Alternate King George V class battleship

[Domobran7]

OK, so KGV class battleships were designed, much like Nelson class, under strict treaty constraints. Despite that, they were very good ships, although one could argue that 14 in guns were a disadvantage. So what about going Nelsol / Richelieu route? As I rather like playing Rule the Waves, I designed a potential variant in it. So if the game calculations are right, a 35 000 ton battleship could have:
- 2 x 4-gun 15 in turrets in all-forward arrangement (a.k.a. Nelsol / Richelieu setup)
- 10 x 2-gun 5 in turrets
- couple dozen low-caliber guns (AAA in WWII context)
- 15 in turret face
- 5 in turret roof
- 15 in armour belt
- 5 in armoured deck
- 27 knot top speed

Caveat here being that it was in RTW1, since I do not have RTW2 (not big fan of carriers). So if anything, WWII battleship should manage this even more easily. And comparing with actual historical designs, this is not unrealistic either - Richelieu class managed a very similar setup just fine, except with less side armour (13 in vs 15 in belt, but 17 in vs 15 in turret face).

From what I have found, KGV was in fact intended to have 15 in guns in beginning, but British shot themselves in the foot by trying to limit maximum armament to 14 in guns in a treaty. Seeing how they already had perfectly fine 15 in guns, what happened? And would this design perform better than historical ship, or maybe even be available earlier?

 

[jsb]

And would this design perform better than historical ship, or maybe even be available earlier?

When is your POD?

I dont think 15" works as USN/IJN only have 14" or 16" and if you can have 15" then you can go to 16" and potentially breach the 35kt limit....

I think 27 Kn is also to slow you really want,
2x 14" quad forward
8x twin 4.5" (with split loading)
lots of light 40mm AA
protection as KVG (maybe with more TDS on rear shafts & more none turbo pumps if you have a crystal ball)
as much speed as you can 28-30+.... (this is a big deal to catch raiders S&G or B&T)

 

[Peg Leg Pom]

They're not laid down till 1937 due to the treaties. War is extremely likely either against Germany or Japan. Lie about the tonnage to get the ship you want.

 

[Cryhavoc101]

OK, so KGV class battleships were designed, much like Nelson class, under strict treaty constraints. Despite that, they were very good ships, although one could argue that 14 in guns were a disadvantage. So what about going Nelsol / Richelieu route? As I rather like playing Rule the Waves, I designed a potential variant in it. So if the game calculations are right, a 35 000 ton battleship could have:
- 2 x 4-gun 15 in turrets in all-forward arrangement (a.k.a. Nelsol / Richelieu setup)
- 10 x 2-gun 5 in turrets
- couple dozen low-caliber guns (AAA in WWII context)
- 15 in turret face
- 5 in turret roof
- 15 in armour belt
- 5 in armoured deck
- 27 knot top speed

Caveat here being that it was in RTW1, since I do not have RTW2 (not big fan of carriers). So if anything, WWII battleship should manage this even more easily. And comparing with actual historical designs, this is not unrealistic either - Richelieu class managed a very similar setup just fine, except with less side armour (13 in vs 15 in belt, but 17 in vs 15 in turret face).

From what I have found, KGV was in fact intended to have 15 in guns in beginning, but British shot themselves in the foot by trying to limit maximum armament to 14 in guns in a treaty. Seeing how they already had perfectly fine 15 in guns, what happened? And would this design perform better than historical ship, or maybe even be available earlier?

The idea that going 14" caused all sorts of problems largely is a myth - there were delays imparted on the KGVs but my understanding is this is mostly to do with changing the B turret from a 4 gun to a 2 gun turret in order to increase armour and stability worries that the much heavier 4 gun turret would have riding as it would have been higher up in the hull.

Whatever gun they decided on it was going to have all of the same safety features, anti flash etc built into it as the 14" system generating teething issues that would need to be overcome and obliged to shoehorn it into a limited hull size and tonnage as the 14" system.

