Alternate ship designs: Bismarck

[Shadow Master]

Hmm. Does this one qualify? Here

 

[Admiral Beez]

For an ATL Bismarck class, could a 2 X 4-15" gun design have made a better ship that OTL 4 X 2-15" gun design? I know of the historical theory that made them go the route they did, as well as the historical fact that the theory was wrong (2 turrets disabled by 1 hit, from HMS Rodney, IIRC), but what changes would result from my posited redistribution of main armament?

I like it, sounds like a Super Deutschland PBS. With fewer turrets you can make them better protected so that Rodney can't get a repeat, but also, bear in mind Rodney was hitting an already disabled ship. Improve torpedo protection, especially for the props and rudder, plus make it 35 knots capable, with long range, no point mulling about in the RN's backyard.

 

[CV12Hornet]

How much redistribution are we talking about here?

Bismarck had a 175mm upper belt and end belts going fore and aft that I believe were around 3" thick. Against battleship shells, both are pretty useless, as Prince of Wales demonstrated by piercing that fuel tank at Denmark Straight.

Remove those, and you might be able to return to the 350mm main belt, probably a bit higher and longer than her OTL armor, originally planned for Bismarck. It was reduced to 320mm as a weight-saving measure. Or, beef up the upper deck or main gun turrets. Or simply make the ship a bit smaller, or any of a number of things.

 

[Shadow Master]

I like it, sounds like a Super Deutschland PBS. With fewer turrets you can make them better protected so that Rodney can't get a repeat, but also, bear in mind Rodney was hitting an already disabled ship. Improve torpedo protection, especially for the props and rudder, plus make it 35 knots capable, with long range, no point mulling about in the RN's backyard.

Thanks. I like the idea of "pushing the envelope", and going with a maximized main armament layout. As has been mentioned, the Germans going with the Quad turret would take some doing, and this would need some careful attention in order to 'get it right'. As for the engines, the TED does look intriguing, and a 4 shaft design might well be in order, but how to get 35 kts is beyond me.

Every time I look at the "all forward" designs, I wonder about why no "all aft" designs were built. Historically, fleets that would want a 'Persuit' BB in their mix, must be thinking that it is their fleet that will be doing the chasing, and fleets that expect to be chased, might want to consider the "all aft" design choice.

Of course, in the situation where an OTL Nelson class was being persued by an ATL Bismarck class, might have funny things happen, what with neither vessal able to bring a single main gun to bear on the enemy...

 

[edgeworthy]

Shouldn't that be cubic foot? Or are we talking a certain specific thickness of steel here?

A 1 foot square, 1 inch thick plate weigh 40lbs.

At least according to Janes.

 

[NoMommsen]

If you are at this site already, for the 'number of shafts' theme read this article. It nicely explains the pros and cons of the different number of shafts, ... esp. the cons of the german triple shaft design.

Little note on the latter :
It was already known to german ship designers - prior to WW I !! - by hydrodynamical research, that double and/or quadruple shafts were superior to the triple shaft design. But Tirpitz decided : "the navy is used to the triple-shaft design. No need to change that." and therefore stayed to the triple-shaft design for the BBs.

However, the german designer did use quadruple designs esp. on fast(er) ships :Von der Tann, Goeben, Seydlitz, Derfflinger.

 

[Admiral Beez]

If commerce raiding is Bismarck's role, then you need range, range and more range, plus high burst and good sustained speed, to get out of the RN's backyard, leaving that to the U-Boats, and attack Allied shipping elsewhere. A Super Deutschland with two 15" triple guns will suffice against most Allied battleships or CAs that get too close. Also, understanding that strike aircraft, both from carriers and land are your greatest risk, a significant part of the design needs to be AAA. For recon you want a sizable airgroup of recon aircraft and good radar and whatever communications jamming systems were available at the time.

Start with a D-class cruiser layout, change to 2 x triple 15" guns. https://en.wikipedia.org/wiki/D-class_cruiser_(Germany) Include diesels for range, turbines for speed.

 

[King Augeas]

Can anyone, in simple terms, explain what happened, what with the Rodney taking out the turret mechanism for turning two turrets with one hit (assuming, of course, that I even understand that correctly, lol))?

Nobody knows. From memory of Warships1 discussing this, it may be that there were actually two hits, as an insufficient number of splashes were reported, apparently. Alternatively, you can imagine a hit deflecting off one turret to hit the other, with shock or spalling disabling both, but it seems a little unlikely. Or a hit causing a fire that induced both magazines to be flooded because of crew error.

 

[King Augeas]

There are also improvements to be made to the armor scheme. The turtle-deck layout should be left alone, as the designers did have an appropriate rationale for it, but the upper and end belts should have been deleted, which frees up weight for other areas.

