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Nakajima Ki-62

Nakajima Ki-62


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Nakajima Ki-62

Nakajima Ki-62 var et design for en jagerfly som skulle drives av den japanske versjonen av Daimler-Benz DB 601A-motoren, produsert i tilfelle Kawasaki Ki-61-designet mislyktes.

Kawasaki hadde kjøpt rettighetene til å bygge DB 601A-motoren i Japan, der den fikk betegnelsen Ha-40. De ble deretter (1940) beordret til å designe to jagerfly basert på denne motoren, den tunge avskjæreren Ki-60 og den generelle Ki-61. På denne datoen hadde det japanske hærens luftvåpen forlatt konkurransedyktige anbud, og i stedet ga et enkelt selskap i oppdrag å produsere hvert nytt design, men det var en stund siden Kawasaki hadde produsert en jagerfly for hæren.

De tre siste hærskjemperne (Ki-27, Ki-43 og Ki-44) hadde vært Nakajima-produkter, og de ble nå bedt om å produsere sitt eget design for en jagerfly basert på Ha-40, som en sikkerhetskopi i tilfelle Ki-61 mislyktes. Et designteam ledet av T. Koyama ble opprettet, og i løpet av 1941 produserte de design for både Ki-62 og en radialmotorversjon, Ki-63.

Ki-62 var veldig lik Kawasaki Ki-61, med samme hengende nese som sett på de fleste DB 601-drevne fly (inkludert Bf 109). Ki-62 skilte seg ut ved å ha en avskåret bakkropp og en boble cockpitkalesje, noe som ville ha gitt bedre sikt enn den innkjørte cockpiten som ble brukt på Ki-61. Luftinntaket for radiatorene var også i en annen posisjon, rett foran vingen, mens den på Ki-61 var bak vingen.

En gang var det klart at Ki-61 kom til å bli et suksessarbeid på Ki-62 og Ki-63 tok slutt. I stedet ble Nakajima bedt om å produsere en ny allsidig jagerfly som ville ha mye mer til felles med allierte design enn med tidligere japanske fly, med vekt på hastighet, beskyttelse og ildkraft i stedet for manøvrerbarhet. T. Koyama og teamet hans begynte arbeidet med den nye Ki-84 tidlig i 1942, ved å bruke mange funksjoner utviklet for Ki-62.


Imperial Japanese Army Air Service Fighters

En lett jagerfly som gikk i tjeneste med den keiserlige japanske hærens luftfartstjeneste i 1938. Selv om den ble ansett som foreldet i 1942, forble den i tjeneste hos den keiserlige japanske hærens lufttjeneste til de siste eksemplene ble trukket tilbake fra tjenesten i 1945.

Et eksperimentelt jagerfly designet for Imperial Japanese Army Air Service og ment som en erstatning for Kawasaki Ki-10. Den fløy i 1936, men ble aldri produsert for faktisk bruk ettersom Imperial Japanese Army Air Service velger Nakajima Ki-27.

En eksperimentell jagerfly avledet fra Mitsubishi A5M transportjager som utviklingen ble forlatt til fordel for Nakajima Ki-27.

En eksperimentell tomotors jagerfly som utviklingen ble forlatt til fordel for Kawasaki Ki-45

En jagerfly som gikk i tjeneste, gikk i tjeneste i 1941 og ble raskt en av de mest fryktede japanske jagerflyene som opererte over Kina. Produksjonen ble avsluttet i 1944 og siste fly trukket ut av drift innen 1946.

En interceptor beregnet for forsvar av det japanske hjemlandet, ble senere distribuert i Kina for å beskytte byer okkupert av japanske styrker. Produksjonen avsluttet 1944, siste fly trukket ut av drift i 1946.

En tomotors jagerfly som den tok i bruk i 1941 som et langdistanse jager- og bakkeangrepsfly, den ble brukt under hele krigen i Kina og forble i tjeneste hos den keiserlige japanske hærens lufttjeneste til begynnelsen av 1950-årene. Mange Ki-45-er ble overført til Republic of China-Nanking Air Force og Manchukuo Imperial Air Force som opererte dem inn på 1960-tallet.

Suksessen til Kawasaki Ki-45 førte til at Kawasaki startet utviklingen av en utviklet versjon. Kawasaki Ki-46 hadde større og kraftigere motorer enn Kawasaki Ki-45. Den fløy først i 1943 og gikk i tjeneste med den keiserlige japanske hærens lufttjeneste i 1944. Kawasaki Ki-46 forble i tjeneste til slutten av 1950-tallet.

