301 replies to this topic

[J311yfish]

*crickets*

[J311yfish]

Japanese Aircraft Torpedoes -- and the prospect of torpedo bomber aircraft for WoWP

 

Source:  Target Report - Japanese Torpedoes and Tubes, Article 2 - Aircraft Torpedoes (03/07/1946), p.8

  "Japanese aircraft were not designed to meet requirements of specific airplanes but instead, the aircraft were modified to suit the torpedo."

 

Introduction
Much attention has been paid in previous posts to the discussion of aircraft and associated engine and armament development, but no consideration has been given to the development of aircraft torpedoes.  This is unfortunate because, as identified, an entire line of naval aircraft is devoted to their use.  This post will provide a summary of torpedo development with emphasis on technical limitations in order to help characterize or imagine the function of Japanese torpedo bombers in relation to other aircraft in game.

 

Torpedo performance - summary

Year	Torpedo	Total Weight	Explosive Weight	Max Launch Velocity*	Speed	Range
1931 (year 2591)	Type 91 Mod 1	784 kg	150 kg	482 km/h	77.8 km/h	2012 m
1940-1941	Type 91 Mod 2	835 kg	204 kg	482 km/h	77.8 km/h	2012 m
1942	Type 91 Mod 3	849 kg	240 kg	482 km/h	77.8 km/h	2012 m
1943	Type 91 Mod 3 Improved	857 kg	240 kg	556 km/h	77.8 km/h	2012 m
1944	Type 91 Mod 3 Strong	857 kg	240 kg	648 km/h	77.8 km/h	1500 m
1944	Type 91 Mod 4 Strong	921 kg	308 kg	648 km/h	75.9 km/h	1500 m
	Type 91 Mod 7 Strong	1052 kg	420 kg	648 km/h	77.8 km/h	1500 m
1944 - 04/1945	Type 4, warhead Mk 2 Type 4, warhead Mk 4	984 kg 1105 kg	304 kg 417 kg	741 km/h 741 km/h	75.9 km/h	1500 m

* the maximum speed at which the torpedo can hit the water without breaking up.

 

The typical torpedo drop is performed at 330 feet (100.6 m) and 180 knots (333.4 km/h) to achieve entry angle of 17-20 degrees.

-- The maximum drop altitude is about 1000 feet (305 m).
-- The minimum drop altitude is about 50 feet (15.2 m).

... At this speed and altitude a torpedo bomber in the current game would be very vulnerable, unless that vulnerability was mitigated by:

    1) air support -- reliable supporting fire, such as that provided by bots, or related objectives provided for human players
    2) stealth mechanics -- reduction in visibility due to camouflage, night time, radar obfuscation, etc.

 

The H.M.S. Prince of Wales was sunk by 7 Type 91's (Mod 1 and 4), and the H.M.S. Repulse was sunk by 17 of the same.

... this just means that multiple torpedo bombers are necessary to sink a battleship, further emphasizing the need for air superiority or support.

 

There is one speed for Japanese torpedoes (42 knots), which translates to 77.8 km/h:
-- At that speed a maximum range of 2012 meters is reached in 1.54 minutes (92.4 sec).
-- At that speed a maximum range of 1500 meters is reached in 1.15 minutes (69 sec).

... This means that if you succeed at launching a torpedo moments before you die in-game, you'll have to wait at most 92 seconds before getting the results; this in turn suggests that some form of camera tracking of the torpedo (such as after death) might be favorable.

 

There is one fin configuration for Japanese torpedoes (4-fins), and it achieves proper depth after 348 meters of travel:
-- If proper depth is desirable in all cases, then the minimum range can be considered to be equal to 348 meters.

-- At the standard speed this means 0.27 minutes (16.2 sec) to achieve proper depth.
... Given that there is a 1664 meter "window of opportunity" (2012 m - 348 m) for torpedo deployment , and given the previous conditions for deployment, this suggests that a helpful HUD element would be one that accounts for range, altitude, speed; or perhaps a voiceover that advises you to drop altitude, drop speed, etc.  A tutorial might also be appropriate.

