The Maine was to become the US-answer to european monstrosities like H44- and Superb-classes. Once it was clear, the Yamato-class would outtake any existing battleship but the planned ultraBBs, the US Navy went for her members of the 1st class fighting vessels.
The planned 20"-gun was mainly a simply enlarged 16"/50 Mk. 7-gun, the goal was to deliver enough punch to counter anything existing or planned. Further the ship should be fast.
The Design 1 was much like the late CC-1 (Lexington) design three time pumped up to 115.000 tons empty and stretched to a ridiculous 401m length. The stern still had four shafts and two rudders, but all somehow oversized.
The 12 20"-guns where installed in four triple-turrets. Also unusual was the amount of 5"-turrets. Eleven Mk.28 turrets per side was seen as a need to protect the big vessel against air raids and the ship was expected to run without any escort shield sometimes. So that much aa and directors were planned.
The Design 1 would have been the lightest of the ultraBBs. But also the fastest one. The hull was very sleek, it was more something like a ultraBC, what is not really correct, due to the fact she still would have outtaken any smaller battleship.
The battlecruiserish look was the reason the design was rejected.
@all: when I posted the drawing, I said 'wait for edit, please'. Until now you could only see the drawing without any explanation or data. I sometimes have a lot of fun doing 'did not make it'-designs. This is one of them.
@bezobrazov: not an american design? You will find any detail of her on existing or at least planned american ships, sorry friend, she fully authentic US-style of 1939/1940.
@Carthaginian : you are right with the armor. The Main is a pumped up South Dakota from about 50% of the drawing.
@SrGopher : yes, it has another big amount of inspiration from Chuckshiparts Lex. Oh his Lex was indeed a never-built. You could see the Maine like the BB-follow up of his Lexington.
@emperor_andreas: I was really thinking about the amount of 5". But I did not want to introduce another, bigger DP-gun, but I saw the need for more aa-shield, so I decided to install more turrets
@Clonecommander6454: no, Montana is later, it's South Dakota-ish
@Portsmouth Bill : a little excessive? All those ultraBBs are so far from reality it is not worth the discussion.
@emperor_andreas : many guns aren't it alone, they have their directors for making their day, too.
@heuhen : That kamikaze had his lucky day, he made a scratch in my deck...
@klagldsf : very constructive comment! Would be the total k.o. for the design.
@Portsmouth Bill : Redundancy: yes, and it is wanted that way. Empty hull space: not really, the hull is not that much wide. Dry dock: right, dry docks for 400m-vessels are rare on this planet, even today.
Finally @all : this is not 'never built', this is AU and in that alternative reality 400m-docks do exist and the economics do allow to build that ships. The question of design comes only up if it is clearly not working. It's an always lurking trap with that AUs, I know. On this side they look so much like real ships on the other they do even not. Don't worry, just imagine.