Den første japanske jagerflyet med enfly utstyrt med en væskekjølt motor. Kawasaki Ki-61 forble i drift til den ble erstattet av Kawasaki Ki-100 i 1945.

En eksperimentell jagerfly som ble utviklet fra Kawasaki Ki-61, den hadde et 10% større vingeareal og et litt annet flyblad. Prototypen ble første gang fløyet i desember 1943, men flyprøver viste at den nye fløyen var utilfredsstillende og at bare åtte Ki-62 ble bygget.

Ki-83 ble utviklet som et svar på en spesifikasjon fra 1943 for en ny tung jagerfly med stor rekkevidde. Den første av fire prototyper fløy i november 1944 og viste seg å ha bemerkelsesverdig manøvrerbarhet for fly av deres størrelse. Ki-83 tok i bruk i 1946 og forble i tjeneste med den keiserlige japanske hærens lufttjeneste til 1955. Flere Ki-83 rekognoseringsversjoner ble levert til Republikken Kina-Nanking luftvåpen hvor de så handling når de utførte rekognoseringsoppdrag over den delte provinsen Sichuan på begynnelsen av 1960 -tallet.

Nakajima Ki-84 regnes som den beste av den keiserlige japanske hærens luftfartssjefers enkeltstempelkrigere, de første Ki-84-ene gikk i tjeneste i 1944 som erstatning for både Ki-43 og Ki-44. De første eksemplene ble brukt av den keiserlige japanske hæren for forsvaret av det japanske hjemlandet. I 1947 var Ki-84 de mest mange jagerflyene og forble i tjeneste med den keiserlige japanske hærens lufttjeneste til 1948, men ble raskt avviklet til fordel for jetjager som gikk i tjeneste med den keiserlige japanske hærens lufttjeneste. Ki-84-er ble solgt eller overført til alliansenasjoner i Øst-Asia som staten Manchuria, Vietnam-riket, kongeriket Kambodsja og republikken Kina-Nanking.

Den første jagerflyet som opererte ved et servicetak på over 40 000 fot og var i stand til å fly på 42 000 fot, fløy den først i februar 1945 og hadde i begynnelsen av 1946 startet produksjonen. I 1946 ble Ki-87-II, drevet av en sterkere motor og med en turbolader, introdusert. Ki-87-II forble i tjeneste med den keiserlige japanske hærens lufttjeneste til 1953.

Utviklet for Imperial Japanese Army Air Service langs de samme kravene som Nakajima Ki-87, som hadde vært Imperial Japanese Army Air Service fall-back design for Tachikawa Ki-94. Ki-94 viste seg å ha en bedre høydeytelse enn Ki-87 og dermed mer der den ble produsert. Ki-94 forble i tjeneste med den keiserlige japanske hærens lufttjeneste til 1954.

Ki-100 var den siste stempelmotoren med en sete for å gå inn i storskala japansk tjeneste. Lettere, raskere og mer manøvrerbar enn Ki-61 var det en umiddelbar suksess, og ble ansett som mer pålitelig og lettere å fly enn Ki-84. En senere versjon, Ki-100-II hadde en turboladet motor som tillot den å nå 40.000 fot. Selv om Ki-100-II ikke ble ansett som en fighter i høyder som Nakajima Ki-87, var den en god allsidig utøver og forble i tjeneste til 1957.

En langdistanse tung jagerfly utviklet for å erstatte Kawasaki Ki-45 og som viste seg å være en meget vellykket jagerfly. Kombinasjonen av tung bevæpning, hastighet og smidighet gjorde det til et populært fly, og det erstattet raskt Ki-83 på produksjonslinjene. I 1949 ble Ki-108 høydejager med trykkhytte introdusert. Ki-102-II ble brukt av den keiserlige japanske hærens lufttjeneste til bruk i forsvaret av det japanske hjemlandet til slutten av 1950-tallet.

Ki-108 var en utvikling av Ki-102 ved å ha en trykkhytte montert på den for å la den cruise i stor høyde. Det ble brukt av den keiserlige japanske hærens lufttjeneste i forsvaret av det japanske hjemlandet til midten av 1950-tallet.

