Mitsubishi Tozan

[Pelzig]

The Tozan seems to be as mysterious as the Gunzan. Depending on the source, the Tozan was either an attack aircraft or a bomber. That more lean towards it being a bomber is referenced by the fact Tozan means Eastern Mountain which is keeping with the naming convention for IJN bombers.


Still, it is suggested that the Tozan was Mitsubishi's design as a successor to the G4M and G7M and was meant to meet a 19-shi bomber specification. Of course, like the Gunzan, nothing much turns up in sources about exactly what it was, let alone if it existed.

 

[airman]

http://www.daveswarbirds.com/Nippon/aircraft/Projected.htm - Navy Experimental Attack Plane no more info !

 

[hesham]

Hi Hikoki,


I opened a general discussing about it from 2007,but I got no answer;
http://www.secretprojects.co.uk/forum/index.php?topic=661.0

 

[Pelzig]

I had checked that thread but as you say, an answer wasn't received. So, I thought I'd give the Tozan its own topic to open discussion on it.

Hi Hikoki,


I opened a general discussing about it from 2007,but I got no answer;
http://www.secretprojects.co.uk/forum/index.php?topic=661.0

 

[hesham]

I hope we get answers.

 

[blackkite]

Hi! From Japanese wikipedia,
Development of “Taiyo(大洋)” was started as all wooden G4M at the beginning, and the name was experimental “Tozan(東山)”.

 

[Pelzig]

Hmm. So, the Tozan was in reality the Mitsubishi attempt to make a nearly all wooden version of the G4M? Mitsubishi attempted to utilize wood in the tail and bomb bay doors of a G4M2A Model 23. The testing wasn't a success, though. I know that in the Taiyo, the attempt was made to utilize wood in the construction, so, perhaps Mitsubishi was working on such a project prior to initiating the Taiyo?

Hi! From Japanese wikipedia,
Development of “Taiyo(大洋)” was started as all wooden G4M at the beginning, and the name was experimental “Tozan(東山)”.

 

[airman]

Hmm. So, the Tozan was in reality the Mitsubishi attempt to make a nearly all wooden version of the G4M? Mitsubishi attempted to utilize wood in the tail and bomb bay doors of a G4M2A Model 23. The testing wasn't a success, though. I know that in the Taiyo, the attempt was made to utilize wood in the construction, so, perhaps Mitsubishi was working on such a project prior to initiating the Taiyo?

Hi! From Japanese wikipedia,
Development of “Taiyo(大洋)” was started as all wooden G4M at the beginning, and the name was experimental “Tozan(東山)”.

Then i suppose Mitsubishi Tozan was like Tayo but based on G4M2A Model 23 .

 

[blackkite]

Although the development plan of "Tozan" was materialized around the autumn of 1944 (Showa 19), once became seen off because there was a plan that twin engine attack/bomber was unified into 1 model of "Ginga(銀河)".
But G4M was planned to use as the night patrol aircraft by the IJN, Tozan project was revived and planned to develop as the all wooden night patrol aircraft in Mitsubishi.
Tozan project was dismissed by the IJN, although the Mitsubishi was seemingly highly motivated to work on this aircraft and proposed to the IJN with the expectation as a G4M succeedingaircraft carrying a new engine.
The wooden land attack plane "Tozan" turned into a land patrol aircraft "Taiyo" in June, 1945 (Showa 20).

 

[Pelzig]

So, let me see if I get this progression right. Ietsuro Hikita undertakes the replacement of the tail and bomb-bay with wood components with a G4M2A Model 24. It isn't a success following testing but Mitsubishi sees enough merit to expand the usage of wood in the G4M to initiate the Tozan project which could be seen as the wooden evolution of the G4M3A Model 34 Ko (the maritime patrol bomber variant). The IJN puts the kibosh on it but Mitsubishi pitches it again with a new engine (likely to overcome the added weight by the wood materials) and the Tozan rolls into the Taiyo program, of which the G4M based plan is approved.

 

[Pelzig]

Article by Minoru Akimoto sent along by Tadeusz Januszewski.

 

[Pelzig]

Con't.

 

[Pelzig]

Fin.

 

[blackkite]

Oh! These are from MARU(丸) magazine. MARU means the rising sun.
泰山＝Taizan, 太洋（大洋）=Taiyo(ocean).
泰山(Mt. Taishan)
http://www.google.com/search?q=Taishan&hl=ja&tbm=isch&tbo=u&source=univ&sa=X&ei=_zg1Uff7PNGVkgXKmIDADQ&ved=0CEcQsAQ&biw=1366&bih=641

http://whc.unesco.org/en/list/437

 

[blackkite]

Ed! Do you have any information about Gunzan? Sorry for off topic.
http://en.wikipedia.org/wiki/Gunsan

 

[Stargazer]

Let's stick to the Tozan for now...

Two questions:

1°) Were Tozan and Taizan one and the same project or not?
2°) Could the Tozan have been the Kawanishi K-100 or a direct competitor (I thought of that yesterday, and now your article mentions it...).

 

[windswords]

Hikoki and everyone,

The picture of the engine on page number 3 from Maru has a turbo supercharger. Can you tell me what engine it is? Is it the new engine for Tozan?


I wonder if it occurred to the Japanese that the use of wood would reduce the radar cross section of the airplane? It would not make it stealthy, true stealth involves much more than just the material you use, but it would reduce the radar return, and if the Tozan was to be used at night like the G4M for patrol duties that could be significant.

 

[Grey Havoc]

I wonder if it occurred to the Japanese that the use of wood would reduce the radar cross section of the airplane? It would not make it stealthy, true stealth involves much more than just the material you use, but it would reduce the radar return, and if the Tozan was to be used at night like the G4M for patrol duties that could be significant.

