Nakajima Aircraft
  Desperate War of Japan in the Pacific

Nakajima Aircraft was established by Nakajima Chikuhei in Gunma of Japan in 1917. Nakajima flew test flight in the Tone River at first. Nakajima began to make autos after the Pacific War. Nakajima Chikuhei became a minister of Muitions after surrender of the Pacific War. Nakajima changed its name Fuji. The brand is SUBARU. Sales of autos in Japan decreases now. Fuji announced that it would accept Toyota's capital of 17% share in Apr 2008. By the way, Hasegawa Tatsuo, a chief engineer of Toyota Corolla was an engineer of Tachikawa Aircraft.
Ministry of Munitions
Hasegawa Tatsuo(1916-2008)

  1. Production of fighters
    Production of fighters and makers 1937-1945
    NameEngineNakajima MitsubishiKawasakiKawanishiTachikawaArsenalSum
    ZeroSakae6,5453,880 ----10,425
    OscarHa-253,208- --2,545-5,753
    TojoHa-411,227- ----1,227
    Hamp-327- ----327
    TonyHa-40- -3,159---3,159
    FrankHa-453,449 -----3,449
    JackKasei- 470----470
    ShidenHa-45- --1,000--1,000
    GerogeHa-45- --400--400
    Production of makers16,763 5,1323,1591,4003,92420030,578
    Ratio of makers54.8 16.810.34.612.80.7100%
    Japan made 30,000 fighters in WWII. The table shows production of fighters of makers in Japan in 1937-1945. Nakajima made more than half of them and 3 times of Mitsubishi.
    Aoki p.33

    The tables did not conclude seaplane fighters of Kawanishi. The production of Rex(Kyoufu) was 97. And another important fighter was Ki-100 of Kawasaki. The production was 397.

  2. Production of engines
    Nakajima bougt manufacturing license of Cyclone R-1820F engine from Wright of US in 1933. Nakajima also bought a lot of casting machines, when a shop foreman went to learn manufacturing engines at Wright.
    Ikari p.200

    Nakajima made 88% of engines loaded on fighters of Japan. These were Kotobuki(Clade, Nate), Sakae(Oscar, Zero), Ha-109(Tojo), Homare(Frank, Shiden, George). Nakajima won sales of 2,000hp class aircraft engines between competitor Mitsubishi. While Mitsubishi made more than half of bombers engines. Itogawa Hideo was an engineer of Nakajima.
    Aoki p.37
    Kessaku-ki no tanjyou
    Itokawa Hideo

    Director of IJA ministry Nagata Tetsuzan thought that IJA air force was old and a demand of ¥200 million budget for aircraft and air defend in 1934 or 1935.

  3. Factory evacuation
    Production of Nakajima
    Nakajima Aircraft planned to build underground factories in 1942. It began to build them at Ouya in 1945 where was area of stone production and located in the northern Kanto. The underground factory was to make 300 aircraft a month. It was 56,435 m2 area, 5,702 workers. But it made 11 engines, 55 repairs of engines and 4 aircraft only for 4 months till end of the war. Production of Nakajimas slowed down because of threat of air raids before acutual B-29s bombardment.

  4. Defense engine plants
    B-29 tried bombardment at Musashino Factory on 24 November 1944 for the first time. Carriers aircraft of US burned an engine assembly of Nakajima Musashino Factory on 17th Feb 1945, though B-29 tried to destroy it called #357 target. Helldivers and Avengers flew 200km the south east off the Tokyo Bay and raided accurate bombardment. They used rockets too. New York Times told the story and praised USN. B-29 bombed there on 2th, 7th and 12th Apr 1945. At last Musahino Factory stopped the production on 30th Apr 1945.
    Kerr, p116-117
    Watanabe, p314
    Morimoto, p254

    I think the raid was easier than charge of running warships suppored AA guns, if escort fighters got the air control. How about flaks of Nakajima Mushashino?