En japansk lisensversjon av den tyske Messerschmitt Me 163 brukt av Imperial Japanese Army Air Service og med Imperial Japanese Army Air Service som J8M. Ki-200 var det første rakettdrevne flyet som opererte med den keiserlige japanske hærens lufttjeneste, og begge ble omfattende utplassert som punktforsvar rundt japanske byer og hær- og marinebaser. Ki-200 forble i drift til 1954.

Nakajima Ki-201 sammen med sjøversjonen J10N ble designet ved hjelp av etterretning, tegninger og fotografier av Messerschmitt Me 262 som ble oppnådd av den japanske militærattachéen i 1944. Nakajima-selskapet foretok å omkonstruere Me-262 for japansk produksjon. Flyet gikk i tjeneste i 1947 og hadde på begynnelsen av 1950-tallet erstattet de fleste stempelmotorjagerne i bruk med den keiserlige japanske hærens lufttjeneste. Ki-201 forble i drift til den ble erstattet av Ki-202 fra slutten av 1950-tallet og utover.

Nakajima Ki-202 er et redesign av Nakajima Ki-201 i bruk av den keiserlige japanske hærens lufttjeneste og Nakajima J10N i bruk med den keiserlige japanske marinen lufttjeneste som har 35% feide vinger og vingrotmotorer og helt ny flykropp. . Den ble først introdusert i 1952 og erstattet Ki-201. I 1957 ble Ki-202-II introdusert, som var en oppgradert konvertering av Nakajima Ki-202 med ny elektronikk, revidert cockpitoppsett og oppgradert motor, denne versjonen forblir i bruk med den keiserlige japanske hærens lufttjeneste til slutten av 1970-tallet.

En redesign av Nakajima Ki-200 i bruk av Imperial Japanese Army Air Service og Nakajima J8N i bruk med Imperial Japanese Navy Air Service, Ki-203 som sin marineversjon J9M inneholdt en strupbar rakettmotor, mye forstørret drivstoff tanker en helt ny flykropp med boble cockpit. Den hadde en maksimal hastighet på 880 km/t ved 14 000 m, en drevet utholdenhet på 15 minutter på 11 000 m. Det første flyet tok i bruk i 1947 og forble i tjeneste til midten av 1960-tallet.

Da Tachikawa Aircraft Company så Mitsubishi og Nakajima bygge jetfly for den keiserlige japanske hærens lufttjeneste, bestemte de seg for å ansette ekstern hjelp da de inviterte tyske Kurt Tank til å jobbe for selskapet. Tank som brukte sin kunnskap om svevet vingedesign og turbojet-teknologi begynte å jobbe med et design fra 1957 og utover som førte til at Ki-205 som først fløy i 1961 og startet produksjonen i 1963. I stand til å nå en hastighet på Mach 2 the Ki -205 viste seg å være et fly med flere roller som er egnet for både avlytning i høyden og angrep på lavt nivå. I 1971 begynte en forbedret versjon av Ki-205 kalt Ki-205-II med en forlenget vingesnor som gir den større vingeareal og dermed større løft, mange cockpitendringer og et sofistikert pistolsikt, som begynte å ta i bruk med den keiserlige japanske hæren Air Service. Ki-205-II er sammen med Ki-206 fra 1982 det viktigste jagerflyet i bruk med den keiserlige japanske hærens lufttjeneste.

På midten av 1960-tallet resulterte et felles Imperial Japanese Army Air Service og Imperial Japanese Navy Air Service-prosjekt i Mitsubishi Ki-206 for Imperial Japanese Army Air Service og Mitsubishi J14M kyoufuu enkeltsete nærluftstøtte og bakkeangrepskjemper fly for de landbaserte skvadronene fra Imperial Japanese Navy Air Service. Ki-206 sammen med Ki-205-II er fra 1982 det viktigste jagerflyet som ble brukt i forhold til den keiserlige japanske hærens luftfartstjeneste.


Nakajima Aircraft Industries History.

(2) Motorutvikling på Nakajima 1923 - 1945

Mr. Nakajima, som spilte en aktiv rolle i utviklingen av innenlandsk teknologi, begynte å bygge Tokyo -fabrikken (på Ogikubo, vist på bildet til venstre) i 1924 for å få innenlands produksjon av flymotorer. Selv om Nakajima Aircraft ble født i Ota, Gunma, bestemte Chikuhei Nakajima at & quotFabrikken skulle være i Tokyo for å rekruttere personell i toppklasse & quot og våget å skille kropp og motorproduksjon ved å velge et sted i forstedene i Tokyo.

