The Indianapolis was a heavy cruiser, not a battleship. In fact, the Indianapolis was a “treaty ship,” built under the restrictions of the 1922 Washington Naval Conference. Heavy cruisers were restricted to 10,000 tons. The Indianapolis was built for speed and lacked armor protection. No surprise that a pair of torpedoes put in her forward part while she was steaming at speed put her under in less than 30 minutes.
As for the battleships, they generally were able to take a pounding before going under.
After Pearl Harbor, the only American battleship struck by a torpedo after Pearl Harbor was the USS North Carolina, struck in the bow by a shot from I-19, the same spread that sank the USS Wasp. The “Showboat” steamed back to Pearl for repairs and continued to a brilliant war record.
The British lost a modern battleship (HMS Prince of Wales) and a WW1 vintage battlecruiser (HMS Repulse) to aerial torpedoes on December 8 off Malaya. Other than that, most battleships sunk were Japanese, and they either took a gunfire pounding (IJN Kirishima, by USS Washington; IJN Yamashiro by several older BB’s), or a combination of aerial bombs & torpedoes (IJN Yamato & Musashi).
One or two torpeodes, bombs or shells were usually not enough to kill a battleship, unless it was a “lucky hit,” such as scored by Bismarck on HMS Hood.
Wasn't she a battlecruiser?
(big guns, less armor, for speed)
I believe IJN KONGO was sunk by torpedo. And IJN SHINANO, although an aircraft carrier, was built on the third YAMATO class hull, and was also sunk by torpedo [U.S.S ARCHERFISH?]
As I recall, no post Pearl Harbor battleship was ever hit by a torpedo, so we don’t know if the hull worked. We do know, based on James Cameron’s visit to BISMARCK that the British torpedoes [H.M.S CORSETSHIRE] didn’t sink him [Kapitan Lindemann refused to call BISMARCK ‘her’].
?? HMS Hood was a WWI era battlecruiser
Yes, she’d had some up-armoring done due to the losses of Royal Navy battlecruisers at Jutland, but wasn’t she still less armored and less well designed to take hits than any new battleship of 20+ years later? I’m no expert..... but I thought the cordite/ammo rooms were poorly placed compared to what came later, and that HMS Hood blew up from one direct hit to a magazine?
If you ever visit the USS North Carolina, berthed in Wilmington, NC, you can see the crack in the armor belt from that torpedo.
Don’t forget the Italian battleships sunk by SWORDFISH torpedo bombers at Taranto in 1940, the raid that put the bee in Yamamoto’s bonnet about Pearl Harbor. They were all post WW I designs, and were built in the 20s and 30s