  5. Productivity
    Productivity per std labor[lb]
    US succeeded in increase of aircraft productivity during WWII. Japan's productivity did not increase. I think innovation occurred in US during the WWII. Japanese aircraft industry did not have knowledge to use a lot of jig and could not prepare machine tools such a special lathe.
    Hinkoku, p71
Commons and students labored at aircraft factories under bad requisition by government. The absence rate of aircraft factories had been 21% in Jul 1944. UK workers of aircraft went on strike during Battle of Britain.
 VHF wireless telephone
IJN adopted a VHF wireless telephone (30-50MHz) of 40W and A3 type which was amplitude modulation (AM) in 1939. While USN used VHF wireless telephones of FM. IJN escort warships heard communication among USS wolfpack submarines in ASW. So IJN warships must be equipped with FM wireless telephones. Why did IJN aircraft continue to AM telephones?
98 shiki ku 4 go taini musen denwa-ki

 Armor behind pilot
Armor of Zero Ikari p.165
1944 Apr52-otsu(A6M5b)armor glass canopy, fire extinguisher
1944 Sep52-hei(A6M5c)armor behind pilot, inner self-sealed fuel tank
Fighter Nate(Ki-27) of IJA fought with I-16 of Russia, when Nomonhan Incident ocurred. IJA Air Force lost a lot of pilots on the battle. So the next type Oscar(Ki-43) was equiped with armor behind the pilots and self sealing fuel tank. Although Morimoto wrote that IJA did not learn modern war at all, It is not true about armor of fighters. But I admit IJA did not have very serious concern about loss of pilots. Osaka Asahi Newspaper wrote it was necessary to mobilize IJA for modern wars on 4 October 1939[1].

IJN also fought with I-16 in China, otherwise Fighters of IJN did not equipped armor or self-sealed tank. IJA thought cool that it was diffcult to grow pilots in a short time than IJN. IJN realized armor of fighters in the air battle of Solomons. Zero equipped in 1944 as the table shows. As for bombers, Betty eqipped armor plates and self-sealed tanks in 1943. While B-17 had been already equipped with both in 1941.

Genda insisted the necessity in his report about Battle of Britain in fall of 1940. Genda p.238

Is it true?

 Wing load
IJN was late for preparing a new next fighter to Zero early as shown in chrology. The table shows wing load of fighters of Japan and US. US Marines began transferring their fighters F4F to F4U from Sec 1942. USN called the F4U 'Ensign Eliminator' because VF-12 lost 14 pilots while trainning. The wing load of F4U increased 70%. Otherwise Raiden (J2M2), code name Jack was called 'Killer Machine' in IJN. The wing load of J2M2 increased 50%. Eight Marine fighting squadrons (VMF) transferred to F4U in Solomon Islands in 1943.

Wing load of US and Japanese fighters
Date1939Feb1941Jun 1939Oct1940Oct1944Apr 1939Mar1943Sep1942Feb1943Dec1943Mar
Wing load[kg/m2]110182 188208251 107128160170179
Wing span[m]11.5810.23 12.4911.2911.29

 Production of Fighters in IJA and Russia
Production and date of Russian and IJA fighters
I-16 7.6mmx41,1002,059 0.53hp/kg1934-427,000
Yak-720mmx1 12.7x21,2103,005 0.40hp/kg19426,400
La-520mmx21,7003,360 0.51hp/kg1942-449,900
Yak-920mmx1 12.7x21,3603,082 0.44hp/kg1943-463,058
Yak-320mmx1 12.7x21,2902,967 0.43hp/kg1944-454,797
La-720mmx31,8503,240 0.57hp/kg1944-457,500
Ki-277.7mmx26501,790 0.36hp/kg1938-413,386
Ki-4312.7mmx21,1502,642 0.44hp/kg1941-445,751
Ki-4412.7mmx2 7.7x21,2502,571 0.49hp/kg1942-441,200
Ki-8420mmx2 12.7x21,8603,750 0.50hp/kg1944-453,500
Ki-10020mmx2 12.7x21,3503,4950.38hp/kg 1945393
The table shows fighters of IJA and Russia to compare 2 nations.
Soviet p.100 - p.343

Russia and Japan were underdeveloped with aero industry. I-16 showed its performance to other nations in Spanish Civil War and Nomonhan Incident. IJA lost a lot of pilots in Nomonhan. So next to Ki-27, Ki-43 equipped self sealed oil tank and armor behind pilot. Otherwise IJN did not learn as USN learned the Battle of Britain. So Zero had no sealed fuel tank and armor behind pilot till the end of the Pacific War.

