AP penetrations for no damage

[SkaerKrow]

So something that has always bothered me, that I've never fully understood, are AP shots that show the penetration ribbon but do no damage. I think that I've convinced myself that what's happening is the shell successfully arming, but detonating in a non-essential part of the ship, and thus doing no damage. Whether that's true or not is a different matter though. I've always had a few pens for no damage in games, but since I started playing the Giulio Cesare I've been seeing them with much greater regularity.

 

So with all of that in mind, what causes these zero damage penetrations and what, if anything, can I do to avoid them?

[Lert]

The ribbons aren't always accurate to what happens. For example, I remember a few times where I got normal pen damage for what showed as an overpen. The other way around could also happen, especially if there's even a little bit of packet loss / desynch.

For the rest, if you hit an external module like an AA mount, secondary turret or torpedo mount with an AP shell that doesn't penetrate the actual hull / superstructure of the ship it'll show a pen but not do damage to the actual hitpoints of the ship. Some ships, like some of the french cruisers if I'm not mistaken, also have spaced armor along the outside of the side that can 'eat' an AP shell and return 0 damage with a pen ribbon.

[The_first_harbinger]

Pretty much what Lert said.

At lower tiers, it's not that rare for entire sections of bbs' hulls to be saturated and take 0 damage from normal 1/6 or 1/3 penetration areas.

It's also possible for your shell to penetrate battleships' torpedo bulkheads, but stops dead before penetrating the main belt, in which case penetration ribbon would be shown but deals no damage.

 

 

[SireneRacker]

Your hitpoints are seperated from the modules. So you can take a crap ton of damage with your modules but the hitpool would not be bothered. And, as Lert mentioned, there is this trollish armor on French Cruisers.

Take this for example, I definitely got penetrated, and I definitely took damage. It's just not showing on my hp-bar. But the shells had an effect, and that's why I wouldn't worry about it too much.

Spoiler

 

[Sotaudi]

The most likely explanation is often module damage.  A pen can be registered when a module is hit, but module HP (e.g., an AA mount) is not counted against the ship's HP.  If you don't knock the module out or incapacitate it, you can get a penetration with no damage showing.

However, keep in mind that the four sections of a ship each has its own HP pool.  Damage against a section's pool is deducted from the ship's HP.  Each section has three damage thresholds as well.  When a section takes a certain amount of damage and reaches the first threshold, it will start taking reduced damage after that.  There is a second threshold where it will start taking even less damage.  When the hit points of that section are completely depleted, it will take no further damage.

This is known as "damage saturation."  And here is the thing.  Damage saturation only affects penetrating hits.  Over pens and citadels are not associated with a specific section hit point pool, so they always do either 10% or 100% of the listed shell damage, respectively.  Pens, however, are associated with the section where they penetrate, so they do reduced damage or even no damage if the section they hit has reached the aforementioned thresholds.

Thus, you can also get a penetrating hit that does zero damage if the section that was penned is fully damaged saturated (i.e., that section has no more hit points).

[SkaerKrow]

Thanks for the replies everyone, I really appreciate the clarification. 

[Final8ty]