As to what happened - well the expected 2nd London Naval treaty was expected to limit gun sizes to 14" and while the US waited for the escalator clause to allow them to go up to 16" the British pressed on deciding that it was better to start building them now and having modern battleships in service earlier and then to build 16" armed ships later if needed (with 2 laid down in 1939)

After all they had a block obsolescence problem with 10 old Battleships (all built between 1913 and 1915) and 3 old Battle-cruisers all them pre-Jutland and only 2 post Jutland Battleships (NelRod).

At the time of making the decision the following was going on.....

Germany had 4 modern fast battleships building or planned

Italy had started building 2 modern fast Battleships and planned to build 2 more

Japan had modernised or were modernising all 10 of its battleships

So Britain had to do something then rather than later and had to hedge its bets on the 2nd LNT

At the end of the day there is nothing the KGVs did that could have been done better by another treaty battleship and given that Battleships were found increasingly 'wanting' in the face of modern air-power any extra resources used on them would have been squandered.

Regarding 5" guns - there were no 5" guns in British service - a 5.1" had been under development but was abandoned due to ammunition weight issues

The twin 4.5s would have been the best answer

I understand why Britain went 5.25" - Aircraft were operating from increasingly higher altitudes requiring larger guns and a larger warhead as well as Torpedo ranges were now to the horizon requiring a secondary gun system capable of reaching out to that range capable of damaging Destroyers and Crusiers.

 

[HBsennah94]

Wasn't the OTL-Admiralty's originally preferred design a 3x3 15-in plus the rest as was built OTL anyway?

 

[Domobran7]

When is your POD?

I dont think 15" works as USN/IJN only have 14" or 16" and if you can have 15" then you can go to 16" and potentially breach the 35kt limit....

I think 27 Kn is also to slow you really want,
2x 14" quad forward
8x twin 4.5" (with split loading)
lots of light 40mm AA
protection as KVG (maybe with more TDS on rear shafts & more none turbo pumps if you have a crystal ball)
as much speed as you can 28-30+.... (this is a big deal to catch raiders S&G or B&T)

Don't know what POD is, but the idea is to have ships operational at the same time or even earlier than OTL King George V design. So basically you already have good 15' guns, so all you need is design turrets for them. Or, alternatively, you can design entirely new guns, but still have the advantage of already having ammunition stocks and production lines.

I used 27 kts to be conservative, but I do believe that even with 2 x quad 15'' ships could go at least 30 kts. This is the original KGV stats:
- 227 m overall length
- 31,5 m beam
- 10 x 14 in main armament (1 590 lbs projectile; 15 900 lbs broadside)
- 14,7 in belt armour
- 5 in deck armour
- 12,75 in turret face
- 28,3 kts speed
- 35 000 t standard displacement (36 750 t)

Richelieu stats:
- 248 m overall length
- 33,1 m beam
- 8 x 15 in main armament (1 950 lbs projectile; 15 600 lbs broadside)
- 12,9 in belt armour (inclined)
- 6,7 in deck armour
- 17 in turret face
- 32 kts speed
- 37 250 t standard displacement

Now, using quad 15'' in two forward turrets:
- BL 14'' Mk.VII is 16,31 m bore length; 380 mm/45 modele 1935 is 17,26 m barrel length
- BL 14'' Mk.VII weight 78,99 t; 380 mm/45 modele 1935 weight 94,13 t
- KGV turret weight: 1 582 t quad, 915 t dual; Richelieu quad turret weight: 2 274 t
- Total turret weight: 4 079 t KGV, 4 548 t Richelieu

Thus 15 in guns if copied from Richelieu should have following stats:
- 8 x 15 in main armament (1 950 lbs projectile; 15 600 lbs broadside)
- Turret weight: 2 274 t
- Total turret weight: 4 548 t

Using grandmother's dentals a.k.a. Vanguard would result in 1 938 lbs projectile and 15 504 lbs broadside (97,5% of OTL), but also much quicker build process.

