If a torpedo hits in the right area, like the Hit on the Pennsylvania, it can hurt. Warspite I would like to hear your sources on how serious the hit was to the Pennsylvania, and why you claim my source was dated-which is not that big of a deal- or not reliable. I have stated my source- what is yours?
In Whitley, M. J., "Battleships of WW2" and Breyer, S.: "Schlachtschiffe und Schlachtkreuzer 1905-1970", you can search for the specific items.
In Whitley:
"Anti torpedo protection was conferred by a 1.5 in. longitudal bulkhead on 3/4 in. plating, inboard of which was a retaining bulkhead extending from frames 10 to 127. Total width of torpedoprotection each side was 11 ft 9 in." (page 260, ISBN 1-85409-386-x.)
This suggests the torpedobulkhead was relatively shallow at less than 4 meters wide, considered by German naval architects to be the norm. (Bismarch and Scharnhorst both used a 20 ft. norm, according to Whitley.) In otehr words, the USN design was providing more a direct protection, rather than an indirect one, which would give more protection overall, as it could contain more of the energy of an underwaterblast, rather than take the full force of it.
Breyer, S.:
"Panzerung und Unterwasserschutz entsprachen hinsichtlich Anordung und Dicken im Wesentlichen der Nevada Klasse.
Unerwasserschutz: Torpedo Schott: 38 mm (seit die umbau dafür 3 T-Schotte: 19, 19 und 19 mm und zusätzlich T-Wulste)"
(Breyer, S., Page 233, ISBN3-88199-474-2.)
The torpedohit on USS Pennsylvania in 1945, at Okinawa crippled her, as it destroyed three shafts and caused serious flooding, due to the propellorshafts running wild, after being bented by the blast, desintegrating the hullintegrety and causing heavy flooding through the shafttunnels. On 10 dec. 1941, HMS Prince of Wales was hit in a simmilar fashion, reulting in the same massive flooding. In this case, the British ship was additionally hit by three or four more torpedoes, which luckily was not the case in the Pannsylvania's case. (Middlebrook, M., Mahoney, P.: "The Sinking Of The Prince Of Wales & Repulse", ISBN: 1-84415-075-5.)