Shichido-class Battleship
Length: 1,299.5 feet;
Armament: 15 x 20-inch main; 12 x 8-inch secondary; 20 x 3.9-inch tertiary; 112 x 40-mm. Bofors AA (28 twin mounts on either side)
Ship commissioned by february 1950 (late 1945-late 1949 built, this ship is so GIGANTIC that it consumes 2/3 of the ENTIRE Japanese military industrial 1946-1949 resources , only for 1 ship...).
Sunk April 7, 1950 by a U.S. nuclear attack
(This gigantic battleship is a too tick/large armor (and a too extensive internal sub-division/compartmentalization) to be sunk by a conventional attack).
April 01, 1950 : In Kure harbor/anchorage, an American B-45 bomber
(or a B-36 or a B-50 ?) drop a Mk-4 bomb
(C pits type, 20-30 Kt yield) on this ship. The A-Bomb explode as a
"near-miss" (65 meters east & 95 meters above the ship).
All exterior superstructures are torn/blown-down.
Due to this large size & armor, the hull-integrity of this ship is "almost" not deadly-affected, but the
(global/general/extended) damage are so large that the entire
(remaining) crew
(in any case, all fatally contaminated) are forced to abandon the ship that will sink a few hours later
(or in the best case, up to few days later...) in the bay.
First off, in this AU, the USN and Japan are at peace from September 1946 onward, so this is irrelevant.
Secondly, I think you completely missed the point of this being an
AU, so I'll just refrain from commenting here and post anything I have on the Rant Thread.