Removing the aft turret while replacing dual turret with quad mount and also increasing calibre to 15'' should result in:
- belt armour weight reduction to 95% of original (used Rule The Waves ship designer for this)
- deck armour weight reduction to 95% of original
- assuming all armour reduction is 95% (turret armour was counted under "armaments weight"), armour weight savings are 621 t (12 413 t to 11 792 t)
- hull if reduced also may be reduced in weight by 692 t (13 830 t to 13 138 t)
- main turrets weight increase is 469 t (4 079 t to 4 548 t)
- OVERALL: weight reduction by 844 t
- 844 t is 6,8% of KGV's armour weight; if applied to thickness equally, 6,8% increase would increase belt armour from 14,7 in to 15,7 in, deck armour from 5 in to 5,3 in and turret face from 12,75 to 13,62 in. Alternatively, and more usefully, 844 t would allow for installation of additional 48 pom-poms (which would add 384 barrels to ship's AAA suite - probably not physically possible due to space restructions).

They're not laid down till 1937 due to the treaties. War is extremely likely either against Germany or Japan. Lie about the tonnage to get the ship you want.

The entire idea is to get maximum out of allowable tonnage, so I wouldn't go that route.

The idea that going 14" caused all sorts of problems largely is a myth - there were delays imparted on the KGVs but my understanding is this is mostly to do with changing the B turret from a 4 gun to a 2 gun turret in order to increase armour and stability worries that the much heavier 4 gun turret would have riding as it would have been higher up in the hull.

Whatever gun they decided on it was going to have all of the same safety features, anti flash etc built into it as the 14" system generating teething issues that would need to be overcome and obliged to shoehorn it into a limited hull size and tonnage as the 14" system.

I am aware of that. 14'' gun itself was a very good design; it was flash protection system that was too complex. The idea here is to use 15'' guns to a) get more firepower for tonnage or protection for tonnage/firepower (keep up broadside weight while going one turret down) and b) potentially reduce design time, build time, or both, as guns are one of most important long-lead items. Using 15'' guns would (theoretically) allow to build turrets with preexisting 15'' guns, and then swap those guns with more modern variants as they became available.

As to what happened - well the expected 2nd London Naval treaty was expected to limit gun sizes to 14" and while the US waited for the escalator clause to allow them to go up to 16" the British pressed on deciding that it was better to start building them now and having modern battleships in service earlier and then to build 16" armed ships later if needed (with 2 laid down in 1939)

After all they had a block obsolescence problem with 10 old Battleships (all built between 1913 and 1915) and 3 old Battle-cruisers all them pre-Jutland and only 2 post Jutland Battleships (NelRod).

At the time of making the decision the following was going on.....

Germany had 4 modern fast battleships building or planned

Italy had started building 2 modern fast Battleships and planned to build 2 more

Japan had modernised or were modernising all 10 of its battleships

So Britain had to do something then rather than later and had to hedge its bets on the 2nd LNT

At the end of the day there is nothing the KGVs did that could have been done better by another treaty battleship and given that Battleships were found increasingly 'wanting' in the face of modern air-power any extra resources used on them would have been squandered.

Part of the idea here is to get ships designed and into service as quickly as possible by using old 15'' guns which would then be swapped with more modern variants as they became available. I believe it was precisely guns and turrets which were limiting factor in British battleship building capacity - hence the Vanguard. And Brits had awful lot of ancient 15'' guns lying around from all pre-World War I ships that were scrapped due to treaties, so... of course, turrets themselves would still need to be built, but if you used 2x2 setup (essentially, two twin mountings side-by-side) it might - in theory - be possible to even reuse whole mechanism, not just guns.

Regarding 5" guns - there were no 5" guns in British service - a 5.1" had been under development but was abandoned due to ammunition weight issues

The twin 4.5s would have been the best answer

I understand why Britain went 5.25" - Aircraft were operating from increasingly higher altitudes requiring larger guns and a larger warhead as well as Torpedo ranges were now to the horizon requiring a secondary gun system capable of reaching out to that range capable of damaging Destroyers and Crusiers.

Wasn't the OTL-Admiralty's originally preferred design a 3x3 15-in plus the rest as was built OTL anyway?

I found something to that effect but never any details.

