I'm pretty sure pre-gunpowder
weapons had miltiple cases to be used as anti-moving targets, such as personnel, such as Romans's scorpions, Song dynasty's arcuballista, Alexendar's catapults or ballistas during his campiagns against Schytia, and so on. In addition,
Numenor did have gunpowder weapons such as MLRS, correct me if I'm mistaken. To sum up, might Numenor have naval anti-personnel arty?
Torsion-powered artillery could be used in such a manner, yes, and it is
technically possible for
Numenoreans to have had it. I do not recall any mention of such artillery in
Tolkien's work, however, though tension variants of ballistae may have been used instead (Numenoreans did have steel
bows, after all). At any rate, such artillery was used in exclusively anti-personnel role, to suppress enemy crew prior to boarding. In
sieges, some warships would mount larger stone-throwers, but these again were used into anti-personnel role - for suppression and decrenellation.
As I said, however: I do not recall any mention of such artillery in Tolkien's work or even any mention of Numenor ever fighting a naval battle - unless it happened during the Late
Numenorean civil
wars - meaning they will have had little reason to develop such artillery or even equip their
ships with land-based versions of torsion artillery; assuming they had torsion artillery at all.
Gunpowder weaponry for Numenor only appears in the Lost Road, which is as non-canon as non-canon goes... in that same book Numenoreans also have airships, steam-powered ironclads and so on. In the "main canon", Numenoreans most likely deployed variants of Greek Fire as their ultimate naval
weapon and also during sieges - variant of which
Sauron then stole and used in the siege of
Minas Tirith.