Fugaku : Z-plane, G10 or G12

[blackkite]

Hi! Chikuhei's dream. The ultimate Fugaku and Fugaku. And TB.
I believe that the ultimate Fugaku died at the biginning of Fugaku committee, because it was too costly and too risky.
Source: Internet site.

 

[windswords]

blackkite-san,

The second picture of the unfolded paper is incorrect about the labeling of the aircraft at the bottom below the G10N. The paper says (from left to right) Shinryu, Baika, and Ki-98. It should be: Ki-98, Shinryu, and Baika.

 

[T-50]

Hi Blackkite san nice drawings you send again! the photo with the fugaku and the little X planes is from a plastic kid and a completed model is shown on a Japanese site about plastic model kid.
Its truly a aw some model I must say!

 

[blackkite]

From "富嶽(FUGAKU)" ,Author:Maema Takanori(前間孝則)／Yoshiro Ikari(碇義朗), No.(3)

Chikuhei thought these variants from Z long range bomber.
1. B-36 interception gun ship variant, which had 96× 20mm cannons. Chikuhei thought only 10 gun
ships could destroy 500 flying formation of B-36.(Chikuhei called B-36 as six engined bomber.)
2. Anti ship variant, which had 400×7.7mm guns, which operated combined with long range
bomber with 20 ton bomb and torpedo bomber with 20 ×1 ton torpedo.
3.Cargo variant.
Chikuhei hoped following armed forces to assault the United States. (Targets were iron/ aluminum/oil industries
and cities.) ①Z long range bombers:4,000 ②Z gun ships:2,000 ③Z cargo variants:5,000 ④Soldiers:3,000,000
Iwao Shibuya(渋谷巌) designed flexible Z-plane wing prior to B-47 and B-52, wing tip deflection was 1.3m in take off.
Minoru Ohta(太田稔) designed undercarriage of Z-plane, which had four tires, diameter of tire was 2.5m breadth was 0.5m and each weight was 1ton. Two tires were dropped after take off. He did not realize the possibility of multiple tire undercarriage.

 

[blackkite]

Shoda Creative Co.Ltd, Gunma Japan has a 1/20 scale Z-model.
Source:Japanese secret weapons collection, TAKARAJIMA SHA,Tokyo,Japan ISBN978-4-7966-6366-3 C9431

 

[T-50]

Wow! these pics are very impressive Blackkite San! especially the photos of the model Zplane is very interesting.
It looks like wind tunnel models of this bomber.
Thanks again for sharing these pics with us! the book cover pic depicts in my eyes a version a very pimped version of G8N Renzan .I think this is a Nakajima design proposal

 

[blackkite]

From "富嶽(FUGAKU)" ,Author:Maema Takanori(前間孝則)／Yoshiro Ikari(碇義朗), No.(4)

Prior to the basic design activity of Z-plane, Chikuhei explained the idea of super large bomber which could bomb the United States from Japan, to the prime minister Hideki Tojo(東条英機) in 23th of April 1943. Hideki Tojo asked Chikuhei to show the drawing of large bomber.(He was a Air Enthusiast,too ;D. His son is Teruo Tojo(東条輝夫),the designer of YS-11. ). BTW Chikuhei did not have the design of super large bomber, only said “We can do it”. Chikuhei also explained this idea to the IJA aviation head office in 26th of April in 1943. After completion of Z-plane basic design, Chikuhei wrote “Winning game plan” ,finished in 8th of August in 1943, explained to IJA, IJN and Takamatsunomiya(高松宮)，brother of emperor Hirohito(裕仁),etc. Finally emperor Hirohito knew this plan.
Following drawings are from internet site.

 

[airman]

Fantastic images ! B)

 

[royabulgaf]

I have noticed that several G10N drawings and reconstructions, such as Blackkite's, seem very derivative of the B-29 to the extent that were someone ignorant of the Fugaku program would say they were some sort of 6-engined B-29 program. Are these accurate views of the Fugaku concept, or did someone in the postwar era use the B-29 as a template in producing drawings and plans?

