Armor - how does it work?

[scheerpower]

Hey guys - so I promise this won't be as dumb as the title might sound. I was wondering if anybody knew the details of WHEN armor actually affects enemy shells, and how it covers ships. Like when a shell hits a ship, how often does it hit the belt or extended belt? The turrets or secondaries? The deck, or the unarmored hull? Does anybody have hard figures on this or know how the simulation actually works?

I know the general armor scheme - belt protects the vitals, deck protects the...well, deck, from plunging shots and shrapnel, the "extended" versions cover areas that are uncovered by the main deck and belt.  But...if my belt has 20 inches of armor, will that stop the ship from sinking under heavy fire? Is there enough flotation in the belt-protected compartments to do that? How about if I added 20 inches to the extended belt? The deck?

I'd really appreciate anyone who knows more about this than me jumping in! I started thinking about the details when I designed a 21,000 ton pre-dreadnought with 12 inches of belt armor, designed to be able to take a beating even 5 or 10 years down the line. But then I thought - is it worth it to spend money on this, considering it'll only have 4 12-inch guns? Will it sink now matter how much armor I give it? And then I realized it'd be very useful to know this kind of stuff for plenty of other designs too.

[noshurviverse]

Like when a shell hits a ship, how often does it hit the belt or extended belt? The turrets or secondaries? The deck, or the unarmored hull? Does anybody have hard figures on this or know how the simulation actually works?

To the best of my knowledge, the hit location is largely a dice toss. It has been said that in RtW2 the more turrets that a ship contains the more likely it is that those will be hit, but as of RtW1 a lone turret on a single-gun ship has the same likelihood of being hit as any of the turrets on a turret farm ship.

But...if my belt has 20 inches of armor, will that stop the ship from sinking under heavy fire? Is there enough flotation in the belt-protected compartments to do that? How about if I added 20 inches to the extended belt? The deck?

Reserve buoyancy is a part of what makes the AON scheme worthwhile, as it was a major factor in their design. In-game, I believe this is simply abstracted by making AON ships more resistant to flooding damage. As far as I know, other armor schemes assume that protected compartments are insufficient to keep a ship afloat. It is also worth mentioning that, as nearly all ships had a taper to their belts, that belt armor is assumed to get thinner near the edges. While I can't say for certain, I think that a 20"B/20"BE might still occasionally fail to stop a round with 19" penetration. This is both due to assumed tapers and inaccurate penetration values.

I designed a 21,000 ton pre-dreadnought with 12 inches of belt armor, designed to be able to take a beating even 5 or 10 years down the line. But then I thought - is it worth it to spend money on this, considering it'll only have 4 12-inch guns? Will it sink now matter how much armor I give it?

This is a bit of a tricky argument, because everyone has different design philosophies. Some people here value armor over speed, while others like myself consider a knot of speed to be worth several inches of armor. In any case, I personally wouldn't see much use in a 21,000 ton predread, even with good armor. I simply don't see it having much presence on the battlefield, especially for the cost. Also, what nation are you playing as? Every nation has different requirements, which can affect ship design significantly.

EDIT: Also, perhaps you should post a few of your designs for us to debate endlessly over give feedback on.

[dorn]

Feb 25, 2019 22:45:08 GMT -6 scheerpower said:

Hey guys - so I promise this won't be as dumb as the title might sound. I was wondering if anybody knew the details of WHEN armor actually affects enemy shells, and how it covers ships. Like when a shell hits a ship, how often does it hit the belt or extended belt? The turrets or secondaries? The deck, or the unarmored hull? Does anybody have hard figures on this or know how the simulation actually works?

I know the general armor scheme - belt protects the vitals, deck protects the...well, deck, from plunging shots and shrapnel, the "extended" versions cover areas that are uncovered by the main deck and belt.  But...if my belt has 20 inches of armor, will that stop the ship from sinking under heavy fire? Is there enough flotation in the belt-protected compartments to do that? How about if I added 20 inches to the extended belt? The deck?

I'd really appreciate anyone who knows more about this than me jumping in! I started thinking about the details when I designed a 21,000 ton pre-dreadnought with 12 inches of belt armor, designed to be able to take a beating even 5 or 10 years down the line. But then I thought - is it worth it to spend money on this, considering it'll only have 4 12-inch guns? Will it sink now matter how much armor I give it? And then I realized it'd be very useful to know this kind of stuff for plenty of other designs too.

The percentages of hits same part of hits is hidden in the game.

However I remember that Frederick wrote that for RTW2 the probability hit of main guns would be scaled to number of turrets so I take it as it is not done that way in RTW and that there is same probability even if you have 1 or 5 turrets.

Relating to armor protection, there is AoN scheme if you "invented it" using armor scheme flat deck on top. If you choose this armor scheme and your main belt and deck armor is not penetrated the only way ship could be sink is through torpedoes or flash fire from some of the turret.

