 The torpedo defense system was designed to withstand torpedoes with warheads equivalent to 750 kg ( 1 @,@ 653 lb ) of <unk> . The ships were intended to be able to remain afloat with any five adjacent compartments flooded or with three torpedo hits and the destruction of the <unk> above @-@ water side . The Pugliese system protected 123 meters ( 403 ft 7 in ) of the ships ' <unk> . At the aft end was a multi @-@ bulkhead protection system that extended another 33 meters ( 108 ft 3 in ) to the rear from the Pugliese system . The depth of the system was 8 @.@ 2 meters ( 26 ft 11 in ) amidships , but it reduced to 7 meters ( 23 ft 0 in ) fore and aft . The outer plating ranged from 11 to 14 mm ( 0 @.@ 43 to 0 @.@ 55 in ) in thickness while the inner bottom was 7 mm ( 0 @.@ 28 in ) thick . The cylinder of the Pugliese system was also 7 mm thick while the semi @-@ circular main bulkhead was 35 mm ( 1 @.@ 4 in ) thick with a flat 10 @-@ millimeter ( 0 @.@ 39 in ) bulkhead behind it . The 3 @.@ 15 @-@ meter ( 10 ft 4 in ) diameter cylinder was intended to be immersed in fuel oil or water . 
