battleship Yamato-class battleship, Yamato (1945): King of the Monsters

[aizenns 3,590]

軍艦大和

Warship Yamato

Yamato, at the Battle of Cape Bonomisaki (April 1945)

 

Classification

Category: 軍艦 / Warship

Sub Category: 戦艦 / Battleship

Class: 大和型 / Yamato class

Design number: A140-F6

Temporary name: 第一号艦 / No.1 Ship

 

Rough History

Yamato(大和) is a name-ship of Yamato class Battleship that completed in 1941. Name was taken from old name of Nara-pref, and it is one of the another name of Japan. Lots of Japanese warships were using another name of Japan (Fuso, Akitsushima, Shikishima, Yashima, Mizuho Shinshu-Maru etc.), but the Yamato is the most famous another name.

English Wikipedia translate it to "Great Harmony", but actually there is no such meaning. There are various theories about origin of the word "Yamato", but almost all theories says the kanji "大和" (yamato) was used only pronounce of kanji without regard to the semantically. (read more: https://en.wikipedia.org/wiki/Ateji)

 

Project of New Capital Ship was started since 1934. In that time, Japanese newer battleship is only Nagato class, and other battleships are very old so they needed to replace them. Also, London Naval Treaty limited Japanese battleship than UK and US. To overcome this inferiority, Japanese Navy decided to build battleship that larger than Panamax size with superior 18-inch cannons. At first, they re-start the project of 20-inch and 18-inch guns. Originally, this project was started for next-gen battleship of Eight-Eight Fleet. They prohibited to call it 18-inch for secrecy and they call it "Type 91" alternately. Afterwards, in the order to experimental production of 18-inch gun in July 1934, IJN named it "Type 94 40 cm naval gun".

Around this time, Japan was isolated by the militarism policies. Because of it, in July 1934, Prime Minister Okada decided to discard naval treaty. Because of it, in October, IJN General Staff ordered new battleship with 18-inch guns to IJN Technical Department.

his project get design number A140, and 22 design were considerate. Finally, design A140-F5 was submitted to the Imperial Diet. To camouflage real-size of battleship, they also submitted fake destroyers and submarines. Specification of Design A140-F5 was bellow.

• Trial displacement: 65,200 t
• Waterline length: 253 m
• Max width: 38.9 m
• Depth: 18.667 m
• Draft; 10.4 m
• Main gun: 3x Type 94 40 cm triple
• Secondary gun: 4x 15.5 cm triple
• High angle gun: 6x 12.7 cm twin
• Machine gun: 12x 25 mm twin & 4x 13 mm quadruple
• Aircraft: 6
• Speed: 27 kt
• Cruise range: 16 kt/ 7,200 mile
• Power: 135,000 SHP
• Main engine: 2x Turbine (75,000 SHP) & 2x Diesel (60,000 HP)
• Protection: prevent 18 inch gun at 20,000~30,000 m

Design A140-F5 planned to equip diesel engine. It was the first attempt for them so they did not have enough experience. During the experiment, prototype of diesel engine had fatal problems and they decide to cancel the A140-F5. Because of it, they start to make the new plan A140-F6. It had conventional steam turbines and this plan become a Yamato class.

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The No.1 Ship, under fitting-out works (September 20, 1941)

The "No.1 Ship" was ordered in August 21, 1937. It laid down in November 4, 1937 and construction started. In that time, around 20 years have passed since they build last battleship so it was very difficult project. However, construction was progressed properly and 6 months shorter than planned.

No.1 ship was launched in August 8, 1940 and named Yamato. Since then construction was progressed, but in October 1939 they forced to move up the deadline. Further more in March 1941, deadline was moved up again. At this point, scheduled completion date was end of January 1942 but Ministry of Navy moved up the deadline again in July. By this order, construction was significantly accelerated and completed in December 16, 1941. She was deployed at 1st Squadron of Combined Fleet with Nagato and Mutsu.

In February 12, 1942, flagship was changed from Nagato to Yamato, and in March 29 she participated the Battle of Midway. In this battle, she never fought and returned to the port. Afterwards Japanese Navy and US Navy fought a fierce battle around Southern Pacific, but she did not fought and did only modification to add AA equipment.

