Fugaku : Z-plane, G10 or G12

[lark]

There were at least two gunship versions planned by Nakajima.

One for use against hostile bomber formations and an
other against deck crews of enemy ships.

The first should use a battery of guns in the belly
of a Fugaku variant to rain down a hail of 20mm
grenades on incoming bomber formations.

The other a series of machine guns in ventral
position to wipe out the the AA guncrews on the ships
and to facilitate also the air attacks on the ships.

These two planned versions were only a few of the several
Mukade - centipede- projects.

Source : Arawasi International Magazine May 2006 issue-Nr.4

 

[blackkite]

Nakajima Chikuhei anticipated strategic bombing to Japan by B-29 in early 1942. To protect Japan from strategic bombing,he planned strategic bombing to the United States!! by very large bombers utilizing the westerlies(jet stream).(Ki-46Ⅳmarked over 700km/h average speed from Beijing to Tokyo utilizing jet stream.) In April 1943, he assembled elite Nakajima's designers(Yasushi Koyama,Yasuo Naito,etc) to the Nakajima club(welfare facility) and ordered them to perform basic design of this large bomber until June 1943. The design result was 6 engine(5,000hp take off power) bomber, which range was 16,000km with 20 ton bomb. After this effort, Chikuhei made 50 copies of "Winning strategy(必勝戦策)" in secret, explained to the political world, the financial world and the circle of government officials in August 1943. "Winning strategy" included two plans for this large bomber, one plan was designed by Nakajima aircraft Koizumi(小泉) factory IJN aircraft design department, which had single vertical tail stabilizer. Another one was designed by Nakajima aircraft Ohta(太田) factory IJA aircraft design department, which had double vertical tail stabilizer. Attached illustration for IJN aircraft design department's plan is from Fuji Heavy Industries calender in 1980.
These two designs are base for variants.
These designs were called Z-plane.
http://www.ne.jp/asahi/airplane/museum/nakajima/FUGAKU.html

 

[lark]

Excellent.The color illustration produced by the design dept. is
clearly based on the 3-view on page 260 of Aireview's General view of
Japanese Military Aircraft in the Pacific War- Kantosha,Tokyo.
One of the oldest I ever have seen.
According your interpretation, should there have been two initial 'Z' plan concepts ..?

 

[blackkite]

Excellent.The color illustration produced by the design dept. is
clearly based on the 3-view on page 260 of Aireview's General view of
Japanese Military Aircraft in the Pacific War- Kantosha,Tokyo.
One of the oldest I ever have seen.
According your interpretation, should there have been two initial 'Z' plan concepts ..?

That's right!! There was a design competition between Koizumi factory and Ohta factory of Nakajima aircraft.

 

[lark]

This confirms the info which I found and received.

Naval design section-Koizumi factory proposed a single tailfin version
Army design section-Ota factory proposed a design with twin tailfins.

A third an final 'Z' plan bomber by Nakajima was inspired on the best
of the two initial concepts.

This 3e design formed the basis for what
should become the Fugaku.

among the sources : correspondence with Mr.Ryusuke Ishiguro ,author of
Japanese Special attack aircraft & flying bombs.
(with Tadeusz Januszewski a.o)

 

[blackkite]

Hi! I made a table for Fugaku variant specification.
In my No2 Bible(ENCYCLOPEDIA OF JAPANESE AIRCRAFT 1900-1945,NAKAJIKA Volume), there is a 3-side view of Fugaku.
It has single propeller, I think it is Fugaku HA44 or HA50 varint.
The Fugaku design team faced many difficult problems at the day,such as engine cooling, under carriage including big tires,wing root strength, pressurized cabin.
One of the most hard one was a HA54 engine cooling problem,and they must considered some variants for early realization of Fugaku.
(Sorry B-36J's J47 number is 4 while my table is 6.)
http://matever.com/archives/ct01complete/_1144.html
http://blogs.yahoo.co.jp/yuunagi_dameya/7557760.html

 

[airman]

well , it's solved also question of Kawanishi TB !!
Thanks blackkite ! ;D

 

[blackkite]

Hi airman! You are welcome.
I got 3-side view of Z-plane which designed by IJN aircraft design department of Nakajima Aircraft. Enjoy!
(Or perhaps this is the final Z-plane.)
Source;Fugaku, Kodan-sha Co.Ltd,Tokyo

 

[blackkite]

Hi airman! Another data of Kawanishi TB.
Engine:2,100hp class air cooling radial 18 cylinder with turbo super charger×4.
Wing span:32.4m, Length:28.0m, Height:7.0m, Wing Area:220m2, Empty Weight:26.5ton, MTOW:74ton, Max Speed:601.9km/h@12,000m, Service Ceiling:12,000m, Range:20,372km(4.6ton bomb), 25,557.6km(2to bomb)
Source:All the Experimental Aircraft in Japanese Army, Minoru Akimoto, KANTOSHA, Tokyo.2008.