Spending money on pre-dreadnought is not worth it because several reaasons:

1. your firepower will be missing very quickly against dreadnoughts as usual dreadnoughts have 8 and more guns for broadside

2. you speed is limited on pre-dreadnought, it is link of the hull

3. you level of technology at that time is quite low making it quite inefficient against 10 years newer battleship

4. level of torpedo protection would be probably nil

The isssue is that building large predreadnought would cost you a lot of money however it would get old quite quickly. It would be more costly than first dreadnoughts but not better.

[Fredrik W]

Feb 26, 2019 6:24:06 GMT -6 @dorn said:

However I remember that Frederick wrote that for RTW2 the probability hit of main guns would be scaled to number of turrets so I take it as it is not done that way in RTW and that there is same probability even if you have 1 or 5 turrets.

This is incorrect. The probability of a turret hit is related to the number of turrets, and has always been so in RTW.

[williammiller]

I can vouch for this as well as I distinctly recall helping to perform some analysis on that for RTW...

[scheerpower]

Alright, so not a lot of hard numbers on the inner workings. That's a bit of a shame - I didn't really expect a complete breakdown of % hits on each area of the ship, but it'd be really useful to know more about flotation. I'm glad to hear that turret hit chances depend on the number of turrets though! Although I always expected it to work like that, nice to have it confirmed. The opposite would probably make me think about some pretty radical design changes, especially to secondaries.

I'd really like to maximize flotation for these pre-dreads, does anyone have suggestions on how to do that? Where to put armor, or maybe how much free weight to leave in the design? Some background: I'm playing as Germany, it's mid-1903 and I'm at war with France. Had a great battle off the Netherlands - my 2 pre-dreads in Europe (another is in Southeast Asia) escorted by a light cruiser and 10-15 DDs ran into a smaller French DD group led by a CA. I manually designed my starting fleet, so the pre-dreads could hit 22 knots, luckily the exact same as the French CA. Sank it and some of its DD escorts with no losses, and then ran when 2 French pre-dreads found us (they had 13" guns to my British-built 12 inchers, but only 18 or 19 knots). I noticed that my pre-dreads had taken a few extended belt hits during the battle from the French CA's 6" guns, very minor damage but worrying that they got through. Believe they had 2-4" BE armor, with 9" or 10" in the full belt. So my next pre-dread that I started construction on last night is the 21k ton one. I increased the BE armor to something like 8" or 9", hoping that early shells won't be able to pen it at medium-long range, and it would be able to take a constant beating. The plan is to use their respectable speed and heavy armor in the future to hang in a battle line and draw fire from my valuable heavier-armed dreadnoughts. I'll need to do a lot more monitoring of battle logs in the future though, since heavy armor might be useless if dreadnoughts can still rip big holes in the hull and sink them without having to penetrate the belt or BE.

Some background on the economics of my pre-dreads: I did decide initially to just hoard my money until I could build full dreadnoughts, but did some cost analysis of ships of various sizes and found that dreadnoughts are actually cheaper, in $ per ton, than smaller ships (DDs excluded). Since I generally think of increasing tonnage as providing exponential gains in effectiveness, it was basically a no-brainer to build big pre-dreads instead of some CLs or CAs that'll be completely useless in 5 years when they can't outrun anything. I am still trying to conserve some of my budget for the future, though.

"Relating to armor protection, there is AoN scheme if you "invented it" using armor scheme flat deck on top. If you choose this armor scheme and your main belt and deck armor is not penetrated the only way ship could be sink is through torpedoes or flash fire from some of the turret."

I'm taking this to mean that AoN is a flat deck, not that the flat deck is another armor scheme that would provide a similar kind of protection to flotation. Please correct me if that's wrong. Ok, then I guess all I can do is research and hope I eventually discover AoN.

Appreciate the comments guys - I'll post some screenshots for reference when I get home! Having a lot of fun so far - just managed to develop 12" guns of 0 quality last night to start domestic construction of my 21k pre-dread -- nobody else has the docks for it.

[bcoopactual]

Feb 26, 2019 13:33:59 GMT -6 scheerpower said:

Alright, so not a lot of hard numbers on the inner workings. That's a bit of a shame - I didn't really expect a complete breakdown of % hits on each area of the ship, but it'd be really useful to know more about flotation. I'm glad to hear that turret hit chances depend on the number of turrets though! Although I always expected it to work like that, nice to have it confirmed. The opposite would probably make me think about some pretty radical design changes, especially to secondaries.

