KGV or Lions in response to ATL German BB

[Naval Aviation Fan]

Edit:
Revised OP can be found here, in post #27.

Unlike OTL, in TTL, the first pair of German BB are built (Laid down) on the historical dates, but are built to 42,000 ton, 8X15" gun designs, but with either 4 x twin 15" gun turrets, or 2 x quad 15" gun turrets, so basically Bismarck class ships, in 1935. Let's call them 4 year and 3 months from laid down to commissioned, so the first pair are commissioned in Aug and Sep, 1939, and cannot be sent to sea before the outbreak of the war. So both design choices have 4 x 15" guns on both bow and stern, difference is just 2 x 2 or 1 x 4 15" gun turrets.

OTOH, the KGV ships can be laid down and ready at OTL dates, but the Lions cannot be ready until 1942 (a year earlier here than in OTL, if they skip building the KGV's), so what will change if the Germans build 2 BB in the 1935-1939 timeframe, but with 8 x 15" guns, instead of OTL's 9 x 11" guns?

For the sake of my sanity, let's just assume that the Germans are able to construct these two ships by the dates in question, and move the discussion along what I want to know, and that is, what the British do, 5 10 x 14" gunned ships (+laying down 2 Lions prewar, with their 9 x 16" guns, ready in 1943 earliest), or do they rush the Lions by a year (1937 laid down, ready in 1942), or something else.

 

[Finbarr the Fair]

As the revised Scharnhorst class would clearly breach the WNT and 1LNT limits, I suspect the UK would lay down Lions in 1936 and not agree the 35k tonnes and 14" gun limits for 2LNT

 

[Cryhavoc101]

Its also the case that German would struggle to deliver 15" guns at the same time as they OTL produced 11" guns so the Terrible twins would also be delayed

The AGNA allows for a 30% allowance compared to the RN in all ship types etc Subs which was initially 40% later 100%

So in capital ships Germany is 'allowed' pre April 1936 to build 30% of 15 which is 4.5 - Post April 36 with the laying down of the KGVs 30% of 20 is 6 Treaty BBs

So equipping the twins with 15" guns is not going to change much really other than as I said likely delay the Twins as Germany struggled to build larger artillery which is one of the reasons why they went for 11" and to appease the British with whom they wanted the AGNA to work with.

But technically they could build what they liked so long as it was within the limits agreed by the AGNA and conformed to the various international Naval treaties ie 35K tons, 15" guns etc.

So other than no 'appeasing' the British as much as it did - no real change IMO!

Edit: Just reread your post - Building above 35,000 Tons is breaking pretty much every international Naval treaty - so is a non starter - that's not happening

It would make the AGNA still bourn and this was tacit agreement from the British for Germany to rearm so it would not happen and this has a massive impact on Britain's interactions with Germany from the second these ships are laid down.

 

[Cryhavoc101]

As the revised Scharnhorst class would clearly breach the WNT and 1LNT limits, I suspect the UK would lay down Lions in 1936 and not agree the 35k tonnes and 14" gun limits for 2LNT

Yes -I missed the 42000 tons bit - that's a no no!

 

[Finbarr the Fair]

Yes -I missed the 42000 tons bit - that's a no no!

TBF I'm assuming the displacements for the upscaled Scharnhorsts are Standard, not full load. But having 15" guns also breaches Versailles and would trigger the UK a bit too.

 

[Cryhavoc101]

TBF I'm assuming the displacements for the upscaled Scharnhorsts are Standard, not full load. But having 15" guns also breaches Versailles and would trigger the UK a bit too.

No 15" would not breach WNT or 1st LNT

The 14" was added at 2nd LNT in 1936

And the AGNA gave Germany permission to 'throw of the Shackles of Versailles' so long as they conformed to the WNT and 1LNT

Obviously the French were not happy with this but Britain decided it was better to try and control the German naval rearmament rather than have them build the perfect fleet to blockade the UK (Germany until May 1939 was limited to about 50 odd submarines as per agreement with the British)

It would have been an absolute disaster if Germany had built a full on commerce raiding fleet of cruisers and U-boats

 

[Peg Leg Pom]

The KGV's would be laid down on schedule but instead of 10 14" guns the main armament would be 9 15" and the 35,000ton limit ignored altogether. I'm of two minds about the Lions, not sure whether they'd be repeat 15" KGV's or the OTL design. Personally I'd opt for a repeat design with modest improvements rather than a fresh design that will need debugging.

 

[Naval Aviation Fan]

Having some trouble getting dates to line up.

