Of Battleships and Cruisers and Good Red Meat

 Yesterday, the Secretary of the Navy announced a new Trump class battleship design. Displacing approximately 30,000 tons, it is supposed to have approximately the following characteristics:

nuclear powered

128 Mk41 (strike length?) VLS tubes with SLCM, potentially with low-yield nuclear warheads

12 Conventional Prompt Strike tubes

2 RAM point defense launchers

1 32Mj rail gun

2 Mk45 5" gun turrets

2-4 30mm local defense turrets

4 AN/SEQ-4 ODIN point defense lasers

2 300-600kw lasers

2 Counter UAS systems

Flight deck (can accept MV-22 and FVL airframes) with 2 helicopter hangers

An AN/SPY-6 radar system, presumably with AEGIS battle management

(wikipedia entry here).  Oh, and it's supposed to be built at  the Philly shipyard now owned by Hanwha.

What's not talked about in the slightest is armor or any kind of armor protection scheme.  Which... bluntly,  matters a lot.

OK, from here, there's a variety of things to talk about.

The Concept

I'll be blunt here. I've been thinking about something of a similar concept for a while now. I wouldn't build it as a new-build hull as a first instance, because I want to test everything out. No, what I'd planned on was making an offer to the Ukrainians for their Ukrainia hulk.  Have them strip off the gun turrets, the missile launch racks, and the electronics, then tow it out of the Black Sea.  Ultimately, before rebuild, it would be stripped pretty much down to the deck line, with the machinery/etc. removed as well. Then... rebuild.  What specs was I thinking of?
Powerplant: 6x LM2500 gas turbines generator sets  (6x 25,000kw - 150,000kw generated power)
Drive: 3 20MW Azipods.

Speed: BOE math suggests a top speed in the 30-35knot range.
Sensors: AN/SPY-6, plus all the other standard things one would expect.
Weapons: 
128-150 Mk41 VLS tubes

1 127mm Mk45 main gun
2x 300kw lasers
1x railgun (TBD)

4x RAM point defense systems
4x 30mm local defense turrets (probably chain gun or equivalent)
2x counter UAS systems
flight deck with a 2 helo hanger (not as big as that proposed for the BBG(N)
spots and cranes for 6-8 Typhon containers or other containerized solutions.

If we can get an AEGIS to put in there, of course I would. Or...something beyond that.

This is basically a test ship for a lot of the technologies that are being discussed for the BBG(N).   I want to do it off an existing hull.

Armor

So, this is a pretty important question to ask, given what we know about battleships and modern weapons. Because the reality is, modern warships are (except for carriers) eggshells with hammers. And a battleship implies that it's able to take a licking and keep on ticking. So, within this, there's a few things to ponder.

Most American battleship belt armor was 12.1" Class A Armor made up from 30lb Special Treatment Steel (STS). Some areas were up-armored using 60lb STS.  Beyond that, the rest of the protective area was armored in Class B Armor.. Oh, worth noting - post WW2, the Navy developed variants on STS, which led to HY-80 steel, which is a current standard for US naval shipbuilding. Which means... we actually know how to fabricate a class B or class A STS armored hull. We're already doing it.  

Now, where this gets interesting is... we already know how to fabricate foot thick armor. And it's superior, based on live testing, to the steel armors of the 1930s and 40s.  The composite armor we currently use on the M1A2/M1A3 series tanks is what we're looking for. We just need it quite a bit bigger.

1. Armor type and thickness

We know from historical records that the maximum thickness of the Iowa's armor was 12.1", tapering down to about 1" as the armor belt reached the double bottom.  Coincidentally, the physical armor thickness on the M1A2 and upcoming M1A3 tanks is even thicker, and offers over 1000mm of RHA-equivalent protection. 

Oh, for conversion purposes? It appears that RHA and STS are approximately the same. So Abrams-grade armor protection on a battleship citadel would wind up giving 2-3x the armor protection of the best American battleship designs of the 1940s.

2. Compartmentalization and Citadel Defense

Now we can take a solid look at the armor schemes used by the Iowa class BBs - including the mid-stride changes made by the USN after the war started.  Frankly, we have multiple examples to examine, plus detailed design studies by a WIDE variety of nerds who have dug into this over the last 50 years. 

3. Torpedo bulges

So this is a sticky one. Why? Because how we use torpedoes has changed over the last 75 years.  During WW2, torpedoes were direct-impact devices. They hit the side of a ship. Which necessitated torpedo bulges and void spaces to absorb the energy of torpedo hits (and if you question the effectiveness of that, look up how many torpedoes INS Musashi and INS Yamato absorbed in their final battles).

Modern torpedoes, in contrast, are designed to run beneath and explode under their target, breaking its back via a huge gas bubble.  So I'm not at all sure that 1940s torpedo defenses are even appropriate. Modern sonars and counter-torpedo solutions might do a lot more good - and mass less.

4. Other lessons to be learned from the design of the Treaty Battleships and the Iowa Class

open for the moment

Battleships? Cruisers? Neither Fish Nor Fowl Nor Good Red Meat

So this is another subject of a great deal of debate. I've already seen assertions that these ships are too small to be "real battleships" (an argument to which I'll simply say bullshit - Treaty battleships (specifically the North Carolina and South Dakota class battleships were all approximately 35,000 tons standard displacement, and the Standard-type battleships  were slightly smaller than that.  So on a size basis, the argument doesn't hold

The other question is, what is their role? Well, as a line-of-battle ship, that's one thing. As the air defense core of a surface or carrier group, then logically they're more cruiser than battleship. Except... with their weapons load, I don't see that.  Too many strike-length VLS tubes, plus that set of Prompt Global Strike missiles, and that railgun all add up to more punch, and not as much dedicated group air defense. They can definitely humm that tune, with 128 VLS cells and an SPY-6 radar and associated battle management equipment.  But I don't think that's what they're designed to do. 

You know what I'd really like to see? The wargames that produced this design.    Because I'm reasonably certain that somebody gamed the hell out of this against a notional Chinese fleet around Taiwan, and...came up with a design that offers a way to win an all-out war.

So that's all for now. I'll probably come back and revisit this.  But those are my thoughts for now.