Would make sense.

 

[Pelzig]

I am not sure that the emphasis placed by the Japanese on using wood had anything to do with making aircraft "stealthy." The primary purpose, to them, of using wood was to be able to continue building aircraft in the face of ever dwindling supplies of metals. This is shown by the intense Japanese interest in German glues and bonding techniques. I also feel that using wood in the likes of Q3W and Q2M was more to limit interference on the detection gear as well as minimize metal use for construction.

 

[Pelzig]

Keep tabs on that thread at:


http://www.secretprojects.co.uk/forum/index.php/topic,6529.0.html


But, no, nothing has turned up on the Gunzan.

Ed! Do you have any information about Gunzan? Sorry for off topic.
http://en.wikipedia.org/wiki/Gunsan

 

[LAW]

The picture of the engine on page number 3 from Maru has a turbo supercharger. Can you tell me what engine it is? Is it the new engine for Tozan?

Hi,

It is Mitsubishi MK10C or MK10A engine (factory designation A-18, joint Army-Navy designation Ha-42-31, old Army designation Ha-214 or Ha-214 Fu - Fu like Furukan, i.e. Vulcan in Japanese transcription). It had double, 2-stage 2-speed fluid coupled (hydrodynamic) Vulcan supercharger (not turbo!), just like MK9D Kai (Ha-43-42) for example, used in the J7W1 Shinden prototype. These engines were planned for the G7M Taizan. According to Gakken #42 book, Tozan was to be powered by two Kasei 25 Otsu engines.

Regards,

LAW

 

[windswords]

Law, thanks for the speedy reply to my question!

 

[blackkite]

Hi!
Mitsubishi hoped to use MK9A engine, but the IJN did not think so, because of lack of MK9A engine.
Wooden structure Taiyo's mission were mainly Anti Submarine Warfare and transport. 　

 

[airman]

Hi!

By table surely Mitsubishi Tozan and Tayo was same project : Tayo was a final evolution of Tozan !

 

[Pelzig]

I'm not so sure that the Tozan, at the beginning, was intended for the Taiyo project. Mitsubishi had been experimenting with replacing metal components on the G4M with wood and the Tozan was an evolution of that. The chart looks a lot like the G7M Taizan with revision after revision of the Tozan and while it was initially to be a ASW aircraft, that role changed during the discussions. But I suspect the IJN wasn't too interested in bombers so when they wanted a ASW platform, Mitsubishi brought in the Tozan design as Plan A for the Taiyo as well as submitting a more dedicated design (and departure from the G4M) as Plan B.

Hi!

By table surely Mitsubishi Tozan and Tayo was same project : Tayo was a final evolution of Tozan !

 

[blackkite]

Additional information(1)
Taiyo's electrical equipments
1.19-shi Kuu-4 Go radio communication equipment
2.19-shi radio return direction finder
3.98-shiki Kuu-4 Go group radio telephone
4.3-shiki Kuu-6-Go type-4 radar
5.Prototype 2-shiki Kuu-7 Go radar(Reverse detector)
6.Identification friend or foe(IFF)
7.3-shiki 1-Go magnetic anomaly detector(MAD)
Taiyo's take off run(Attacking over load condition) : 600m
Taiyo's landing run(Without bomb, fuel 60%) : 600m

 

[blackkite]

Hi Taiyo(大洋)!

 

[zzy2001]

First, the other name we have for Tozan is G4M4 or 一式陆攻四四型, which means that this plane is NOT G9M or something new, she WAS EXACTLY Betty and her relationship with other betties was exactly the same as g4m2 and g4m3 or so on.
But this thing looks so different from other G4Ms, it looks more like the later Q2M Taiyo and in fact Taiyo herself was a kind of weird G4M.
Again netiher Q2M nor Tozan has any relationship with the army ki67 Hiryu, the only thing that navy had that did had some relationship was G7M Taizan.

 

[snark]

First, the other name we have for Tozan is G4M4 or 一式陆攻四四型, which means that this plane is NOT G9M or something new, she WAS EXACTLY Betty and her relationship with other betties was exactly the same as g4m2 and g4m3 or so on.
But this thing looks so different from other G4Ms, it looks more like the later Q2M Taiyo and in fact Taiyo herself was a kind of weird G4M.
Again netiher Q2M nor Tozan has any relationship with the army ki67 Hiryu, the only thing that navy had that did had some relationship was G7M Taizan.
View attachment 711022View attachment 711023

Hi

Do you have a Japanese source for your association of the designation "G4M4" with the name "Tozan"? I have only seen the SADP designation "M-80" associated with this design.

Thanks for your time. Harry

 

[zzy2001]

Hi

Do you have a Japanese source for your association of the designation "G4M4" with the name "Tozan"? I have only seen the SADP designation "M-80" associated with this design.

Thanks for your time. Harry

I heard that from a famous IJNAS studier called Komine Bunzo (he wrote most of the Maru magzine about IJNAS). He had posted twitter about Taiyo twice and one of them consisted a picture of Tozan. He said that it was the plan of boosted G4M3(the same relationship between A7M and A7MJ) and that picture really looks like Taiyo.

 

[Mavrick5]

This is getting interesting, Any more information om Tozan?

 

[zzy2001]

This is getting interesting, Any more information om Tozan?

it was too lack of information, I had something that you might want to see

 

[Stargazer]

It has been said earlier in this topic that the Tozan was supposedly Mitsubishi's answer to a 19-Shi Bomber bomber specification. But wasn't the Yasukuni transfered from the Army for the same role? And if so, did it replace the Tozan?