Stormester i flyteknikk på den tiden ble sagt å være rivaler, "Tukagoshi for Zero fighter på Mitsubishi" og "Tei Koyama på Nakajima". Motoren på Nakajima ble mestret av "Ichiro Sakuma fra Nakajima Engine". Sakuma hadde studert design av forbrenningsmotorer på egen hånd mens han jobbet på Yokosuka Naval Arsenal, og ble valgt som den første unge ingeniøren som ble rekruttert av Mr. Nakajima da han opprettet Airplane Institute etter at han ble pensjonist.

I begynnelsen, delvis på grunn av Sjøforsvarets instruksjon, produserte Nakajima en vannkjølt VPS-motor på 400 hk som var lisensiert av Loren, Frankrike. Deretter ble det produsert 127 enheter av den samme W-typen 450 PS-motoren til 1929. Loren Dietrich var en bilprodusent med en stor historie og begynte i flymotorproduksjon i 1915, ett år etter at første verdenskrig startet. De startet med en rett seks, vannkjølt 100 PS motor, og produserte deretter Type 15, 275 PS motoren som ble installert i et 2-seters Spud-fly. Motoren fikk gode anmeldelser på grunn av sin utmerkede pålitelighet. Loren-motoren, laget av Nakajima, ble installert i Nakajima Breguet 19A-2B rekognoseringsbærerfly og Type14-3 rekognosjonsbærerfly, men motorens utseende med de eksponerte ventilene var ikke like attraktivt som Hispano-Suiza.

Ikke lenge etter at Loren -produksjonen startet, så Nakajima på det nyeste produktet fra Gloster i England - kampflyet Gamecock, og vurderte at radialmotoren ble hovedstrøm. Deretter skaffet han seg en produksjonslisens for den luftkjølte 9-sylindrede radialmotoren, Jupiter, fra Bristol i England i 1925. Luftkjølte motorer brukte på den tiden radielle sylindere som roterte sammen med propellen, men Nakajima hørte at en motor med god kjøleevne med faste sylindere ble utviklet i England. Jupiter-motoren var forut for sin tid og brukte allerede de mest avanserte teknologiene, for eksempel en automatisk justeringsenhet for tappeklaring, spiralrør for jevn inntaksfordeling og et fire-ventilers inntaks- og eksosanlegg. I 1927, etter å ha invitert to produksjonsingeniørinstruktører fra Bristol -selskapet, ble Jupiter Type 6 420PS og Type 7 450PS med turbolader satt i produksjon. 150 enheter av Type 6 -motoren ble installert i jagerfly av type 3 og transportfly fra Nakajima Fokker. I tillegg ble rundt 350 enheter av Type 7 -motoren installert i jagerfly av type 91 hær.
På den tiden ble flymotorer delt inn i tre grupper Jupiter fra Nakajima (luftkjølt), Hispano-Suiza fra Mitsubishi (vannkjølt) og BMW fra Kawasaki (vannkjølt), og Nakajimas vidtrekkende visdom var langt foran de andre . Senere ble det produsert rundt 600 enheter inkludert motorene Type 8 og 9.

Loren -motordesigninstruktøren, Moreau fra Frankrike, bodde i et japansk romhus og holdt en rekke forelesninger i andre selskaper og skoler. Han adopterte seg til japansk kultur, men den andre instruktøren, Burgoyne fra Bristol i England, fortsatte å leve som en britisk herre. Burgoyne hatet lukten av Takuan (japansk gul syltet reddik). Han bodde på Imperial Hotel, og det sies at han gikk av toget på Ogikubo, en stasjon før Nishiogikubo (den nærmeste stasjonen til selskapet) fordi det var en sylteagurk foran den.