 

Torpedo bombers - summary

First Flight	Production	Aircraft	Engine	Speed	Armament	Torpedos/Bombs
1923		B1M
12/1929		B2M
1933	1933-1936	B3Y	Hiro Type 91	219 km/h	1x7.7mm fixed forward 1x7.7mm flexible rear	1x800kg torpedo or 1x500kg bomb or  2x250kg or 6x30kg
08/1934		B4M1	Mitsubishi 8-Shi		3x7.7mm	up to 800kg
late 1935	1937-1938	B4Y1	Hiro Type 91 Kotobuki 3 Hikari 2	278 km/h	1x7.7mm Type 92 (rear)	1x800kg torpedo or up to 500kg of bombs
1936	1937	B4N1	Kotobuki 3 Hikari 1
1937	1937	B5M1	Kinsei 43	380 km/h @ 2200m	1x7.7mm	1x800kg torpedo or up to 800kg of bombs
01/1937   12/1939	____-____   1942-1943	B5N1   B5N2	Hikari 2 Hikari 3 Sakae 11 Sakae 21	369 km/h @ 2000m 378 km/h @ 3600m	1x7.7mm Type 92 (rear)	1x800kg torpedo or up to 800kg of bombs
spring 1941	02/1943-08/1945 06/1943-08/1945	B6N1 Model 11 B6N2 Model 12 B6N2a Model 12a B6N3	Nk7A Mamoru 11 MK4T Kasei 25   MK4T-C Kasei 25c	469 km/h @ 4800m 482 km/h @ 4900m	1x7.7mm Type 97 (VT) and 1x7.7mm Type 97 (rear) or 1x7.7mm Type 97 (VT) and 1x13mm Type 2 (rear)	1x800kg torpedo or up to 800kg of bombs
05/1942+	05/1942-02/1944 04/1944-08/1945 Projected	B7A1 B7A2 B7A3	NK9B Homare 11 NK9C Homare 12 NK9H-S Homare 23 MK9A	567 km/h @ 6550m	VII  2x20mm Type 99 Model 2 (W) and 1x7.92 Type 1 rear (early) or 1x13mm Type 2 rear (late)	up to 800kg
08/1943+	1943-1945	P1Y1   P1Y2 P1Y3 Model 33 P1Y4 Model 12 P1Y5 Model 14 P1Y6 Model 17	NK9B Homare 11 NK9C Homare 12 MK4T-A Kasei 25a NK9H Homare 21 Homare 23 MK9A MK4T-C Kasei 25c	547 km/h @ 5900m   523 km/h @ 5400m 547 km/h @ 6100m	VII  1x20mm Type 99 (N) + VII  1x20mm Type 99 (rear)   or tail gun variation, or night fighter oblique configuration	1x800kg torpedo or up to 1000kg of bombs   up to 1600kg of bombs or MXY7 Ohka Model 21 or MXY7 Ohka Model 22

 

Combined Conclusions

-- Type 91 Mod 1 was used up to and including the Nakajima B5N.

-- The transition to Type 91 Mod 2 probably occurred with the B5N1.

-- It can be reasonably assumed that the transition from Type 91 Mod 3 Improved to Mod 3 Strong occurs with the Aichi B7A2 because the maximum speed of the B7A2 (567 km/h in level flight) exceeds the capability of the Mod 3 Improved (which experiences loss of durability if water entry >556 km/h).  The B7A2 was planned for a new generation of carriers but were ultimately allotted to land-based units.  The B7A3 was projected but the torpedo bomber function was ultimately replaced by more capable land-based units such as the twin-engine Ki-67 and P1Y.  The Ki-67 could be included above (IJA counterpart to IJN's P1Y) because it served as a torpedo bomber for both IJA and IJN.

-- The Mod 3 Strong, Mod 4 Strong, and Mod 7 Strong developments (allowing greater deployment velocity) make sense given that Ki-67 and P1Y lack dive brakes (unlike the previous B-series of aircraft).