 

[airman]

Hi airman! Another data of Kawanishi TB.
Engine:2,100hp class air cooling radial 18 cylinder with turbo super charger×4.
Wing span:32.4m, Length:28.0m, Height:7.0m, Wing Area:220m2, Empty Weight:26.5ton, MTOW:74ton, Max Speed:601.9km/h@12,000m, Service Ceiling:12,000m, Range:20,372km(4.6ton bomb), 25,557.6km(2to bomb)
Source:All the Experimental Aircraft in Japanese Army, Minoru Akimoto, KANTOSHA, Tokyo.2008.

thanks blackkite ;D
seems a little small and four - engine versions of Fugaku ! :
oh yeah : it's a derived project !
I hope to see in future also the version cg (computer graphic) of Kawanishi TB.
Could be Kawanishi TB and Kawanishi G9K awesome derived project of Fugaku ? ???

 

[blackkite]

This confirms the info which I found and received.

Naval design section-Koizumi factory proposed a single tailfin version
Army design section-Ota factory proposed a design with twin tailfins.

A third an final 'Z' plan bomber by Nakajima was inspired on the best
of the two initial concepts.

This 3e design formed the basis for what
should become the Fugaku.

among the sources : correspondence with Mr.Ryusuke Ishiguro ,author of
Japanese Special attack aircraft & flying bombs.
(with Tadeusz Januszewski a.o)

Hi lark! Your are absolutely right. I modified the table.So colored illustration from FHI calender might be the final Z-plane.I add Koizumi plan which had single prop, but it's apparently mistake.
It had double prop.

 

[blackkite]

Kawanishi TB was the competitor of Fugaku,ordered by Ministry of Military Supplies in 1943. TB means "toyo bakugeki(渡洋爆撃)", in English,oversea bombing. TB was defeated by Fugaku in January 1944. TB's design was joint work between Kawanishi and Tokyo imperial university. Hidemasa Kimura(木村秀政,designer of A-26 and YS-11) was the chief designer of Tokyo imperial university team.
TB had laminar flow wing(LB wing) developed by Ichiro Tani(谷一郎), and had very aerodynamically clean shape. L/D was 35.
Kawanishi G9K was a derivative of H8K 2-shiki flying boat?

 

[lark]

Great work Blacklite..

 

[T-50]

Hello blackkite and others I must say this is awesome stuff! didn't know there was so much info about the Z program I know that Kawasaki was also developing a contender to the Nakajima G10N Fugaku.But I was surprised to read that there is such detailed info,I'm glad that a lot of info survived the war.
there are even pics of mock-up models of the huge and very powerfull engines then in development for the Zbomber
great work guys!

 

[blackkite]

Recently I got this big book "富嶽(FUGAKU)" ,Author:Maema Takanori(前間孝則),Kodansha Tokyo published in 1991. It has almost 600 pages.
I will read this book and report near future. Z/FUGAKU was a very mysterious plane. Almost all drawings and data were burned out entirely.
Ed's "JAPANESE SECRET PROJECTS EXPERIMENTAL AIRCRAFT OF THE IJA AND IJN 1939-1945" include very impressive colored 3-side view of Fugaku. It's the ultimate Fugaku. It has HA54 engine, not Z-plane.

 

[lark]

Maybe this bit of additional info can be usefull..

In August 1944 it was realized that the technology was beyond reach and Nakjima gave up
on the engine and aircraft as it was originally conceived.
The superbomber was scaled down.
A smaller design was to be powered by 6 Nakajima NK 11A engines that could produce 2500hp.
The scaled down Fugaku would have a wingspan of 207ft and a length of 121ft.
(instead of the 237ft span and 144ft length of the former design)

Source :The second attack on Pearl Harbor-chapter:Extending the range-page 270

 

[blackkite]

Hi!

"Super large bomber Fugaku(富嶽)'s engine(4)"
The HA54 engine was required high reliability,the design team wanted to perform several basic tests and full scale mock up model construction prior to fix final design. But the schedule was very severe to perform every test and mock up construction that design team planned.
The HA54 development plan in March 1944 was as follows.
1.Machine manufacturing of parts for No1 and No2 engine:March 1944 to September 1944.
2.Assembly of No1 engine:October 1944.
3.Assembly of No2 engine:Nobember 1944.
4.Endurance test finish:February 1945.
5.The first flight of No1 Fugaku:May 1945.
But in July 1944, Nakajima received order to terminate Fugaku project from IJA and IJN after Saipan island fall(1944/07/07),because IJA and IJN concentrated on fighter manufacturing which used for B-29 Interception and KAMIKAZE special attack.
At the time, the HA54 design team already finished the design and prepared all parts drawings.
The materials for crank shaft and crank case already delivered to Nakajima. Machine manufacturing began.
The design team disappointed very much to receive stop order. They wanted to complete HA54 engine very much.
Chikuhei Nakajima instructed design team that Nakajima Aircraft will crush after WW2.The automobile age will begin.Study hard!!
(same as my mother ;D)
Nakajima Aircraft became Fuji(Fugaku) heavy industries.
http://www.fhi.co.jp/english/

 

[T-50]

I was wondering if the scaledown version of Fugaku was capable of nonstop flying from Japan to the USA and back.
Has this design a greenhouse cockpit or was this design equipped with a conventional design,and could this design carry the Japanese atombomb?
I'm also very curious was there a transport version of this aircraft? It seems logical that Engineers of the Nakajima company were thinking of a huge cargo aircraft that was capable to carry battle tanks and troops to a battle field far away of the Japanese motherland

 

[lark]

In his presentation Chikuhei Nakajima mentioned a transport
variant of his "Z' plan bomber but no details were given.
I strongly doubt about a Japanese A-bomb. In my personal opinion
it is as much a blown up myth as the nazi germany bomb was ...

