weight distribution on ships more specificaly battleships

[bcoopactual]

imryn , I don't believe that adding more armor to the citadel than you think you need (assuming you've met your speed/firepower goals) is wasted. What you are really doing is increasing the ship's immune zone not not truly making the ship "more immune" (i.e. not making an already invulnerable ship more invulnerable) to whatever weapons it was designed against. Immune zones are misnomers and not only are they not absolutes (as I have no doubt you were already aware) but the designers (and the captains who would fight the ships) could never be sure that the enemy didn't have to audacity to employ guns more powerful than what the designers initially planned for. So if you have the extra tonnage available, adding more armor than what you believe you need for your desired immune zone at worst provides a bit of insurance in case you've underestimated the enemy's capabilities and/or better may actually extend the ship's immune zone against the enemy giving the captain additional flexibility to fight at a range where his ship's strengths are maximized and the weaknesses minimized compared to his enemy. That's certainly not a waste in my book.

I would agree there would be real life tradeoffs. The ship would end up being larger and more expensive and perhaps have greater fuel consumption than if you had stuck to the original immune zone armor tonnage. That's not trivial although I personally would be willing to spend the little extra to get that edge to survivability but that easy for me to say when I'm not spending real money. Fortunately in the game most of those negatives (additional steel production required that could have gone to tanks or submarines for example) aren't simulated.

[dorn]

There is another possibility to increase vertical protection. You can incline your main belt so it is more effective.

However this has some disadvantages. In case you are hit than part of ships is damage and could be flooded as inclined belt are not usual external part of ship (HMS Hood was exception). In RTW2 according to developers journal, it should have effect that they are more likely hits to deck and less likely hits to belt and that there would be some risk of belt edge hits.

In real life, this different philosophy get different ships for RN which emphasized on maximum protected volume with thicker belt in KGV class. On opposite was USN, IJN, French, Yamato and Italians.

[director]

dorn - I was pointing out that ships with older armor schemes - which are, of definition, older ships - take and react to damage differently from more modern, AoN-scheme ships. If you only compare ships of similar age you will never have a comparison of AoN versus extended-belt schemes.

[oldpop2000]

I would like to point out that when the All or Nothing armor scheme was developed and implemented, two of the dreadnought most dangerous enemies were already progressing in technology. The aircraft was being powered by larger and better designed engines, cantilever wing, stronger fuselage structures etc. By the time of WW2, a naval bomber, be it a dive bomber or torpedo bomber, could now carry at least a 1000 lbs. armor piercing bomb and at least a 22 inch torpedo. These two weapons could either mission kill a ship or sink it, regardless of the AON. Submarines were now improving, bigger torpedoes, higher loads, faster underwater speeds etc.


These two weapons now added to the enemies arsenal, now gave him and you, three weapons to be concerned about in designing your ships. The battleships sunk in WW2, excluding the Japanese battlecruisers, in most cases were sunk by aerial torpedoes. The German Scharnhorst was sunk by a combination of gunnery and torpedoes. However, we must understand that most historians and naval experts have always considered her a battlecruiser. So be it. Bismarck of course was sunk by surface action but was put into that position by a torpedo hit in the stern by a torpedo bomber. Barham was sunk by torpedoes from a submarine. The list goes on and on.


I am not entirely convinced that in the new game, AON is really that important. I would not, and I won't rely on it to save my ship or ships. I do not believe that All or Nothing actually saved any ships, at least no one has been able to prove it to me, not Friedman or any one else. I agree that it was better than the older scheme, but against the new and improved weaponry, it was just another system. My point is that in the new game, beware that there are new and improved weapons, don't focus on all or nothing and sacrifice other aspects of the ships design. There maybe more attacks by land and sea based air and submarines than in RTW. Time changes things. 


BTW, I am writing this piece from memory so I might get some facts wrong, so be it. 

[dorn]

Jan 16, 2019 11:00:54 GMT -6 director said:

dorn - I was pointing out that ships with older armor schemes - which are, of definition, older ships - take and react to damage differently from more modern, AoN-scheme ships. If you only compare ships of similar age you will never have a comparison of AoN versus extended-belt schemes.

