Battleship Armour Matches Guns

Generally speaking, a battleship was expected to have armour to match that of its guns:  if it fired 16 inch shells, it's armour should be able to defeat incoming 16 inch shells.

This was a much harder requirement to meet for battleships that had been left over from world war one, or had been built between the two world wars.

The British learnt this lesson the hard way, when for example, HMS Hood was lost to the German Bismarck.

Unlike the American South Dakota class, HMS Hood did not feature 6 inch deck armour, instead only having a maximum of 3 inch deck armour.

As world war two progressed, it was to be seen that even 9 inch deck armour (as found in the IJN Yamato), was to be proved in-sufficient.

Battleship Building Frenzy

The attack on Pearl Harbor, caused a battleship building frenzy within the US.  A direct result of this was the rapid completion of the four South Dakota class battleships.

Although featuring the same armament as the North Carolina's (nine 16 inch guns and twenty 5 inch guns), the South Dakota class was "on paper" an improvement over the North Carolina's, because they were designed to withstand hits from 16 inch shells (where as the North Carolina's protection was limited to 14 inch shells).  This resulted in a shortened hull form/superstructure area, most "visible" in the single funnel (where North Carolina had two).

In iron sight, it appears that the North Carolina's were better ships to have served on, as they were not "half as cramped".

WW2 Battleship Pacific Workhorse

For me, the USS North Carolina was the main "work horse" of world war two (in the Pacific).

There's a very good reason for this:  both her and her sister (USS Washington) were completed early in 1941, meaning they were available immediately after the attack on Pearl Harbor (December 7, 1941).

They were also the first class to feature nine sixteen inch guns (in the standard two fwd one aft turret arrangement).  They were also the first battleships built by the US after the "Washing Treaty" building holiday expired, and were a vast improvement over earlier vessels.