-- The Type 4 was essentially a Type 91 modified to ease production and does not appear to correlate to any particular aircraft.

 

Lack of air superiority necessitated an improvement to standoff distance and therefore it can be argued that 'torpedo' development continued sequentially by the way of glide bombs and the Ohka/Baika human-guided jet-powered bombs.  The Army instead developed radio-guided bombs (I-Go), trialed on Ki-48 but meant ultimately for the Ki-102b.

 

Ohka/Baika performance - summary

[chart]

work in progress

 

 

Torpedos in WoWS:

-- speed has been reduced from 42 knots to 35 knots (-16.7%).

-- range has been increased from 2012 meters to 3400 meters (+69.0%)

 

 

Edited by J311yfish, 25 May 2016 - 07:02 PM.

[J311yfish]

J311yfish, on 31 October 2015 - 04:39 PM, said:

Fighter, Torpedo Bomber, Dive Bomber progression for carrier-borne aircraft in World of Warships:

 

Tier	Carrier	Fighter	Torpedo Bomber	Dive Bomber
IV	Hosho	Mitsubishi 1MF Nakajima A2N2	Mitsubishi 1MT Mitsubishi B1M	(none)
V​	Zuiho	Nakajima A2N2 Nakajima A4N	Mitsubishi B1M Nakajima B3N	Aichi D1A1 Aichi D1A2
VI	Ryujo	Nakajima A4N Mitsubishi A5M2	Nakajima B3N Yokosuka B4Y	Aichi D1A2 Aichi D3A1
VII	Hiryu	Mitsubishi A5M2 Mitsubishi A6M2	Yokosuka B4Y Nakajima B5N2	Aichi D3A1 Aichi D3A2
VIII	Shokaku	Mitsubishi A6M2 Mitsubishi A7M1	Nakajima B5N2 Nakajima B6N	Aichi D3A2 Yokosuka D4Y2
IX	Taiho	Kawanishi N1K5-A Kyushu J7W1	Nakajima B6N​ Aichi B7A	Yokosuka D4Y2 Yokosuka D4Y3
X	Hakuryu	Mitsubishi A8M Nakajima J8N1 (Kikka)	Aichi B7A Yokosuka R2Y1-B	Yokosuka D4Y3 Nakajima J5N1

 

 

 

Fighter, Torpedo Bomber, Dive Bomber progression for carrier-borne aircraft in World of Warships as of 05/25/16.  These changes were probably made months ago (~02/2016):

 

Tier	Carrier	Fighter	Torpedo Bomber	Dive Bomber
IV	Hosho (1922)	Nakajima A4N (1935-1940) Mitsubishi A5M4 (1939-1942)	Mitsubishi B1M Yokosuka B4Y (1937-1938)	(none)
V​	Zuiho (1937)	Mitsubishi A5M4 (1939-1942) Mitsubishi A6M2 (12/1939-1943)	Yokosuka B4Y (1937-1938) Nakajima B5N2 (12/1939-1943)	Aichi D1A2 (1936-1940)
VI	Ryujo (1933)	Mitsubishi A5M4 (1939-1942) Mitsubishi A6M2 (12/1939-1943)	Nakajima B5N2 (12/1939-1943)	Aichi D1A2 (1936-1940) Aichi D3A1 (1937-08/1942)
VII	Hiryu (1939)	Mitsubishi A6M2 (12/1939-1943) Mitsubishi A6M5c (1944)	Nakajima B5N2 (12/1939-1943)	Aichi D3A1 (1937-08/1942) Aichi D3A2 (08/1942-08/1945)
VIII	Shokaku (1941)	Mitsubishi A6M5c (1944) Kawanishi N1K5-A (Imagined)	Nakajima B5N2 (1942-1943) Nakajima B6N (02/1943-08/1945)	Aichi D3A2 (08/1942-08/1945) Yokosuka D4Y2 (04/1944-08/1944)
IX	Taiho (1944)	Kawanishi N1K5-A (Imagined) Mitsubishi A7M1 (05/1944+)	Nakajima B6N​ (02/1943-08/1945) Aichi B7A2 (04/1944-08/1945)	Yokosuka D4Y2 (04/1944-08/1944) Aichi B7A2 (04/1944-08/1945)
X	Hakuryu (____)	Mitsubishi A7M1 (05/1944+) Mitsubishi A8M (Projected/Imagined)	Aichi B7A2 (04/1944-08/1945) Nakajima C6N1-B (Projected)	Aichi B7A2 (04/1944-08/1945) Wakusei (Projected/Imagined)