Nakajima Jupiter Type 6
Luftkjølt, total forskyvning på 28,7 kull
Ta av strømmen: 420 PS ved 1500 o / min
Vekt: 331 kg

Ved å bruke denne motoren ble produktnasjonaliseringsplanen utført gradvis. Ved å studere en luftkjølt 9-sylindret radialmotor (American Wasp), ble den første opprinnelig designet luftkjølte 9-sylinderen (450 PS & quotKotobuki & quot-motoren) fullført i 1930. Jupiter ble laget basert på håndverksteknikk, og produktiviteten var ikke god . Som et eksempel ble kjøleribber dannet ved maskinering. Nakajima prøvde deretter å kombinere gode poeng som finnes i Jupiter -design med den rasjonelle utformingen av USAs laget Wasp. Ved denne anledningen konstruerte Nakajima fire motortyper, AA, AB, AC og AD som ingeniørøvelser, men de ble aldri produsert. Det neste motordesignet, AE, var svært innovativt med en boring på 160 mm og et slag på 170 mm. Prototyper ble laget og ytelsestester ble utført, men dette ble ikke vedtatt på grunn av den for dristige teknikken. I 1929 ble det arbeidet med AH med boring/slag på 146/160 mm og en total fortrengning på 24,1 kull. Dette skulle være den siste versjonen av motordesignet og feil ville ikke bli tolerert. Teknikken var basert på et prinsipp om solid, enkel og oversiktlig konstruksjon. I juni 1930 ble den første prototypen ferdig, og besto holdbarhetstesten for typegodkjenningen om sommeren. Deretter ble det startet flyprøver med et rekognosjonsfly av typen 90 om høsten. I desember 1931 ble denne motoren godkjent og vedtatt av marinen. Den ble deretter installert i Type 90 rekognoseringsfly, Type 90 transportfly og de berømte Zero -krigerne i Mitsubishi. I begynnelsen viste ikke hæren noen interesse for at denne motoren ble utviklet gjennom marinens instruksjon som vanlig, men senere vedtok den som Ha-1 Ko-motor som ble brukt i type 97 jagerfly, og hadde lite annet valg enn å anerkjenne dens overlegenhet.
Motoren ble navngitt, i forbindelse med Jupiter, & quotKotobuki & quot, som uttales & quotJu & quot i uttalen i kinesisk stil av Kanji. Siden da brukte Nakajima en enkelt Kanji (japansk karakter) for å bringe lykke til motornavnene. Mitsubishi brukte stjernenavn, og Hitachi brukte også vindnavn.

Nakajima -motorer ble mye brukt, ikke bare i krigsfly, men også i sivile fly. Omtrent 7000 enheter for sivil bruk ble produsert fram til slutten av krigen.

I hæren navngav de flymotorer etter typekoder som Ha-25 eller Ha-112, mens de i marinen brukte kallenavn som & quotHomare (honor) & quot eller & quotKasei (Mars) & quot. På Nakajima, som nevnt tidligere, ble det brukt en enkelt Kanji (japansk karakter) som hadde lykke som "Kotobuki (auspicious)", "Sakae (herlighet)", "Mamori (vakt)" eller "Homare". Mitsubisi brukte stjernenavn som & quot; Kinsei (Jupiter) & quot; Hitachi brukte vindnavn som & quotTen-pu (vind på himmelen) & quot

& QuotKotobuki & quot; motoren ble forbedret ytterligere og utviklet seg til & quotHikari (lett) & quot; motoren med boring og slaglengde utvidet til sylinderens grense (160

180 mm for å få en forskyvning på 32,6 kull) og effekten ble økt til 720 PS. & quot I 1933 ble en 1.000 PS klasse Ha-5-prototype fullført, som benyttet boring/slag på & quotKotobuki & quot og en dobbellinet 14-sylindret. Den ytterligere forbedrede Ha-5 ble utviklet til 1500 hk, og rundt 5500 enheter ble produsert.

På samme tid ble det utviklet en motor etter marinens forespørsel kalt & quotSakae & quot; som hærens navn var Ha-25 (crick her for detaljer). Denne motoren var unikt konstruert som en motor av liten størrelse, lett vekt og høy ytelse i liten slagvolum og færre sylindere. Dette ble deretter installert i Type 97 transportangrepere, Type Zero carrier jagerfly, "Gekko (måneskinn)" type 99 dobbeltmotor lette bombefly, og også de berømte Type 1 "Hayabusa (falken)" jagerflyene. Denne motoren ble hovedsakelig produsert på Tokyo -fabrikken og på Musashino -fabrikken (bygget i 1938 og ble senere Musashi -fabrikken etter sammenslåing med Tama -fabrikken), og mer enn 30 000 enheter ble produsert (det høyeste tallet i historien).