Gneisenau for instance.
Laid down: 6 May, 1935
Launched: 8 Dec, 1936 (1 year, 7 months, and 2 days)
Completed: 21 May, 1938 (3 years, 2 weeks and 1 day total)

Then there is the Scharnhorst.
Laid down: 15 June, 1935
Launched: 3 Oct, 1936 (1 year, 3 months, 2 weeks, and 4 days)
Completed: 7 Jan, 1939 (3 years, 6 months, 3 weeks, and 2 days total)

Looking at the above, I'm trying to use the longest time as a base, but then when looking at the second pair, the above time bear no relation to the dates for the latter ships. I'm guessing that, the first pair were launched as quickly as possible to free up the slipways for the follow on pair, but can anyone confirm this?

The Bismarck's took 4 years and 3 months to build (total), and this can be directly used to plan when they can start training up their crews, but doesn't give me anything useful for when they could have launched the first two ships if trying to lay down the next pair as quickly as possible. Any ideas?

For the guns and turrets, let us assume that TTL Germany sidestepped the ToV, and by 1933 has 15", 16", and 18" naval guns developed in Japan, along with working twin, triple, and quadruple turrets for these guns, also designed and built in Japan, and thus not a treaty violation, as the German government is not the owner of these gun works and related facilities.

So, back to the first pair, when should I be looking to have them be 'launched' so the second pair can be laid down?

 

[Naval Aviation Fan]

As the revised Scharnhorst class would clearly breach the WNT and 1LNT limits, I suspect the UK would lay down Lions in 1936 and not agree the 35k tonnes and 14" gun limits for 2LNT

When did the escalator clause get added? I honestly don't remember right now.

snip

Many of the same issues, plus see my post above.

HMS Hood, 42,000 tons and 8 x 15" guns, so not too far fetched that TTL AGNA allows this, especially if the Germans agree to limit their ships to 15" guns, rather than the 16" guns the big three already possess.

My own thinking is that the UK will respond with a pair of KGV in 1937, and pair of Lions in 1938, and a pair of 15" gunned ships, the first of which will be quick to build by using existing spares (Vanguard) of 15" guns/turrets, but not sure how many total ships get laid down, let alone built.

The 14" gunned KGV are fast to build, the Lions are slow to build, while the initial 15" gunned ship will be fast. This ship is what interests me the most, as I wonder if it will be a modern Hood, or something even bigger?

 

[Cryhavoc101]

When did the escalator clause get added? I honestly don't remember right now.


Many of the same issues, plus see my post above.

HMS Hood, 42,000 tons and 8 x 15" guns, so not too far fetched that TTL AGNA allows this, especially if the Germans agree to limit their ships to 15" guns, rather than the 16" guns the big three already possess.

My own thinking is that the UK will respond with a pair of KGV in 1937, and pair of Lions in 1938, and a pair of 15" gunned ships, the first of which will be quick to build by using existing spares (Vanguard) of 15" guns/turrets, but not sure how many total ships get laid down, let alone built.

The 14" gunned KGV are fast to build, the Lions are slow to build, while the initial 15" gunned ship will be fast. This ship is what interests me the most, as I wonder if it will be a modern Hood, or something even bigger?

The whole point of the various treaties was to prevent the proliferation of larger warships - no one was supposed to build any battleship above 35000 tons and 15" main guns up until the signing of the 2nd London treaty in 1936

Hood predated it and so was allowed to remain in service

The escalator clause came into effect on 1st April 1937 in the case that Japan or Italy refused to sign up to the 2LNT

"However, a so-called "escalator clause" was included at the urging of American negotiators in case any of the countries that had signed the Washington Naval Treaty refused to adhere to this new limit. This provision allowed the signatory countries of the Second London Treaty—France, the United Kingdom and the United States—to raise the limit from 14-inch guns to 16-inch if Japan or Italy still refused to sign after 1 April 1937"

This allowed the US to up arm its treaty BBs to 16" guns

The British having already laid down the KGV class choose not to and to be fair there is little that a 16" gun can do that a 14" gun cannot

The Twins would be restricted by the Washington and 1st London treaty limits at the time of their construction May and June 1935.

 

[Naval Aviation Fan]

The whole point of the various treaties was to prevent the proliferation of larger warships - no one was supposed to build any battleship above 35000 tons and 15" main guns up until the signing of the 2nd London treaty in 1936

My brain is damaged, but didn't the WNT state 35,000 tons and 16" guns? Else how Nel/Rod, Natago, Colorado class?

