# Japanese carirer-borne and land based bombers, reserching and questions



## Bootch (Nov 15, 2014)

Good day, Ladies and Gentlemen!!!)))

I encountered a number of questions in the construction of models of Japanese bombers B6N2 Jill in 48 scale. 
Start in order:
*1. Quantity of fuel tanks in the aircraft.*
I'll try to explain the history of question.
In book "Mechanic of World Aircraft №14" materials present contradicting each other.














it is obvious that the three fuel tanks, but appear additional description photo surviving plane.






*I have two versions*
a) remaking the original construction by american technics
b) Tenzan had modification with two fuel tanks, it was possible modification with the search radar.

*2. Quantity of exhaust*
According to documents, Tenzan had a 14 cylinder engine with individual exhaust pipe for each cylinder. But if you try to count the number of exhaust pipes at the pictures, you will find only 13 pipes. Probably two of some pipe put together, but what? This is a serious question if in model engine design without cover.

*3. The shape and configuration of the navigator-bombardier control panel.*








*again two versions*
a) remaking the original construction by american technics
b) Tenzan had modification with different dising of this control panel. 

*4. Using navigator viewfinder in real aircraft*
Hasegawa gives in model two optical device - bombsight and navigator viewfinder. But studying the drawings and photographs were not found for the blister navigator viewfinder. If we believe the model, finder located in the area of suspension points torpedoes and bomb armament. Large-bomb or torpedo close review for this device, so its location seems doubtful. In addition, the bombers of this type use only one optical device - a bomb sight. Navigational viewfinder used most often at the spy plane. Therefore the presence of navigator viewfinder, highly doubtful at Tenzane.

*5. Design,drawings of trailed radio antenne*
*6. Design, drawings, photo of wheel bay*

I hope for your help.

This some "big" question about Tenzan in this moment.Tomorrow I will try to continue. About Tenzan and another bombers.

P.S. Please forgive me for the bad english. This post took about 1.5 hours for writing and translation. And maybe some of the terms or expressions are not true.


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## Shinpachi (Nov 15, 2014)

Welcome to the forum, Bootch 

1. Tenzan had 3 fuel tanks per wing plus one spare tank in the nose (B6N1: 65L for 95 octane fuel/B6N2: 85L for water-methanol). Image attached.











2. The lowest two exhaust pipes on the port side were combine to one though I wonder why. Image attached.






3. I don't know why the navigator-bombardier control panel design is different for the same B6N2.

4. I wonder if the navigator viewfinder means Drift Indicator (Type 97 Mark 1). That was a standard equipment.

5. The trailed radio antenna was a wire which had a weight on the end. Wire length unknown. Image attached.









6. No photos of the wheel bay at the moment.

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## Wurger (Nov 15, 2014)



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## Bootch (Nov 15, 2014)

Shinpachi said:


> Welcome to the forum, Bootch



Thank you for the warm welcome and answers!



Shinpachi said:


> 1. Tenzan had 3 fuel tanks per wing plus one spare tank in the nose (B6N1: 65L for 95 octane fuel/B6N2: 85L for water-methanol).



thanks for the translation and explanation, but why in the photo is missing the third switch?



Shinpachi said:


> 2. The lowest two exhaust pipes on the port side were combine to one though I wonder why. Image attached.



Ok,This question is resolved for me,thanks!



Shinpachi said:


> 3. I don't know why the navigator-bombardier control panel design is different for the same B6N2.



And i don't now.But to me it seems more likely option shown in BW photo.



Shinpachi said:


> 4. I wonder if the navigator viewfinder means Drift Indicator (Type 97 Mark 1). That was a standard equipment.



Yes, it's means drift indicator. But I still doubt on this issue, try to explain why:
1. B6N2 from Willow Grove is considered in two books( Japanese Aircraft Interiors 1940-1945 Robert C. Mikesh and Maru Mechanic mechanism of military aircraft #14). This is the most detailed materials. Robert C Mikesh nowhere describes the presence of drift indicator 





Because the Japanese is "great secret" for me , i study the Maru Mechanic just for the pictures and photos . Diagrams and pictures of this device in a book I have not found. Perhaps in the text there is a detailed description of the using of drift indicator at Tenzan.
2. If we study the evolution of the carirer-borne bombers: Kate - without drift indicator, Jill - may be yes/may be not, Grace - without drift indicator.
3. I have not found in the drawings and photos a placement of window, blister or peephole for this device. 












Shinpachi said:


> 5. The trailed radio antenna was a wire which had a weight on the end. Wire length unknown. Image attached.



Sorry,my question was not complete. I found hints about trailed radio antenna. 








But I have not found drawings with accurate dimensions and details of the mechanism.

*Shinpachi*, thanks again for your answers!

Some time ago I made a request to the Smithsonian's National Air and Space Museum about technical documentation for B7A B6N, now waiting for an answer, I hope for a positive response and I look forward to the results.. Perhaps the museum archives answers will help find answers.


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## Shinpachi (Nov 15, 2014)

You are welcome, Bootch.

Data for the B6N are generally not so many but the Maru Mechanic describes the Drift Indicater was usually equipped on the starboard side of the navigator seat, together with 6 flash balls for the night operation. A set of binoculars was also one of the standard equipments. There was a flight chart on the retractable table.

