles?

To show a transmission line using PTM method.

A certain doctor was interested in this fish-finding device and asked me to try to use this device to diagnose on the human body, the conditions of organs. I was at first very surprised but tried to develop a device. It was a very difficult process, and it took about twenty years. I was also asked to use this device for meteorological purposes. When did meteorological radar begin to be used in the United States?

All principal points have been covered. You know that this fish finding and diagnosis is the beginning of his present company, Aloka. Fish finding is one of the best sales of JRC, and it was a peaceful application. Communication was a peaceful application, the main peaceful application of radar technology. I think he contributed much not only to the military application, but also.

Also to these commercial ones.

Yes, and I think that he is very proud of that, being one of the real original developers of the magnetron technology.


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Komentari:

  1. Dugor

    U njemu je nešto. Thank you for the explanation, easier, better ...

  2. Rufio

    Ako kažeš da si varao.

  3. Pomeroy

    an Interesting moment

  4. Gilmer

    ne možeš to više imenovati!

  5. Cadmus

    Ja - ovo mišljenje.

  6. Leopoldo

    Mogu potražiti referencu na stranicu na kojoj ima mnogo članaka o ovom pitanju.



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