In December 1943, she was joined Bo-Go operation. During this operation, Yamato transported IJA 1st Independent Mixed Regiment to New Ireland island. During this operation, USS Skate (SS-305) discover her and attacked with Mk.14 torpedo. In this attack, no crew injured but surprisingly 3rd main gun magazine was disabled by flooding caused by only one torpedo. She entered Truck island, but factory ship Akashi could not repair this damage so she need to return to Kure naval base. She docked and get restoration work and modifiaction. In this modification, they removed two 15.5 cm turret on midships and install additional AA guns.

After modification, she moved to southern seas and did training etc. After a while, in May 28, 1944, the Allied forces start to landing operation to Biak island. To intercept it, Yamato, Musashi and 2nd Torpedo Squadrons dispatched (Operation Kon). But just after the Battle of the Philippine Sea (JP: Battle of offshore of Mariana Islands). Japanese navy cancelled the Operation Kon and this force joined with 3rd Air Squadron for escort. During this battle, Yamato fired main gun AA shells but there weren't noticeable results and one of the escort target, aircraft carrier Hiyo was sunk.

Next large battle for Yamato is Battle of Leyte Gulf (JP: Battle of Philippines Sea). It was the last naval battle between battleship and battleship, but Yamato could not fought against US battleships. She assigned with Kurita fleet to attack enemy landing forces but she fought against only Taffy 3 (force of escort carriers and escort destroyers for air support). It was the first opportunity for Yamato that fire main gun to enemy ship, but 46 cm gun could not get noticeable results.

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Yamato, at Battle of Layte Gulf

 

After overwhelming defeat of Japan, US forces start to invade Okinawa island. To intercept it, Japanese Navy and Army started desperate last counterattack, "Operation Kikusui". This is the largest suicide operation, and Yamato joined part of Operation Kikusui 1, Operation Ten-go. Now this operation is known Maritime Special Attack.

She leaded the 2nd Fleet (Yamato, Yahagi, Fuyutsuki, Suzutsuki, Isokaze, Hamakaze, Yukikaze, Asashimo, Hatsushimo, Kasumi) and dispatched to Okinawa in April 7, 1945. They spends slightly left fuel oils for this operation, but they couldn't do anything. Hundreds of aircraft from 11 aircraft carriers flocked to the last fleet of IJN and destroyed almost all. Withstood more than two hours but finally she sunk. About 3,300 crews were on boarded on Yamato but only 276 crews was survived. Wreckage of Yamato was scatted on sea bottom of East China Sea. Now, this battle is called Battle of Cape Bonomisaki.

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The last of Yamato (April 7, 1945)

 

Afterwards, in 2199, the Gamilons Empire start to invade the Earth. Humankinds formed the Earth Defense Force but inferiority was apparent. The sea evaporates and radioactive contamination progresses so mankind will be destruct within one year. At this time, one message comes from outer-space. That message said that come to planet Iskandar to take Radioactivity removal device, and they attached blueprint of warp engine. This engine was mounted on Space Battleship Yamato (they camouflage the building of new spacecraft by the wreckage of Yamato), and she dispatched to outer space to save the earth. End of the strict battles against the Gamilons Empire, they succeed the mission and revived the earth. Since then she has been active in various battles.

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Design

Protection

For protection, Yamato class had excellent armor. Generally able to prevent 46 cm gun 

Fig 1 ~4 are based upon drawing written after war by the designers of Yamato.

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Fig 1, profile of Yamato

• VH, VC: Hardened (Cemented) Armor
• MNC, CNC and NVNC: Rolled Homogeneous Armor
• DS: Structure steel for splinter protection

 

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Fig 2, frame 96 (Around 2nd main turret)

 

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Fig 3, frame 135 (Around boiler room)

 

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Fig 4, frame 176 (Around 3rd main turret)

 

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Center sectional view of Yamato, from "Naval Shipbuilding Technology Overview"

注排水区画: Water injection/ draining compartment (FL.C.?), a section for damage control.