 

[jsb]

So basically you already have good 15' guns, so all you need is design turrets for them. Or, alternatively, you can design entirely new guns, but still have the advantage of already having ammunition stocks and production lines.

Using grandmother's dentals a.k.a. Vanguard

Part of the idea here is to get ships designed and into service as quickly as possible by using old 15'' guns which would then be swapped with more modern variants as they became available. I believe it was precisely guns and turrets which were limiting factor in British battleship building capacity - hence the Vanguard. And Brits had awful lot of ancient 15'' guns lying around from all pre-World War I ships that were scrapped due to treaties, so... of course, turrets themselves would still need to be built, but if you used 2x2 setup (essentially, two twin mountings side-by-side) it might - in theory - be possible to even reuse whole mechanism, not just guns.

The problem is pre war that will never be accepted without hindsight, as swapping guns was agaisnt WNT and newer ones would be much better as would new turrets even more so than the old for the 20-25 year life and also hurt the industrial base and take up limited BB slots in new treaties......

With hindsight we know the old 15" would be sufficient for the 5 years you actually care about and nothing matters more than getting them afloat yesterday, with hindsight Vanguard can be built even if maybe with 6 guns in three old mounts is much faster and is the obvious answer.....

 

[Domobran7]

The problem is pre war that will never be accepted without hindsight, as swapping guns was agaisnt WNT and newer ones would be much better as would new turrets even more so than the old for the 20-25 year life and also hurt the industrial base and take up limited BB slots in new treaties......

With hindsight we know the old 15" would be sufficient for the 5 years you actually care about and nothing matters more than getting them afloat yesterday, with hindsight Vanguard can be built even if maybe with 6 guns in three old mounts is much faster and is the obvious answer.....

Why would swapping guns be against WNT? I believe every or almost every pre-WWI battleship got significant rebuilds of their main battery - at the very least, elevation was increased (British battleships except for R-s as well as US Standards all got this modification).

 

[jsb]

Why would swapping guns be against WNT? I believe every or almost every pre-WWI battleship got significant rebuilds of their main battery - at the very least, elevation was increased (British battleships except for R-s as well as US Standards all got this modification).

Part 3 D,

No retained capital ships or aircraft-carriers shall be reconstructed......No alterations in side armour, in calibre, number or general type of mounting of main armament shall be permitted......

History and Technology - Washington Naval Limitation Treaty of 1922 - NavWeaps

www.navweaps.com

Yes everybody interpreted the rules as they please, and once US did it to increase elevation RN did the same (but only to the 4 rebuilds?), but early on ie 34/36 when you need to make the plan this might stop you?

 

[Peg Leg Pom]

That doesn't prevent you reusing guns and turrets from decommissioned ships to reduce the building time of new ones, nor does it prevent you modernising the turrets of old ships to improve the performance of the guns.

 

[SsgtC]

Part 3 D,

History and Technology - Washington Naval Limitation Treaty of 1922 - NavWeaps

www.navweaps.com

Exactly this. Even increasing the elevation of the main battery was considered sketchy in terms of whether the treaty allowed it or not. IIRC, the UK's position was that increasing the elevation was "altering the general type of mounting" and was thus forbidden. They only increased the elevation when every other signatory basically told them to shove it and increased the elevation on their ships. Of all the signatories, the British are the least likely to try and swap main batteries on their battleships

 

[alfredtuomi]

stick with the original 3x3 15 inch design.
forget about having aircraft aboard and install more pompom mounts of an improved type.
fund earlier development of high pressure boilers and double reduction turbines.
basically The whale has wings line of development.

 

[Domobran7]

Part 3 D,

History and Technology - Washington Naval Limitation Treaty of 1922 - NavWeaps

www.navweaps.com

Yes everybody interpreted the rules as they please, and once US did it to increase elevation RN did the same (but only to the 4 rebuilds?), but early on ie 34/36 when you need to make the plan this might stop you?

"In calibre, number or general type"... I do not think that would prevent you from swapping old 15 in guns for newer type. It would only prevent you from e.g. using 14 in guns in 15 in mountings and later installing 15 in guns. EDIT: Although @SsgtC does have a point, UK did what it could to prevent any new developments on battleships - probably trying to live off of WWI glory as long as possible.