 

It looks reasonable overall, but here are the problems that I see:

 

Problem 1: N1K5-A to A7M1 sequence is not correct.  

N1K5-A should instead be called N1K4-A, if Francillon's notes are complete on the matter, and both of those variants would be more powerful in engine and armament than A7M1.  A7M1 development was protracted and when it did come out it was a disappointment with Homare 22.  N1K4-J/N1K4-A used Homare 23, and both N1K5-J and A7M2 used MK9A.  N1K4-J/N1K4-A and N1K5-J used 2x13.2mm and 4x20mm, whereas A7M1 used 2x13.2 and 2x20mm only, or 4x20mm only.  So anyway a better choice would be:

VIII	Shokaku (1941)	Mitsubishi A6M5 (08/1943+) Mitsubishi A7M2 (after 05/1944)
IX	Taiho (1944)	Mitsubishi A7M2 (after 05/1944) Kawanishi N1K4-A (spring 1945+)
X	Hakuryu (Projected/Imagined)	Kawanishi N1K4-A (spring 1945+) Mitsubishi A8M (Projected/Imagined)

 

Problem 2: Tier X inconsistency

-- Mitsubishi A8M, Nakajima C6N1-B, and Aichi B8A Mokusei have been substantiated by Francillon, Dyer, or both, though not in any great detail.  "Wakusei" on the other hand uses the internet as a secondary source, and the primary source ("recent Maru magazine") has not been verified.

Edited by J311yfish, 27 May 2016 - 10:58 PM.

[pyantoryng]

The changes had been done for quite some time now...it got rid of the biplane tier that people complain about so much...in comparison, the US gets straight to F4F at tier 5 (after the F3F in tier 4), then to F6F, then F4U, and finally stops at F8F. This also rid the carriers of jet planes (F2H Banshee/Kikka, and even the J7W1 Shinden, which was planned to be converted into jet).

It's not like WoWS needs to care about that kind of detail...you can just slap numbers on planes and they'll work. It's not like having machine guns only is handicapping in firepower for the US nor having cannons offering firepower advantage to the Japanese. Besides, people does not really go there for planes, anyway.

 

I'll admit, though, I had been wondering what the heck is the Wakusei bomber for quite a while...not much of a problem for devs who are okay with float MUSTANGS, I guess...

Edited by pyantoryng, 26 May 2016 - 06:50 PM.

[J311yfish]

Addendum

 

This post is reserved for minor updates and edits such as information that cannot be added to the main data due to forum constraints (Ex: size/format).  The goal will be of course to limit the size of the addendum to only extremely relevant information that might not otherwise get to be included in the original/appropriate place.

 

---

 

Nakajima B6N Tenzan -- some of the information for this aircraft is not entirely correct, and could be far more comprehensive, especially as it relates to development leading to Nakajima Kikka.  The definitive source in English is not Francillon but rather Wieliczko.  Due to forum constraints on post sizes, and due to time constraints, I am going to leave this information as it is, and will only update it if it becomes apparent that IJN torpedo bombers are to be included in game.

Edited by J311yfish, 08 July 2016 - 06:09 PM.