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• Engine room
  • Main belt armor (waterline): 410 mm VH
  • Main belt armor (underwater): 200-45 mm NVNC
  • Deck armor (horizontal): 200 mm MNC
  • Deck armor (inclined): 230 mm MNC
  • Bulkhead (bottom):  100-50 mm CNC
  • Side splinter protection: 16 mm DS
  • Deck splinter protection: 9 mm DS
• Ammo stowage
  • Main belt armor (waterline): 410 mm VH
  • Main belt armor (underwater): 200-75 mm NVNC
  • Magazine bottom armor: 80-50 CNC
  • Deck armor (horizontal): 200 mm MNC
  • Deck armor (inclined): 230 mm MNC
  • Side splinter protection: 16 mm DS
• Main gun
  • Barbette: upper 550 mm VH, lower 490 mm VH
  • Turret front: 660 mm VH
  • Turret side: 250 mm VH
  • Turret back: 190 mm NVNC
  • Turret roof: 270 mm VH
• Secondary gun
  • Barbette: 25 mm DS + 50 mm CNC
  • Turret: 25 mm HT
• Main steering room
  • Roof: 200 mm MNC
  • Side: 300-360 mm VC
  • Bottom: 25 mm DS
• Auxiliary steering room
  • Roof: 200 mm MNC
  • Side: 250 mm VC - 300 mm VH
  • Bottom: 20 mm DS
• Funnel
  • Uptake: 380 mm MNC ("honeycomb" armor)
  • Some part of funnel: 50 mm CNC
• Watertight compartment
  • Number of watertight compartment: 1,147

 

Yamato designed to prevent below:

• 2 t bomb, dropped from lower than 2,200 m
• 1.5 t bomb, dropped from lower than 2,600 m
• 1 t bomb, dropped from lower than 3,400 m
• 800 kg bomb, dropped from lower than 3,900 m
• 46 cm AP shell, fired from more distant than 20,000 m - 30,000 m

 

Weapon

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45 caliber Type 94 40 cm naval gun / 四十五口径九四式四十糎砲

The most symbolic weapon of Yamato. The world's largest naval gun actually mounted on the vessel. It was separate charge type and there aren't "first-stage ammo stowage".

• Rate of fire: 1.5-2 per minute
• Elevation: -5° / +45°
• Elevation rate: 8°/s
• Train: about 150°
• Train rate: 2°/s
• Loading angle: +3°
• Shell stowage: 120 per shell room + 180 per shell feeding room, 100 shells per each barrel
• Ammunition
  • Type 91 AP shell
    • Type: APC
    • Projectile weight: 1,460 kg
    • Explosives: 33.85 kg
    • Velocity: 780 m/s
  • Type 1 AP shell
    • Type: APC
    • Projectile weight: N/A
    • Explosives: 33.85 kg
    • Velocity: 780 m/s
  • Type 0 Common shell
    • Type: HE
    • Projectile weight: 1,360 kg
    • Explosives: 61.7 kg
    • Velocity: 805 m/s
  • Type 3 Common shell
    • Type: Incendiary Shrapnel
    • Projectile weight: 1,360 kg
    • Incendiary tubes: 25 mm type (incendiary 23 g), 1056
    • Stays: 504
    • Velocity: 805 m/s

http://www.navweaps.com/Weapons/WNJAP_18-45_t94.php

http://navgunschl.sakura.ne.jp/koudou/ijn/buki/ammo/proj/3shiki.html

▼Original drawings▼

Spoiler

Side view

Spoiler

Front view

Spoiler

Top view

Spoiler

Layout of shell room (lower image)

 

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60 caliber 3rd Year Type 15.5 cm naval gun / 六十口径三年式十五糎五砲

Main gun for Mogami class and Oyodo class light cruisers. Barrels of secondary gun of Yamato was taken from Mogami class. Turret for Yamato is NOT taken from Mogami class.

• Rate of fire: 5-6 per minute
• Elevation: -7° / +55° (some people says 75°)
• Elevation rate: 10°/s
• Train rate: 5-6°/s
• Loading angle: +7°
• Ammunition
  • Type 91 AP shell
    • Type: APC
    • Projectile weight: 55.87 kg
    • Explosives: 1.15 kg
    • Velocity: 920 m/s
  • Type 0 Common shell
    • Type: HE
    • Projectile weight: 55.87 kg
    • Explosives: 3.1 kg
    • Velocity: 920 m/s

http://www.navweaps.com/Weapons/WNJAP_61-60_3ns.php

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40 caliber Type 89 12.7 cm high angle gun

Standard Japanese naval AA gun during WW2. Yamato mount several types of shield.