Hood predated it and so was allowed to remain in service

Can we just assume that in TTL, the Germans agree to 35%, no 16", but demand 42,000 ton cap?

 

[Naval Aviation Fan]

The KGV's would be laid down on schedule but instead of 10 14" guns the main armament would be 9 15" and the 35,000ton limit ignored altogether. I'm of two minds about the Lions, not sure whether they'd be repeat 15" KGV's or the OTL design. Personally I'd opt for a repeat design with modest improvements rather than a fresh design that will need debugging.

What would you see the displacements of these ships being?

 

[Cryhavoc101]

My brain is damaged, but didn't the WNT state 35,000 tons and 16" guns? Else how Nel/Rod, Natago, Colorado class?

Can we just assume that in TTL, the Germans agree to 35%, no 16", but demand 42,000 ton cap?

No it was 16" - the 2LNT tried to reduce it to 14" - its me having the brain damage

All the main players agreed not to build new Battleships after 1922 and have a battleship Holiday - Britain was allowed to build NelRods because they did not have any 16" armed ships while USN and IJN did.

16" guns? Germany would probably get but no one was allowed to build 42000 battleships at the time so I cannot see the Germans - who are minows when it came to naval power doing this.

Not if they want buy in (from Britain and others) to throw of Versailles and be allowed to rearm.

 

[Peg Leg Pom]

What would you see the displacements of these ships being?

From what I can tell the 9 x 15" version they looked at was not much different in displacement to the 10 x 14" KGV's that were actually built. Britain wanted to stick to the 14" limit in the 2nd London treaty and not exercise the escalator clause in the treaty. With Germany now building 15" gunned ships the choice to stick to 14" guns is likely to change. As for exceeding the 35000 ton displacement, that would allow either more armour or greater speed but is more "Nice to have" rather than "Have to have".

 

[Schlock]

Of course, Germany would state that the new ships would conform to the 35k treaty standard displacement, They cheated on the displacements with the earlier Deutschland class, so why would they do any different here?

​

 

[Naval Aviation Fan]

From what I can tell the 9 x 15" version they looked at was not much different in displacement to the 10 x 14" KGV's that were actually built. Britain wanted to stick to the 14" limit in the 2nd London treaty and not exercise the escalator clause in the treaty. With Germany now building 15" gunned ships the choice to stick to 14" guns is likely to change. As for exceeding the 35000 ton displacement, that would allow either more armour or greater speed but is more "Nice to have" rather than "Have to have".

I was thinking about Hood/Vanguard, they have all those 15" guns and twin turrets sitting around, enough for one ship IIRC, so what about an improved Hood, or would then go for the the extra 15" gun, but loose 7,000 tons of the displacement?

Of course, Germany would state that the new ships would conform to the 35k treaty standard displacement, They cheated on the displacements with the earlier Deutschland class, so why would they do any different here?

^^
That to, at least until the ships are launched, the exact displacement can't be determined instantly upon day one of the keel being laid down, but the OTL Scharnhorst class was 51 feet shorter and 20 thinner than the Bismarck class.

I'm really not up to trying to invent a new class of German BB right now, so I need to stick to the OP premise of a Hood/Bismarck like first class, because we know how long those took to build, and then I can plug in the different responses the RN will try, and make a nice little production chart.

 

[CalBear]

As the revised Scharnhorst class would clearly breach the WNT and 1LNT limits, I suspect the UK would lay down Lions in 1936 and not agree the 35k tonnes and 14" gun limits for 2LNT

What is really interesting is that this will start the exact sort of building race that the WNT was meant to avoid.

The carrier airpower revolution (i.e. 1,000+ HP radials) hasn't arrived. With a date of mid 1935 that is going to have a massive follow on. The British will immediately abandon the 14" gun standard (something they greatly desired to retain into the 1936 LNT II for cost containment reasons) meaning either 15" or 16" guns for the KGV and the treaty 35,000 limit is out the window (the Americans and Japanese will make sure of that). KVG are likely 45-50,000 tons, likely 3x3 16"/45) 28-30 knots with a very likely plan for a follow-on Lion class with 4x3 16"/45 MK IV) in the 65,000+ ton range to ensure a continuing 2:1 superiority of modern fast BB over the KM.

Same sort of thing happens with the American designs, with the North Carolinas rolling in around 50,000 tons full load, the South Dakotas being bulked up to 4x3 16"/50 at 70-72,000 tons (the Montana class design, which was actually a full post treaty version of the South Dakota class design) with the Iowas remaining the "Fast BB" designed to hang with the carriers across the Pacific. Might even get a "super Iowa" at least on designs, if not to first steel, before it becomes clear that the Carrier is new real power on the seas.

