Talk:Pugliese Underwater Protection Bulkhead/@comment-26135416-20150429145209/@comment-24093250-20150430080641

Perhaps I can add my two cents.

The Pugliese system was a rather early anti-torpedo defense (having first been tested in the early 1920s), and as such was expected to deal with torpedoes whose warhead was relatively small (in terms of TNT); more importantly, it was supposed to encounter torpedoes with contact fuzes (i.e. which exploded upon hitting the ship's hull, right in the bulkhead).

What happened? By the time the Littorio-class was in service, not only had torpedoes with greater and/or more effective warheads appeared, but magnetic influence detonators had arrived; this meant that a torpedo could now explode under the hull, and the system simply wasn't meant to deal with it. That's what happened to Taranto, in which this type of torpedoes did a good deal of damage.