• Rate of fire: 14 rounds per minute initially, 8 rounds per minute sustained
• Elevation: -7° / +90°
• Elevation rate: 6-7°/s
• Train rate: 6-7°/s
• Loading angle: any
• Shell stowage: 300 rounds per each gun
• Ammunition
  • Type 0 Common shell
    • Type: HE
    • Projectile weight: 23.45 kg
    • Explosives: 1.88 kg Shimose
    • Velocity: 700-725 m/s
  • Type 3 Common shell
    • Type: Incendiary Shrapnel
    • Projectile weight: 23.45 kg
    • Incendiary tubes: 20 mm Otsu type (Incendiary 10g), 37
    • Stays: 16
    • Velocity: 720 m/s

http://www.navweaps.com/Weapons/WNJAP_5-40_t89.php

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Type 96 25 mm Machine Gun / 九六式二十五粍機銃

Japanese most famous naval AA gun machine gun during WW2.

http://navgunschl.sakura.ne.jp/koudou/ijn/buki/ammo/proj/25mm.html

▼Types of shells▼

Spoiler

Projectile

• Common
  • Explosives: TNT 66 % + Aluminum 34 %, 15.3 g
  • Tracer: N/A
  • Fuse: Impact
• Tracer Common
  • Explosives:  TNT 66 % + Aluminum 34 %, 20.4 g
  • Tracer: Red, 5.7 seconds (about 2,600 m)
  • Fuse: Impact
• Tracer Common Kai 1
  • Tracer: Blue (2.9 s, 1,600 m) ⇒ Red (5.7 s, 2,600 m)
  • Fuse: Impact
• Tracer Common Kai 2
  • Tracer: Yellow, over 4.5 seconds
  • Fuse: Impact
• Tracer Common Model 2
  • Self-destruction: 3,000 m (7 sec) - 4,100 m (12 sec)
  • Tracer: Yellow, over 4.6 seconds (2,600 m)
  • Fuse: Impact
• Tracer Common Model 2 Kai 1
  • Self-destruction: 4,000 m (10 sec) - 4,500 m (16 sec)
  • Tracer: Yellow, over 6 seconds (3,100 m)
  • Fuse: Impact
• Tracer
  • Explosive: N/A
  • Tracer: Red
  • Fuse: N/A
• Tracer Kai 1
  • Explosive: N/A
  • Tracer: Blue ⇒ Red
  • Fuse: N/A
• Tracer Kai 2
  • Explosive: N/A
  • Tracer: Yellow
  • Fuse: N/A
• Tracer Indicator (Paint shell to indicate submarines)
  • Tracer: Yellow
  • Paint: Green
  • Fuse: Impact
• Incendiary Common
  • Explosive: TNT 66% + Aluminum 34 %, 5.7 g
  • Incendiary: Yellow phosphorus, 13 g
  • Tracer: N/A
  • Fuse: Impact
• Incendiary Common
  • Explosive: TNT 66% + Aluminum 34 %, 5.7 g
  • Incendiary: Yellow phosphorus, Amount unknown
  • Tracer: N/A
  • Fuse: Impact
• Armor-Piercing
  • Special filling: Red Iron Oxide
  • Tracer: Yellow, 8.65 g
  • Fuse: N/A
• Armor Piecing Model 2
  • Special filling: N/A
  • Tracer: Yellow
  • Fuse: N/A
• Training shell

 

 

 

Inside Layout

All fuel tanks are placed on bottom of ship. This is a unique future of Japanese battleships: they did not use fuel tanks for torpedo protection. It because in the result of test during Taisho era by the Vice Admiral Hiraga, they thought spaced protection is better than liquid protection. In the examination around 1935 IJN find advantage of liquid anti-torpedo protection but it was not adopted for Yamato class.

I indicated compartments that will affect to in-game damage models. Note, this drawing shows early-built state, so there are some difference between 1945 state. (eg. secondary gun magazine on center of hull)

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Midship section

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Layout

Red: Ammo stowage

Green:Inside equipment

Orange: Fuel tanks 

 

Specification

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Examples of historical research of Yamato 1945 (from Wikipedia)

Probably the wooden deck was painted black. Also, perhaps at the last battle she rise the flag "非理法権天".