Japanese have no way to go except the Yamato class, which will now clearly be insufficient as the Americans will have 6-12 hulls capable of matching up with the five Yamatos. Even the A-150 would be a questionable improvement, since it would be the same overall tonnage as the Yamatos except with possibly 51cm (20.1") guns, unless the Japanese built yet another even larger yard to accommodate them, as had been the case with the Yamato and her sisters. Japanese will go broke somewhere around the the 4th Yamato, possibly the 5th if everything breaks their way, but that will preclude the construction of the Shokaku and Zuikaku.

As likely as not the Italians and French just throw up their hands at the cost and possibly build some fast 12"/30.5cm BC for use in the Med.

Butterflies the size of B-17s.

 

[Peg Leg Pom]

I was thinking about Hood/Vanguard, they have all those 15" guns and twin turrets sitting around, enough for one ship IIRC,

Britain has the turrets to build two 8 x 15" gun battleships with the 4 stored turrets from the follies, the two Erebus class monitors and the two that were used on the two wartime built Roberts class monitors. The problem would be building a four turret ship that was fast enough to catch The Twins within an acceptable displacement for the late 1930's.

 

[Gudestein]

Of course, Germany would state that the new ships would conform to the 35k treaty standard displacement, They cheated on the displacements with the earlier Deutschland class, so why would they do any different here?

​

What is really interesting is that this will start the exact sort of building race that the WNT was meant to avoid.

The carrier airpower revolution (i.e. 1,000+ HP radials) hasn't arrived. With a date of mid 1935 that is going to have a massive follow on. The British will immediately abandon the 14" gun standard (something they greatly desired to retain into the 1936 LNT II for cost containment reasons) meaning either 15" or 16" guns for the KGV and the treaty 35,000 limit is out the window (the Americans and Japanese will make sure of that). KVG are likely 45-50,000 tons, likely 3x3 16"/45) 28-30 knots with a very likely plan for a follow-on Lion class with 4x3 16"/45 MK IV) in the 65,000+ ton range to ensure a continuing 2:1 superiority of modern fast BB over the KM.

Same sort of thing happens with the American designs, with the North Carolinas rolling in around 50,000 tons full load, the South Dakotas being bulked up to 4x3 16"/50 at 70-72,000 tons (the Montana class design, which was actually a full post treaty version of the South Dakota class design) with the Iowas remaining the "Fast BB" designed to hang with the carriers across the Pacific. Might even get a "super Iowa" at least on designs, if not to first steel, before it becomes clear that the Carrier is new real power on the seas.

Japanese have no way to go except the Yamato class, which will now clearly be insufficient as the Americans will have 6-12 hulls capable of matching up with the five Yamatos. Even the A-150 would be a questionable improvement, since it would be the same overall tonnage as the Yamatos except with possibly 51cm (20.1") guns, unless the Japanese built yet another even larger yard to accommodate them, as had been the case with the Yamato and her sisters. Japanese will go broke somewhere around the the 4th Yamato, possibly the 5th if everything breaks their way, but that will preclude the construction of the Shokaku and Zuikaku.

As likely as not the Italians and French just throw up their hands at the cost and possibly build some fast 12"/30.5cm BC for use in the Med.

Butterflies the size of B-17s.

If the Germans declare Bismarck at 42000 tons its likely to go as Calbear says. More likely they will declare them at 35000 tons just as OTL, being fully treaty compliant except with ToV. Then the butterflies might be considerable smaller.
I wonder if the OTL KGV instability issues from the original 3x4 design will happen in this TL 3x3 15’’ as well.

 

[CalBear]

If the Germans declare Bismarck at 42000 tons its likely to go as Calbear says. More likely they will declare them at 35000 tons just as OTL, being fully treaty compliant except with ToV. Then the butterflies might be considerable smaller.
I wonder if the OTL KGV instability issues from the original 3x4 design will happen in this TL 3x3 15’’ as well.

A major part of the stability issue was trying to stuff six gallons into a five gallon bucket. Of all the “last of the BB” designs the JGV were, by far, the class that ran closest to the Treaty limits, even after the Japanese walked away. The result of that was a bit too little beam, a bit less draft, and a resulting reduction in reserved weight. It wasn’t enough to make the ship actually hazardous, they wouldn’t turn turtle in a storm, but it was enough show. Give then an extra 5,000 - 8,000 tons and that stability issue may well self correct.