 

[blackkite]

Fugaku's nose was more clean than B-29's nose. Japan already knew the shape of B-29 when designed Fugaku. These drawings are almost same scale. B-29's fuselage diameter is about 2.6m,Fugaku's fuselage diameter was about 4m.

 

[airman]

So, about G10N and B-29, so Me-264 have a nose that reminds B-29 , could be not really strange if nose of G10N reminds B-29 !

 

[windswords]

royabulgaf,

About your question of the similarities of the G10N to the B-29 - Earlier in this thread, I had this exchange with Blackkite:

Windswords:

"I have always wondered about this. Some drawings of G10N show traditional cockpit and others look like the B-29. Is that a fact that a B-29 style cockpit is someones post war imagination of what might have been?"


Blackkite:

"Hi windswords-san! I don’t think so, because there is a Fugaku drawing in my No.2 bible which has the B-29 type cabin. My No.2 bible was made by all Japan line up.(Tadashi Nozawa, Mitsubishi Heavy Industries, Kawasaki Heavy Industries, Fuji Heavy Industries, etc)
It might be true that all of Fugaku’s drawings were burned out and we can’t see the official blue print of Fugaklu. But It’s impossible to erase memory of engineers who engaged in Fugaku project. They must be remember the detail of Fugaku’s data very clearly. This is the reason why I believe Fugaku’s B-29 style cabin is true."

 

[blackkite]

Thanks windswords!
Fugaku v.s B-29 and B-36. Almost same scale. Enjoy.
In Fugaku v.s B-36, Fugaku's length become about 5% small. Sorry.
Fugaku's wing span:63m, B-36's wing span:70.1m.
Fugaku's length:42m, B-36's length:49.4m

 

[blackkite]

Hi! Brief history of Z and Fugaku.

 

[T-50]

Fugaku's nose was more clean than B-29's nose. Japan already knew the shape of B-29 when designed Fugaku. These drawings are almost same scale. B-29's fuselage diameter is about 2.6m,Fugaku's fuselage diameter was about 4m.

Hi Blackkite San I totally agree with you that the nose of Fugaku has nicer and cleaner lines than the nose of B-29!
The whole aircraft is of a better aerodynamically design than the fuselage of B-29 although the B-29 is a beautiful aircraft too.
But the lines of the B-29 are with its more knotted wings and flatter nose,make the plane more air resistand than the Fugaku .thats my vieuw on this matter

 

[blackkite]

Hi T-50 san. We are looking forward your new Fugaku model.

 

[T-50]

Hi Blackkite San I'm now making the drawings of my new model,before Ill cut the first wooden part.
Ill inform you when I made progress.
Do you know were the Z bomber was going to build? were there new factories planned? and are they underground factories? for example.
I'm very curious if there is some info about this

 

[blackkite]

Fugaku's assembly plant was located near Nakajima aircraft research institute near Chofu airport Mitaka Tokyo. You can see the assembly factory with large opening upper side of the picture. Large plants located middle of the picture were Nakajima aircraft experimental aircraft manufacturing plant.
There were IJA experimental aircraft design department and HA54 engine design department in Mitaka research institute.
Last picture was Nakajima Aircraft Musashi engine plant, most important target for B-29s.
Of course Chikuhei had the plan for large scale production plants for Fugaku. They were ten plants(each plant had 30,000 workers) for the aircrafts and seven plants(each plant had 20,000 workers) for the engines.

 

[T-50]

Hi Blackkite San thanks for these very interesting photos! Like the B-29 production line the Fugaku would build by separate factories.I assume they planned to work with sub contractors,for example with Mitsubishi or Kawasaki to produce parts for this huge bomber.
best regards T-50

 

[blackkite]

From "富嶽(FUGAKU)" ,Author:Maema Takanori(前間孝則)／Yoshiro Ikari(碇義朗), No.(5)