Spoiler

http://sidonia.blog.fc2.com/blog-entry-259.html?sp

In the legend, Japanese samurai Kusunoki_Masashige used this flag. Also the "Kikusui" mark on the funnel is his symbol.

 

 

Data at early-built state

• Standard displacement: 64,000 t
• Trial displacement: 68,200 t
• Full-load displacement: 72,809 t
• Max length: 263.40 m
• Max width: 38.9 m
• Average draft at trial state: 10.4 m
• Main boiler: 12x Ro-Go Kampon boiler
• Main engine: 4x Kampon turbine
• Power: 153,553 SHP
• Speed: 27.46 kt
• Aircraft: 6 (F1M2 / E13A)

Data of Yamato 1945

• Crew: 3,332
• Main gun: 3x 46 cm/45 Type 91 cannon, triple mount
• Secondary gun: 2x 15.5 cm/60 3rd Year Type cannon, triple mount
• High Angle gun: 12x 12.7 cm/40 Type 89 AA gun, twin mount
• Machine gun
  • 52x 25 mm Type 96 machine gun, triple mount
  • 6x 25 mm Type 96 machine gun, single mount
  • 2?x 13 mm Type 93 machine gun, twin mount
• Depth charge: A little?

 

Pros & Cons

Pros

• Mighty 46 cm naval gun
• Excellent armor
• Better speed
• Over 150 barrels of machine gun

Cons

• No VT shell for AA gun
• Slow turning speed of turret
• Weak armor for secondary gun
• Hundreds of machine guns will crash weak PCs

 

 

 

Reference

Spoiler

(Eds.) Makino Shigeru[牧野茂], Fukui Shizuo[福井静雄] (1987) "Navy Shipbuilding Technology Overview[海軍造船技術概要]" KON NICHI NO WADAISHA [今日の話題社]

ISBN4-87565-205-4

 

Hara Katsuhiro [原勝洋], (1999) "Secret Histories of Construction of Battleship Yamato [戦艦大和建造秘録]", KK Best Sellers

ISBN4-584-17076-2

(most of drawings are comes from here)

 

Each weapon pages of NavWeaps

 

Links on each section

 

https://ja.wikipedia.org/wiki/大和型戦艦

https://ja.wikipedia.org/wiki/大和_(戦艦)

 

[BlackFlagger 199]

Its a negative for me. From the battleships that were build it doesn't have a counter so adding will open a huge can of worms with paper battleships designs, either way it is not the time for it now, we don't even have large cruisers / battlecruisers yet in game, If I were you I would look into smt like kongo.

[OsirisD 4,025]

GJ already confirmed that situation with unfinished and blueptint-only ships are way difrent cause unlike tanks or planes ships are ready when blueprint is ready. 

But tbh it's way too early for this behemoth.

[leroyonly 4,310]

While obviously its slightly early to see yamato in naval, i also have no doubt that we will end up seeing her in due time. Due to the mixed nature of naval battles in my opinion it wouldnt be that unbalanced as other nations will also have their own BB's.

 

Also a slightly late, Open for discussion. 

[Optical_Ilyushin 5,554]

Well it's going to be coming eventually, for when that is the case, +1 for me!

[WiseMinerva 454]

It's definitely coming at some point so +1

[eleks12 1,079]

+1 can't wait for player controlled Battleships!

[arczer25 5,202]

• Weak armor for secondary gun (same as other battleship)

Not exactly, USN post standards had 50.8mm (sufficient against DD's) and German twin 150mm were also pretty armored (face was 100mm if I remember properly)

[Hronomant 182]

Another option is possible with the armament composition of 3 towers of 2x510 mm. It seems from materials that I saw when the Japanese suspected the appearance of 18-inch guns on American battleships, they urgently began developing two-armed 510 mm towers suitable for installation on the Yamato type (as a result, the 2x510 mm tower even turned out to be several tens tons lighter than a 3x460 mm tower). When the project was canceled due to the tragedy of Midway, all parts of the gun turrets were produced, fist gun turret was assembled by 80%, the second by 40%. Of course, these are not 100% assembled towers, but the game is full of vehicles that did not reach such stages of assembly, plus the developers said that they would be noticeably less strict in the criteria for introducing ships into the game in terms of their implementation.

