How does HE & splinter penetration work?

[summersnows]

I’ve gotten a lot of conflicting information about this topic, not in the least because HE shell penetration and splinter penetration are separate things that are frequently mixed up. I think I have a decent understanding of the topic, but I would like to check in with some other players to confirm.



HE Shell Penetration: The direct armor penetration value of an HE shell directly impacting armor.



Most of this seems to come from this Developer Post.

"A HE shell should penetrate (roughly) 40% of its diameter (plus or minus approx 10%). An 11" shell would thus have a max penetration of ~ 4.0" to 4.8", although this can and will vary based on circumstances.

Also bear in mind that "penetration" for a HE round can include an occasional near-penetration case with significant through-armor effect, spalling and transmitted shock damage being the primary factors; in these cases the effective damage is reduced however over full penetration hits."


Meaning a 6” HE shell would penetrate between 1.8” (6 x 0.3) to 3” (6 x 0.5) in direct fire.



I’m not clear if this penetration applies equally to Belt Armor and Deck Armor or if it differs.



Splinter Penetration: The explosion of an HE shell creates splinters that can cause damage to a ship, cause fires, kill crew, cripple critical systems (electrical power) and in certain cases cause turret flash fires and/or magazine detonations. According to the manual 100% of splinters can be stopped by 2” of armor.



One thing I’m not clear on is if AP shells and SAP shells also produce splinters.



Turret Top Armor: I’m extremely unclear how this works. I’ve tested 2” TT armor against 6” HE shells but keep getting [TT* by splinters, turret disabled] messages. I’m not sure if this means splinters penetrated the TT or a direct impact HE shell penetrated TT or the turret wasn’t penetrated and is just disabled for some reason.



If an experienced player (or developer) could chime in, I would greatly appreciate it.

[wlbjork]

It's not 0.3D to 0.5D but 0.36D to 0.44D, as shown by the example.

The base penetration of a 6" shell is 2.4", plus or minus 10% giving it a range of 2.16" to 2.64"

[bobrose]

I never had 2 inch of armor being penetrated by splinters ingame, beside 6 inch guns and below in single turrets with no more than 2 inch armor, they are considered being not fully closed, rather shields. Shields offer only partial protection for gun crew, there is chance to get "Main gun crew cut down by splinters". Also, if coning tower armor is less than 2 inch, there is chance to get "Officers cut down by splinters" message from hit to superstructure.

AP and SAP ammo type for sure creates splinters. Even near miss of AP can create splinters that occasionally hits hull or B/BE area.

Also, I see regularly 1890 tech armor of 4 inch thickness being penetrated by 6 inch HE shell of 1890 tech. Armor quality seems to contribute for protection as well as thickness from direct HE hit.

[summersnows]

Sept 10, 2024 21:07:15 GMT -6 wlbjork said:

It's not 0.3D to 0.5D but 0.36D to 0.44D, as shown by the example.

The base penetration of a 6" shell is 2.4", plus or minus 10% giving it a range of 2.16" to 2.64"

Oh that makes things a bit more reasonable. Thanks for pointing that out. 

I never had 2 inch of armor being penetrated by splinters ingame, beside 6 inch guns and below in single turrets with no more than 2 inch armor, they are considered being not fully closed, rather shields. Shields offer only partial protection for gun crew, there is chance to get "Main gun crew cut down by splinters". Also, if coning tower armor is less than 2 inch, there is chance to get "Officers cut down by splinters" message from hit to superstructure.



AP and SAP ammo type for sure creates splinters. Even near miss of AP can create splinters that occasionally hits hull or B/BE area.

Good to know about the AP & SAP splinters. 

Inccidentally, would you know if 2" of Belt Upper [BU] has any effect for pure splinter protection in the predreadnought era or is it just dead weight?

Also, I see regularly 1890 tech armor of 4 inch thickness being penetrated by 6 inch HE shell of 1890 tech. Armor quality seems to contribute for protection as well as thickness from direct HE hit.

I... really hope you're wrong on that otherwise figuring out my armor thicknesses will be a nightmare.

[abclark]

Sept 11, 2024 12:13:29 GMT -6 summersnows said:

I never had 2 inch of armor being penetrated by splinters ingame, beside 6 inch guns and below in single turrets with no more than 2 inch armor, they are considered being not fully closed, rather shields. Shields offer only partial protection for gun crew, there is chance to get "Main gun crew cut down by splinters". Also, if coning tower armor is less than 2 inch, there is chance to get "Officers cut down by splinters" message from hit to superstructure.



AP and SAP ammo type for sure creates splinters. Even near miss of AP can create splinters that occasionally hits hull or B/BE area.

