Extended Armor? How much?

[Peksern]

Hey guys. I have a question about ship designing.

Currently - I think @brothermunrosaid something like that in a yt tutorial long time ago - I create ship armor the following way:

Main armor: Like a realistic value of penetration by the AP of the ship's own gun, for example 35cm (14 In)
Extended armor: Like the penetration of HE by the very same main guns, for example 7cm (3 in)
Same procedure with Deck armor.

So my main armor is always by far stronger than the extended armor. But that has two problems:

First, it's not historical accurate. In that point, I'm not quite sure, but I think usually ships had something like 30cm main belt and 20cm extended belts? So there would be a much smaller difference between main and extended belt? But I may be wrong.

Second, ingame that system is making ships very prone to AP-damage and especially floodings in the extensions. That won't make a ship unable to fight, but reduces it's maneuverability and engine power potentially critical.

 

So, long story short: How do you create your main and extended armor? Same way, is the proneness "normal" and the way to go? Or would you try to have a 2:3 ratio between extended and main armor? Or something like that?
 

[brothermunro]

With your questions:

Q: Historical accuracy of a 14”/3” main/extended belt. This depends on which ship you look at, but yes this would be a historically acceptable layout for an all or nothing ship. As an example a KGV had a 14.7”/1.5” scheme. However older ships had much thicker extended belts in a distributed armour scheme, the Bayern for instance had 13.8”/6.7”.

Q: AP hits to extended. The idea here in real life would be to reduce the armour so that AP shells go right through and don’t explode, but still strong enough to block HE shells. Ships were designed so that the stuff in the unprotected bits of the ship were not mission critical (stores, berths etc) and the ship could stay afloat even if they flooded (not all ships stuck to that but it was a good idea).

Q: how do you armour? I still use the method you describe but I play on a modded game where the penetration is way lower. 

[Peksern]

7 minutes ago, brothermunro said:

With your questions:

Q: Historical accuracy of a 14”/3” main/extended belt. This depends on which ship you look at, but yes this would be a historically acceptable layout for an all or nothing ship. As an example a KGV had a 14.7”/1.5” scheme. However older ships had much thicker extended belts in a distributed armour scheme, the Bayern for instance had 13.8”/6.7”.

Q: AP hits to extended. The idea here in real life would be to reduce the armour so that AP shells go right through and don’t explode, but still strong enough to block HE shells. Ships were designed so that the stuff in the unprotected bits of the ship were not mission critical (stores, berths etc) and the ship could stay afloat even if they flooded (not all ships stuck to that but it was a good idea).

Q: how do you armour? I still use the method you describe but I play on a modded game where the penetration is way lower. 

Okay, thanks for the interesting answers! 

Okay, I got convinced, that all or nothing is fine. At least it's the formula of the most powerful and most successful navy until World War II.

Anyway, overpen happens when pen of the grenade is more than twice of the effective armor thickness. Therefore, for maximum extended protection with this overpen-tactic in mind would be a bit less than half of the main belt, right? 30 inch main belt, maybe 13 inch extended. Mathematical correct?

 

[brothermunro]

Overpens can be a little off, in vanilla I believe they are still twice the penetration but there’s quite a lot of other factors going on. I mean in vanilla you’re probably best off just armouring against the HE spam, ignore AP protection for extreme speed and more guns and embrace your inner Jackie Fisher.

[justMike247]

5 minutes ago, brothermunro said:

ignore AP protection for extreme speed and more guns and embrace your inner Jackie Fisher.

Become a vertically challenged concieted biggot with a fetish for dancing??

**le violent shudder**

[Peksern]

20 minutes ago, brothermunro said:

Overpens can be a little off, in vanilla I believe they are still twice the penetration but there’s quite a lot of other factors going on. I mean in vanilla you’re probably best off just armouring against the HE spam, ignore AP protection for extreme speed and more guns and embrace your inner Jackie Fisher.

Well, playing with NAR.

[justMike247]

2 hours ago, Peksern said:

So, long story short: How do you create your main and extended armor? Same way, is the proneness "normal" and the way to go? Or would you try to have a 2:3 ratio between extended and main armor? Or something like that?

Historically there's two, possibly three schools of thought on this... First, Jacklie Fisher's Battle Cruiser plan, where armour is sacrificed in favour of speed... See Jutland for how well that worked...

 

Second and third are sorta kinda related;- most BB's were designed to have an armour plan that was "proof against their own guns at battle ranges". This invariably leads to asking, what exactly is battle range? That... depends on how you picture the ship fighting... Stand off at long range and snipe (circa Iowa class) or to get in close and maul the target. The problem with the mauling concept is it's impossible to armour any vessel to the point that it's invulnerable to everything, so... you need to make educated guesses re which potential threats the class is most likely to meet, and design accordingly.

 

The primary thing to bear in mind; it's impossible to protect any vessel against stupidity... (see USS South Dakota at Savo Island).

[Северная]

On 11/7/2024 at 12:08 PM, brothermunro said:

With your questions:

Q: Historical accuracy of a 14”/3” main/extended belt. This depends on which ship you look at, but yes this would be a historically acceptable layout for an all or nothing ship. As an example a KGV had a 14.7”/1.5” scheme. However older ships had much thicker extended belts in a distributed armour scheme, the Bayern for instance had 13.8”/6.7”.

Q: AP hits to extended. The idea here in real life would be to reduce the armour so that AP shells go right through and don’t explode, but still strong enough to block HE shells. Ships were designed so that the stuff in the unprotected bits of the ship were not mission critical (stores, berths etc) and the ship could stay afloat even if they flooded (not all ships stuck to that but it was a good idea).

Q: how do you armour? I still use the method you describe but I play on a modded game where the penetration is way lower. 

The way I look at it is like this:

By the time you are doing long range combat and have AoN (or really even TB) armor scheme, small ships should not be getting close at all to your BB or BC, the days of the pool noodle battles are over.  The increased range and effectiveness of torpedoes and the durability and firepower of screening DD/CL is more than enough of a buffer to keep your BB at capital ship engagement distances.  
 

This means I do not care about 1) cruiser caliber protection, because any cruiser closing to my BB line will be torpedo bait if not overwhelming firepower bait if there is no higher priority target, and the AI is not great at coordinating pressure and 2) I do not care about armoring the BB within short distances where it implies I am close enough to the enemy BB to be within a threat distance of their own screen firepower, particularly torpedoes.  Ironically, this means that I see the main benefit of higher torpedo defense technology is increasing resistance, not actually defending against torpedoes, which isn’t a common threat to a BB because this game doesn’t have submarines (in battle), torpedo bombers, or area-denial ability for torpedoes (torpedoes have to be targeted at a ship in range, not fired as an area-denial screen).

As a result, by the mid 1920s and certainly by the 1930s and radar era, I find the most success with AoN, considerably more deck armor focus than previous eras, maybe 1.5” of belt extended, 2.5” of deck extended or so, otherwise put belt and belt citadel to a point of good protection beyond like 10km and the rest into deck armor turret armor, and speed.

[Peksern]

Another question, that might fit this topic. 

Is it useful to have a stronger aft armor than fore armor, to protect the rudder a little bit better? Historically this happens for Iowa (who had a slim 343mm aft belt right behind the main belt, to protect the steering geer.) The AI often has such an arrangement and I wonder if it's actually useful. For example having 2 inch fore belt, but 3 or 4 inch aft belt?

[Zuikaku]

I have stronger aft armor, forced to have one in order to balance bow heavy ships.