[J311yfish]

A post here on EU forum mentions a certain 3D modeling site that claims to leak the IJA line of aircraft:

 

I	Nakajima Type 91
II	​Kawasaki Ki-10
III	​Nakajima Ki-27
IV	​Nakajima Ki-43-I
V	​Nakajima Ki-43-II
VI	​Kawasaki Ki-61
VII	​Nakajima Ki-84
VIII	​Tachikawa Ki-94-II
IX	​Tachikawa Ki-162
X	Tachikawa Ki-162-3

 

If true, then it is interesting to note that they chose the fictional Tachikawa Ki-162 over the actual Nakajima Kikka, Kugisho R2Y2, Nakajima Ki-201, and Rikugun Ki-200/202, presumably because it helps to maintain a consistent theme.  Also interesting that Japan gets Ki-162 before Germany gets Heinkel He 162.

 

If true, then it cannibalizes identified progression, but on the bright side it should make for interesting premiums, such as:

 

• Kawasaki Ki-28
• Kawasaki Ki-100
• Nakajima Ki-11
• Nakajima Ki-84 variants
• Nakajima Ki-87

[J311yfish]

IJA aircraft baseline specs/models leaked via Russian youtube video.  Added comparison to max-spec aircraft of same tier.

 

II - Kawasaki Ki-10

 

III - Nakajima Ki-27

 

IV - Nakajima Ki-43-I

 

V - Nakajima Ki-43-II

 

 

VI - Kawasaki Ki-61

 

VII - Nakajima Ki-84

 

VIII - Tachikawa Ki-94-II

 

IX - Tachikawa Ki-162

 

X - Tachikawa Ki-162-3

 

Edited by J311yfish, 17 July 2016 - 10:55 PM.

[outwardpanicjoe]

J311yfish, on 03 July 2016 - 03:13 PM, said:

IJA aircraft baseline specs/models leaked via Russian youtube video.  Added comparison to max-spec aircraft of same tier.

 

II - Kawasaki Ki-10

 

III - Nakajima Ki-27

 

IV - Nakajima Ki-43-I

 

V - Nakajima Ki-43-II

 

 

VI - Kawasaki Ki-61

 

VII - Nakajima Ki-84

 

VIII - Tachikawa Ki-94-II

 

IX - Tachikawa Ki-162

 

X - Tachikawa Ki-162-3

 

 

 

 

I was kinda hoping to see if they were going to put any japanese heavies in.

[J311yfish]

Tachikawa Ki-162 makes an appearance on the July 2016 wallpaper/calendar (off to the right):

spotted by Pentakon on EU forum, image presumably modified by Pentakon.

Edited by J311yfish, 06 July 2016 - 01:26 PM.

[J311yfish]

If the information made public before the official release is true, then here is quick overview of all Japanese aircraft in-game, in the context of other developments:

 

After the IJA line is released, and modules are made public, it should be easier to confirm placement of aircraft at all tiers.

Edited by J311yfish, 06 July 2016 - 01:46 PM.

[outwardpanicjoe]

J311yfish, on 06 July 2016 - 01:44 PM, said:

If the information made public before the official release is true, then here is quick overview of all Japanese aircraft in-game, in the context of other developments:

 

After the IJA line is released, and modules are made public, it should be easier to confirm placement of aircraft at all tiers.

 

wait is this the planned tech tree for japan?

[J311yfish]

outwardpanicjoe, on 06 July 2016 - 05:36 PM, said:

wait is this the planned tech tree for japan?

 

​Blue = current tech tree = IJN = Imperial Japanese Navy

Yellow = new line of aircraft coming this month = IJA = Imperial Japanese Army

 

Premiums are labeled as such

 

All else is speculative in nature based on the works of Francillon, Dyer, Mikesh, Bueschel, and others.

Edited by J311yfish, 07 July 2016 - 12:58 AM.

[pyantoryng]

Ki-94-II shows Ki-84 pic...

[J311yfish]

fixed.  Forum won't let me link the youtube video, but you should be able to find it by searching for:

Новые японские истребители в World of Warplanes

[carson_643]

Thanks for the info!