I'm not sure about the upper belt, but the waterline belt extensions were a reasonable idea, based on the assumption that maintaining buoyancy and hence speed was a good idea and noting the possibility of close-range engagements in poor visibility in the North Sea with British destroyers and light cruisers in pre-radar days. The Germans had to face a quite different threat environment to the British and particularly the Americans, and the armour scheme is rational. The lack of development from WW1 ideas seems to represent the fact that, when designed, the battle area appeared to be the same as that in WW1.

 

[marathag]

I'm not sure about the upper belt, but the waterline belt extensions were a reasonable idea, based on the assumption that maintaining buoyancy and hence speed was a good idea and noting the possibility of close-range engagements in poor visibility in the North Sea with British destroyers and light cruisers in pre-radar days. The Germans had to face a quite different threat environment to the British and particularly the Americans, and the armour scheme is rational. The lack of development from WW1 ideas seems to represent the fact that, when designed, the battle area appeared to be the same as that in WW1.

They Ignored 'All or Nothing' and wasted a lot of armor over areas that would really do nothing, protection wise.

Why do you think the USN and RN adopted All or Nothing?

It made sense after looking at WWI combat results. All thinner armor did was activate the fuze on incoming shells

That's what was learned from Jutland.

WWI armor scheme in Hiei allowed her to be crippled by USN 8" gunfire

 

[CV12Hornet]

I'm not sure about the upper belt, but the waterline belt extensions were a reasonable idea, based on the assumption that maintaining buoyancy and hence speed was a good idea and noting the possibility of close-range engagements in poor visibility in the North Sea with British destroyers and light cruisers in pre-radar days. The Germans had to face a quite different threat environment to the British and particularly the Americans, and the armour scheme is rational. The lack of development from WW1 ideas seems to represent the fact that, when designed, the battle area appeared to be the same as that in WW1.

Agreed, to a point. Like I said, the turtle-back deck layout was quite rational for the kind of gun battle the designers expected Bismarck to get into. I still find the end belts rather pointless (seriously, cruisers and destroyers are far more likely to shoot at the upperworks than the ends of the ship), but the upper belt represents the larger weight penalty anyway, so... Eh.

They Ignored 'All or Nothing' and wasted a lot of armor over areas that would really do nothing, protection wise.

Why do you think the USN and RN adopted All or Nothing?

It made sense after looking at WWI combat results. All thinner armor did was activate the fuze on incoming shells

That's what was learned from Jutland.

WWI armor scheme in Hiei allowed her to be crippled by USN 8" gunfire

Considering at the ranges that battle was fought at American 8" guns could punch through over ten inches of armor, I don't think All or Nothing would have helped her all that much.

 

[NHBL]

They Ignored 'All or Nothing' and wasted a lot of armor over areas that would really do nothing, protection wise.

Why do you think the USN and RN adopted All or Nothing?

It made sense after looking at WWI combat results. All thinner armor did was activate the fuze on incoming shells

That's what was learned from Jutland.

WWI armor scheme in Hiei allowed her to be crippled by USN 8" gunfire

A little detail: The USA put "All or Nothing" armor into place well before Jutland, starting with Nevada. Through the treaty era, the USA had 12 All or Nothing ships, compared to two for Britain, none for France, IIRC, and only a very few for Japan, if any.

Regarding Hiei, she was a rebuilt battlecruiser classified as a battleship. A battleship with all or nothing armor would have rejected the US 8" shells; most genuine battleships had 12" or more of armor.

 

[marathag]

Considering at the ranges that battle was fought at American 8" guns could punch through over ten inches of armor, I don't think All or Nothing would have helped her all that much.

But 8" AP would pass thru unarmored areas without the burster going off. 3-4" just is enough to get the fuze to activate.

Much more damaging than an 8" hole thru the ship

 

[marathag]

A little detail: The USA put "All or Nothing" armor into place well before Jutland, starting with Nevada. Through the treaty era, the USA had 12 All or Nothing ships, compared to two for Britain, none for France, IIRC, and only a very few for Japan, if any.

Regarding Hiei, she was a rebuilt battlecruiser classified as a battleship. A battleship with all or nothing armor would have rejected the US 8" shells; most genuine battleships had 12" or more of armor.

And how many new battleships were built after the WT?

Dunkerque class was also All or Nothing, as were the larger Richelieu

So all the Allied ships would be All or Nothing from that point on, as were the Italian

Hiei, as I posted above, had just enough armor to get that 8" AP to explode, rather than passing thru, like the 16" and 18" thru the Tincans of Taffy 3

Germans and Japanese were still thinking WWI, to their detriment.

more compartments and pumps/DC control was the future, with more armor for machinery and magazines

 

[NHBL]

And how many new battleships were built after the WT?