There was no battle between new fast battleship of WW2 era and old WW1 era battleship. The most close was Hood vs. Bismarck as sinking of Japanese battleships as Yamashiro was not fight to do any comparison.

[ddg]

Jan 16, 2019 6:20:47 GMT -6 imryn said:

Thank you for your response, it made me review what I have said here and realise that I have strayed quite a long way from my original point.

Originally I was complaining that AoN armour is presented in RTW1 as a "top of the tech tree" option with its own check box in the ship design screen. At that time I knew that many late era battleships were not pure AoN designs and yet were effective ships, and so I was looking for less emphasis on AoN as a "tick the box" obvious option in the game.

*****

Despite the need to reduce weight to achieve their design speeds all of the later US battleships incorporated multiple armoured decks that did not follow AoN design principals.

*****

Historically, we have evidence of several ships that use (in RTW1 terms) sloped deck and belt armour performing very well in short to medium range battles. We have no examples of flat deck on belt armoured ships performing any where near as well at any range. Technically, every battleship built after 1911 is an AoN ship to some degree however RTW1 considers AoN to be purely an armour design and there is little historical evidence on the performance of flat deck on belt armour at any range, whereas we have ample evidence that sloped deck and belt armour performs very well at short to medium range.

Given the way that the RTW AI handles spotting the enemy forces engagements into that medium to short range environment I think that the sloped deck and belt armour scheme should outperform flat deck on belt. I don't think it should be removed from RTW but I do think the ship design and the armour aspects should be separated into different tech advances. "Armoured Citadel" could offer a % weight saving for both belt and deck armour regardless of the armour scheme used, along with the current entry but that should have its affect reduced so that AoN + Armoured Citadel equals what we have now.

I appreciate you taking the time reevaluate your arguments. Apologies for cutting up your post but there are only a handful of things I think I specifically need to respond to.

With respect to AoN's position in the tech tree and special interface, the former is, I think, entirely due to chronology: "All or nothing" doesn't really appear as a design philosophy until well into the period covered by RTW. The latter is a piece of the game's development history that you may be unfamiliar with. Early on, players had difficulty determining whether a ship design did in fact incorporate AoN. It's easy to overlook extended armor and difficult to distinguish the effects in action, so Fredrik added the AoN indicator to make it clear. That was a fairly early patch, I think, but it was not present in the initial release version.

I'm curious why you feel that the layered horizontal protection system used in later American ships is inconsistent with the AoN principle. I think your posting suggests that it is the layering in and of itself that is the issue. If so, I disagree. Each deck has a specific purpose, but together they form a single protection system that covers the ship's vitals and not its ends. To me, that is the heart of the AoN philosophy.

You've also made repeated reference to the combat experience of Bismarck versus the lack of similar experience for AoN designs with the conclusion that a proven design is superior to an unproven one. I don't think that follows logically. Certainly we can say that Bismarck absorbed an enormous amount of punishment before sinking, but we cannot say from experience whether an AoN ship of equivalent tonnage and priorities would have absorbed more or less (and, as I think you've mentioned, armor design is only a piece of this equation in any case). In the absence of direct, unambiguous, combat-tested evidence, it's not clear to me why the null hypothesis should favor the older system, or alternatively why the burden of proof must rest on the newer. Instead, I would expect RTW to roughly follow the path of historical naval architects, who overall certainly moved more towards an AoN system than away from it.

To return to actual in-game performance, I think there's good reason to believe that Sloped Deck can outperform Flat Deck at shorter combat ranges even in the late game. At least one of the regulars here (dorn, iirc) uses it for just that reason. You can make an argument that some of the benefits of the AoN technology (e.g. improved resistance to flooding in the unarmored ends) should be applicable to other armor schemes, but other elements of the AoN philosophy require the increased protected volume produced by raising the armor deck. You might be more successful in your campaign if you narrow your focus.