Edited February 8, 2020 by Hronomant

[Tasty95215 2,099]

I like how you included this section as part of the history 

9 hours ago, aizenns said:

Afterwards, in 2199, the Gamilons Empire start to invade the Earth. Humankinds formed the Earth Defense Force but inferiority was apparent. The sea evaporates and radioactive contamination progresses so mankind will be destruct within one year. At this time, one message comes from outer-space. That message said that come to planet Iskandar to take Radioactivity removal device, and they attached blueprint of warp engine. This engine was mounted on Space Battleship Yamato (they camouflage the building of new spacecraft by the wreckage of Yamato), and she dispatched to outer space to save the earth. End of the strict battles against the Gamilons Empire, they succeed the mission and revived the earth. Since then she has been active in various battles.

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This was also funny:

9 hours ago, aizenns said:

Cons

• Hundreds of machine guns will crash weak PCs

 

 

Edited February 8, 2020 by Tasty95215

[Tasty95215 2,099]

More seriously, here's something very interesting that could be useful for modelling Yamato. Between 2005 and 2006, there was a 1-1 scale model for the forward section of Yamato, built for the movie 男たちの大和 or Otoko-tachi no Yamato that people could visit.

 

 

Pictures from Wikipedia and this blog. While I'm sure there were errors with the model (the pagoda mast is missing, for instance) this should still be helpful for when Gaijin decides to add battleships in the future.

[Bend_Ova 110]

Wait until people realize it takes multiple ships to bring down just one Battleship. Bismarck ring any bells? And she was already crippled on top of that. Battleships can only be implemented side by side with AIRCRAFT CARRIERS. Let that get through your heads. I made a detailed post about how Aircraft Carriers could be implemented but it got denied for no reason, yet BB's are being suggested more and more for multiple nations with no counters but themselves. 

[aizenns 3,590]

10 hours ago, arczer25 said:

• Weak armor for secondary gun (same as other battleship)

Not exactly, USN post standards had 50.8mm (sufficient against DD's) and German twin 150mm were also pretty armored (face was 100mm if I remember properly)

Thanks! I will update information.

[Hronomant 182]

Perhaps this midship-frame battleship "Yamato" will be a little more convenient to perceive.
 

Spoiler

Edited February 8, 2020 by Hronomant

[Fireraid233 4,274]

+1 she will be a tough opponent in WT but there will be counters to it in the form of Iowa, Montana and other ships/unfinished/paper ships.

[aizenns 3,590]

3 hours ago, Hronomant said:

Perhaps this midship-frame battleship "Yamato" will be a little more convenient to perceive.
 

  Reveal hidden contents

Thanks, I completely forgot to attach midship section view. I added drawings written after war by designer team of Yamato.

However, your drawings is easier to see.

Spoiler

 

[Hronomant 182]

21 minutes ago, aizenns said:

Thanks, I completely forgot to attach midship section view. I added drawings written after war by designer team of Yamato.

Thank you so much for the original documents.

[Valcour 1,141]

+1 for either of the pre-2199 variants.  Otherwise you will have to have ships with Desslar Cannons.

 

[Optical_Ilyushin 5,554]

1 minute ago, Valcour said:

+1 for either of the pre-2199 variants.  Otherwise you will have to have ships with Desslar Cannons.

 

 

Personally, I can't wait to utilize the WMC to permanently delete maps from the game.

[Hronomant 182]

47 minutes ago, Fireraid233 said:

+1 she will be a tough opponent in WT but there will be counters to it in the form of Iowa, Montana and other ships/unfinished/paper ships.

Montana is not an adequate opponent for the Yamato type. Perhaps even more paper version with 457 mm guns could compare with it. According to the American post-war study, the best american 406 mm projectile could penetrate Yamato only in board at a right angle and from a distance of no more than 18.5 km. That is, in a real battle Montana would not have been able to get through the armored belt. The armor of Montana did not protect from 460 mm guns. In addition, this calculation was obtained on the basis of the controversial assumption about the poor quality of armor, but as far as we know this assumption was obtained on the basis of shelling of a defective armor plate found at a dump in Kure.

