I've been on the North Carolina and Alabama, almost indiscernible to me, and seen the Missouri up close but didn't board, it also looks about the same, to me. They turned out to be kind of wastes of resources but nothing like what the Japanese did. I think only the Washington used its main battery to sink a Japanese ship in the war among US BBs. aside from Surigao Strait when the old BBs got into the act.
The standard description of how the
South Dakotas differed from the
North Carolinas is that they were an attempt to get the same firepower and speed, with thicker armor, while staying within the 35,000-ton weight limit per the Washington Naval Treaty (even though the Treaty system had collapsed with the Japanese withdrawal from it). The result was a shorter (by 49 feet) ship with a shorter armored citadel and more powerful engines (to compensate for the less efficient hull shape). One result of that is that the
South Dakotas were more cramped than both the
North Carolinas and the
Iowas.
That is consistent with my subjective experience aboard
North Carolina,
Alabama, and
Iowa.
Alabama seemed tighter belowdecks than either of the other two. But I saw those three ships quite a few years apart, so you can take my impression with a grain of salt.
FTR, the
Iowas were longer than the
South Dakotas by 107 feet and more powerful by 82,000 hp. No surprise that the
Iowas could do 33 knots, while the
South Dakotas could do 27.5 knots and the
North Carolinas could do 28 knots.
The
Iowas did pay back their cost somewhat through service in the Korean and Vietnam Wars and beyond.
I would have been good to see what those fast battleships could have done off Samar had Halsey not taken them with him in the wild-goose chase of Ozawa's empty carriers. We could have seen a fight between the
Iowas and
Yamato.