Targetware :: View topic - Promised scans nad more...

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Target Rabaul - Promised scans nad more...

Zabatt - Dec 18, 2003 - 06:37 AM
Post subject: Promised scans nad more...

Hi!

I've finally replaced my old and very broken scanner yesterday and I cab scan again... I remember I promised Yak scans of the trim indicator for Zero, but it seems I have only pictures from Maru Mech... If you need them here are the links:

This one looks like there are two scales - one on the inner side like in type 21 and one on the outer. However the arrow for second one is not visible... I took a good look with magnifying glass and it looks like the secons arrow is maybe hidden behind the trim knob, but it's hard to tell and it is almost invisible on the scan. Anyway those are drawing not pictures.

The only picture I have is from the Type 52 which is still flying - it looks very rudimentary, but I wouldn't be surprised if that was how japanese made them at the end of the war... One arrow only...

If I promised something more, but forgot about it, please tell me.

And here are some interesting drawings... Attack patterns for B5N Kate Smile

First - low level bombing pass. They used those mainly in close support mission. Pilot would always attack with the wind, since that helped get higher ground speed and that simplified aiming... Here's the picture how it should look like... btw. it says pilot should look for things like smoke from the chimneys or flags to determine wind direction... I hope we have those once wind is here Very Happy

Anyway, this pattern is pretty useful in TR.

Second is more interesting - this is high altitude pattern for attack on ships with 800kg AP bombs. It takes 5 Kates formation to do it... Pictures on the right side show the results of one plane not being trimmed well and slipping.

Now something for Stiglr Wink

Torpedo attack patterns. First illustration shows the importance of proper aircraft attitude (pitch as close to 0 deg as possible). Contrary to what other sims have, if pitch is wrong the torpedo would either sink or pop out of the water and go in unpredicted direction after falling to the water again.

And how it should be aimed:

(notice the error - 25 deg and 30 deg labels are switched)

And a picture showing perfect torpedo drop by B5N1 - take a look at how high it seems to be. It is not as if those guys in IJN had to skip over the waves (well, Japanese had the best airplane torpedos... Before they developed them the drop alt was 10m if I remember it right). The label says "Position and stability in flight were the main factors which attributed to accuracy increase".

And finally some landing patterns for carrier landing. First the approach of standard 5-Kates formation. Note the typical positions of ships in line.

Then how final approach looks from the pilot's perspective. Picture shows also the signalization lights used to signalize the right approach slope.

And finally how IJN's 3-point landing with wire arrest should look like.

And last but not least, something little known. First picture shows the attack pattern for skip bombing in Kate. I'm not sure yet what bombs japanese used for skip bombing and if they really did it in any famous battle or anything, but I've read in few places that all the pilots practiced for this technique. The lower part shows the attack on formation of B-29s with special anti-air bomblets dispenser. The theory goes that bombers would fly in very tight formation and small bomblets spread over huge are can do some damage to them. From what I know Tenzan and Ryusei had much more luck with this tactic, due to much higher speeds...

And now please answer to our poll and back online and train it! Very Happy

(P.S. I will add translations to the drawings as soon as I find some more free time)

Stiglr - Dec 18, 2003 - 11:02 AM
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Zabatt: I love you, man!!!!! <tearful, beersoaked emotion>

Will we be able to either a)reprint this info or b) re-do it to make it "copyright OK" so we can add it to the plane-specific doc for Kate? What a coup it would be to share this info with all our players!!!!

P.S. You got any scans of the Kate level bombing station (the middle guy of the 3, right?) and perhaps doc on how the sight works???

rydog - Dec 18, 2003 - 11:02 AM
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Wow, excellent post!

BLOWHARD - Dec 18, 2003 - 11:31 AM
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Great stuff Z !!!!!!! Now who's gonna get stuck painting the cockpit for ours?
(that's a joke for the dev team Wink

)

Scorpion - Dec 18, 2003 - 04:39 PM
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Wow!!!! Nice Zabatt!

Jckentjr - Dec 18, 2003 - 07:40 PM
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I think you broke my modem! Smile

olddog - Dec 18, 2003 - 07:57 PM
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Zabatt,

Outstanding <S>

Zabatt - Dec 20, 2003 - 03:28 AM
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Stiglr wrote:

Will we be able to either a)reprint this info or b) re-do it to make it "copyright OK" so we can add it to the plane-specific doc for Kate? What a coup it would be to share this info with all our players!!!!

P.S. You got any scans of the Kate level bombing station (the middle guy of the 3, right?) and perhaps doc on how the sight works???