Good to know about the AP & SAP splinters. 

Inccidentally, would you know if 2" of Belt Upper [BU] has any effect for pure splinter protection in the predreadnought era or is it just dead weight?

I usually use ~3" upper belt armor, as that will also protect against most 6" AP rounds. 2" should protect from splinters, but even a 5" HE shell should penetrate it ~50% of the time (5" HE penetration range being 1.8"-2.2"). Even 2.5" would offer full protection against 5" shells, protection against 6" HE ~70% of the time, and against 6" AP at some ranges and angles.

[bobrose]

Sept 11, 2024 12:13:29 GMT -6 summersnows said:

Sept 10, 2024 21:07:15 GMT -6 wlbjork said:

It's not 0.3D to 0.5D but 0.36D to 0.44D, as shown by the example.

The base penetration of a 6" shell is 2.4", plus or minus 10% giving it a range of 2.16" to 2.64"

Oh that makes things a bit more reasonable. Thanks for pointing that out. 

I never had 2 inch of armor being penetrated by splinters ingame, beside 6 inch guns and below in single turrets with no more than 2 inch armor, they are considered being not fully closed, rather shields. Shields offer only partial protection for gun crew, there is chance to get "Main gun crew cut down by splinters". Also, if coning tower armor is less than 2 inch, there is chance to get "Officers cut down by splinters" message from hit to superstructure.



AP and SAP ammo type for sure creates splinters. Even near miss of AP can create splinters that occasionally hits hull or B/BE area.

Good to know about the AP & SAP splinters. 

Inccidentally, would you know if 2" of Belt Upper [BU] has any effect for pure splinter protection in the predreadnought era or is it just dead weight?

Also, I see regularly 1890 tech armor of 4 inch thickness being penetrated by 6 inch HE shell of 1890 tech. Armor quality seems to contribute for protection as well as thickness from direct HE hit.

I... really hope you're wrong on that otherwise figuring out my armor thicknesses will be a nightmare.

BU protects ship from critical hits, damage to uptakes (lose of speed) and superstructural damage. Before AoN, I tend to keep the same B\BU\BE thickness and narrow belt armor — critical hits and/or lose of speed, in my experience, are most common case of ship being lost on par only with poor crew quality (when they fail to perform damage control).



2 inch of BU is very limited amount of protection. If you find BU equal to B as extreme measure and do not want to make narrow belt, I would at least design BU with protection of secondary guns fire and hits on sharp angles: something like 6 inches in 1890-1900s, for example.



Keep in mind that 6 inches is not really a thickness that shell need to penetrate. Plate of armor has weak points, not to mention places where two plates are adjacented (something like 25% variety, but I am not entirely sure), it is a bit extra layers of armor for ammo storage areas and little less for "non-inportant" parts and ends.



Even 4 inch slope of 1890 protected cruiser sloped deck, B in reports, is closer to 3 inches in some places. It is unlikely to hit magazine of such cruiser with 6 inch HE shell directly, but you can damage machines badly trough B areas. Not to mention that BE and DE covers machines of protected cruisers as well.



Also, horizontal and vertical armor are made of different alloys, not to mention deck receives some extra protection from wood and shipbuilding steel. I am sure by gaming experience that HE performs drastically different against 2 inch deck, 2 inch turret top and 2 inch belt. So, "rule of a thumb", if it possible, make turret top armor a bit thicker than deck and do not worry much about HE penetrating deck from direct hit. It unlikely, I never saw HE penetrating deck armor in battle reports if deck is reasonably protected from AP. For example, 2 inch of deck armor in 1890s is reasonable protection from both splinters and direct HE hits.

And, technology level of armor is key component both in defense from AP and HE, as much as technology level of shells. Since tech level of armor is locked on year in what ship were built, and shells progress in time, it is indeed nightmare. Penetration table in gun menu during ship design process is something you should not really take serious. It does not consider tech development of time where ship would be fighting. Any ship is rather in vulnerable position if fight goes at "sure" firing range, exchanging full broadsides.

[bobrose]

Sept 11, 2024 12:13:29 GMT -6 summersnows said:

Sept 10, 2024 21:07:15 GMT -6 wlbjork said:

It's not 0.3D to 0.5D but 0.36D to 0.44D, as shown by the example.

The base penetration of a 6" shell is 2.4", plus or minus 10% giving it a range of 2.16" to 2.64"

Oh that makes things a bit more reasonable. Thanks for pointing that out. 

