How does inner armor work?

[thu]

I got a BB with 12''belt + 4''1st inner +2'' 2nd inner + 12'' barbette, so I supposed a 30'' protection. Fact was ammo detonation received from a direct penetration hit. Have I made a wrong calculation?

[thu]

The concept 'min and max ricochet angle' also confuses me a lot.

[Nick Thomadis]

1 hour ago, thu said:

I got a BB with 12''belt + 4''1st inner +2'' 2nd inner + 12'' barbette, so I supposed a 30'' protection. Fact was ammo detonation received from a direct penetration hit. Have I made a wrong calculation?

The system does not work purely additively.
When a shell penetrates the 12 inch belt, then it loses a large portion of its penetration power and checks to penetrate the next layer of armor. This is done successively and then if the shell reaches the barbette, it has to have enough penetration to pierce it.

So the overall protection can be up to 30 inches in your example, but not always 30 inches, and so sometimes, depending on the circumstances, it can be defeated by a large shell.

EDIT:
The Citadel armor schemes save a lot of weight compared to pure armor equivalence, which could be impossible without this system, as in your example, 30 inches of armor would cost a tremendous amount of extra tons, and if the tonnage would be available, then it would be restricting you to use it for other vital aspects of your ship. 

[AdmiralObvious]

6 hours ago, Nick Thomadis said:

The system does not work purely additively.
When a shell penetrates the 12 inch belt, then it loses a large portion of its penetration power and checks to penetrate the next layer of armor. This is done successively and then if the shell reaches the barbette, it has to have enough penetration to pierce it.

So the overall protection can be up to 30 inches in your example, but not always 30 inches, and so sometimes, depending on the circumstances, it can be defeated by a large shell.

EDIT:
The Citadel armor schemes save a lot of weight compared to pure armor equivalence, which could be impossible without this system, as in your example, 30 inches of armor would cost a tremendous amount of extra tons, and if the tonnage would be available, then it would be restricting you to use it for other vital aspects of your ship. 

I still don't entirely understand how this system works after the explanation. With the old models before the Citadel rework, penetration was a 1 or 0. After this, it's harder to understand when a shell should penetrate the inner armor of a ship.

So, for example (if you took out the RNG) how would a shell perform when it has ~80 inches of pen, and hits a 30 inch belt and a 15 inch back layer (assuming 0 armor quality)? Mainly I'm wondering, how much actual penetration is lost as a result of this, and does fusing make a difference in determining wether the shot actually goes through or not.

Edited July 22, 2022 by AdmiralObvious

[Norbert Sattler]

Two 5" plates are easier to penetrate than a single 10" plate. This isn't game-machanics, this is real-world physics.

That's why you can't just add the thickness of the seperate armour layers together.

So lets say for example that each time a shell passes completely through a layer of armour it loses 3/4 of the penetration of said armour. You have 20 main belt, and then two layers of inner belt 10 and 5" thick.
The shell comes in with enough penetration to go through 29" of armour.
Just by adding up the values you'd think you have 35" armour vs 29" penetration will hold... but it won't.

After punching through your main belt it loses 15" (3/4 of 20") penetration, so it hits the first inner belt with 14" pen, which is still enough, so it goes through that as well, but loses speed again and thus comes down to 11.5" (14 remaining pen minus 3/4 of 10). And now it hits the final layer with 11.5 pen vs 5" plate and goes through with 10.25 penetration left.

That of course is a simplified model, since I just picked out random numbers and am disregarding a lot of factors that are also going on (like factoring in armour material, propellant and bursting charge, barrel length, angle both horizontally and vertically and so on).

[UncleAi]

It is a very complex question. Usually one thick plate is better than multiple thinner plate equal total thickness, but multiple thinner plate with good calculation and design can also have good defence. It called spaced armour.

In real world, armour above the main armour deck can : 1. Detonate the aerial bomb 2. Prevent fragment 3. Damage or destroy the AP cap. 

Scharnhorst and Bismarck is the typical spaced armour. A 1.97 inch armour above the main armour deck. Their calculation is that it equals 6 inch normal design.

Higher the main armour deck, bigger defensed volume. But the cost is stability.(KGV)

Lower main armour deck can save weight, but the cost is survivability.(Richelieu and Nelson)

But in the game we don't have air attack, and I don't think there is fragment and cap peel. So just make a thick plate.

 

 

[Dman1791]

On 7/23/2022 at 3:11 AM, Norbert Sattler said:

Two 5" plates are easier to penetrate than a single 10" plate. This isn't game-machanics, this is real-world physics.