I'd really like to maximize flotation for these pre-dreads, does anyone have suggestions on how to do that? Where to put armor, or maybe how much free weight to leave in the design? Some background: I'm playing as Germany, it's mid-1903 and I'm at war with France. Had a great battle off the Netherlands - my 2 pre-dreads in Europe (another is in Southeast Asia) escorted by a light cruiser and 10-15 DDs ran into a smaller French DD group led by a CA. I manually designed my starting fleet, so the pre-dreads could hit 22 knots, luckily the exact same as the French CA. Sank it and some of its DD escorts with no losses, and then ran when 2 French pre-dreads found us (they had 13" guns to my British-built 12 inchers, but only 18 or 19 knots). I noticed that my pre-dreads had taken a few extended belt hits during the battle from the French CA's 6" guns, very minor damage but worrying that they got through. Believe they had 2-4" BE armor, with 9" or 10" in the full belt. So my next pre-dread that I started construction on last night is the 21k ton one. I increased the BE armor to something like 8" or 9", hoping that early shells won't be able to pen it at medium-long range, and it would be able to take a constant beating. The plan is to use their respectable speed and heavy armor in the future to hang in a battle line and draw fire from my valuable heavier-armed dreadnoughts. I'll need to do a lot more monitoring of battle logs in the future though, since heavy armor might be useless if dreadnoughts can still rip big holes in the hull and sink them without having to penetrate the belt or BE.

Some background on the economics of my pre-dreads: I did decide initially to just hoard my money until I could build full dreadnoughts, but did some cost analysis of ships of various sizes and found that dreadnoughts are actually cheaper, in $ per ton, than smaller ships (DDs excluded). Since I generally think of increasing tonnage as providing exponential gains in effectiveness, it was basically a no-brainer to build big pre-dreads instead of some CLs or CAs that'll be completely useless in 5 years when they can't outrun anything. I am still trying to conserve some of my budget for the future, though.

"Relating to armor protection, there is AoN scheme if you "invented it" using armor scheme flat deck on top. If you choose this armor scheme and your main belt and deck armor is not penetrated the only way ship could be sink is through torpedoes or flash fire from some of the turret."

I'm taking this to mean that AoN is a flat deck, not that the flat deck is another armor scheme that would provide a similar kind of protection to flotation. Please correct me if that's wrong. Ok, then I guess all I can do is research and hope I eventually discover AoN.

Appreciate the comments guys - I'll post some screenshots for reference when I get home! Having a lot of fun so far - just managed to develop 12" guns of 0 quality last night to start domestic construction of my 21k pre-dread -- nobody else has the docks for it.

Having available tonnage left over does not affect the number of flotation points a ship has.  Leaving unused tonnage is really only useful for refitting additional equipment later, such as fire control or mines, without having to remove something else.  I usually use the tonnage I would normally leave available for those kinds of upgrades to add additional ammunition since it is easy and free/cheap to remove it later.  

Being overweight does remove float points though and the effect gets worse per-ton as the ship gets more overloaded.  It also increases the likelihood of adverse ship traits like being unable to reach design speed. (And no, leaving unused tonnage available does not increase the chance of positive ship traits.)   

As far as pre-dreadnought armor there are, I believe, two main schools of thought.  Legacy pre-dreads usually have secondaries of either 6 or 7 inch guns.  So you can design the belt extended armor to resist those guns.  8 inch (and greater) secondaries get unlocked within the first year but those ships will take another 2 1/2 years to build so you won't see them until about 1904.  Also, many AI designs stay with 6-7 inch guns so they can ship more of them.  

The other main option is to only armor the extended belt to 2 - 2 1/2 inches for splinter protection.  The combination of improving AP tech and unlocking larger secondaries means that it becomes increasing difficult and then basically impossible to armor the ends of the ship fully.  The same problem that eventually led designers down the road to all-or-nothing schemes.  So since early designs are vulnerable to progressive flooding, you need to protect against splinter damage but adding more armor might not be worth the tonnage. 


Flat deck and AoN are two different things although you need to use flat deck to get the benefits of AoN after AoN is researched.  You can choose flat deck from the beginning of the game for battleships if you want but while the flat deck is lighter and leaves more tonnage to use for armor and weapons you don't get the armor bonus of having the sloping deck behind the belt.  Personally, for battleships, I don't switch to flat deck until I have researched or stolen the AoN "tech".  


      

[director]

One consideration is that 12" of armor in-game does not actually equal 12" of armor. As I understand it, it equates to the amount of protection that 12" of armor would provide in 1925. So 9" of armor in 1900 might actually be considerably thicker - it just resists as well as 9" would in 1925.

Classic battleship design considered the 'ideal' armor belt to be equal in thickness to the caliber of the main battery: 12" guns, 12" of belt and so forth. This ideal was rarely achieved since things like speed, secondary armament and so forth kept taking tonnage, but it is not a bad starting point. My personal goal for battleships is to set the main turret armor at .5" to 1" less than the main gun caliber and drop the belt an inch below that - some fiddling is usually necessary, but that's where I start.