In 9th of August 1943, the IJA and the IJN aviation technology committee was established to develop new aircrafts effectively. In September 1943, in the meeting of this committee, there was a discussion about Z-plane. Many positive and negative opinions were offered from the IJA and the IJN, finally Z-plane was selected as the IJA and the IJN joint research program same as following planes Ki-87, Ki-90, Ki-91, Ki-94, Ki-95, Ki-99, Ki-101 and Renzan. (Fugaku was a special treatment.) In this committee, Experimental Fugaku committee was established, members were from IJA No.1 aviation research institute, No.1 to No.8 aviation technology research institute,
IJN Kugisho engine department, Tokyo imperial university aviation research institute, Central Aviation research institute, Nakajima, Mitsubishi, Sumitomo metal, etc. Project manager was Nario Ando from IJA No1. Aviation research institute. The meeting of Fugaku committee held once per month. BTW the IJA and IJN's stance for Fugaku was not so eager, especially IJA because they already experienced Shinzan's failure. Substantial technical leader was Satoshi Koyama. Fugaku design team was located in Koizumi factory of Nakajima aircraft consisted of several ten engineers.
They worked very hard, did not had enough time for lunch and hand wash, looked at a slide rule every day to calculate fuel consumption utilizing jet stream in various conditions.
HA54 design team was located second floor of Mitaka research institute of Nakajima Aircraft, consist of 50 engineers,finally 200 engineers. Chief engineer Tanaka said that the design activity of HA54 went smooth although HA54 was a very complicated engine.
The report which offered the meeting in April 1944 did not include the explanation for turbo super charger , because it was still unstable to work, need more technical study, engineer Toda said after the war.

Please watch the picture of Nakajima Aircraft's Ohta factory and Koizumi factory under the bombing by B-29 in winter day.

 

[blackkite]

This is the drawing which carried in Japanese “Mach club” 's magazine Soku(蒼空，the blue sky) in some year from 1965 to 1974 as Fugaku G10N1. Source was Japanese aviation authority, doctor of engineering. Nakajima's engineers said that they did not consider such a wing,because it's hard to manufacture. Fake or private venture. ;D
Source: Giant aircraft story,Minoru Akimoto, KOJINSHA TOKYO,2002, ISBN4-7698-2359-2 C0195

 

[blackkite]

The engineer who engaged in Fugaku project said that "the Fugaku had a slanting cocoon type pressurized cabin located front end of the aircraft, Fugaku's nose had no step!" At the beginning of the Fugaku project, there was a plan to had a stepped nose, BTW the person in charge rejected this plan saying “It's bad. It's like a Japanese spaniel sneezing.” It must be a Shinzan style cabin. ;D
Source:following site.
http://www.warbirds.jp/kakuki/kaksasie/hon/hon_fugaku.htm

 

[blackkite]

I believed that HA54 engine had contra rotating propellers, but in this Nakajima's official drawing ,we see single propeller. Finally HA54 had a single propeller?
This HA54 drawing shows that it had a mechanical super charger. If HA54 had turbo super chargers, it became very long engine, because of big inter cooler,big turbo super charger and complex piping.
中間冷却器 means inter cooler, 過給器 means super charger, 排気 means exhaust gas, タービン means turbine.
排気タービン過給器 means turbo super charger. 機械式過給器 means mechanical super charger.

 

[airman]

blackkite thanks for drawings : they explain very well the various types of super chargers ,especially of Ha-254 !

 

[blackkite]

Hi! I find another drawing of Fugaku.
We see the concept of slanting cocoon type pressurized cabin located front end of the aircraft.
Source:The IJA military aircraft perfect guide from 1910 to 1945. Gakken, January,2005. ISBN4-05-603757-4 C9421

 

[airman]

Hi! I find another drawing of Fugaku.
We see the concept of slanting cocoon type pressurized cabin located front end of the aircraft.
Source:The IJA military aircraft perfect guide from 1910 to 1945. Gakken, January,2005. ISBN4-05-603757-4 C9421

nice drawing !

 

[blackkite]

Hi Z-OHTA. We see very large under carridge cover under the wing.
Source:「幻の新鋭機,Illusion of new aircraft」,Kojinsha,Toshihiko Ogawa, ISBN4-7698-2142-5 C0195.

 

[windswords]

Blackkite-san,

I see this is the twin tail design. Was this an early design or a later design? Or was the twin tail and single tail worked on at the same time by two different design teams?