Stiglr, I suppose that if I translate it and we put the note that it comes from Maru Mech, then it won't be copyright violation. Especially if the docs are player-made and distributed in non-profit way. But I don't really know all the meanders of copyrights. It is surely OK to do it that way in scientific publications, but TR manual is not exactly same, is it? Wink

I have some pictures and drawings of middle station. I have also tables with all kinds of bombs they used (quite a lot of different kinds - for example there were 3 or 4 different 800 kg bombs). The Maru Mech contains also the top drop speed table and other info for all types of torpedos used by IJN aircraft. It generally ranges from 260 kt for oldest variants to 400 kt for most advanced. I will post all the info in few days - I have already scanned it but I want to translate some of basic info first.

And finally one thing I don't have is precise description of how the bombsight worked. I know it was attached on the right hand to the wall when not used. Before bombing observer/bombardier would move his seat right-wise, open small trapdoor in the floor and mount the bomb sight in the hole.
And last but not least the Maru Mech mentions, that the bomb sight used in B5N was based on the "boikofu" (pronounced without last 'u' and 'b' stands probably for 'v' or 'w'.) type bombsight by "gerutsu" company. Those are of course japanese transcriptions of german names (I guess) so I have to do some search on what it may be... unless someone here is well informed and can guess what they mean by seeing those transcriptions. Anyway that could be great help in determining how that bomb sight was operated.

Zabatt - Dec 20, 2003 - 12:07 PM
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Ok... here is the first one I have finished. All types of torpedos widely used by IJN. What we have here in TR timeframe is mod. 2 and first variants of mod. 3 I think. I will have to read further to see if they give introduction dates. In Pearl Harbor attack mod. 2 were used. Anyway, here you go:

I will add more info on Kate to this thread later.

Interesting comparisions I have found are between the number of produced B5N and B6N (Tenzan). Seems a lot of people think the Kate was mainstay of IJN attack forces through the whole war, pretty much as Zero was the main fighter, but it is in fact not true. From what I understand Kates served as frontline attack plane as long as to Marianas campaign (their last mission), but the Tenzan was deployed in summer 1943, show it's first battle in Bougainville on 5th of November 1943 and was produced in total amount of 1268 machines. Kate was produced in total amount of 1245 machines + 150 transitory variant by Mitsubishi (with ginsei engine - stronger than hikari, but weaker than sakae). I think all Mitsubishi variants were refitted with sakae and maybe they count towards the number of 1245, but I'm not sure. If not then total number of Kates would be 1395. Pretty much the same as Tenzan. Tenzan is not that much different than Kate. It is the same idea, but with 1850HP engine and top speed increased to 251kts at 4800. The weapons are carried in the same configurations and it had 2 MGs in the back - 7.7mm same as Kate and 7.9 mm deployable through the doors in the tail section which would shoot below tail - pretty much like in the US torpedo bombers. Also first variants of Tenzan had forward firing 7.7mm in the wings but they have stopped mounting them after making first 71 planes.

Can we have Tenzan too, please? Very Happy

Stiglr - Dec 20, 2003 - 01:26 PM
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*cough*...it's on the radar....*cough* Wink

Zabatt - Dec 21, 2003 - 12:30 AM
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Quote:

Bomb drop levers were on the left hand of the pilot seat (those three red levers we have in the cockpit - leftmost is master arm switch, central is torpedo/800 kg/central pylon and rightmost is right bomb pylon if 30, 60 or 250 kg bombs are loaded) so the bombardier in RL had to call the drop to the pilot, I think.

Above was a mistake. I have deleted it from original post. Levers work as described, but the device was doubled by another one at the bombardier/observer station, so bombardier could release the ordnance without calling pilot. The bombardier's one had 4 levers - maser arm, two levers for 250kg bombs and 1 lever for torpedo/800kg bomb. 6x60kg bombs had separate release trigger made of 6 small levers and one "pickle" lever to release all at once - this one was available only from bombardier's station. Usual practice was for pilot to release torpedos and for bombardier/observer to release bombs.

Monty - Dec 24, 2003 - 03:20 PM
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Quote:

*cough*...it's on the radar....*cough*

Man..that'd be greaaaatt..The tenzan was a beautiful airplane..Get that in and add the B-26, and I'd be a happy camper..every other one I want in is already otw.

Zabatt - Dec 29, 2003 - 10:22 PM
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Some more stuff to chew on:

First the bombsight. I have two pictures - the cockpit "mount" is from Tenzan I think, but it was very simillar to what they had in Kate. I have drawing of the Kate I will post later on so you can compare. I have problems with Japanese transcription of German names as I don't know german and I don't know nothing about optics, so the names of companies and models connected to german optical industry mean nothing to me - if anybody knows, please correct me.