Dunkerque class was also All or Nothing

Hiei, as I posted above, had just enough armor to get that 8" AP to explode, rather than passing thru, like the 16" and 18" thru the Tincans of Taffy 3

Quite a few were built, but I specifically mentioned the treaty era. After the treaty, there were new battleships: 10 American, 4 Italian, 6 British, 4 French, 4 German, and only 2 Japanese-and some weren't even completed until after the war.

Hiei was a severely obsolescent ship, but was what Japan had.

 

[marathag]

Quite a few were built, but I specifically mentioned the treaty era. After the treaty, there were new battleships: 10 American, 4 Italian, 6 British, 4 French, 4 German, and only 2 Japanese-and some weren't even completed until after the war.

Hiei was a severely obsolescent ship, but was what Japan had.

But only the Japanese and Germans stayed with belting as much as possible, and so, had the Bismarck and Yamato, far overweight for what they were.

As All or Nothing ships, would have had far better turret and deck armor, that would have been useful to them, along with better compartmentation and pumps

 

[CV12Hornet]

But 8" AP would pass thru unarmored areas without the burster going off. 3-4" just is enough to get the fuze to activate.

Much more damaging than an 8" hole thru the ship

You missed the point I was trying to make, which is that at such close range 8" AP is getting through her 8" main belt, which means something vital's gonna get wrecked.

And how many new battleships were built after the WT?

Dunkerque class was also All or Nothing, as were the larger Richelieu

So all the Allied ships would be All or Nothing from that point on, as were the Italian

Hiei, as I posted above, had just enough armor to get that 8" AP to explode, rather than passing thru, like the 16" and 18" thru the Tincans of Taffy 3

Germans and Japanese were still thinking WWI, to their detriment.

more compartments and pumps/DC control was the future, with more armor for machinery and magazines

Also, Yamato was an All or Nothing design. The incremental ships were all pre-Treaty. And compartmentation was certainly not a weakness in either design. Oh, and I find myself wondering how much more armor the Yamato class needs.

 

[Shadow Master]

Some good discussions and information here, guys, keep it coming please.

Some things I have just had explained to me here, because of the back and forth's, is that less than impenatrable armor is undesirable because:
It takes up more weight, that could have been used to make the main armored citadel either a bit bigger w/o thinning the armor, or a bit thicker instead, making the protection it affords just a little better;
It not only will not stop an enemy heavy AP shell, but will instead ensure that such a shell will detonate within the hull, rather than passing through w/o detonating.

In both cases above, better flooding control would be needed anyway for improving survivability.

So even if not going with the "all or nothing" layout, you still need more tonnage for extra pumps and internal (watertight) partitions, in the un(der)armored sections of a ships hull?

Hmmm.

So far in this thread, we have touched upon fore and aft armament layout schemes, compared with all fore/all aft designs, although much still needs to be done here with respect to the affects on other critical ship systems these changes may have, we have also touched upon quad (or possibly, triple) main gun turrets instead of twin turrets, as well as TED, and 4 shaft propulsion plans.

What big things are we overlooking? The rudders need to be discussed, and why the Bismarck was loosing so much fuel from one hit, I would think.

 

[NHBL]

Rudders and screws are an inherent vulnerability in any ship at all. They're all together in one fairly concentrated portion of the ship, so a good hit there, and anyone is in bad shape. Triple screws make it worse, for the reasons already mentioned.

Regarding turrets, incidentally, Germany's built triple 11" turrets, and twin 15's (Badens) so triple 15's shouldn't be too bad.

The biggest single factor, however, is the design environment for Germany's World War II ships that's been mentioned earlier. No matter what good concepts, I think they'd get ruined by the mindset of the time.

 

[Shadow Master]

Rudders and screws are an inherent vulnerability in any ship at all. They're all together in one fairly concentrated portion of the ship, so a good hit there, and anyone is in bad shape. Triple screws make it worse, for the reasons already mentioned.

Regarding turrets, incidentally, Germany's built triple 11" turrets, and twin 15's (Badens) so triple 15's shouldn't be too bad.

Were the triple 11" gun turrets the same guns and turrets on both the Deutschland-class and the Scharnhorst-class's?

The biggest single factor, however, is the design environment for Germany's World War II ships that's been mentioned earlier. No matter what good concepts, I think they'd get ruined by the mindset of the time.

Yep, that link goes along way to explaining how things got so badly messed up for the Nazi navy, lol. My POD {If/When I ever get around to starting an ATL}, removes this problem, as well as many others like it.

I'm going to put all of the links I have recieved in this thread into the OP, with a bit on what each link has to offer.