[archelaos]

I do agree that there should be some sort of "advanced turtledeck" design that, at the cost of additional weight, has the flooding protection similar to AoN.

But, as I mentioned this already, I think that by ww2 no amount of armour could protect the ships from the available weapons. This resulted from the fact that while vitals could be protected at the high cost, those vitals were not enough to keep the ship in fight. And as the capital ships were no longer operating in large fleets but either single or in small squadrons, a mission killed ship was almost certainly lost as they could be easily finished off or forced to scuttle by continued pressure (by surface forces) or another strike (by air force). In fact any sort of damage was threatening, as it is an opening to further attacks. What's more, in a world of radars and long range air spotters it was very difficult to disengage with damaged ships. Often sea worthy ships were scuttled just because they would slow the squadron down endangering other ships.

In ww1 it was different, as weapons were less damaging, and further a damaged ship could be often covered by a fleet. And without a strong airforce to finish off crippled ships breaking contact was most often sufficient to save damaged ships.

[bcoopactual]

Jan 16, 2019 23:12:44 GMT -6 archelaos said:

I do agree that there should be some sort of "advanced turtledeck" design that, at the cost of additional weight, has the flooding protection similar to AoN.

I agree with this as well to an extent.   My understanding is the Bismarcks at least were certainly designed this way to prevent flooding from the ends getting into the citadel.  I'm not sure it should cost extra weight because I think that the game already takes into account the armored bulkheads at the front and rear of the citadel.  The developers would have to verify that and then check to see if the WW2 era German designs used a beefed up (i.e. heavier) armored bulkhead design compared to their WW1 designs to see if the added weight in game is appropriate.   

My main question would be did the design actually work to to do that.  The sloping portion of the armored deck is mostly below the nominal waterline and the flat portion of the turtleback is only a foot or so above it.  Any kind of a list or of the ship is down by the bow or stern would seem to me to make the spaces above the deck vulnerable to progressive flooding.  I have to assume that any battle damage sufficient to cause a significant list or trim would probably compromise the watertight integrity of the unprotected spaces above the armored deck to some extent as well.   And since the armored deck is so low does the protected portion have enough reserve buoyancy to save the ship if one or both relatively unprotected ends are flooded and the spaces above start to flood?  The historical answer would seem to be no but the ships had the advantage that their armored citadels covered a greater percentage of the hull length than contemporary battleships (I assume due to having to cover the space between four turrets instead of others' three or two) and the ships were quite beamy (thicc as the kids today would say) so maybe that makes up for the lower armored deck but I kinda doubt it.  I haven't done the math so I don't know for sure.

I would presume that as late game designs, they would benefit from continued improvements in Subdivision and Damage Control techs and that may be enough to account for any real life benefits of the design rather than give them similar protections to AoN. 

Interesting idea with plenty of food for thought one way or the other though.    

[imryn]

Jan 16, 2019 21:10:13 GMT -6 ddg said:

Jan 16, 2019 6:20:47 GMT -6 imryn said:

Thank you for your response, it made me review what I have said here and realise that I have strayed quite a long way from my original point.

Originally I was complaining that AoN armour is presented in RTW1 as a "top of the tech tree" option with its own check box in the ship design screen. At that time I knew that many late era battleships were not pure AoN designs and yet were effective ships, and so I was looking for less emphasis on AoN as a "tick the box" obvious option in the game.

*****

Despite the need to reduce weight to achieve their design speeds all of the later US battleships incorporated multiple armoured decks that did not follow AoN design principals.

*****

Historically, we have evidence of several ships that use (in RTW1 terms) sloped deck and belt armour performing very well in short to medium range battles. We have no examples of flat deck on belt armoured ships performing any where near as well at any range. Technically, every battleship built after 1911 is an AoN ship to some degree however RTW1 considers AoN to be purely an armour design and there is little historical evidence on the performance of flat deck on belt armour at any range, whereas we have ample evidence that sloped deck and belt armour performs very well at short to medium range.

