I have to agree with Grass Hopper, but only because in house rule packets damaged battleships were always stated as being able to defend but make no attacks due to reduced speed of it’s engines, damage to its powder rooms, lost gun castles, leaking oil, etc.
But Krieg is the official arbiter of the rules, whether or not they make sense from an analytical standpoint, he says they get full function just unable to sustain more damage before sinking, that’s what they get. /shrug.
More importantly, I want destroyer bombards! (Hey, they have guns!) Ah, 24 American destroyers bombarding Japanese shores, now there’s a sight to behold!