Yak-7 fought Bf109F at first. At last La-5 was competitive in Stalingrad. La-7 and Yak-3 overwhelmed enemy in Berlin. Yak-3 was excellent aero dynamic and designed light. La-7 equipped an air cooled engine, ASh-82FN (1,850hp) and could climb 5,000m in 4min 30sec.

Otherwise Japan failed to product the 1,860hp engine designated Ha-45. Ki-100 exchanged liquid cooled to air cooled radial engine, Mitsubishi Kinsei-62 too late, as LaGG-3 did well.
Syoumou to hoten

 Production of aircraft in US, Germany, UK and Japan and parity
Tbl.1 US vs Japan in 1944 Ishii, p243
Machining aircraft parts
Japan and US deployed almost the same at the Pacific War on 8 December 1941, though US made 3 folds of Japan in 1941. It meant Japan had to continue air combat with kill ratio of 3 to 1 to win the Pacific War. Education Ministry decided to make boys and girls work for military use in August 1944.[4] Ninomiya was a minister of Education Ministry then. For example, 28,000 people labored at Handa Workshop of Nakajima Aircraft in February 1945. Half of them were school boys and girls.[5] They were allowed to have a day for rest in a month. Handa Workshop of Nakajima Aircraft was destroyed by bombardment of B-29s on 24 and 27 July 1945. As for other workshops of Nakajima, Ohta Workshop was bombarded on 10 February and lost 74 half assembled Ki-84. Ohta was completely destroyed on 25 February. Koizumi Workshop was bombarded on 25 February by USN aircraft. It was difficult to assemble IJN Frances. Press workshop of Ohta was destroyed on 3 April. Utsunomiya Workshop was difficult to assemble aircraft on 10 July by USN bombardment. Musashino Workshop of Nakajima Aircraft stopped the production on 30 April 1945. Young unskilled pilots rode the rude aircraft by boys and girls. Most of them were shot down easily by enemies.
Morimoto, p202-205, p215, p224, p254
Kinrou douin no Ryou

Tbl.3 Aircraft in the Pacific
Tbl.2 Aircraft production
YearUSUKGermany Japan
194119,43320,094 11,7665,088
194247,83623,672 15,5568,861
194496,31826,461 39,80728,180
Tbl.2 shows aircraft production of US, UK, Germany and Japan. US aircraft production increased 246% in 1942, while Japan 175% only. Did Japan think she won the Pacific War? Japan made aircraft with desperate effort in 1944 and increased the production. How about other productions? Tbl.1 shows US vs Japan production ratio in 1944 fiscal year. Basic material for production decreased very few. Japan productioned only one fortieth of steel, compared with 17.7 in 1941[1]. This might mean that merchant ships could not ferry iron to Japan mainland. Japanese leaders did not plan the war well, though Japanese researchers studied the total war in 1941. Tbl.3 shows how many aircraft US and Japan deployed in the Pacific[2]. What happened in 1943? US and Australia could supplied with aircraft, but IJA failed to ferry and IJN lost too aircrews in 1943. 20 Ki-45 kai of 13th Sentai departed from Japan to Rabaul on 20 April, but only 6 arrived there because of unskilled pilots and out of order[3]. Although Japan productioned more than 3 fold aircraft in 1944 than the previous year, Japan could not deploy them enough. I think that Japan could not ferry gasoline, ammo, parts and aircraft well from Japan mainland. IJN could not defend merchant ships even from Taiwan to Philippines in 1944. While US could ferry aircraft with a lot of escort aircraft carriers. US wartime merchant ships transported huge munitions far from US mainland.

IJA airforce
IJA had 1,800 operational aircraft on 15 September 1943. The force was despersed all around the Pacifice, as followed 36 SQ in domestic, 51 SQ in Manchuria, 24 SQ in China, 71 SQ in the Pacific. IJA 7th Wing Group moved to Buto from Ambon in July 1943, which had 250 aircraft. The 7th Wing Group moved to Ambon in November and its aircraft decreased to 150 in December. IJA deployed half of aircraft in China and Manchuria, though Japan had to defend thePacific against 3 folds of US aircraft in 1944.