 

[ArtosStark]

"In calibre, number or general type"... I do not think that would prevent you from swapping old 15 in guns for newer type. It would only prevent you from e.g. using 14 in guns in 15 in mountings and later installing 15 in guns. EDIT: Although @SsgtC does have a point, UK did what it could to prevent any new developments on battleships - probably trying to live off of WWI glory as long as possible.

It was actually not a bad play for Britain. As a global empire they needed a large fleet, but with WW1 debt and their own struggling economy, they could not afford a major naval arms race. Plus the British public saw the Anglo-German Naval arms race as part of the cause of WW1. A lot of people believed in treaties to keep the peace. And it made sense for Britain to try to limit everyone to less powerful ships. Since the treaties gave Britain and the US parity they did not have to worry about trying to out build the US. And if everyone had less powerful ships they could outnumber anyone else without meeting a threat they could not counter.
Not to say it didn’t come back to bite them, but it made sense at the time.

 

[jsb]

UK did what it could to prevent any new developments on battleships - probably trying to live off of WWI glory as long as possible.

The other problem is once you start rebuilding you quickly lose all the saving from the treaty (ie the entire point!) as rebuilt ships are nearly (well 1/2+) as expensive as new and far less good value long term......

GB wanted everybody to do as little as possible to the old ships so they could all save as much money as posible then potentially transition to new smaller cheaper ships once the old where so old that they could not be decisive, rebuilding them with new guns/elevation/decks rendered that useless....

 

[CV12Hornet]

From what I have found, KGV was in fact intended to have 15 in guns in beginning, but British shot themselves in the foot by trying to limit maximum armament to 14 in guns in a treaty. Seeing how they already had perfectly fine 15 in guns, what happened? And would this design perform better than historical ship, or maybe even be available earlier?

The 14" limit was about grandfathering in their 15" guns on the old battleships and making them a little more viable a little longer.

This design would probably perform better due to the turret design not being as rushed and not having design resources split between the twin and quad - otherwise it's pretty similar to the OTL design. It would probably not be available faster.

Don't know what POD is, but the idea is to have ships operational at the same time or even earlier than OTL King George V design. So basically you already have good 15' guns, so all you need is design turrets for them. Or, alternatively, you can design entirely new guns, but still have the advantage of already having ammunition stocks and production lines.

I used 27 kts to be conservative, but I do believe that even with 2 x quad 15'' ships could go at least 30 kts. This is the original KGV stats:
- 227 m overall length
- 31,5 m beam
- 10 x 14 in main armament (1 590 lbs projectile; 15 900 lbs broadside)
- 14,7 in belt armour
- 5 in deck armour
- 12,75 in turret face
- 28,3 kts speed
- 35 000 t standard displacement (36 750 t)

Richelieu stats:
- 248 m overall length
- 33,1 m beam
- 8 x 15 in main armament (1 950 lbs projectile; 15 600 lbs broadside)
- 12,9 in belt armour (inclined)
- 6,7 in deck armour
- 17 in turret face
- 32 kts speed
- 37 250 t standard displacement

Now, using quad 15'' in two forward turrets:
- BL 14'' Mk.VII is 16,31 m bore length; 380 mm/45 modele 1935 is 17,26 m barrel length
- BL 14'' Mk.VII weight 78,99 t; 380 mm/45 modele 1935 weight 94,13 t
- KGV turret weight: 1 582 t quad, 915 t dual; Richelieu quad turret weight: 2 274 t
- Total turret weight: 4 079 t KGV, 4 548 t Richelieu

Thus 15 in guns if copied from Richelieu should have following stats:
- 8 x 15 in main armament (1 950 lbs projectile; 15 600 lbs broadside)
- Turret weight: 2 274 t
- Total turret weight: 4 548 t

Using grandmother's dentals a.k.a. Vanguard would result in 1 938 lbs projectile and 15 504 lbs broadside (97,5% of OTL), but also much quicker build process.