Given the way that the RTW AI handles spotting the enemy forces engagements into that medium to short range environment I think that the sloped deck and belt armour scheme should outperform flat deck on belt. I don't think it should be removed from RTW but I do think the ship design and the armour aspects should be separated into different tech advances. "Armoured Citadel" could offer a % weight saving for both belt and deck armour regardless of the armour scheme used, along with the current entry but that should have its affect reduced so that AoN + Armoured Citadel equals what we have now.

I appreciate you taking the time reevaluate your arguments. Apologies for cutting up your post but there are only a handful of things I think I specifically need to respond to.

With respect to AoN's position in the tech tree and special interface, the former is, I think, entirely due to chronology: "All or nothing" doesn't really appear as a design philosophy until well into the period covered by RTW. The latter is a piece of the game's development history that you may be unfamiliar with. Early on, players had difficulty determining whether a ship design did in fact incorporate AoN. It's easy to overlook extended armor and difficult to distinguish the effects in action, so Fredrik added the AoN indicator to make it clear. That was a fairly early patch, I think, but it was not present in the initial release version.

I'm curious why you feel that the layered horizontal protection system used in later American ships is inconsistent with the AoN principle. I think your posting suggests that it is the layering in and of itself that is the issue. If so, I disagree. Each deck has a specific purpose, but together they form a single protection system that covers the ship's vitals and not its ends. To me, that is the heart of the AoN philosophy.

You've also made repeated reference to the combat experience of Bismarck versus the lack of similar experience for AoN designs with the conclusion that a proven design is superior to an unproven one. I don't think that follows logically. Certainly we can say that Bismarck absorbed an enormous amount of punishment before sinking, but we cannot say from experience whether an AoN ship of equivalent tonnage and priorities would have absorbed more or less (and, as I think you've mentioned, armor design is only a piece of this equation in any case). In the absence of direct, unambiguous, combat-tested evidence, it's not clear to me why the null hypothesis should favor the older system, or alternatively why the burden of proof must rest on the newer. Instead, I would expect RTW to roughly follow the path of historical naval architects, who overall certainly moved more towards an AoN system than away from it.

To return to actual in-game performance, I think there's good reason to believe that Sloped Deck can outperform Flat Deck at shorter combat ranges even in the late game. At least one of the regulars here (dorn, iirc) uses it for just that reason. You can make an argument that some of the benefits of the AoN technology (e.g. improved resistance to flooding in the unarmored ends) should be applicable to other armor schemes, but other elements of the AoN philosophy require the increased protected volume produced by raising the armor deck. You might be more successful in your campaign if you narrow your focus.

I am a newcomer to RTW so I wasn't aware of the history behind the interface. Now that you have explained it it makes perfect sense, but I wish they had found another way to clarify what armour scheme was in use.

I am referring to a wikipedia article on AoN link Section 3 "In Practice" talks about this. I realise that this is not exactly the most authoritative source however some cross checking has shown me that the additional decks referred to did exist and had the purpose stated.

It bugs me that so much of my argument is based on the performance of the Bismark, because there were several other German ships that had the same armour scheme and did very well, but Bismark is just so damn famous that it eclipses the rest. The Bismark was an AoN ship in the real world, but would be classed as a non AoN ship in RTW terms. She was built with an armoured citadel and the armour scheme was built into the design and not added on afterwards so she definitely qualifies as AoN there, but the armour scheme that was used was the older banded style with a sloped turtledeck over the citadel, which definitely doesn't conform to the RTW Flat Deck on Belt scheme. In addition she had significant armour on the bow and stern and layered horizontal deck armour similar in purpose to contemporary US ships. The performance of the armour scheme on these ships was excellent, and i think it is fair to say that they would out perform one of the US fast battleships under similar circumstances. The US ships were designed for long range engagements which presents a different threat and if forced into a short / medium range battle with modern opponents I think their armour would be suspect. I also think that if they were able to use their speed advantage to open the range, and if the sea state / visibility allowed them to engage at long range they would do much better.