That's why you can't just add the thickness of the seperate armour layers together.

So lets say for example that each time a shell passes completely through a layer of armour it loses 3/4 of the penetration of said armour. You have 20 main belt, and then two layers of inner belt 10 and 5" thick.
The shell comes in with enough penetration to go through 29" of armour.
Just by adding up the values you'd think you have 35" armour vs 29" penetration will hold... but it won't.

After punching through your main belt it loses 15" (3/4 of 20") penetration, so it hits the first inner belt with 14" pen, which is still enough, so it goes through that as well, but loses speed again and thus comes down to 11.5" (14 remaining pen minus 3/4 of 10). And now it hits the final layer with 11.5 pen vs 5" plate and goes through with 10.25 penetration left.

That of course is a simplified model, since I just picked out random numbers and am disregarding a lot of factors that are also going on (like factoring in armour material, propellant and bursting charge, barrel length, angle both horizontally and vertically and so on).

Laminated armor, that is, an attempt to emulate a thick plate via slapping two thinner plates on top of each other, is weaker, yes. But properly designed multi-layer armor is much more effective than a monolithic plate in many cases, one of which was mentioned by @UncleAi in armored decks. The first layer of armor is able to cause damage to the projectile, saps its energy, and, if sufficiently thick, starts its fuse. If the next armor plate is thick enough and at an appropriate distance, the shell may shatter against it or explode prematurely. Additional layers of armor also limit damage due to spalling or splinters, by having some armor between the fragments and the delicate internals. The effects of spaced armor are one of the reasons that the "turtleback" armor scheme was so effective before ranges got too far and air attack became common. Shells that made it through the main belt would be severely blunted, greatly slowed, and have their fuses set, leading them to explode on, glance off of, or simply shatter against the sloped deck armor behind the belt.

You can see some of these ideas in the armor scheme shown for the KGV battleships above, where the main armor belt has an additional layer of armor behind it, presumably to catch splinters and prevent explosions from propagating inwards. There is another layer after that over the magazines, further improving the likelihood of shell failure and reducing the chances of collateral damage. You can also see that the fuel oil is kept between the main belt and inner layer, which would further hamper enemy shells due to oil's much higher density and viscosity compared to air.

It's really quite complicated, and as far as I'm aware we don't really have any definitive empirical answers to just how effective various spaced armor schemes were, such as the Italian "decapping belt." Honestly, I'd suspect that there's not much tangible benefit to having more than about three total layers of armor anywhere, maybe four over the magazines. By the time you're up to four or five layers, those last one or two are probably protecting very little of the ship. As a result, I'd expect the system to work something like this:

• The first armor layer acts as expected. It's a slab of steel.
• Having a second layer of sufficient thickness leads to the armor being better than the sum of its parts. I'd expect this to take the form of a buff to the first layer's effective thickness if the second layer is substantial enough, with the total thickness (including buff) being the number to beat for shells. Full pens become rarer due to the improved armor, and partial pens become blocked shots or have their damage reduced considerably (depending on how close they were to a pen, and the thickness of the second layer).
• The third layer and on serve mostly to reduce damage taken, rather than change hit types, and reduce the chance of critical hits. If a shell has made it through your two thickest layers of armor, it's likely quite deep in the ship at this point due to spacing, and clearly had a lot of power behind it, so you should still be taking some damage at this point. Third and on layers, being so deep in the ship, would likely be found only over highly important areas, primarily the magazines. As such, they should reduce the chances of ammo detonation in particular and critical hits in general.

Edited July 30, 2022 by Dman1791

[Kane]

On 7/22/2022 at 8:49 AM, Nick Thomadis said:

The system does not work purely additively.
When a shell penetrates the 12 inch belt, then it loses a large portion of its penetration power and checks to penetrate the next layer of armor. This is done successively and then if the shell reaches the barbette, it has to have enough penetration to pierce it.

So the overall protection can be up to 30 inches in your example, but not always 30 inches, and so sometimes, depending on the circumstances, it can be defeated by a large shell.

EDIT:
The Citadel armor schemes save a lot of weight compared to pure armor equivalence, which could be impossible without this system, as in your example, 30 inches of armor would cost a tremendous amount of extra tons, and if the tonnage would be available, then it would be restricting you to use it for other vital aspects of your ship. 

It would be very helpful to have some idea of what this penetration-reduction formula is.  Be a lot easier to do things like scale our armor to the main guns of our ship.  Is it half each time, 3/4-1/2-1/2? etc.

[Norbert Sattler]

@Dman1791I know, as I said in my post I was massively simplifying to explain the game-mechanics.

