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Wouldn't have four turrets of two instead of three turrets of three increase survivability? In the former case, a lucky shot incapacitates 25% of your main guns; in the latter, 33% (and leaves a larger field of fire uncovered.)

Possibly, but your turrets are among the most heavily armored spaces on the ship. There aren't many lucky shots that will manage to wreck an entire turret of guns. My main reason for suggesting it is that with fewer turrets you can shorten the citadel and save yourself tonnage on your main belt.

I seem to recall many cases from WWII where a hit on a turret knocked it out of action, as did mechanical problems.

GrahamKennedy wrote:I seem to recall many cases from WWII where a hit on a turret knocked it out of action, as did mechanical problems.

Indeed, one good hit from Rodney early in the final action knocked out both Bismarck's forward turrets.

Right; a hit doesn't need to destroy a turret - or any component - in order to incapacitate it. In fact, a turret could easily be rendered immobile or otherwise incapacitated with very little other damage.

I'm aware of this, but I'm not sold on there being a big benefit survivability wise by going with 4 turrets instead of 3 when compared with the weight savings of a shorter main belt.

Tyyr wrote:I'm aware of this, but I'm not sold on there being a big benefit survivability wise by going with 4 turrets instead of 3 when compared with the weight savings of a shorter main belt.

Well, you're an engineer and I'm not so this isn't meant sarcastically: what is the operational benefit of that weight savings? Surely, modern propulsion technology means that the same speeds and accelerations can be achieved with little difficulty no matter which configuration is used.

A couple reasons really. First, you can make the ship a bit smaller if you want as it doesn't have to be able to carry the same mass. And while you can use bigger engines to get the same speed out of a ship diminishing returns is a real bitch and you can wind up needing some truly huge engines to make the same speed with a larger ship. Alternately keeping everything else the same you can afford to put thicker armor in other places increasing survivability. Finally, you can keep the ship the same size, keep the armor the same thickness, and pick up added flotation reserve and maybe improve sea keeping.

And there's cost as well. Thick, armor grade steel isn't cheap. Shaving off a few hundred tons of it can save you a lot of money.

Tyyr wrote:And there's cost as well. Thick, armor grade steel isn't cheap. Shaving off a few hundred tons of it can save you a lot of money.

Yes, that's why I said "operational" differences. Cost probably isn't a determinant; we're talking about the same military that began (and scrapped after spending a ton in each case) the SCAR program, the USSOCOM IAR trials, the OICW program, the USMC IAR trials, and the LSAT program (not scrapped yet, but probably soon - a 3,000+ fps bullet isn't a huge advantage when it's limited to 20 grains in a 4.92 caliber.)

Tyyr wrote:And while you can use bigger engines to get the same speed out of a ship diminishing returns is a real bitch and you can wind up needing some truly huge engines to make the same speed with a larger ship.

This was my question - for the difference in weight, would modern engines really need to be that significantly larger/less efficient for the same top end/acceleration?

It's less weight and more the shape of the ship. Without getting into some fairly detailed calculations I can't give you a precise answer. All I can tell you is that it will be in general more efficient moving less ship through the water for a given power output. And the big alternate is being able to increase the thickness of the armor elsewhere by saving the weight.

Tyyr wrote:t's less weight and more the shape of the ship. Without getting into some fairly detailed calculations I can't give you a precise answer. All I can tell you is that it will be in general more efficient moving less ship through the water for a given power output. And the big alternate is being able to increase the thickness of the armor elsewhere by saving the weight.

Actually it is opposite. It is more efficient to move a bigger ship through the water at a given power and speed. Example: Iowa's are rated at 212,000 SHP for 32.5 knots at 50,000+ tons give or take whereas a treaty cruiser requires half the power for a fifth of the displacement. Much larger carriers require 50% more power for almost twice the displacement on a larger hull. Nimitz class carriers are very tubby too.

Twins have advantages being roomier than triples. Their barrels are more widely seperated.

There is also the possibility of using the latest technology in the turrets. Weight saving measures, rapid fire designs, etc.