I suppose a Flat Deck on Belt ship could be designed for short range engagements, but I think at the shorter ranges where secondary guns will also be used the lack of BE and DE armour will hurt them.

In game terms, where the AI pretty much precludes long range gunnery I think the armour scheme that was designed for and proven to be very effective in short range battles should have precedence.

The whole subject is complicated by the fact that AoN was not just an armour scheme in the real world, and I think it would be much better if they separated out the design elements from the armour scheme elements.

[imryn]

Jan 16, 2019 8:52:24 GMT -6 bcoopactual said:

imryn , I don't believe that adding more armor to the citadel than you think you need (assuming you've met your speed/firepower goals) is wasted. What you are really doing is increasing the ship's immune zone not not truly making the ship "more immune" (i.e. not making an already invulnerable ship more invulnerable) to whatever weapons it was designed against. Immune zones are misnomers and not only are they not absolutes (as I have no doubt you were already aware) but the designers (and the captains who would fight the ships) could never be sure that the enemy didn't have to audacity to employ guns more powerful than what the designers initially planned for. So if you have the extra tonnage available, adding more armor than what you believe you need for your desired immune zone at worst provides a bit of insurance in case you've underestimated the enemy's capabilities and/or better may actually extend the ship's immune zone against the enemy giving the captain additional flexibility to fight at a range where his ship's strengths are maximized and the weaknesses minimized compared to his enemy. That's certainly not a waste in my book.

I would agree there would be real life tradeoffs. The ship would end up being larger and more expensive and perhaps have greater fuel consumption than if you had stuck to the original immune zone armor tonnage. That's not trivial although I personally would be willing to spend the little extra to get that edge to survivability but that easy for me to say when I'm not spending real money. Fortunately in the game most of those negatives (additional steel production required that could have gone to tanks or submarines for example) aren't simulated.

In the real world it just doesn't work that way. Capital ships are designed by committee over years of time and the finalised designs account for every gram of available weight. once the ship starts building it is almost impossible to make changes as fundamental as changing the citadel armour, so even if it turns out that somehow you have surplus weight capacity it can't be used to increase citadel armour without virtually scrapping the ship and starting again.

As for the trade offs, that's why capital ships are designed by committees. they argue back and forth over every aspect of the design, commission umpteen versions of the plans considering every variation they think of and eventually come up with a compromise that nobody really likes but everyone can live with.

[alexbrunius]

Jan 15, 2019 9:30:40 GMT -6 imryn said:

I think you don't understand me at all. To be absolutely clear: A non AoN ship can be built with a citadel and have just as much protection for it as an AoN ship, as well as having more protection elsewhere. It would mean a trade off for something else so it would be slower or bigger or carry fewer guns in it main battery for example, but it would benefit from just as much citadel protection as an AoN ship and more protection for its bow and stern.

In good visibility firing at long range AoN offers no advantage whatsoever over a sufficiently armoured non AoN ship. I repeat; there is no reason you can't protect a non AoN ship just as well as an AoN ship, it will just weigh more.

So your basically comparing apples to oranges here? If we are going to compare the effectiveness of two different armor schemes it can't be with one of them having substantially more percentage armor weight than the other.

I can turn that argument around and say that instead it's the AoN armor design ship that's designed slower or carry fewer guns in it's main battery, so it will have more than twice as thick Citadel armor!

At one point it will get silly though, so instead of comparing apples to oranges, let's compare same total armor weight of the different schemes which naturally mean AoN will have a thicker armored Citadel.

Jan 15, 2019 9:30:40 GMT -6 imryn said:

Yes, Bismark actually had armour on its bow and stern and was still mission killed. AoN ships have none and are even more vulnerable than Bismark was.

Which well proves the futility and waste of even trying to protect these areas... Thank you for helping prove my point.