I'll be looking forward to your nice job in the future


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## Shinpachi (Nov 15, 2014)

Bootch said:


> thanks for the translation and explanation, but why in the photo is missing the third switch?



The third switch is missing because the water-methanol injection device is probably not equipped on the engine.

The 95 octane fuel was necessary when the B6N1 was launched from the aircraft carrier.
Regular fuel in other 6 tanks was 87 octane though the airframe was designed for 91 octane.
Later, the tank was used for the water-methanol injection as a land-based aircraft.

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## Bootch (Nov 16, 2014)

Shinpachi said:


> You are welcome, Bootch.
> 
> Data for the B6N are generally not so many but the Maru Mechanic describes the Drift Indicater was usually equipped on the starboard side of the navigator seat, together with 6 flash balls for the night operation. A set of binoculars was also one of the standard equipments. There was a flight chart on the retractable table.



I have no reason to doubt your words. However, now it is necessary to solve two "easy task"
1. Determine the correct structure of the navigator control panel.
2. Find a place for viewing window.



Shinpachi said:


> I'll be looking forward to your nice job in the future



Some photo of my Tenzan in 48 scale.

Exhaust pipes.This is done by electro galvanic. On the experiments took almost 3 weeks












Resin Engine from "Vector"






Gun amount









Fuselage with lower weapon emplacements









My first experiment with homemade photoetching









After identifying gross mistakes in the design of the floor of the cockpit, it was decided to make the interior of the cockpit with my own hands.


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## vikingBerserker (Nov 16, 2014)

Excellent information as always Shinpachi!

Welcome aboard Bootch, beautiful job!


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## Shinpachi (Nov 16, 2014)

Bootch said:


> I have no reason to doubt your words. However, now it is necessary to solve two "easy task"
> 1. Determine the correct structure of the navigator control panel.
> 2. Find a place for viewing window.



The sighting window was originally a sheet of glass in early version of the B6N2. That would have been replaced later with a metal panel for the security reason. I think the Smithsonian collection which Mr. Mikesh referred is showing the early version and photos in the Maru Mechanic does the later one. Matter would be which version you choose.

Nice job, Bootch.


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## Bootch (Nov 17, 2014)

Shinpachi said:


> The sighting window was originally a sheet of glass in early version of the B6N2. That would have been replaced later with a metal panel for the security reason. I think the Smithsonian collection which Mr. Mikesh referred is showing the early version and photos in the Maru Mechanic does the later one. Matter would be which version you choose.



Again, I apologize for the incomplete question
I meant sighting window for Drift Indicater. But the situation with the "main" viewing window is not fully understood. So, at first viewing window are present at the design, but was later replaced by a metal panel, as well do not understand the situation with the panel, marked with the letter "B". How it can play the role of the doors for the bomb sight when bombsight are placed much further. I approximately designated location.








My assumption is that the overview window was protected by a metal plate, but I think that this panel was movable and had two positions:
1. the blister review for bombsight is open , the main sighting window is closed, the panel indicated the letter "B" is closed.
2. the main sighting window is open, the panel is marked with letter "B" as well open and playing role of wind shield, review blister for bombsight is closed.
This is just my guess and I could be wrong, indirect gives only this photo.





However, this guess explains the presence and function of the lettered "B".

Some more questions about Tenzan.
1. What is the function of this part?






2. I do not know the location of the radar equipment (transmitter, receiver and related equipment). I would like to look into this matter.


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## Bootch (Nov 17, 2014)

You might probably think l'm a wimp


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## Shinpachi (Nov 17, 2014)

Bootch said:


> Some more questions about Tenzan.
> 1. What is the function of this part?
> 
> 
> ...



1. The side tube in the photo is explained "This is estimated a ventilation tube from the water-methanol tank".
2. The radar (Type 3 Ku Mark 6) was not a standard equipment for the ordinary B6N because the set occupied large space in the compartment.

Regarding the sighting window for the bomb sight, your guess may be right but I can't assure it from the description in the photo as it's so simple.

Also I find no descriptions about the drift indicator except the device was equipped on the starboard side of the navigator. According to it, here (image attached) is a vertical tube.

You are a true researcher, Bootch.


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## Bootch (Nov 18, 2014)

Unfortunately this vertical tube is much easier. This vertical tube - a support strut for the navigator's seat...Photos and diagrams of the support strut.








I ask for your help in the translation of this inscription


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## Wurger (Nov 18, 2014)

A great help Shinpachi-san.

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## Shinpachi (Nov 18, 2014)

Bootch said:


> Unfortunately this vertical tube is much easier. This vertical tube - a support strut for the navigator's seat...Photos and diagrams of the support strut.



OK. I have no other answer about the drift indicator window.
You will find answer by yourself.


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## Shinpachi (Nov 18, 2014)

This is the Type 97 Mk 1 Drift Indicator.
Doesn't look a good shape?


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## Wurger (Nov 18, 2014)



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## Shinpachi (Nov 18, 2014)

I would appreciate if no one asks me the genuine translation work as it often takes a lot of my time.
Thank you very much.

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