 

[blackkite]

Hi windswords-san! I am sorry I confused you very much. ;D Z means very early design. Please watch No1 page of this topic.

From "富嶽(FUGAKU)" ,Author:Maema Takanori(前間孝則)／Yoshiro Ikari(碇義朗), No.(6)

In fall of 1943, there were four plans which could bombing the United States. They were Nakajima
Z-plane, Kawanishi TB, Kawasaki Ki-91 and Tachikawa Ki-74Ⅱ, the IJA and the IJN confused very much. Finally the IJA and IJN Aviation technology committee asked Chikuhei Nakajima to be the chairman of Fugaku committee in 24th of November 1943. In 26th of January 1944, the IJN
held the meeting to compare with Fugaku and TB. The specifications of Fugaku and TB were
as follows.(Source:Ministry of Defense official documents) The IJA held same meeting in 27th of January.

[Fugaku]: Wing span:61m, Wing area:310m2, Range:18,500km with 5ton bomb, Service ceiling:15,000m, Armament:13mm gun×1, 20mm cannon×3, Max speed:700km/h(15,000m), MTOW:116ton, Takeoff run:1,500m, Engine:Nakajima modified six HA219(HA44) ,2340hp in 15,000m.

[TB]: Wing span:52.5m, Wing area:220m2, Range:23,700km with 2ton bomb, Service ceiling:12,000m, Crew:6, Armament:13mm gun×4, Max speed:600km/h(12,000m), MTOW:74ton, Takeoff run:1,900m, Engineerhaps Mitsubishi modified four HA214(HA42) or HA211(HA43).

 

[blackkite]

From "富嶽(FUGAKU)" ,Author:Maema Takanori(前間孝則)／Yoshiro Ikari(碇義朗), No.(7)

From January 1944, almost all design managers of Nakajima Aircraft concentrated Fugaku design in parallel with other aircraft design for example Renzan design. The Fugaku design team were consisted of 200 engineers including Mitsubishi and Kawasaki's engineers, 40% engineers were from the IJA and the IJN's aviation technology institute, worked as computers.
In the middle of March 1944, the IJA and IJN joint meeting was held to compare with Fugaku, TB and Ki-74Ⅱ. Finally Fugaku was selected as the United States bombing aircraft, settled following two plans. HA54 engine was judged too risky. But Nakajima Aircraft kept development of HA54.

[The first plan] Wing area:330m2, Range:18,200km with 10ton bomb, 21,200km with 5ton bomb,Service ceiling:15,000m, Armament:20mm cannon×24, Max speed:640km/h(12,000m), MTOW:122ton, Takeoff run:1,700m, Engine:Nakajima modified six HA219(HA44) ,2500hp in take off, 2,050hp in 7,000～15,000m. Take off run:1,700m. Wing loading:370kg/m2

[The second plan] Wing area:330m2, Range:16,500km with 10ton bomb, 19,400km with 5ton bomb,Service ceiling:15,000m, Armament:20mm cannon×24, Max speed:700km/h(12,000m), MTOW:122ton, Takeoff run:1,200m, Engine:Mitsubishi six HA50, 3300hp in take off, 2,370hp in 10,400m. Take off run:1,200m. Wing loading:370kg/m2

 

[blackkite]

From "富嶽(FUGAKU)" ,Author:Maema Takanori(前間孝則)／Yoshiro Ikari(碇義朗), Final

Chikuhei Nakajima wanted to proceed Fugaku project in parallel with development and preparation for mass production, but IJA and IJN thought to realize only prototype at the first stage. Fugaku's four main tire's diameter was 1.9m, breadth was 0.5m, inner two tires were dropped after take off. Fugaku had remote controlled turrets to prevent air leak from penetration of cannons and gaps between rotating turrets and fuselage if turrets were installed directly to the pressurized cabin. After fall of Saipan island, Prime minister Tojo retired, Fugaku lost a supporter. In August 1944, Vice Admiral Endoh ordered Nakajima Aircraft to stop Fugaku project. He said to Satoshi Koyama that “Stop Fugaku design or you will be send to Manshu or the southern hard front.” Endoh wanted more fighters. All Nakajima's engineers who engaged in Fugaku project disappointed very much. They think Fugaku was possible to realize. (Turbo supercharger was already realized by Ki-46Ⅳ, pressurized cabin was realized by Ki-74, remote controlled turret was studied for Aichi Denko.) BTW Nakajima aircraft's all elite engineers did not think Japan could win the pacific war, because they knew the ability of the United States very much through studying their aviation technology, said what a fool the IJA and IJN were. Also some American aviation engineers knew the ability of Nakajima aircraft very much because they taught NaKajima aircraft's engineers in Japan before the Pacific war. After the Fugaku project, Nakajima aircraft began to design Ki-115 Tsurugi(剣,the Japanese sord) and Kitsuka(橘花) special attack aircraft. 　