[Valcour 1,141]

1 minute ago, Hronomant said:

Montana is not an adequate opponent for the Yamato type. Perhaps even more paper version with 457 mm guns could compare with it. According to the American post-war study, the best american 406 mm projectile could penetrate Yamato only in board at a right angle and from a distance of no more than 18.5 km. That is, in a real battle Montana would not have been able to get through the armored belt. The armor of Montana did not protect from 460 mm guns. In addition, this calculation was obtained on the basis of the controversial assumption about the poor quality of armor, but as far as we know this assumption was obtained on the basis of shelling of a defective armor plate found at a dump in Kure.

It was tested against a turret faceplate that had been intended for Shinano, but when she was converted to a carrier the turret armor was not needed.  I have never read that it was considered to be defective by the IJN.

 

[Hronomant 182]

4 minutes ago, Valcour said:

It was tested against a turret faceplate that had been intended for Shinano, but when she was converted to a carrier the turret armor was not needed. I have never read that it was considered to be defective by the IJN.

In all the Japanese materials that I saw, it was written everywhere that it was a rejected part of the battleship. During its production as a result of the accident, the production technology was violated.

[arczer25 5,202]

2 hours ago, Hronomant said:

Montana is not an adequate opponent for the Yamato type. Perhaps even more paper version with 457 mm guns could compare with it. According to the American post-war study, the best american 406 mm projectile could penetrate Yamato only in board at a right angle and from a distance of no more than 18.5 km. That is, in a real battle Montana would not have been able to get through the armored belt. The armor of Montana did not protect from 460 mm guns. In addition, this calculation was obtained on the basis of the controversial assumption about the poor quality of armor, but as far as we know this assumption was obtained on the basis of shelling of a defective armor plate found at a dump in Kure.

more than, performance of latest US 16inch was comparable with that of a Japanese 18.1inch, and Montana was desingned to protect against that new super heavy US 16inch. (Iowa scheme was to protect against regular 16inch rounds)

in return Yamato would also struggle penetrating Montana at 18.5km (both ships have similar Belt), while in term of Deck protection Montana have bit lower effectivness (due to multiple layers) US 16inch have better performance aginst deck armor than IJN 18.1inch resulting in both having immune zone to 35km...

both also have so heavly armored turret's and barbettes that unless you hit weakspots, of armor failures there's no chance for penetrating hits

 

so practically both ship would have 19-35km immune zone against eachother.

 

still main advantage of Montana is extra turret (3 more shells to get lucky hit)

Edited February 8, 2020 by arczer25

[Hronomant 182]

1 hour ago, arczer25 said:

more than, performance of latest US 16inch was comparable with that of a Japanese 18.1inch, and Montana was desingned to protect against that new super heavy US 16inch. (Iowa scheme was to protect against regular 16inch rounds)

This is not true. Even with later shells, it was inferior both in weight and in the speed of ammunition. The difference in kinetic energy was a whopping 25%. In addition, American guns tried to achieve a similar armor penetration due to a heavy shell, however, as British tests showed, such a heavy shell did not work well on inclined armor because it was prone to destabilization.

 

1 hour ago, arczer25 said:

in return Yamato would also struggle penetrating Montana at 18.5km (both ships have similar Belt), while in term of Deck protection Montana have bit lower effectivness (due to multiple layers) US 16inch have better performance aginst deck armor than IJN 18.1inch resulting in both having immune zone to 35km...

406 mm Monatna’s side armor is not an obstacle for 460 mm ammunition. Competent positioning of the ship could significantly increase protection by converging to the Yamato guns at an angle that increases armor resistance, however, the relatively weak armoring of the traverse coupled with the primitive booking form without rational tilt angles will make it a rather large vulnerable area. Plus in order to use both rear towers, he will have to expose at a dangerous angle own armor. Yamato will have to do the same, but at a safer angle due to the shorter gun base, and as shown by American calculations against 406-mm shells, this angle is not dangerous all the way to extremely short distances. In principle, Yamato can stand up to the target and only firing from 2 front towers - in this form, the american 406, in principle, will not be able to penetrate the traverse due to the rational inclination of the armor plates of traverse.

