IJN Kongo/Haruna missing armored deck?

Hello everyone.
Have you noticed that the IJN Kongo and Haruna are the only battleships of the line in the Japanese fleet that are missing an armored deck in the preview? All other ships have some layer of armor at this level, but Kongo and Haruna have a huge hole the entire length of the ship. Honestly, I don’t know if it can be reported as a bug, because I only have a few battles on Haruna, mainly due to the fact that this ship in 2022 took on HE shells from Chinese bots on cruisers 6.0 in all the battles (with fatal results), So I assumed that this ship did not actually have the first layer of the armored deck modeled and I didn’t play with it anymore. I am attaching screenshots of the armor preview in the game. Write what you think about it.

  1. IJN Haruna
  2. IJN Kongo
  3. IJN Fuso for comparsion

because it is made of structual steel, which is not considered as armor ingame.

that’s lame lol
so is it like there but doesn’t show or is the game just considering it as unarmored

it is there but doesn’t show as structual steel on naval is not shown at armor view


So the HE from 152mm can penetrate to the engine compartment or not? I don’t understand Gaijin logic. When I was playing on Haruna in 2022 it was unplayable with this hole in the middle.

I don’t understand why the Kongo class is ONLY japanese battleship class that did had structural steel deck instead normal armored deck. Is there any historical proof that these ships did’t had armored deck? That’s unbeliveble.

No it can’t the armor is there it just isn’t shown in the viewer since otherwise it would be too cluttered if you saw all structural steel parts.

Why the Kongo have structural steel deck, IDK Kongos in general are very lightly armored maybe that’s why. But there are more knowledgeable people here who know more

Because it’s a fraud. The Japanese use high tensile steel as structural steel, for example Ducol Steel. Ballistic test data show what Ducol about 0.9 times the resistance of American armor. The Americans used a similar STS steel, which has a resistance of 0.95 of armor. But Ducol in the game it is structural steel, when STS is armor. As a result, Japanese ships literally lack hundreds of tons of armor. The problem has been known for a long time, but no one has fixed it almost since the advent of the fleet.


Japanese HTS is not Ducol Steel. It’s much before Ducol Steel developed. Some of British cruisers with ducol steel get RHA in those place ,which is even better than STS.

Also, not every STS on American cruisers treated as armor. We lack armor on Cleveland, Fargo and Des moines classes.

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Fundamentally wrong. It is the main structural steel in Japanese shipbuilding after the end of the First World War. Please study the issue.

But Japanese ships do not receive it at all.

“It’s missing on several ships” is one thing (which still needs to be checked), and its complete absence on all ships is quite another. Besides, is this an attempt to look poor compared to the Japanese ships? Are you serious?


And IJN Kongo is not a ship that built after the WW1, it is built during the WW1 even before Ducol Steel is invented in GB.

Never. Just to say that Gaijin is not an attempt to discriminate Japan. Just they don’t have single standard about Ducol Steel, and Kongo does not apply to those Ducol Steel.

Kongo underwent heavy reconstruction from 1929 onwards.

IJN Settsu, for example, received additional Ducol plating in 1924 despite being a ship from 1912.



And Kongo didn’t receive Ducol Steel on mid deck.

This topic was already on the forum and Moderator denied the implementation of ducol steel on engine deck with adequate resource. There are nothing to say more.

You know what, you might be right.

All the sources I’ve found mention Nickel Steel which would fall under the “armor” class.

Worth mentioning that the blueprint states sections 106 to 188 are similar, with the one in the picture being section 140. This space is occupied by the boilers/machinery.

The only opening in the armor would be around the funnels.

Moreover, these two book by John Jordan mention said armor above machinery.

  • 金剛

Even mentions the uparmoring of the Kongo on the Fuso section

  • 扶桑




Books :

  • Warships After Washington: The Development of the Five Major Fleets, 1922-1930 (ISBN 9781473852730)
  • Warships After London: The End of the Treaty Era in the Five Major Fleets, 1930-1936 (ISBN 9781526777508)
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If only nickel steel armor was used then it would seem that “structural steel” label is somewhat apropriate since that in game only signifies the armor quality and nickel steel is considerably worse then RHA of WW2 tanks or the Cemented Armor.

Mind you the armor is still there even if it isn´t displayed in armor viewer.

I tend to lean towards armor more than structural steel. Mostly due to this:


It’s obvious it wasn’t meant to tank shells like the belt armor but it did serve as secondary armor if the main belt failed.

Is it though? This bit here (if it’s even there) gets the structural steel treatment despite being a combination of HTS and NVNC.

It’s because that flat section was not covered by NVNC, it’s ignored. The moment two different type of steels are sandwiched together, only the strongest steel type is counted, and the inferior one becomes backing plate.

That sounds awfully a lot like composite armor. No? Main hard surface to shatter/deform main penetrator, softer but abrasive material behind to catch and degrade penetrator further.

If it works for composite, it can work for decks since its not meant to catch the main shell anyways but secondary fragments from armor breaking off, shrapnel, or to separate compartments to not have everything blow up all at once from HE effect, which coincidentally, is the issue that plagues these ships right now.

As it stands, a shell detonating at the bow can have fragments travel all the way to the stern because the interior compartments aren’t modelled at all. OR a HE shell exploding on the deck can have its HE effect and fragments travel all the way to the boiler rooms.

No not at all. Doesn’t have space(or elements) between plates like composites do. Backing plate is there for basic structure of hull and fixing armor to hull.

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when I think about it I get engine damage quite often from things like cruisers.