Removing the aft turret while replacing dual turret with quad mount and also increasing calibre to 15'' should result in:
- belt armour weight reduction to 95% of original (used Rule The Waves ship designer for this)
- deck armour weight reduction to 95% of original
- assuming all armour reduction is 95% (turret armour was counted under "armaments weight"), armour weight savings are 621 t (12 413 t to 11 792 t)
- hull if reduced also may be reduced in weight by 692 t (13 830 t to 13 138 t)
- main turrets weight increase is 469 t (4 079 t to 4 548 t)
- OVERALL: weight reduction by 844 t
- 844 t is 6,8% of KGV's armour weight; if applied to thickness equally, 6,8% increase would increase belt armour from 14,7 in to 15,7 in, deck armour from 5 in to 5,3 in and turret face from 12,75 to 13,62 in. Alternatively, and more usefully, 844 t would allow for installation of additional 48 pom-poms (which would add 384 barrels to ship's AAA suite - probably not physically possible due to space restructions).

The problem with the Richelieu comparison is that it assumes equal shipbuilding technology, which was not the case. The French were ahead in boiler design, having stumbled into a very effective high-pressure design almost by accident. British boilers were reliable, but they were low-pressure designs that in terms of power and compactness were well behind their American and French counterparts. This is how the French could cram so much engine in a 35,000-ton design and have the deepest TDS of any of the post-1930 battleship designs.

I am aware of that. 14'' gun itself was a very good design; it was flash protection system that was too complex. The idea here is to use 15'' guns to a) get more firepower for tonnage or protection for tonnage/firepower (keep up broadside weight while going one turret down) and b) potentially reduce design time, build time, or both, as guns are one of most important long-lead items. Using 15'' guns would (theoretically) allow to build turrets with preexisting 15'' guns, and then swap those guns with more modern variants as they became available.

The flash protection complexity wasn't really the problem; the whole turret system was simply badly designed. The list of defects encountered in the Navweaps page is far too long to be solely a problem of overcomplex flash protection.

Part of the idea here is to get ships designed and into service as quickly as possible by using old 15'' guns which would then be swapped with more modern variants as they became available. I believe it was precisely guns and turrets which were limiting factor in British battleship building capacity - hence the Vanguard. And Brits had awful lot of ancient 15'' guns lying around from all pre-World War I ships that were scrapped due to treaties, so... of course, turrets themselves would still need to be built, but if you used 2x2 setup (essentially, two twin mountings side-by-side) it might - in theory - be possible to even reuse whole mechanism, not just guns.

The British did not have a lot of old 15" guns just "lying around", because they didn't put it on any of their pre-World War I ships that were scrapped. The only 15" ships that had been scrapped up to this point were two monitors, and their guns and mountings had already been reused on a new pair of monitors. 186 guns and 58 mountings were all that were ever built; 108 guns and 54 mountings were already afloat on ships at sea and another eight guns and four mountings had been hauled off of Courageous and Glorious when they were converted to aircraft carriers and those were the mountings used on Vanguard. That leaves 70 guns "lying around", as you put it, or rather 68, since two were prototypes.

That is, nominally, enough for your battleship design, but what's the point? Mounting the guns in new-build turrets saves no time at all; the new and vastly superior 15"/45 Mk. II was already ready by 1935, two years before the 14" and right around when the design work for the KGVs was started. And even then the comparisons to Vanguard miss one very big advantage Vanguard had: they didn't need to design a new hull. The appeal of Vanguard was that they already had a hull design ready to go for the Lions, so they could just take that, tweak it to fit four twin 15", and otherwise heavily expedite the design process, which normally took two years. Here, you still need to design an all-new hull anyway; fitting the old guns is a complete false economy.

Oh, and also those old guns would be expected to replace worn-out guns on existing ships, too.

 

[jsb]

The 14" limit was about grandfathering in their 15" guns on the old battleships and making them a little more viable a little longer.

Was this not more the USN/IJN 14" guns than anything RN had?

The flash protection complexity wasn't really the problem; the whole turret system was simply badly designed. The list of defects encountered in the Navweaps page is far too long to be solely a problem of overcomplex flash protection.