Musashino -fabrikken var en eksklusiv fabrikk for hærens motorer, og denne moderne fabrikken, med et areal på 660 000 m2, var kronjuvelen til Ichiro Sakumas fremragende kunnskap og arbeidskraft. Fords toppmoderne samlebåndsoperasjon og den vitenskapelige styringsprosessen til Taylor -systemet ble innlemmet. I tillegg ble produksjonsprosessen, materialflyten og menneskelig bevegelse nøye gjennomtenkt. Et velferdsprogram for ansatte og førsteklasses fasiliteter var uten sidestykke på den tiden. Marinen ble imponert over dette, og ba om at den samme typen eksklusive fabrikken ble laget for dem. Tama -fabrikken ble bygget ved siden av Musashino -fabrikken i 1941. Senere, på grunn av forverring av krigssituasjonen, foreslo Nakajima å forene både hærens og marinens fabrikker for mer effektiv drift, men på grunn av fiendtlighetene mellom dem gjorde de ikke komme til enighet i flere år til de ble slått sammen til Musashi -fabrikken.

Ichiro Sakuma, som tok en aktiv rolle i Nakajima motorteknikk for hvert anlegg, planla og etablerte også Mitaka Research Center, og jobbet som daglig leder i konstruksjonsavdelingen. Intensjonen med Mitaka Research Center var ikke bare flyforskning, men også å etablere et generelt forskningssenter for politikk, økonomi og ingeniørfag. Med tanke på at dette var et vidtrekkende program for Japans fremtid, ble en landmasse overraskende 1,65 millioner kvadratmeter sikret. Tilfeldigvis ble den banebrytende seremonien holdt den 8. desember 1941, dagen da Japan gikk inn i andre verdenskrig. Men senere, på grunn av en forverring av krigstilstanden, var militæret imot å ha et så forseggjort forskningssenter, og anlegget startet sin drift som en prototype ingeniørdivisjon og prototype produksjonsanlegg i 1943. (Etter krigen, nesten alle dens fasiliteter ble solgt. Hovedingeniørbygningen brukes nå som et skolehus ved International Christian University.)

Mitaka Research Center (Prototype Manufacturing, Engineering Center og en henger)

Som et resultat av utbruddet av andre verdenskrig i Europa i 1939, utviklet motorene i Europa og USA beveget seg mot 1500

Japanske fly fra andre verdenskrig

Importere en turbolader Historien til den japanske marinen som utvikler turboladere er overraskende lang, og går helt tilbake til Showa 12 (1937).

Major Jikyu Tanegashima, som var i Frankrike på den tiden, lyktes med å importere en turbolader fra Brown Boveri & amp; Cie AG i Sveits (BBC), og turboladeren kom til Japan. Dette ble spilt inn i Koukuu Gijyutsu Jouhou Tekiroku (informasjon om luftfartsteknologi).

BBCs turbolader ble utviklet for dieselmotorer, som mange land forsket på den gangen. De som ble importert ble designet for dieselmotorer på 500 hk.

Ved å bruke denne BBC -turboladeren som et eksempel, ble Mitsubishi, Nakajima, Hitachi og Ishikawajima beordret til å forske på og utvikle turboladere for fly. Nakajima klarte ikke det, ettersom firmaet konsentrerte seg om å utvikle mekaniske superladere i stedet.

Turboladere utviklet av de tre selskapene ga hvert resultat. Mitsubishis turbolader ble installert på J2M4 Raiden Model 32, og Hitachis turbolader ble installert på Nakajimas C6N2 Saiun. Hva skjedde da med turboladeren utviklet av Ishikawajima Airplanes? Undersøkelsen vår viste at den ble installert på Nakajimas Sakae, Zero Fighter -motoren.

Navy High-Altitude Fighter Project
Rapporten fra Navy ’s Aerial Headquarters, Matter About the Experimental Research After Showa 17 (1942), sier følgende om turboladere:
Fullføring av turboladeren er avgjørende for suksessen til jagerfly over store høyder. Derfor ble den prototypet og holdbarheten ble testet av Ishikawajima, Hitachi og Mitsubishi siden Showa 15 (1940). Imidlertid har den ennå ikke blitt testet i et fly eller under flyging. For å fortsette med testing, er det nødvendig å forberede et masseproduksjonsanlegg etter avgjørelsen av kraften og typen av eksos -turbin -kompressoren som skal installeres på et vedtatt fly.
På det tidspunktet var det tydelig at marinens turboladerutvikling gikk fra en forskningsfase til en operasjonsfase. Deretter nevner Kuugishou Shouhou (The Naval Technical Air Arsenal Journal) som ble trykt 9. februar 1942, testing av en tremockup av en Nakajima Sakae Model 11 -motor utstyrt med en turbolader.