 

[blackkite]

This transparency is not the original Nakajima's design, because Fugaku did not have such a elegant undercarriage. The engineer who designed Fugaku undercarriage said that he could not think multiple tire undercarriage. Fugaku's undercarriage's total number of tires were 4 and 2 were dropped after take off. Fugaku's undercarriage were retracted to the engine nacelles.

 

[airman]

This transparency is not the original Nakajima's design, because Fugaku did not have such a elegant undercarriage. The engineer who designed Fugaku undercarriage said that he could not think multiple tire undercarriage. Fugaku's undercarriage's total number of tires were 4 and 2 were dropped after take off. Fugaku's undercarriage were retracted to the engine nacelles.

Really interesting : but how many cannons as defensive armament was planned ?
In picture i have seen 7 cannons

 

[blackkite]

Hi airman! Very good question! You understand Fugaku very much. Turrets of this drawing are strange,too. Because they are not remote controlled one. It's difficult to prevent air leak. Number and location of armament is the big question for me,too. I will study. I believe the armament of Fugaku were not heavy, because Fugaku's service ceiling was 15,000m with light armament according to the IJN's request.
The IJA's request was heavy armament with service ceiling 10,000m.

 

[blackkite]

Hi! Nakajima final Z-plane. Chikuhei Nakajima's "Winning game plan(必勝戦策, in 1943)" included the drawing of this plane. It had a stepped nose.
This R/C model is 1/15 scale model. Z-plane's wing span was 65m, so this model's wing span is 4.333m.

 

[T-50]

Hi Blackkite San very nice pics of this beautiful RC model of the fugaku,I know there are some people who build a very big RC model of the B-29.
Bet there are a lot of servo engine to control this beautiful beast!

 

[blackkite]

Hi T-50 san! B-36,too.
http://www.youtube.com/watch?v=-uCAQJyVE5E&feature=related

 

[T-50]

Hi Blackkite San I must say a nice RC model of the Convair B-36 Piecemaker,I understand the Fugaku design planned by Nakajima has the same body length as the B-36.
It must become the biggest bomber of WW2 if it was build, the RC model of the Fugaku is in my eyes the most rare and special model I have ever seen! very different than the P-51 or spitfire have seen a thousand of them!

 

[blackkite]

Hi! Fugaku v.s Renzan.
Fugaku was Renzan's brother. Renzan was ordered to develop in December 1942 and the first flight was October 1944. Nakajima Aircraft developed Renzan in parallel with Fugaku.
Renzan's engine were Nakajima Homare(2,000hp in take off), with turbo supercharger and forced cooling fan. I believe Fugaku's engine nacelle shape was similar to Renzan, and Fugaku's turbo supercharged HA44 engine(2,500hp in take off) had forced cooling fan to reduce drug same as Raiden, Renzan and Ki-94Ⅱ.
Engine nacelle size of Fugaku's drawing seems to be little small. Renzan's engine nacelle shape was similar to B-29's. All air intakes(engine cooling air, air to oil cooler, air to supercharger and air to intercooler) were located front end of the engine nacelle. Although the design was based on captured B-17. B-17's air intakes to supercharger and intercooler were located wing leading edge.
Vertical tail stabilizer shape of Renzan were similar to Z and Fugaku.

 

[airman]

Well, about G8N Renzan we know more than G10N : was planned a construction of 64 prototypes for 1945.