But they did fine mid/late war in comparison to other ships in real actions look at the stoppage rates for missed gun salvoes in the later battles they are as good if not better that anybody else in long battles in rough weather, I think its more a combination or being rushed into fights before trials (POW especially) and keeping notes about it in English....

 

[CV12Hornet]

Was this not more the USN/IJN 14" guns than anything RN had?

In the sense that most IJN and USN battleship had 14" guns, yes.

But they did fine mid/late war in comparison to other ships in real actions look at the stoppage rates for missed gun salvoes in the later battles they are as good if not better that anybody else in long battles in rough weather, I think its more a combination or being rushed into fights before trials (POW especially) and keeping notes about it in English....

Citation on the stoppage rates for other ships? Because Duke of York at North Cape still suffered so many stoppages she missed a full third of her firing opportunities.

 

[Jellico]

The usual excuse on North Cape is DoY was fighting in a gale. As so often in these questions is the RN is so well documented compared to the others and no one else did all that much fighting with big caliber guns in exciting environments.

14" is probably mostly about a sweetener for the 14" navies.

You are not going to use a BL15" Mk1 on a Treaty battleship. It is too heavy and there are better options when you have time to build from scratch.

 

[Domobran7]

The 14" limit was about grandfathering in their 15" guns on the old battleships and making them a little more viable a little longer.

This design would probably perform better due to the turret design not being as rushed and not having design resources split between the twin and quad - otherwise it's pretty similar to the OTL design. It would probably not be available faster.

Thanks.

The problem with the Richelieu comparison is that it assumes equal shipbuilding technology, which was not the case. The French were ahead in boiler design, having stumbled into a very effective high-pressure design almost by accident. British boilers were reliable, but they were low-pressure designs that in terms of power and compactness were well behind their American and French counterparts. This is how the French could cram so much engine in a 35,000-ton design and have the deepest TDS of any of the post-1930 battleship designs.

I actually only used Richelieu for comparison's sake and to figure out how much the quad turret would weight if using 15 in gun. Actual weight calculation was done by tweaking KGV design. Of course, this somewhat overstates actual weight of my design, as Richelieu turret face had 17 in armour compared to 12,75 in for KGV. Reducing turret face to 15 in might save 500 - 700 tons for a two-turret design compared to 17 in face. How many battleships suffered turret face penetrations anyway?

BTW, how much weight did Nelson's / Richelieu's all-forward main gun arrangement really save?

The flash protection complexity wasn't really the problem; the whole turret system was simply badly designed. The list of defects encountered in the Navweaps page is far too long to be solely a problem of overcomplex flash protection.

Thanks.

The British did not have a lot of old 15" guns just "lying around", because they didn't put it on any of their pre-World War I ships that were scrapped. The only 15" ships that had been scrapped up to this point were two monitors, and their guns and mountings had already been reused on a new pair of monitors. 186 guns and 58 mountings were all that were ever built; 108 guns and 54 mountings were already afloat on ships at sea and another eight guns and four mountings had been hauled off of Courageous and Glorious when they were converted to aircraft carriers and those were the mountings used on Vanguard. That leaves 70 guns "lying around", as you put it, or rather 68, since two were prototypes.

That is, nominally, enough for your battleship design, but what's the point? Mounting the guns in new-build turrets saves no time at all; the new and vastly superior 15"/45 Mk. II was already ready by 1935, two years before the 14" and right around when the design work for the KGVs was started. And even then the comparisons to Vanguard miss one very big advantage Vanguard had: they didn't need to design a new hull. The appeal of Vanguard was that they already had a hull design ready to go for the Lions, so they could just take that, tweak it to fit four twin 15", and otherwise heavily expedite the design process, which normally took two years. Here, you still need to design an all-new hull anyway; fitting the old guns is a complete false economy.

Oh, and also those old guns would be expected to replace worn-out guns on existing ships, too.

I wasn't aware that new 15'' was available; but yeah, that would definitely be the better choice. Especially since most British battleships had 15'' guns, so there would be no need to make new production lines for 14'' ammunition.