I build large pre-dreadnoughts (larger than, say, 16k tons) only if I can fit them with a heavy secondary armament (9-10"), decent speed and stout armor. If they can make 20-22 knots they can keep up with my battle-line for years to come, and they make dandy wartime colonial place-holders in old age. I've had a squadron of semi-dreadnoughts stand off the occasional raiding BB or BC and they have always performed well for me - not as nice as a dreadnought, but of some value.

I build B's and semi's as I have money... keeping money back for dreadnoughts doesn't help me in the early wars but another 4 battleships might.

When I first began playing, I armored-up the belt-extension to 33-50% of the main belt. Now I'm down to 25-33%... can't make myself drop down to 2".

On your economic point, scheerpower, Fisher sold the dreadnought to the Admiralty and government not as a war-winning weapon but as a cost-saving measure. Each BB was at least as powerful as two standard Bs but required less money to maintain and operate.

AoN armor 'in-game' makes the tonnages for belt-extension and deck-extension armor available for other things, as bcoopactual has said (bcoopus is Locutus' pen-name, I suspect). In actuality the 'flat deck' is only flat compared to the curved or sloped armored-deck, but that's a minor point. A domed armored deck provides better resistance from shells coming in flat (IE from short range) both because the curve increases the chance the shell will bounce and because it increases the apparent thickness the shell has to punch through, but it does not defend as well against shells coming from longer range that strike it perpendicularly. The flatter deck is better against plunging fire but contributes little or nothing to the strength of the belt for shells coming in at a flat trajectory.

[aeson]

You can choose flat deck from the beginning of the game for battleships if you want but while the flat deck is lighter and leaves more tonnage to use for armor and weapons you don't get the armor bonus of having the sloping deck behind the belt. Personally, for battleships, I don't switch to flat deck until I have researched or stolen the AoN "tech".

Another reason to consider holding off on using a Flat Deck armor scheme until later in the game is that the weight advantage that the Flat Deck scheme has over the Sloped Deck scheme comes entirely from a roughly 10% reduction in the tonnage cost of the deck (D) and deck extended (DE) armor. D and DE armor is likely to be relatively thin and therefore light in the early part of the game; coupled with the ships themselves being small (at least by comparison to ships built later in the game), using the Flat Deck scheme just won't buy you a lot of tonnage to play with in the early part of the game. Using flat deck instead of sloped deck on a ~15,000t legacy fleet or early-1900s battleship might save you a hundred-odd tons, which isn't exactly nothing but also isn't that useful - it's perhaps an extra pair of casemated 6" guns with 2" armor protection or a few submerged torpedo tubes, maybe with a few extra 12" shells for the main battery thrown in.

then ran when 2 French pre-dreads found us (they had 13" guns to my British-built 12 inchers, but only 18 or 19 knots)

For whatever it's worth, early-game French warships with 13" guns are likely to have bad 13" guns; France starts with access to the same 13"/Q-2 guns that Great Britain has, and 13"/Q-2 guns have a very similar armor penetration profile to 12"/Q- guns but are shorter-ranged and slower-firing. The greater tonnage costs for 13" guns and ammunition also tends to hurt them relative to similar predreadnought battleships armed with 12" guns despite the higher per-hit damage. I wouldn't be terribly surprised if your 12" battleships were capable of taking the French 13" battleships in a 'fair' fight, at least if your ships were built on 16,000 tons.

As far as pre-dreadnought armor there are, I believe, two main schools of thought. Legacy pre-dreads usually have secondaries of either 6 or 7 inch guns. So you can design the belt extended armor to resist those guns. 8 inch (and greater) secondaries get unlocked within the first year but those ships will take another 2 1/2 years to build so you won't see them until about 1904. Also, many AI designs stay with 6-7 inch guns so they can ship more of them.

The other main option is to only armor the extended belt to 2 - 2 1/2 inches for splinter protection. The combination of improving AP tech and unlocking larger secondaries means that it becomes increasing difficult and then basically impossible to armor the ends of the ship fully. The same problem that eventually led designers down the road to all-or-nothing schemes. So since early designs are vulnerable to progressive flooding, you need to protect against splinter damage but adding more armor might not be worth the tonnage.

A third option is to use a uniform-thickness (BE = B) narrow belt scheme. A graduated normal belt scheme becomes about as heavy as a uniform narrow belt scheme with the same maximum thickness when the BE armor in the graduated scheme reaches about 40% of the maximum belt thickness, and based on tonnage costs per inch of thickness about 77% of the area covered by B and BE armor under the normal belt scheme will remain covered by B and BE armor under the narrow belt scheme. I am not entirely certain what parts of the ship lose armor protection; however, as the belt scheme does not affect the weight of the deck armor my assumption is that the extent of waterline belt coverage is the same regardless of whether the belt scheme chosen is narrow or normal.