Jan 15, 2019 9:30:40 GMT -6 imryn said:

I can't for the life of me figure the relevance of the battle of Samar. Are you referring to the one on 25 Oct 44? or is there another one? If that is the one then OK, Halsey abandons his post leaving a bunch of small carriers and even smaller escorts to face an IJN task group with 4 BB's 6 CA's 2 CL's and 11 DD's. The escorts attack, get cut up by the IJN screen but succeed in convincing the IJN that they are facing the heavy forces that Halsey stupidly took away, and they withdraw. Not Halseys best day by a long shot but I don't see its relevance here.

The relevancy of Samar is that several of the US Destroyers and CVEs survived thanks to having no armor, meaning the heavy shells from Japanese BB and CA did not arm their fuses and passed right through them without detonation. Had they been armored they would have been sunk or suffered heavier damage.

You claimed all ships or crew areas of Battleships had enough armor to arm the fuses, but that is not true at all. It was common to have structural plates down to 10mm thickness and many Battleship shells required passing through well over 30mm armor thickness to arm fuses.

[bcoopactual]

imryn , everything I mentioned was referring to the design process itself not once construction was underway.  There are plenty of reasons why designers may go back and add armor during the design.  Either because of technological improvements that reduced the required tonnage for the propulsion system or by direction of the people in charge of approving the designs because they aren't happy with the current design as is because of whatever compromises had to be made and they want to see various options.  

I'm aware that past a certain point in the design acceptance/building process that making changes is problematic at best resulting in lengthy delays or even impossible without scrapping the work done to that point.   

[imryn]

Jan 17, 2019 6:17:41 GMT -6 bcoopactual said:

imryn , everything I mentioned was referring to the design process itself not once construction was underway.  There are plenty of reasons why designers may go back and add armor during the design.  Either because of technological improvements that reduced the required tonnage for the propulsion system or by direction of the people in charge of approving the designs because they aren't happy with the current design as is because of whatever compromises had to be made and they want to see various options.  

I'm aware that past a certain point in the design acceptance/building process that making changes is problematic at best resulting in lengthy delays or even impossible without scrapping the work done to that point.   

OK sorry my misunderstanding. To my way of thinking if during the design phase a decision is made to increase citadel armour that probably isn't a case of just adding extra armour, its a case of determining that the threat environment requires more armour to meet the design goal. Any argument presented during the design phase that proposed an increase in citadel armour "just in case" without an associated increase in threat would stand very little chance of being adopted, in my opinion.

I believe there are one or two naval architects here; perhaps one of you could give your opinion based on your experiences?

[imryn]

Jan 17, 2019 2:56:31 GMT -6 bcoopactual said:

Jan 16, 2019 23:12:44 GMT -6 archelaos said:

I do agree that there should be some sort of "advanced turtledeck" design that, at the cost of additional weight, has the flooding protection similar to AoN.

I agree with this as well to an extent.   My understanding is the Bismarcks at least were certainly designed this way to prevent flooding from the ends getting into the citadel.  I'm not sure it should cost extra weight because I think that the game already takes into account the armored bulkheads at the front and rear of the citadel.  The developers would have to verify that and then check to see if the WW2 era German designs used a beefed up (i.e. heavier) armored bulkhead design compared to their WW1 designs to see if the added weight in game is appropriate.   

My main question would be did the design actually work to to do that.  The sloping portion of the armored deck is mostly below the nominal waterline and the flat portion of the turtleback is only a foot or so above it.  Any kind of a list or of the ship is down by the bow or stern would seem to me to make the spaces above the deck vulnerable to progressive flooding.  I have to assume that any battle damage sufficient to cause a significant list or trim would probably compromise the watertight integrity of the unprotected spaces above the armored deck to some extent as well.   And since the armored deck is so low does the protected portion have enough reserve buoyancy to save the ship if one or both relatively unprotected ends are flooded and the spaces above start to flood?  The historical answer would seem to be no but the ships had the advantage that their armored citadels covered a greater percentage of the hull length than contemporary battleships (I assume due to having to cover the space between four turrets instead of others' three or two) and the ships were quite beamy (thicc as the kids today would say) so maybe that makes up for the lower armored deck but I kinda doubt it.  I haven't done the math so I don't know for sure.

