Talk:Spring 2015 Event/@comment-26348726-20150428121329/@comment-26326357-20150428152801

Ahem...

All four ships incorporated a unique underwater protection system named after its designer, Umberto Pugliese. A 40 mm thick torpedo bulkhead extended inboard from the base of the main belt before curving down to meet the bottom of the hull. This formed a void which housed an empty drum 380 mm (15 in) wide with 6 mm (0.24 in) thick walls; the rest of the void was filled with liquid. The drum ran the length of the torpedo defense system, and was designed to collapse to contain the explosive pressure of a torpedo hit. The torpedo bulkhead would prevent any splinters or explosive effects from entering the ships' vitals. The system was designed to protect the ship from torpedo warheads up to 350 kg (770 lb).[14]

The system did not perform as effectively as expected, however.[14]  This was due to two major defects in the design. The riveted joint that connected the interior torpedo bulkhead to the bottom of the hull was not strong enough to sustain the tremendous shear loadings associated with direct contact explosions. The joints failed even in cases of non-contact explosions; this prevented the hollow drum from collapsing as designed and resulted in massive flooding. The fineness of the hull shape prevented the 380 mm thickness from being maintained for the entire central citadel; the width of the drum was reduced significantly abreast of the main battery, down to 228 mm (9.0 in). The ability of the drum to absorb explosive shock correspondingly fell in relation to its size.[28]



While the system was... temperamental, it -did- work on several occasions, such as the First battle of Sirte, when it blocked a torpedo fired by HMS Urge. All in all, I think its in-game stats are more or less justified.