But your post made me think something: The game needs something in addition to penetration and partial penetration.

Unless it triggers an ammo detonation, we don't see a difference in the logs between a detonation within the main armour, but outside the citadel and a detonation within the citadel.

[TK3600]

On 7/30/2022 at 2:36 AM, Kane said:

It would be very helpful to have some idea of what this penetration-reduction formula is.  Be a lot easier to do things like scale our armor to the main guns of our ship.  Is it half each time, 3/4-1/2-1/2? etc.

Anyone knows how armor are stacked? A formula that is. I want my magazine to be impenetrable even if main belt get pen.

[Azerostar]

5 hours ago, TK3600 said:

Anyone knows how armor are stacked? A formula that is. I want my magazine to be impenetrable even if main belt get pen.

In this game,your armor all depend on 2nd or 3rd layer(if you have 3rd layer) of citadel armor.

The main belt/deck,1st and 2nd layer citadel armor just provide extra thick threshold to 3rd layer.

[gsc]

Just to add to the necro-ing of this thread...

Yes, the explanation given in-game for armor penetration / reduction of shell penetration power is wanting/confusing unless im overthinking again and thus failing to grasp properly.

The in-game description for, say, the first inner belt says "The shell has lost minimum 50% of its penetrating power when it reaches this layer...".

So, lets say we have 30* Main Belt and a shell with 50* penetrating power softly touching said Main Belt because reasons...

Does that mean 50% of Original Penetrating power of 50 pen so it has 25 pen left when it reaches the first inner belt after going through the 30 main belt?

Or does it mean it has has 50 Original pen MINUS what it punched through Main Belt (30) and 50% of THAT remaining pen? 50-30 = 20 ; 20/2 = 10?

That was what was described some posts above which was mildly confusing

Or is it indeed just a multiplicator of armor thickness as described somewhere else so that:

1st inner belt/deck thickness = (thickness in units)*2  ("..shell has lost 50% penetrating power...")
2nd inner belt/deck thickness =    ""   *3  ("...shell has lost 75% penetrating power...")
3rd inner belt/deck thickness =    ""   *9  ("...shell has lost 90% penetrating power...")

 

 

 

 

 

 

 

* insert favourite units; cm/inch/mm/football fields etc

[TK3600]

15 hours ago, Azerostar said:

In this game,your armor all depend on 2nd or 3rd layer(if you have 3rd layer) of citadel armor.

The main belt/deck,1st and 2nd layer citadel armor just provide extra thick threshold to 3rd layer.

What is the formula then?

Armor: 6in belt, 2in inner belt

Formula 1: 6+2 = 8in. Requiring 6 inch pen to damage, 8in to crit.

Formula 2: 6 + 2*2 = 10in. Requiring 6 in to damage, 10in to crit.

Formula 3: 7in pen. 7 > 6, therefore outter belt pen. 7/2 = 3.5in pen. 3.5 > 2in inner belt, therefore penetrates.

 

From your wording formula 3 seems to be the right one.

Armor: 4in belt, 2in inner belt

Formula 3: 4in pen, just enough for 4in outer belt. 4/2 = 2in pen. 2in pen just enough for 2in inner belt.

^ As far as inner belt goes it is entirely useless. It could be 0. As long as main belt is penetrated, 2in inner belt do not make a difference. Why not make inner belt thicker? Inner belt is capped to 1/2 of main belt. Whenever inner belt is  50%+ of penetration, it would always require main belt of 100%+ of penetration. The main belt will always stop the shell first. Therefore inner belt is useless.

 

[Azerostar]

4 hours ago, TK3600 said:

What is the formula then?

Armor: 6in belt, 2in inner belt

Formula 1: 6+2 = 8in. Requiring 6 inch pen to damage, 8in to crit.

Formula 2: 6 + 2*2 = 10in. Requiring 6 in to damage, 10in to crit.

Formula 3: 7in pen. 7 > 6, therefore outter belt pen. 7/2 = 3.5in pen. 3.5 > 2in inner belt, therefore penetrates.

 

From your wording formula 3 seems to be the right one.

Armor: 4in belt, 2in inner belt

Formula 3: 4in pen, just enough for 4in outer belt. 4/2 = 2in pen. 2in pen just enough for 2in inner belt.

^ As far as inner belt goes it is entirely useless. It could be 0. As long as main belt is penetrated, 2in inner belt do not make a difference. Why not make inner belt thicker? Inner belt is capped to 1/2 of main belt. Whenever inner belt is  50%+ of penetration, it would always require main belt of 100%+ of penetration. The main belt will always stop the shell first. Therefore inner belt is useless.