Den skriver, "Det er anslått å bli montert på Zero Fighter", så dette kan være den første offisielle skriften der en turbolader for Zero Fighter er nevnt. Kuugishou Shouhou fra 10 dager senere, 19. februar, nevner at "Første forskningsmøte for den turboladede Zero Fighter" skal holdes. Dette beviser skriftlig at det finnes en Zero Fighter utstyrt med en turbolader.

Ishikawajima Aerial Industries 'turbolader
Ishikawajima Aerial Industries ble grunnlagt på Showa 16 (1941) som en del av Tokyo Ishikawajima Shipyard. Ishikawajimas Aero Engine Factory, som det ble kjent, ble et eget datterselskap og etablerte hovedkvarteret i nærheten av Kuugishou (Naval Technical Air Arsenal) i Kanazawa -området i Yokohama. Der fortsatte Ishikawajima å utvikle flymotorer slik de gjorde på Ishikawa Island. Under krigen, bortsett fra forskning og utvikling av turboladere og turbo-sammensatte motorer, konsentrerte de seg om produksjon av Sakae motoromdannelse og bidro sterkt til levering av motorer til Zero Fighters. Sakae -produksjon ble tildelt i 1940, og den første konverteringen av Sakae Model 11 ble sendt ut i slutten av 1941.

Hiroshi Yoshikuni, designeren av Ishikawajima Aerial Industries 'turbolader, uttalte at Ishikawajima laget Sakae Model 11 som ble brukt av Kuugishou til gjennomgang av turbolader i tre. Tatt i betraktning Ishikawajima Aerial Industries ’ Sakae produksjonssituasjon, spekulerer vi i at de valgte Sakae Model 11 for tre-mock-up gjennomgang i stedet for Model 12 eller 21. Turboladeren installert på Zero Fighter var Ishikawajimas IET Model 4-serie, utviklet seg fra dens 500-hk turbolader, som støttet motorer på 1000 hk. Etter hvert som utviklingen av turboladere fortsatte, ble IET modell 5 for motorer i 2000 hk fullført, men kom aldri til de faktiske flyene. Når det gjelder turbinebladene, brukte Ishikawajima og Mitsubishi en studatype Hitachi som brukte en sveiset type.

Problemer med turboladeren
Bilder viser at denne turboladede Sakae -motoren har hatt turboladeren direkte festet, uten intercooler, og den har en veldig enkel installasjon. Japanske turboladere hadde problemer med materialer siden BBCs prøveturbolader ble laget for dieselmotorer. Det var problemer med BBCs turbolader ’s materialer, som var designet for å tåle 500 grader Celsius for dieselmotorer for å kunne brukes på en bensinmotor, turboladeren trengte å tåle mer enn 700 grader Celsius av eksosvarme. Ishikawajimas turboladere var laget av materialer av høy kvalitet, som var i stand til å tåle varmen, for eksempel nikkel-krom-wolframstål (omtrent som materialet som ble brukt til B-17), men ulykker skjedde fortsatt, for eksempel at utblåsningsventilen som eksploderte, og utviklingen gikk ikke jevnt. Problemet med å velge materiale for varmebestandig stål syntes å være et vanskelig hinder for utvikling av turboladere.

Til tross for alle disse problemene, ble en A6M3 Zero Fighter modifisert for å bruke en turbolader, og ble rapportert å være fullført i 1942. Men på grunn av problemer gikk testingen ikke som planlagt, og til slutt ble prosjektet forlatt før den første flyturen test. At Zero Fighter var den første japanske jagerflyet som brukte turbolader er nå kjent, men det er en skam at den aldri fløy.


Lord Mountbatten drept av IRA

27. august 1979 blir Lord Louis Mountbatten drept da terrorister fra den irske republikanske hæren (IRA) detonerer en 50 pund bombe gjemt på fiskefartøyet hans Skygge V. Mountbatten, en krigshelt, eldre statsmann og andre fetter til dronning Elizabeth II tilbrakte dagen med familien i Donegal Bay utenfor Irlands nordvestkyst da bomben eksploderte. Tre andre ble drept i angrepet, inkludert Mountbatten ’s 14 år gamle barnebarn, Nicholas. Senere samme dag drepte et IRA -bombeangrep på land 18 britiske fallskjermjegere i County Down, Nord -Irland.