The torpedo sight we already have:

And finally this one is very nice. I will add english labels later on. The table contains all types of bombs used by IJN. There are light practice bombs in the left upper corner. Then the real ones. Note retarded fall ones - 60kg and 250kg (at least I think those with "twisted" stabilizers are for retarded fall, but I have to check yet) and also 2 types of anti-ship AP 80 kg bomb, 800kg general purpose bomb and 500kg general purpose bomb. Also note two variants of 60kg bomb - one is called "genral purpose" and one is called "land bomb"... I think we have only the second one (judging by the model).

Stiglr - Dec 29, 2003 - 11:38 PM
Post subject:

Excellent stuff, Zabatt! Very Happy

No information on how the sight actually worked, and what the sight picture looked like? I noticed in my Ki-21 Sally Maru, there didn't seem to be a lot of info on the bomberdier station, but then again, since I can't read any of it, I wouldn't notice if it did. Heh.

Zabatt - Dec 30, 2003 - 12:33 AM
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Well, the idea is that since that sight seems to be the copy of the German one, then we can maybe find some stuff on how the German sight worked. I've never seen any picture or drawing explaining the sight operation in Japanese, but I'm pretty sure it is identical to the Gortz's sight. Some Japanese materials indicate the Type 90 sight had been developed on the basis of the German sight, which suggests that it could have been changed somehow. But other materials I have say that the sight had been an "adaptation for national production" only, which seems to suggest that they had simply copied the original sight and adapted it for production in Japanese factories.

tone - Jan 02, 2004 - 10:24 PM
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If you can find more photos of that torpedo sight, I'm sure I can reverse jigger its function. It is similar to one I have simulated.

As a guess, the arm facing to the left is moved to match relative orientation of target ship. The estimated speed of the target ship appears to be input by the sweeping arrow on the 50-0-50 face, with my guess being that one side is used if the target is head on and the other if stern on. The peeps then indicate the proper drop point. If there is a mechanism to factor out time-of-fall, I can't guess it.

To see the sight I simulated and its manual, visit

http://www.gwpda.org/naval/a186365.htm

tone

Zabatt - Jan 02, 2004 - 11:39 PM
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Tone, I think it is relatively simple device. What you don't see on this picture is that the "needle" on the right is really a see-through box. Sight on the picture is in neutral position and the box would be straight before the pilot, whit the scale in front of his eyes. Pilot would use speed and direction of the ship (given by a plane with scouting task; In case of Tenzan every one of three planes was equipped with simple radar antenna and observer trained in calculating all those data, as far as I understand... in case of Kates the planes were not specialized, but probably there were specialized crews.). I'm not sure how exactly they calculated the angle, but I suppose they used some tables or logarithmic ruler. Anyway the pilot would set the sight to the right angle, basing on the speed and turning radius of the ship, and then try to place the plane so that the ship is visible through the box, exactly perpendicularly to the line of sight through the torpedo sight, at 1000m. When the plane is lined up the torpedo would be dropped - just as the picture posted before shows.

That is how I understand it, but I may be completely wrong. The sight mount in Kate and Betty, as it is now in TR, is exactly how it should look like, so you can check it in TR. The only problem (besides torpedos not being operational yet Wink

) is that we can't adjust the sight nor move the head so that we could take a peep through the adjusted sight.

Stiglr - Jan 03, 2004 - 12:04 AM
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I didn't even know Kate HAD a sight mount where you could see it. Far as I know, there's only one player visitable station, and that's the pilot. Isn't the middle of the 3 guys in a Kate the commander/bombardier?

Zabatt - Jan 03, 2004 - 12:25 AM
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Stiglr, the torpedo sight is mounted at the pilot station - just where the gun sight is in normal fighter. Take a good look - it is there - you can see the scale, the box and the needle in the middle of the sight. Same sight is mounted on Betty and Emily.

As for the roles of the crew, there is a pilot in the front seat, observer/bombardier in the second and radio operator/navigator/gunner in the rear. The pilot would drop and aim the torpedos, and the bombardier would drop the bombs. But the pilot could drop 250kg, 500kg or 800kg bombs if it was necessary. The 60kg bombs were dropable only from the bombardier seat. He could also drop all other kinds of ordnance.