I never had 2 inch of armor being penetrated by splinters ingame, beside 6 inch guns and below in single turrets with no more than 2 inch armor, they are considered being not fully closed, rather shields. Shields offer only partial protection for gun crew, there is chance to get "Main gun crew cut down by splinters". Also, if coning tower armor is less than 2 inch, there is chance to get "Officers cut down by splinters" message from hit to superstructure.



AP and SAP ammo type for sure creates splinters. Even near miss of AP can create splinters that occasionally hits hull or B/BE area.

Good to know about the AP & SAP splinters. 

Inccidentally, would you know if 2" of Belt Upper [BU] has any effect for pure splinter protection in the predreadnought era or is it just dead weight?

Also, I see regularly 1890 tech armor of 4 inch thickness being penetrated by 6 inch HE shell of 1890 tech. Armor quality seems to contribute for protection as well as thickness from direct HE hit.

I... really hope you're wrong on that otherwise figuring out my armor thicknesses will be a nightmare.

I also checked for some in-game, 2 inch of BU is sufficient as pure splinter protection (as 2 inches in any other area beside gun shields). It is debatable if it is dead weight, actually... Since, there are players that would fit more guns into humbly armored ship and defeat enemy by pure firepower. And it is purely debatable if you want little-to-no-protection or no protection at all, but a bit more free space or lower cost of individual ship. Frankly, for myself, I would go for decent armor protection or no protection at all. It is a bit better to get passthrough hit to unprotected area and lower weight instead of armor that does not cover something really critical and defend some area only from splinters and 3-4 inch guns for sure. There is no 100% true guide in existence, every design choice is trade-off, even one that is seem suboptimal. Flat deck on armored belt scheme covers a bit more of ship and a little bit more likely to withstand shell with same thickness, yet it is less protected from hits that already penetrated belt, for example.

[summersnows]

BU protects ship from critical hits, damage to uptakes (lose of speed) and superstructural damage.

What kind of critical systems are protected by BU? I had been under the impression that only superstructure was covered by BU and nothing else important. Are uptakes particularly important and how bad is the speed loss if it’s hit? Is it repairable mid-fight or permanent?



Also, how does the protection of these critical systems work with AON when you can’t use BU?

I never saw HE penetrating deck armor in battle reports if deck is reasonably protected from AP. For example, 2 inch of deck armor in 1890s is reasonable protection from both splinters and direct HE hits.

I guess it is a bit pointless worrying about plunging fire from long range HE shells, lol.


If I remember correctly the penetration value of AP shells can vary by +/-20%. Given technological advancements in armor, I usually add 20% to whatever I’m trying to armor against to future proof a design.



For my pre and early dreadnoughts I’m aiming for comprehensive protection against 6” guns firing HE shells since they are the primary threat of the era. Going from this, I would aim for 2” [D] & [DE] for splinter protection, 3” [BU] & for direct fire 6” HE shell protection. I use a uniform thickness narrow & [BE] otherwise.

[bobrose]

Sept 12, 2024 11:31:38 GMT -6 summersnows said:

BU protects ship from critical hits, damage to uptakes (lose of speed) and superstructural damage.

What kind of critical systems are protected by BU? I had been under the impression that only superstructure was covered by BU and nothing else important. Are uptakes particularly important and how bad is the speed loss if it’s hit? Is it repairable mid-fight or permanent?



Also, how does the protection of these critical systems work with AON when you can’t use BU?

I never saw HE penetrating deck armor in battle reports if deck is reasonably protected from AP. For example, 2 inch of deck armor in 1890s is reasonable protection from both splinters and direct HE hits.

I guess it is a bit pointless worrying about plunging fire from long range HE shells, lol.


If I remember correctly the penetration value of AP shells can vary by +/-20%. Given technological advancements in armor, I usually add 20% to whatever I’m trying to armor against to future proof a design.



For my pre and early dreadnoughts I’m aiming for comprehensive protection against 6” guns firing HE shells since they are the primary threat of the era. Going from this, I would aim for 2” [D] & [DE] for splinter protection, 3” [BU] & for direct fire 6” HE shell protection. I use a uniform thickness narrow & [BE] otherwise.

Damage to uptakes and funnels (unlike uptakes, funnels are always unarmored and can topple from even modest gun hit with a probability) appear to be not repairable mid-battle. At least, I never saw it in RTW. Lose of speed seem to vary with max speed of ship and/or slightly random, but it is usually couple of knots. A bit hard to know for sure because report does not state how much speed ship lost exactly from exact hit.

Also, BU area hit can rarely bring critical hits as damage to feeding tanks (seawater enters them, machinery is disabled and max speed is drastically reduced) for sure. It is most dangerous thing I can remember from a top of my head, and why I always keep BU decent if it matters.