 

[blackkite]

Fugaku planned to use jet stream. Please see the direction of jet stream. Fugaku's mission was as follows.
Take off Japan, fly over Pacific ocean, bomb the United States, fly over Atlantic ocean and land to Germany.
Take off Germany, fly over Soviet union, fly over Japan sea and land to Japan.
Designers of Fugaku always watched a terrestrial globe. To use stream, it was expected that the range of Fugaku increased 20% - 30%.

 

[Nick Sumner]

Fascinating info Blackkite! Thank you.

To be clear - the blue lines on the maps you have posted are the jetstream? Or are they the planned course of Fugaku missions?

 

[airman]

cool thread ! B)
We are discovering many interesting things about Fugaku !

 

[blackkite]

Fascinating info Blackkite! Thank you.

To be clear - the blue lines on the maps you have posted are the jetstream? Or are they the planned course of Fugaku missions?

Sorry. It's jet stream line. So jet stream act as strong counter wind for German New York bomber when she goes to there.

 

[T-50]

what were the targets of this huge bomber? I think citys like San Francisco or Los Angeles.

 

[blackkite]

Chikuhei Nakajima thought that the targets were Pittsburgh and New York.
Some Japanese fiction writer says that the target was Los Alamos,not Los Angeles. ;D

 

[T-50]

In his presentation Chikuhei Nakajima mentioned a transport
variant of his "Z' plan bomber but no details were given.
I strongly doubt about a Japanese A-bomb. In my personal opinion
it is as much a blown up myth as the nazi germany bomb was ...

The Japanese were really developing a atom weapon later into the war,so its hard reality not a myth!they experimenting even with a sort of death ray.
and I know one thing for sure if the Japanese were to manage to build a working device,the Fugaku was the ultimate carrier platform for such a weapon

 

[lark]

It should be interesting for us to see your sources...

 

[blackkite]

I heard that Japanese theory for A-bomb was not proper.

 

[royabulgaf]

the Japanese had a couple centrifuges that IIRC were strictly experimental and were destroyed in a bombing raid in 1943. Strictly lab work after that.

 

[T-50]

It should be interesting for us to see your sources...
[/quo
te]
Hello Lark if you go to the wikipedia site and go for Japanese nuclear weapon program,you can read the whole story!
And they have links to other sites about this topic

 

[Jemiba]

Wikipedia is a great project in itself, but due to its nature, statements there should
often be regarded just as unproven clues, not as facts. Nevertheless, the article
you've mentioned, to my opinion contains the answer to the question about a japanese
nuclear weapon in it's very first paragraph:
"Like the German nuclear weapons program, it suffered from an array of problems, and was
ultimately unable to head off the Manhattan Project's ..."
The theoretical possibilty of building a nuclear explosive device was well known then and I
wouldn't be surprised to hear one day, that even in countries like Peru or Ethiopia (just examples
and of course not meant to offend anybody !) single scientists or small groups were tasked with
developing such a weapon. But that doesn't mean, that there ever would have been the slightest
chance for those countries to built a workable nuclear bomb !

 

[blackkite]

Hi! I find some more variants of Z/Fugaku.
They are
(1)Temporary 6 engine bomber.(single propeller)
(2)4 engine bomber.(double propeller)
I modify the table again.
Enjoy.

 

[blackkite]

Hi! 4 engine bomber and another picture of final Z. Enjoy.
Source:Japanese experimental aircraft,Futaba-sha,Tokyo

 

[Nick Sumner]

I heard that Japanese theory for A-bomb was not proper.

My understanding is that the Japanese had the theory correct (unlike the Germans) but a lack of resources and a late start meant the project had no hope of fruition during the course of the war.

 

[lark]

Magnificent discovering Blacklite..
At last , the 'Z' plan bomber and Fugaku history becomes
less misty.. thanks for the detailed work.

 

[Skybolt]

I agree with my friend Lark, Blackkite-san, arigato !

 

[Justo Miranda]

found additional stuff

 

[T-50]

I must say my compliments to Blackkite and Justo Miranda for their awesome pics and info! this topic is getting more and more interesting by the hour.
I made a model of the fugaku couple years ago,but with this new info I going to plan to build a new Fugaku model.
But more accurate than the previous model

 

[blackkite]

I agree with my friend Lark, Blackkite-san, arigato !

Hi! My dear skybolt san. Doitashimashite.(どういたしまして。You are welcome.)
We look forward Ed any your joint venture, Italian Secret Project very much.

 

[blackkite]

Hi! I can't identify this drawing. Someone please help. Was this the Fugaku variant?
We already know that Fugaku had a wing root strength problem, but this shape weakend the strength of wing root!
It looks like He111. ;D