Also the Vanguard was still using a generation below that of contemporary US propulsion designs. So this nuVanguard would have a superior propulsion in a given amount of space. perhaps make 32 knots as opposed to 30 knots. If you stay to 30 knots than you save space for underwater protection or shorten the ship.

It is kind of a decent design (I share the preference for the triples and shortened belt, particularly if it lets me put the VLS at one end of the ship rather than amidships) but battleships serve little purpose anymore. I worry about the number of VLS cells you have and the range at which this thing would have to operate as well and I worry about the armament mix. I think the 15 inch guns are overkill for shore bombardment and that you could do most of the job with 155's as in my view anything you can't kill with a 155 is more safely killed with a JDAM anyway. None the less I would make the following suggestions.

1. The ASuW armament is not to my liking, particularly if you elect to go with the Sylver launchers given the threat environment you would be operating in. Close into shore to fire the guns on target you are going to be faced with, potentially, lots of SSM's and other annoyances like patrol boats and the like. Plus you have the odd aircraft you need to deal with and what not, possibly a major strike on some level from aircraft as well and depending on the lay of the land you might or might not get a bunch of warning, regardless of the radar you have.

Harpoon is a decent weapon for what you would face actually but I don't care for it this close into shore in the crowded littoral environment. Brahmos is worse in that regard in that both are a bit of a fire and forget weapon and you could pretty simply wind up whacking something you did not mean to hit. For close into shore work, particularly with the radar as high as you could mount it in a big ship like this, I would prefer to have something that I could operate with command guidance. Aster does not have an ASuW capability. I have never been a fan of hunting fast boats with a helicopter and Sea Skua like system, particularly in a littoral environment where a missed SA-5 system can blot the thing from the sky in seconds.


2. If we are building this today I worry about a lot of the unknowns with much of the kits. SCALP-Naval is still being put together and has EIS of 2013-2015 assuming nothing major goes wrong with development. CAAMM is even further away. Both of these are major systems you need to make such a project as this even worthwhile. You are talking about a hellishly expensive ship. Adopting risk in the weapons systems and having it come out before a lot of this is ready seems an unnecessary complication.

3. I think, for this specific tactical circumstance (delivering heavy guns close to shore to support a landing), that the US MK 41 VLS system makes more sense for a few reasons. First and most important to me is you can use SM-2 missiles against surface targets under positive control in crowded environments. Aster does not have this capability and I have not heard it will be developed.

Second this makes more sense from a risk reduction standpoint. The ESSM, SM-2, SM-3 and SM-6 combination should do the job as well as Aster-15 and Aster-30. The SM-6 is in production (though probably still not all the way to where it will get though it should be close) and the rest are well proven systems. Taking on the MK-41 gets me two things though. First I can get quad-packed ESSM now when I am not sure when I would see CAAMM deployed. ESSM has a longer range than CAAMM is specified to have so it should get the job done there.

Additionally I can just buy TLAM, which I could buy either way but like you said TLAM has never actually been fitted to the Sylver launcher so there would likely be some cost to do so. TLAM is here and proven, plus it is fairly cheap as far as weapons go. Naval SCALP is still being developed and Storm Shadow (the air-launched variant) is more expensive than TLAM already so I can't imagine Naval SCALP will be cheaper on a per round basis. Assuming Naval SCALP is better (which it may or may not be) I don't think it is better enough to justify taking on the risk of its development and the likely higher cost. I would rather have more TLAM's than a slightly more capable system.

I think by switching to the MK-41 from Sylver you can do those things. You take your two risky systems that are not yet deployed and that you can neither cost control for nor predict an exact in service date for (CAAM and Naval Scalp) and eliminate them from the equation. You don't give up much at all in the AAW portion of your mission. I think you drastically improve your ability to deal with small boats by having SM-2 aboard which can be used in that role under positive guidance.

If I was really starting to feel like making drastic improvements to the survivability of the design I could go to Mk-57 VLS, which is a distributed system that one could place around the periphery of the ship. If you are really going for battleship principals you would distribute them outside the belt so that if they get hit you lose the cells rather than seeing the back broken on the ship like you would in the design offered.