 

Frist of all, the describe about citadel armor in game is totally misguide.

For example, if you have 10 inch main belt, 5inch 1st layer, 4inch 2nd layer and 3.2 inch 3rd layer, the coming shell has 20inch penetration power.

20inch > 10 inch, so your main belt is penetrated, 12inch(20*0/6) > 5inch,so your 1st layer is penetrated, 6inch(20*0.3) > 4inch, so your 2nd layer is penetrated. Finally, 2.5inch(20*0.125) < 3.2inch, so your 3rd layer won't be penetrated by this shell, so your suffer a partial hit.

You can see the sets about citadel armor layer in params.txt file from resources.assets in Ultimate Admiral Dreadnoughts_Data folder.

penetration_1st_layer_reduction,0.6,Base Reduction of  penetration power after penetrating main belt/deck,,,,,,,
penetration_2nd_layer_reduction,0.3,Base Reduction of  penetration power after penetrating main belt/deck & 1st layer,,,,,,,
penetration_3rd_layer_reduction,0.125,Base Reduction of  penetration power after penetrating main belt/deck & 1st layer & 2nd layer,,,,,,,

And it's clear that 1st layer is no use at all, so if you can't build 2nd layer, then you should not build 1st layer too, in this situation thicker main belt will be better.

 

Edited May 10 by Azerostar

[Azerostar]

19 hours ago, gsc said:

Or is it indeed just a multiplicator of armor thickness as described somewhere else so that:

1st inner belt/deck thickness = (thickness in units)*2  ("..shell has lost 50% penetrating power...")
2nd inner belt/deck thickness =    ""   *3  ("...shell has lost 75% penetrating power...")
3rd inner belt/deck thickness =    ""   *9  ("...shell has lost 90% penetrating power...")

* insert favourite units; cm/inch/mm/football fields etc

This is nearly right. However it should be 1st layer = '''' *1.66, 2nd layer = '''' * 3.33, 3rd layer = '''' * 8

[TK3600]

12 hours ago, Azerostar said:

Frist of all, the describe about citadel armor in game is totally misguide.

For example, if you have 10 inch main belt, 5inch 1st layer, 4inch 2nd layer and 3.2 inch 3rd layer, the coming shell has 20inch penetration power.

20inch > 10 inch, so your main belt is penetrated, 12inch(20*0/6) > 5inch,so your 1st layer is penetrated, 6inch(20*0.3) > 4inch, so your 2nd layer is penetrated. Finally, 2.5inch(20*0.125) < 3.2inch, so your 3rd layer won't be penetrated by this shell, so your suffer a partial hit.

You can see the sets about citadel armor layer in params.txt file from resources.assets in Ultimate Admiral Dreadnoughts_Data folder.

penetration_1st_layer_reduction,0.6,Base Reduction of  penetration power after penetrating main belt/deck,,,,,,,
penetration_2nd_layer_reduction,0.3,Base Reduction of  penetration power after penetrating main belt/deck & 1st layer,,,,,,,
penetration_3rd_layer_reduction,0.125,Base Reduction of  penetration power after penetrating main belt/deck & 1st layer & 2nd layer,,,,,,,

And it's clear that 1st layer is no use at all, so if you can't build 2nd layer, then you should not build 1st layer too, in this situation thicker main belt will be better.

 

So in other words the main belt should be minimized, while inner belt maximized.

[TK3600]

12 hours ago, Azerostar said:

Frist of all, the describe about citadel armor in game is totally misguide.

For example, if you have 10 inch main belt, 5inch 1st layer, 4inch 2nd layer and 3.2 inch 3rd layer, the coming shell has 20inch penetration power.

20inch > 10 inch, so your main belt is penetrated, 12inch(20*0/6) > 5inch,so your 1st layer is penetrated, 6inch(20*0.3) > 4inch, so your 2nd layer is penetrated. Finally, 2.5inch(20*0.125) < 3.2inch, so your 3rd layer won't be penetrated by this shell, so your suffer a partial hit.

You can see the sets about citadel armor layer in params.txt file from resources.assets in Ultimate Admiral Dreadnoughts_Data folder.

penetration_1st_layer_reduction,0.6,Base Reduction of  penetration power after penetrating main belt/deck,,,,,,,
penetration_2nd_layer_reduction,0.3,Base Reduction of  penetration power after penetrating main belt/deck & 1st layer,,,,,,,
penetration_3rd_layer_reduction,0.125,Base Reduction of  penetration power after penetrating main belt/deck & 1st layer & 2nd layer,,,,,,,

And it's clear that 1st layer is no use at all, so if you can't build 2nd layer, then you should not build 1st layer too, in this situation thicker main belt will be better.