[Caecias]

J311yfish, on 06 July 2016 - 07:45 PM, said:

 

​Blue = current tech tree = IJN = Imperial Japanese Navy

Yellow = new line of aircraft coming this month = IJA = Imperial Japanese Army

 

Premiums are labeled as such

 

All else is speculative in nature based on the works of Francillon, Dyer, Mikesh, Bueschel, and others.

 

All I have to say is wow - the amount of information and research here in this thread is awesome.

 

Thanks so much for your efforts and the others that contributed!!  I can wait!  I think I am turning Japanese, turning Japanese - I really think so!

 

 

Edited by Caecias, 07 July 2016 - 06:15 PM.

[Fog_Heavy_Cruiser_Chokai]

J311yfish, on 30 June 2016 - 10:10 PM, said:

A post here on EU forum mentions a certain 3D modeling site that claims to leak the IJA line of aircraft:

 

I	Nakajima Type 91
II	​Kawasaki Ki-10
III	​Nakajima Ki-27
IV	​Nakajima Ki-43-I
V	​Nakajima Ki-43-II
VI	​Kawasaki Ki-61
VII	​Nakajima Ki-84
VIII	​Tachikawa Ki-94-II
IX	​Tachikawa Ki-162
X	Tachikawa Ki-162-3

 

If true, then it is interesting to note that they chose the fictional Tachikawa Ki-162 over the actual Nakajima Kikka, Kugisho R2Y2, Nakajima Ki-201, and Rikugun Ki-200/202, presumably because it helps to maintain a consistent theme.  Also interesting that Japan gets Ki-162 before Germany gets Heinkel He 162.

 

If true, then it cannibalizes identified progression, but on the bright side it should make for interesting premiums, such as:

 

• Kawasaki Ki-28
• Kawasaki Ki-100
• Nakajima Ki-11
• Nakajima Ki-84 variants
• Nakajima Ki-87

Those are some beautiful planes, had to look some up. Happy to finally see the Oscar in the tech tree.

[J311yfish]

module reveal on youtube

 

Some highlights:

-- Ki-10 ...

-- Ki-27 engine progression mirrors A5M (cost savings)

-- Ki-43-III is included in the Ki-43-II progression

-- Ki-61 progression does not include the Ki-100 radial-engine adaptation.  Also, a 4x20mm variant (Ki-61-IIb) has not been added --> possible premium.

-- Ki-84 gets a 30mm option .. and everything up from this point gets 30mm's

-- Ki-94-II ...

-- Ki-162 engine progression mirrors J7W2 (cost savings)

Edited by J311yfish, 17 July 2016 - 01:37 PM.

[pyantoryng]

Ki-43 I can be exclusively armed with cannons by tier 4...I don't recall any tech tree planes at tier 4 being armed exclusively with cannons up to this point.

 

Ho 155 II seems to be carrying forward from Ki-84 to Ki-94, seeing that it's the exact same model (Ho 155-II [K])

 

Calibers are often not unified in "fully upgraded" config (mg+20mm and 20mm+30mm). And of course, gotta get those Nakajima/Kawasaki motors and army guns all over again. The Ho-5 already exist in the Ki-88, and I say that it is an okay gun, might be better than the Type 99-2 of the Navy...

 

Top level gun is available already at tier 9 not unlike the existing IJN line...uses the same jets as J7W2. The whole line never gets more than two 30mms.

 

Ho 155-I = basic model, too big to fit into wing mounts, available as cowling mount for tier 9 stock.

Ho 155-II = Ho 155-I modified to fit into wing mounts. These basic Ho 155 apparently performs comparably to the Navy's Type 5 (450rpm@700 m/s velocity; not that muzzle velocity exists in WoWP now)

Ho 155-III...could it be like the top of the line IJN 30mm that used to fire at 600rpm? A logical continuation of this line of guns' development? Doesnt seem to have any info available otherwise...

Edited by pyantoryng, 12 July 2016 - 11:39 AM.

[carson_643]

I'm excited by this. I just recently discovered the game and I'm glad they're making the effort to put this into play. Thanks again for passing the information along.