If implemented in this way, Yamato will easily destroy Montana, possessing invulnerable armor and ultimate weapons. Perhaps the option in which Yamato has 3 towers of 2x510 mm guns and Montana 4 towers of 2x457 mm guns would be balanced - they would both penetrate each other with sufficient success.

Edited February 8, 2020 by Hronomant

[arczer25 5,202]

1 hour ago, Hronomant said:

This is not true. Even with later shells, it was inferior both in weight and in the speed of ammunition. The difference in kinetic energy was a whopping 25%. In addition, American guns tried to achieve a similar armor penetration due to a heavy shell, however, as British tests showed, such a heavy shell did not work well on inclined armor because it was prone to destabilization.

Inferior in weight, but smaller in diameter (more energy in smaller area) kinetic energy dosen't directly transfer into penetration, velocity differience also weren't severe (18m/s).

interestingly enough 16inch was able to archive very similar velocities to IJN 18.1inch despite having lower muzzle velocity and being lighter (lower diameter and differient ballistic cap)

yes they increased either body and cap weight (or both depending on projectile).

when British test's last time they concluded that Light shells are superor wia wrong conclusions, by WW2 not only US used super heavy shell, but Japanese also starting making their own (8inch are most known one).

while there were issues against incined armor it was again's armor at moderate angle (~40 degree) and they managed to fix that issue.

1 hour ago, Hronomant said:

 

 

406 mm Monatna’s side armor is not an obstacle for 460 mm ammunition. Competent positioning of the ship could significantly increase protection by converging to the Yamato guns at an angle that increases armor resistance, however, the relatively weak armoring of the traverse coupled with the primitive booking form without rational tilt angles will make it a rather large vulnerable area. Plus in order to use both rear towers, he will have to expose at a dangerous angle own armor. Yamato will have to do the same, but at a safer angle due to the shorter gun base.. Yes, and in principle, Yamato can stand up to the target and only firing from 2 front towers - in this form, the american 406, in principle, will not be able to penetrate the traverse due to the rational inclination of the armor plates of traverse.

If implemented in this way, Yamato will easily destroy Montana, possessing invulnerable armor and ultimate weapons. Perhaps the option in which Yamato has 3 towers of 2x510 mm guns and Montana 4 towers of 2x457 mm guns would be balanced - they would both penetrate each other with sufficient success.

i arleady sad about belt and deck armor performance (practically the same immune zone....) so if somehow it is resistant against USN 16inch but not obstacle for IJN 18.1inch then whatever...

 

i will add that from US Biuro of Ordinance concluded that 16-inch (40.6 cm) side armor and 6.25-inch (15.9 cm) deck armor would have no immune zone whatsoever from the "super-heavy" 18" (45.7 cm) AP projectile, and not regular 18inch round

while concluding that Regular 18" (45.7 cm) marginally better penetration wasn't worth smaller amount of guns and increased strain on gun loading...

now add that Montana have 19 degree slope on its armor and additional deck protection...

it need's to take note that with ~8% chance of hitting target at ~18km more barrel's = more hits.

 

still funny how you say, yes at full head-on Yamato traverse bulkhead is pretty resistant (albiet there's place of weakness where shell can deflect after penetration of 50mm upper deck and hit sloped plate of traverse bulkhead)

but at actual possition of using all gun's to bear it's not optimal, as instead of both increasing belt and traverse bulkhead protection, you expose 330mm traverse bulkhead "cheek" to enemy fire creating weakspot at both close range (penetration wia lower part) and at long range (penetration wia sloped deck part)

Montana can more than favorably keep angle leaving both belt and traverse bulkhead (with is also thicker at 457mm) at effective range with is more traditional desing.

 

also there's only for so long you can maintain enemy head on... especially at closer ranges were armor becomes susceptible to penetration while at long ranges it hardly matters..

 

it's also funny how you say that Yamato with has 3 towers of 2x510 mm guns and Montana 4 towers of 2x457 mm guns would be balanced while it is exacly the same time it's very similar to how current Yamato and Montana...

btw US 457mm weighted 1,746kg vs Yamato 460mm 1460kg

while supposed 510mm was 1900-2000kg

Edited February 8, 2020 by arczer25