Inspection tour
President Franklin Delano Roosevelt' wartime tour in September and October 1942. A site shows his inspection of Boeing Aircraft Plant Seattle Washington in WW II

 Earthquake on 7 December 1944
A big earthquake damaged factories of aircraft especially Mitsubishi heavily on 7 December 1944. The earthquake was named Tounankai-jishin. Yamagata Factory of Nakajima Aircraft in Handa and Doutoku Factory of Nagoya Aircraft Seisakusyo of Mitsubishi were destroyed by the earthquake. 153 people died in Handa Factory of Nakajima, columns of which were removed to assemble aircraft parts and windows were screened to keep military secrets. A lot of workers dashed into a single exit and walls destroyed. Handa Factory producted carrier bombers and reconnaissance aircraft. 64 junior high school students, who were volunteered officially, died in Doutoku Factory of Mitsubish as the same. Both were built as spinning factories. Mitsubishi gauve up rebuilding of it. Although Japan cover up the earthquake, newspapers of US knew it. It was natural that US watch over the sky. The production might have decreased half. Aircraft industry has not been glorious after the Pacific War. Instead, auto is major industry now.
Syowa no jishin
Nagoya-si no bakugeki-kouka

Piston ring
A recent Niigata-jishin ( Niigataken Chuetsu-oki Earthquake in 2007 ) stopped production of autos all over Japan for a few weeks. Because a manufacturing factory of Niigata has supplied simple piston rings for almost of domestic car engines. Why Riken built such a place unconvinent for transport?
2007 Chūetsu offshore earthquake

Successive earthquakes in Tokyo
Year of Earthquake
OrderTokyo (Edo)Kyoto
I had lived in Tokyo for 8 years. I was surprised that small earthquakes often occures in Tokyo. I also lived in Kyoto and have lived near Kyoto more than 20 years. There are few earthquakes in Kyoto. A scholar predicts, 'Big earthquake will be to occur in Tokyo probability 70% by 2036.' The table shows years of 2 historical recent big earthquakes in Kyoto and Tokyo. Big Earthquake of 1923 is called Kanto Dai Shinsai. Tokugawa Ieyasu selected Edo to govern Kanto. I think Tokugawa Ieyasu did not mind much because he was from Mikawa, of which is near Nagoya. He lived in Sunpu(Shizuoka) near Mikawa after retiring Shogunate. Sooner or later Nagoya or Tokyo will damage in near future. Japan began the Pacific War after the Big Earthquake of Tokyo in 18 years later and Meiji Restoration after Ansei Earthquake in 13 years later.

Great Kantou earthquake damaged 3.7 folds of government budget
Government outcame 10% of budget as restoration expenditure. This occurred curb of arms in 1925.
Morimoto, p286
1923 Great Kantou earthquake
Ansei no Dai-jisin

 Production of ECU for car
A big earthquake damaged tohoku in Japan on 11 March 2011. So production of Japanese auto makers will decrease half, though their assembly lines has restored. Some parts are bottle neck of the production. One is microprocessor. Microprocessor controls engine for car now. It is called ECU ( Engine Control Unit ). Renesas had share of 42% in 2009. Other Freescale Semiconductor, Infineon and TI shared 16%, 6% and 6% each.[6] Japan, Germany and US share 70% in the world.
 Machine Tool
Top 10 machine tool co.
billion $
Yamazaki, jp1.82
Trumpf[10], de1.75
Gildemeister[9], de1.67
Amada, jp1.36
Okuma, jp1.35
Mori, jp1.29
JTECT, jp1.24
大連機床集団, cn1.16
瀋陽機床集団, cn1.20
Japan could not product high quality machine tool in the Pacific War. I think that Japanese military aircraft were less reliable than German and US aircraft. Japan's high class machine tools depended on importing from Europe and US. Japan had supplied with 65,000 in 1939. But Japan supplied with 30,000 only in 1941, because of the German-Soviet War. The war stooped import from Europe via Siberia Railroad. Gears are basic mechanical element. Gleason in US and Maag in Switzland were typical companies.[7][8]
Doku-So Sen(1941Jun22-1945May8)

A college reserves old gear tools of pre War. One of them was made of Maag. Another site shows a chronological list of manufacturing gears in Japan.
Kikai Isan
Nihon Haguruma Kougyou-si

Toshiba was suspected that USN could not trace Soviet silenced submarines because of working propellants by Toshiba's 5-axis machine tool and Swedish NC in the cold war. Although that was not true, the story showed anxiety inferior than machine tool industry of Japan in the cold war. Now, Japan, Germany, China, Italy and Taiwan are nations of machine tools production.
Toshiba Kikai COCOM Ihan Jiken

Japan had been No.1 of machine tool production in the world since 1982. Japan slipped at No.3 in 2009.