 

See bolded portion:

This is not right. If 0.6 reduction, then 20in pen should become 8in pen after main belt. The main belt can be 1 inch, it will still be 8 inch pen after main belt. The main belt could be 19inch, the post main belt pen would still be 8 inch. Am I getting this right?

[Azerostar]

8 hours ago, TK3600 said:

See bolded portion:

This is not right. If 0.6 reduction, then 20in pen should become 8in pen after main belt. The main belt can be 1 inch, it will still be 8 inch pen after main belt. The main belt could be 19inch, the post main belt pen would still be 8 inch. Am I getting this right?

The 'reduction' works on the current layer which is been checking, if a layer is penetrated, then it will not effect the shell's penetration. And the 'penetration_1st_layer_reduction,0.6' here means 'reduce to 60%'.

So if a shell with 20inch penetration go through the main belt, then it still has 20inch penetration, no matter how thick the main belt is. However, it will use 12inch (20inch *0.6) penetration when runs the armor check with 1st inner layer.

This is very ridiculous in some ways, but it is how the armor system working in UAD exactly.

Edited May 11 by Azerostar

[TK3600]

3 hours ago, Azerostar said:

The 'reduction' works on the current layer which is been checking, if a layer is penetrated, then it will not effect the shell's penetration. And the 'penetration_1st_layer_reduction,0.6' here means 'reduce to 60%'.

So if a shell with 20inch penetration go through the main belt, then it still has 20inch penetration, no matter how thick the main belt is. However, it will use 12inch (20inch *0.6) penetration when runs the armor check with 1st inner layer.

This is very ridiculous in some ways, but it is how the armor system working in UAD exactly.

In that case, two layer of armor is useless. To block 20in pen I need 12in inner layer. But to acquire that I need 24in main belt. 24in main will block 20in pen anyway.

In conclusion two layer armor is trash. Maybe can work with 3.

[Azerostar]

8 minutes ago, TK3600 said:

In that case, two layer of armor is useless. To block 20in pen I need 12in inner layer. But to acquire that I need 24in main belt. 24in main will block 20in pen anyway.

In conclusion two layer armor is trash. Maybe can work with 3.

Yes, and that is why I said the armor depends on 3rd layer.

[TK3600]

@Nick ThomadisThis don't feel right. Is our conclusion right? 2 layer armor do not work. 2nd layer reduce pen to 60%, as opposed to removing 60% pen.

[gsc]

Just for sport i've altered the penetration reductions as defined in the params file for 1-3rd inner belt to 60% reduction of previous belt ie.

1 inner 40% of original pen  "penetration_1st_layer_reduction,0.4,"

2 inner 40% of 1st inner pen  "penetration_2nd_layer_reduction,0.16,"

3 inner 40% of 2nd inner pen  "penetration_3rd_layer_reduction,0.064,"

 

For the multiplicaters thats :

1st belt thickness  *  2.5 effective thiccness

2nd         "            *  6.25         ""

3rd          "            * 15.625      ""

 

It makes the first inner belt not totally useless to the point it can safely be renamed "Mandatory Useless Gameplay Balance Ballast" +  the values to armor for a certain immunity zone against certain guns are more in line with historical values calculated by people with way more expertise...

 

Course i have to test this some more yet but im still waiting for the right amount of boredom to kick in

 

 

 

[TK3600]

7 hours ago, gsc said:

Just for sport i've altered the penetration reductions as defined in the params file for 1-3rd inner belt to 60% reduction of previous belt ie.

1 inner 40% of original pen  "penetration_1st_layer_reduction,0.4,"

2 inner 40% of 1st inner pen  "penetration_2nd_layer_reduction,0.16,"

3 inner 40% of 2nd inner pen  "penetration_3rd_layer_reduction,0.064,"

 

For the multiplicaters thats :

1st belt thickness  *  2.5 effective thiccness

2nd         "            *  6.25         ""

3rd          "            * 15.625      ""

 

It makes the first inner belt not totally useless to the point it can safely be renamed "Mandatory Useless Gameplay Balance Ballast" +  the values to armor for a certain immunity zone against certain guns are more in line with historical values calculated by people with way more expertise...

 

Course i have to test this some more yet but im still waiting for the right amount of boredom to kick in

 

 

 

Here is one counter argument: barbette. Maybe barbette count as one layer behind first citadel. So you should have 0.1 1st inner to trigger 2nd layer effect of barbette?