In 1991, the USN decides that the armored, big gun battleship still has a place in the fleet and decides to retain the Iowa class instead of retiring them. Yes, I know this is near ASB and all the reasons why. What I'm curious about is, IF the Navy had kept them, what upgrades/modifications do you think they would carry out to the ships, how much longer would they serve, and what would their replacement be? For the replacement, keep in mind, this is a Navy that has decided to keep armored big gun ships in its fleet. Other than that, go crazy.
They were retired because they were an ship without a good mission. Or put with more precision, the Iowas were a ship where each mission could be done by a much cheaper ship. They were also retired because of the explosion of powder during training exercise. While the Navy did a nice job of framing an innocent guy via the gay lover theory, the Navy knew there was another issue. As powder gets older, it because more unstable and this is what cause the explosion. If the explosion due to routine handling had happened in a powder magazine, the ship would have been cut in two by the explosion and 10 survivors would have been a lot. The state of the art 1943 ships is also missing a lot of very common technologies of today such a sonar. And it is so big, it probably should have nuclear propulsion. So we would really need to build the Ersatz Iowa.
So since we have to retire the class of ships due to age, lets first talk about building another ship of the same type. We have not produced 16" guns in ages. Probably need to design a new version with a higher rate of fire, like we did with the 5" guns on modern ships. Are we really going to build ships with armor schemes that don't stop modern missiles? No, so now I am building a BC with at most a light armor scheme of the "medium" variety. Not very useful. And very expensive ground fire ships for the marines.
So lets go to the much vaunted ground fire. I am not even against this ship, but i looks nothing like an Iowa. It looks like a WW1 Monitor. I could take the old 16" guns off scrapping the Iowa or new guns if you like. Have to produce new ammunition. Then I build a ship with 1-2 guns per ship so I can support a larger area. While it has to be able to travel at sea, it need not be fast. 20 knots is blazing fast, it just has to be able to get there. It is also a shallow draft shift that can go up bays, estuaries and bigger rivers. In fact, it looks at lot like in shore drilling platform, and may well use this type of civilian technology. It probably has legs to let it anchor to the ground for more accurate fire. It needs a medium, not an all or nothing armor scheme since it will be shot at by mortars and land base artillery. At least an inch everywhere, but maybe a good bit more. And if you think about this ship, it could have been easily built at any time since 1950. And it would have been hugely useful as a fire base in the rivers and bays of South Vietnam. Or in the rivers of Iraq. And this ships with some work probably could have been brought deep into interior of rivers, so finding it North of Baghdad is possible. People love to talk about missiles and bombs advantages, and these do exist. However in a world where the enemy does not have counter battery radars, the artillery adjust fires, the F-15 flies back to base to rearm.
I have never seen a person argue that naval gun fire (non-rail guns) is likely to sink a lot of ships. In any case, 16" is too big for the modern world even if you think the 5" is too small. Here you would design a new 8" or so rapid fire gun to put on new or existing ships.
I have not seen credible arguments for ship armor that can't stop missiles or arguments how we can build a ship that stops standards missiles such as the silkworm. All BS aside, if the Iowa gets hit by a 2-3 Silkworms she is in the same amount of trouble as the same size ship without armor.
Ok, you want to build this big a ship that is surface warship. By big, I mean the same length. Probably nuclear power. Carries missiles. Called BBGN. Probably looks like the Kiev, but replacing air wing with even more missiles.
https://en.wikipedia.org/wiki/Soviet_aircraft_carrier_Kiev
So we get to what we really did. We went with CVN, CGN, and DD to do all the jobs the Iowa could at lower cost. There is only one role which these don't do well, it is the Monitor that mentioned before. Probably would have made sense to strip off some 14" or 16" guns and build the Marines 3-7 of these ships. Might even put a little room for a small command area for regimental size units. Probably economical.