    日本工作機械工業会(日工会)が15日発表した2010年主要国の切削型工作機械生産額調査によると日本の生産額は前年比81・6%増の105億8000万ドルで、ドイツを抜いて2位に浮上した。  世界首位は2年連続で中国だった。中国は同27・0%増の146億8000万ドルで、08年の日本の過去最高額135億4200万ドルを超えた。  世界生産額は同23・9%増の483億9800万ドルと2年ぶりに増加した。日本の世界シェアは同7・0ポイント増の21・9%。首位の中国は同0・7ポイント増の30・3%と続伸。3位のドイツは欧州の経済悪化が響き、生産額が同12・6%減の68億6200万ドル、シェアが同5・9ポイント減の14・2%になった。また韓国、台湾がイタリアを抜いて5強に食い込んだ。アジア勢が需要国だけではなく、生産国としても台頭している。

     米調査会社ガードナーの調べによれば、2009年の切削型工作機械の生産額で、日本の世界シェアは約15%となり28%の中国、20%のドイツに抜かれ、82年以降27年続いていた首位の座を明け渡し3位に転落した。日本の同機械の09年生産額は前年比56.5%減の58.9億ドル(約5300億円)と、同35.2%減(78.2億ドル)のドイツと比べ下落幅が大きい。初の首位となった中国は、同8.9%増の109.5億ドルだった。  要因のひとつとして、日本工作機械工業会の中村健一会長は「グローバリゼーションの反動」を挙げる。日本の工作機械業界の主要顧客である日系製造業は、トヨタ自動車 <7203> やコマツ <6301> をはじめ海外市場の強化戦略をとってきた。工作機械メーカーも08年までその恩恵を大きく受けてきたが、景気後退で極端な需要減少に直面。「リーマン・ショック後に円高が進んだことも痛手」(中村会長)となった。輸出比率の高さから、景況感の悪化だけではなく為替影響による競争環境の悪化ものし掛かった。こうした事情が、主力市場をユーロ圏内に持つ欧州メーカーと比べ、シェア後退が顕著となったことの背景にあるという。  牧野フライス製作所 <6135> の牧野二郎社長も、「中国市場などでは実際、欧州メーカーが勢力を伸ばすなど、日本メーカーは苦戦している」と話す。ユーロ安を背景に、欧州メーカーは現地自動車メーカーなどの需要獲得を有利に進めている状況。牧野社長は「中国以外の新興国でも同じようなことが言える」と警戒感を強めている。  一方、中国の生産額が世界首位となったことに対する不安の声は小さい。「中国メーカーは技術的に日本と競合する域にまだ達していない」(中村会長)ことから、当面は大きな脅威にはならないとする見方があるためだ。浜井産業 <6131> の武藤公志会長は「世界需要が回復しても、日本は数の上ではもう中国に追いつけないだろう」と指摘し、「今後は、欧州メーカーと新興国市場でいかに争っていけるかが重要となる」としている。(鈴木草太) 提供:モーニングスター社
[1] NHK1, p32
[2] Morimoto, p205, p215
[3] Ki-45 kai
[4] Kinrou douin-rei
[5] Handa Seisakusyo
[6] ルネサス工場被災 車業界が全面支援
[7] Gleason
[8] Maag
[9] Gildemeister

 Armor for Children's day
Children's DayFlower Ayame
I do not know when commons of Japan began to decorate miniture of armors of lord samurai. The photos show my son's decoration which my wife decorated this year. The right photo shows flowers called ayame which my wife arranged. The ayame were grown in my backyard. Japanese people loved it as the flower of May. The flower appears in tradtional card game. Ogata Korin painted ayame in his style

[1] Nomonhan Jiken Senbotsu-sha su

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