The pilot seats was boostable for landing just like in Zero. In Tenzan there was even small part of the windscreen going up to shield the pilot when he is seating with his head out of the cockpit. Also the floor and seat of the pilot was considerably higher than the rest of the crew - it is a bit unnatural to see all three heads lined up at the same level in TR. The observer/bombardier had his seat mounted on the rod - not only could he push it up quite high and look around, but he would push it almost to the floor when using the bomb sight - at this position his head would be practically invisible hidden in the fuselage. Finally gunner had small foldable seat - he would use it when operating radio or using maps but he would fold it and sit on the floor when manning the gun. I have to find some in-flight pictures where their seating positions are better visible and I would post them.

In Tenzan the observer was navigator I think. There was quite clever map table - the drawer to put the map of the target area was in the instrument panel of the observer/bombardier station. He would stretch the map on it and push it in. Over the instruments panel there was display looking pretty much like modern HUD - quite a wide reflecting glass. the map would be projected over the glass and the observer could use some dials to zoom in-out and to move the map around (I guess they were moving a prism, not the entire table, as it looks like there is no place for that.) I can post a picture later on.

Stiglr - Jan 03, 2004 - 01:51 AM
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OH. The torpedo sight. I was thinking of the LEVEL bomb sight.

MP - Jan 17, 2004 - 11:54 AM
Post subject: Goertz Sight Type 90

Hi Zabatt,
could you please check again the name/spelling (producer) of the bomb sight ? I couldnt find a clue as to a Goertz Bombsight. But it looks alot like the bombsights produced by Zeiss. Zeiss has an excellent online archive and I might contact them on further information.
Thanks. Mp

raffel - Jan 17, 2004 - 01:00 PM
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Where are ya located MP.... just outta curiosity? Smile

-r

Zabatt - Jan 17, 2004 - 01:05 PM
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Japanese text says "Gerutsu-sei,Boikofu-shiki". That means "gerutsu"-made, "boikofu" type. Now of course this is transcription of German names and it's impossible to know what it is unless you are into the subject and already know the original spellings.

Quick search on google produced an interesting link which probably is the explanation: http://www.panix.com/~zone/photo/czlens.htm

Here is relevant part:

Quote:

After Leica introduced the first 35mm camera in 1925, Zeiss's camera division knew that they were behind in small format camera development responded a year later by acquiring four camera manufacturers a year later in 1926, Ica, Contessa-Nettel, Ernemann and Goertz and merging them into Zeiss Ikon AG.

After Zeiss absorbed Goertz in 1926, the American Goertz division became an independent company (Goertz American Optical Co.) and continued to make Goertz lens, as well as innovate new lenses. Goertz American Optical Co. was renamed to Goertz Optical Co. Inc. in 1964, purchased by Kollmorgen in 1971, then in turn, Kollmorgen was purchased by Schneider in 1972.

In other words Japanese may have used what was in fact a Zeiss bomb sight, but they may have got the licence from american division as well...

Stiglr - Jan 17, 2004 - 02:34 PM
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Zabatt, what does "Maru" mean in Japanese?

I see it on the maru mechanics, but in a book i'm reading, many of the ships are named "(whatever) Maru". Can you help me out here?

Auton - Jan 17, 2004 - 03:00 PM
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A quick google on 'goertz bomnbsight' yielded a page from the finnish VirtuaLenteLaiviu (sic?) who have a 'view through Goertz bombsight' image on their page. I thought that might be interesting. Smile

This is a link to the page: http://www.virtualpilots.fi/feature/photoreports/hallinportti2002/ - the sight is about halfway down.

Zabatt - Jan 18, 2004 - 12:16 AM
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Auton, that must be it! It looks very similar!

BTW the bombsight below, the one from Blenheim bombers looks very much like bombsight used in older Japanese bombers. Worth taking for Stigler's China mod maybe. Anyway it seems we've got that Goertz now.

Why hadn't I found it? I've done several searches for Goertz bombsight in google with different spellings... Very Happy

Silo - Jan 18, 2004 - 03:07 AM
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Zabatt, I notice the D4Y has a similar looking device, however in my english diagram, it is labeled "driftmeter" or some such thing. It looks a lot like the "bombsight" in the B5N and B6N. What's the difference?

MP - Jan 18, 2004 - 10:41 AM
Post subject: Good hit !

Hey, yes thats it !
I was about to talk to Zeiss about it, as I had thought it might have been a Goerz Optic Vienna product. That company was as well absorbed by Zeiss and the other link was to that E&G comp. .
Wonder why I missed the other site tho. Nice job all !

tone - Jan 18, 2004 - 01:05 PM
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Quote:

Japanese text says "Gerutsu-sei,Boikofu-shiki". That means "gerutsu"-made, "boikofu" type.

Hmmm.. My sources indicate this means "Garbage in, garbage out". Smile

tone

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