In AoN scheme, at least what I can tell from my experience, B covers what important areas BU used to cover in earlier schemes, but not additional amount of superstructure BU protects. The same applies for BE and so on, BE only protects steering gear, not fore/aft hull and so on.

Also, plunging fire is a thing for turret tops even at point blank range, manual states they are vulnerable to this since they are somewhat sloped.

[bobrose]

Sept 12, 2024 11:31:38 GMT -6 summersnows said:

BU protects ship from critical hits, damage to uptakes (lose of speed) and superstructural damage.

What kind of critical systems are protected by BU? I had been under the impression that only superstructure was covered by BU and nothing else important. Are uptakes particularly important and how bad is the speed loss if it’s hit? Is it repairable mid-fight or permanent?



Also, how does the protection of these critical systems work with AON when you can’t use BU?

I never saw HE penetrating deck armor in battle reports if deck is reasonably protected from AP. For example, 2 inch of deck armor in 1890s is reasonable protection from both splinters and direct HE hits.

I guess it is a bit pointless worrying about plunging fire from long range HE shells, lol.


If I remember correctly the penetration value of AP shells can vary by +/-20%. Given technological advancements in armor, I usually add 20% to whatever I’m trying to armor against to future proof a design.



For my pre and early dreadnoughts I’m aiming for comprehensive protection against 6” guns firing HE shells since they are the primary threat of the era. Going from this, I would aim for 2” [D] & [DE] for splinter protection, 3” [BU] & for direct fire 6” HE shell protection. I use a uniform thickness narrow & [BE] otherwise.

I am afraid to be misleading, since I never took serious research unlike some other people. Please cross-check any info you get.

For example, I stumbled upon post on Reddit where in 1.00.52 RTW3 person took much more serious research of hit distribution and general aspect of armor protection from direct hits and splinters than my personal experience.

www.reddit.com/r/RuleTheWaves/comments/1fdp8mz/version_10052_new_shell_hit_distribution/

It states nothing about some of my observations for some reason. Especially about what BU protects in current game version and what it does not.

[summersnows]

Damage to uptakes and funnels (unlike uptakes, funnels are always unarmored and can topple from even modest gun hit with a probability) appear to be not repairable mid-battle. At least, I never saw it in RTW. Lose of speed seem to vary with max speed of ship and/or slightly random, but it is usually couple of knots. A bit hard to know for sure because report does not state how much speed ship lost exactly from exact hit.



Also, BU area hit can rarely bring critical hits as damage to feeding tanks (seawater enters them, machinery is disabled and max speed is drastically reduced) for sure. It is most dangerous thing I can remember from a top of my head, and why I always keep BU decent if it matters.



In AoN scheme, at least what I can tell from my experience, B covers what important areas BU used to cover in earlier schemes, but not additional amount of superstructure BU protects. The same applies for BE and so on, BE only protects steering gear, not fore/aft hull and so on.

Thanks for the clarification. That sort of critical damage must be relatively rare, but understandably crippling. Most of my current BB designs use 2" BU, so I might as well add an extra inch for the added protection. It helps a lot that BU is actually changeable in rebuilds. Ugh, tradeoffs suck though.

[abclark]

I don't think I've ever seen any critical hits after BU penetrations except for uptakes. Things like feed tanks are below the armored deck, so a shell would ether have to penetrate the BU and D/DE armor or splinters would have to penetrate the D/DE armor.

BU penetrations cause structure damage which impacts damage control though, so between preventing some fires, protecting structure HP, and protecting uptakes I think it's worthwhile. It also makes for good roleplay.

[bobrose]

Sept 13, 2024 14:35:04 GMT -6 abclark said:

I don't think I've ever seen any critical hits after BU penetrations except for uptakes. Things like feed tanks are below the armored deck, so a shell would ether have to penetrate the BU and D/DE armor or splinters would have to penetrate the D/DE armor.

BU penetrations cause structure damage which impacts damage control though, so between preventing some fires, protecting structure HP, and protecting uptakes I think it's worthwhile. It also makes for good roleplay.

Manual states that with narrow belt area that usually is covered by B would be covered by BE/BU or no armor at all. That would be strange if it would not apply for hit zones behind B now covered by BE or BU. I guess, it need further testing and some screenshots, but I am sure that with narrow belt hit to BU occasionally disables or damages machines, not only uptakes. There were even BU/DE hits similar to B/D hits (shell need to penetrate both belt and sloped deck after in corresponding scheme). I did not see electrical power disabled from BU hit, beside. I would just play a bit more in 1.00.52 and share results if found something looking like a proof.

[abclark]

That may be part of the issue. I don't ever use narrow belt designs, so I wouldn't have seen that particular situation.