Attentatet mot Mountbatten var det første slaget som ble slått mot den britiske kongefamilien av IRA under den lange terrorkampanjen for å drive britene ut av Nord -Irland og forene det med Irland mot sør. Angrepet forherdet mange briteres hjerter mot IRA og overbeviste Margaret Thatchers regjering om å ta en hard holdning til terrororganisasjonen.

Louis Mountbatten, sønn av prins Louis av Battenberg og oldebarn av dronning Victoria I, gikk inn i Royal Navy i 1913, da han var i begynnelsen av tenårene. Han så tjeneste under første verdenskrig, og ved utbruddet av andre verdenskrig var han sjef for den femte ødeleggerflottillaen. Hans ødelegger, HMS Kelly, ble senket utenfor Kreta tidlig i krigen. I 1941 ledet han et hangarskip, og i 1942 ble han utnevnt til sjef for kombinerte operasjoner. Fra denne stillingen ble han utnevnt til øverste allierte øverstkommanderende for Sørøst -Asia i 1943 og gjennomførte vellykket kampanjen mot Japan som førte til gjenerobring av Burma.

I 1947 ble han utnevnt til den siste visekongen i India, og han ledet forhandlingene som førte til uavhengighet for India og Pakistan senere samme år. Han hadde forskjellige høye marineposter på 1950 -tallet og fungerte som sjef for Storbritannias forsvarsstab og leder for stabssjefkomiteen. I mellomtiden ble han utnevnt til Viscount Mountbatten i Burma og en første jarl. Han var onkel til Philip Mountbatten og introduserte Philip for den fremtidige dronning Elizabeth. Senere oppmuntret han ekteskapet til de to fjerne fetterne og ble gudfar og mentor for deres førstefødte, Charles, prins av Wales.

Lord Mountbatten ble utnevnt til guvernør og deretter herreløytnant på Isle of Wight i pensjonisttilværelsen, og var et respektert og elsket medlem av kongefamilien. Attentatet hans 27. august 1979 var kanskje den mest sjokkerende av alle fryktene IRA påførte Storbritannia. I tillegg til barnebarnet Nicholas, ble den 15 år gamle båthånden Paul Maxwell drept i angrepet, Dowager Lady Brabourne, bestemor Nicholas ’, ble også dødelig skadet. Mountbattenes barnebarn Timothy –Nicholas tvilling ble skadet som datteren Lady Brabourne og tvillingene Lord Brabourne. Lord Mountbatten var 79 år.

IRA påtok seg umiddelbart ansvaret for angrepet og sa at det detonerte bomben ved fjernkontroll fra kysten. Det tok også ansvar for bombeangrepet samme dag mot britiske tropper i County Down, som tok 18 liv.

IRA -medlem Thomas McMahon ble senere arrestert og dømt for å ha forberedt og plantet bomben som ødela båten til Mountbatten. Han var en nær legende i IRA, og var leder for IRAs beryktede South Armagh Brigade, som drepte mer enn 100 britiske soldater. Han var et av de første IRA -medlemmene som ble sendt til Libya for å trene med detonatorer og tidsinnretninger og var ekspert på sprengstoff. 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:

Wingspan: 10 m (32 ft 10 in)
Lengde: 8.1 m (26 ft 8 in)
Height: 3 m (9 ft 8 in)
Weights: 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 (se 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.


Intervju

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?

Yes. 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.

Yes. 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

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

Yes. 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?

Yes. 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.

Yes. 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? Is that what you are saying?

Ikke sant. 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?

Yes, right. 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.

Yes. 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?

Yes. 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." Er det det?

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.

Ikke sant. 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?

I think so. 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.


Se videoen: Nakajima Ki-84 HEI - Превосходный Японский истребитель в War Thunder (Juli 2022).


Kommentarer:

  1. Thaqib

    the devil is burning !!!

  2. Jugor

    Hvilke ord ... super, flott tanke

  3. Halim

    Du har ikke rett. Jeg kan bevise det.

  4. Foursan

    Etter min mening har det allerede blitt diskutert

  5. Eadelmarr

    Important answer :)



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