I would presume that as late game designs, they would benefit from continued improvements in Subdivision and Damage Control techs and that may be enough to account for any real life benefits of the design rather than give them similar protections to AoN. 

Interesting idea with plenty of food for thought one way or the other though.    

I believe the it was recognised that spaces above the turtleback  were at risk of progressive flooding, however I understand that the ship was build with a comprehensive watertight compartmentalisation scheme to counter this risk. Given that the ships hull above the turtleback was shot to pieces and yet there was apparently no progressive flooding in this area indicates it was fairly effective.

I don't know if the citadel had enough reserve buoyancy to counter the sort of flooding you mentioned - for that matter I can't find any information in whether reserve buoyancy was even considered in her design. I think that the Germans relied on her banded armour to protect the entire hull and extensive watertight compartments to contain flooding, and in the event we can't really say they were wrong.

I think if this armour scheme was introduced in RTW2 (and I hope it is) we would have to assume that it did not have enough reserve buoyancy to preserve the ship against extensive flooding elsewhere, particularly if the scheme was applied to a ship with a more compact citadel than the originals.

EDIT: I have found this article which seems to indicate that the citadel did have sufficient reserve buoyancy link

[dorn]

In game players usually build "proto AoN" ship before AoN technology is researched in way that they use only splinter 2" protection for extended part of ship or no protection for extended parts at all as the same principle AoN applied here too - to protect vital spaces. In case that ship is not AoN than she can be even sunk without penetrating citadel however decreasing citadel armor in favor of incresing protection of extended part does not help either so for this reason the belt armor is max out.

The question in game is that level of deck protection depends on firing distance. At start of game and even a lot of years after the hit just about 20.000 distance is very unlikely to happen so it is questionable to put a lot of armor to deck. A deck armor is quite expensive and could be use to enhance main belt protection. So some players put less deck armor and increase belt protection as the philosophy is if I get hit by long range plunging fire it is very unlucky but one penetrated shot should not jeopardize ship too much. But almost all players armored turret top armor a lot as it is one of cheapest by tonnage point of view.

As game progress and firing distance is higher than visibility, the protection at max. range is almost impossible as plunging fire of 15" guns and higher caliber guns have high penetration power than protection 6" of deck armor. So players usually start to play with immunity zone. With AoN armor applied you can set-up your immunity zone against some caliber and create protection withing certain range.

However as time go forward in RTW another issue arises. Penetration power of guns are still increasing making vertical protection against 15", 16" gun difficult. Around 1920 penetration power of 16" guns start to be higher than maximum armor belt thickness at 15000 yards. And 15000 is still quite common distance of fire for difference reasons as weather, hit reliability etc. So another question arises. How to solve this issue and protect citadel against such hits.

And the possible answer is to put turtle back armor on ship with all the disadvantages that this scheme provide. What they are?

Ship could be sink only by destroying and flooding extended part of ship and destroying superstructure could make ship ineffective.

So again what is possible solution? Either ignore it and take the risk as you get better protection of main citadel or you can armor extended part of ship. This is however quite expensive so the solution could be narrow belt configuration. So we have ship that has higher vertical protection of citadel vs. AoN ship, has covered extended part similarly so do not need to worry about sinking through extended parts of ship (BE,DE) which increase chance to remain in full speed as not only extended part of ship but funnel uptakes too as they used BE armor. On opposite there is higher risk of edge belt hits and structure of ship is less protected as belt and dekc armor protected less of the ship. But it is good alternative especially in Northern Europe where ideal wheather is not so common and vertical protection is more important.

So at the end we have to main solutions in RTW. Either AoN armor or sloped deck armor with narrow belt configuration and complete protection of the ship. AoN armor scheme is lighter however it is question of sacrificing some speed or fipower. If it helps to protect ship and be able to penetrate enemy armor than volume of fire or speed are not so important.

Frankly speaking I use both principles as I can see them as very similar effective and when I use one of system it is more linked to current conditions and taste.