[>>>Alpha-9 Feedback<<<]

What I would like to see from any hotfix patch in the coming days is to also include the French experimental battlecruiser hull - suitably downscaled - to the heavy cruiser category, from 10,500 to 14,000 tons. It's a clear candidate for re-creating classes like the C5 A3 and C5 SA1 proposals, as well as being a better hull for France's cruisers as opposed to something like, say, the downscaled Bismarck and Yamato hulls we have in that category right now.

[Armor Layouts and Replicas]

3 hours ago, disc said:

I think it should be noted that other nations either did not find such a drop-off in their armors, or perhaps more simply did not think it much of an issue.

The Americans used up to 439mm of Class A (face-hardened cemented) armor in the barbettes of the Iowas and South Dakotas, and up to 406mm for the barbettes of the North Carolinas. The barbettes of the Montanas would have reached 541mm of Class A, with the conning tower 457mm and the belt 406mm.

For Japan, the Yamatos had a 410mm Vickers Hardened (VH, a cemented face-hardened armor) belt, 500mm VH main conning tower, 560mm VH barbettes (max), and 660mm VH turret face plates. The A-150 design supposedly would have yet heavier armor, but details are not available.

It's my belief that the average quality of the armour plates may help to explain the difference. The Americans and British simply had higher-quality armour than the Germans were capable of manufacturing (though not the Italians, as Terni Variable-Face-Thickness Cemented was the best shipboard armour to ever go to sea). The reasons for this difference are numerous but we can point out two main factors: the relatively long hiatus in the production of cemented naval armour post-World War I, and Krupp's testing procedures, which appear to have used uncapped AP projectiles.

As for the Japanese, they did discover defects in face-hardened plates over 400 mm thickness: the cooling rate for the interior of these plates was different from the outer layers, and so the brittle steel crystal bainite (shirome) formed in lieu of the desired martensite. They developed a quenching and tempering process to deal with the problem but by that time, no new battleships were being built, as Shinano was being converted to an aircraft carrier. They also developed new armour plates around the same time - if you look on Navweaps, I believe Nathan Okun has an article on the subject.

As for A-150, the known requirements for the resistance of its own projectiles from 20,000 to 30,000 metres have led me to calculate a required belt of 460 mm and a 250 mm deck. At least one 51-cm turret was apparently under construction, so if I ever find data on that, I will be very happy.

[Armor Layouts and Replicas]

2 hours ago, IronKaputt said:

Source, please?

'Questions have been raised as to the wisdom of providing a vertical side belt less than the traditional standard—thickness equal to the bore of the main battery. Gunnery tests of the new composition KC n/A 320-mm armour plate showed that its thickness and resistance capabilities equaled an optimum thickness of 360 mm, but as thickness was increased, little was gained (the point of diminishing return). Krupp considered the thickness of 320 mm to be optimum and 400 mm neared the limit of effective production.'

—Axis and Neutral Battleships in World War II, Garzke & Duilin (section on the Bismarck class)

 

[Armor Layouts and Replicas]

47 minutes ago, Microscop said:

Shell fall angle at 15km is 10 degree or more, 20 degrees for inclined belt and add to that even slight angle of the ships even as little as 10 degrees.

The total angle is over 30 at the lest and in practical terms rarely less than 40 degrees. If you ditch the distributed armor scheme and turtleback you should be able to afford 15 inch belt which won't have issues stopping 15 inch shells with the impact angles i mentioned and probably have enough tonnage left to uparmor the turrets.

Bismarck at Denmark strait and when it was sunk was fired at from well above 20km in both cases. Sinking of Glorious happened at over 20km too so long range fights were quite common. Also worth remembering that radar was making gunnery in bad visibility conditions more and more feasible as the war progressed.

I believe the penetration table already accounts for angle of fall. They didn't want to move away from the distributed armour scheme because they were concerned with medium-calibre shell holes as well as containing the damage of large calibre shells (see Lützow at the Skagerrak battle). I won't deny that you might have the displacement left over to up-armour the turrets, but it would probably be reinvested back into hull protection (such as in KGV, which also left her turrets and barbettes woefully underprotected). However, I can't necessarily agree with being able to reinvest that weight solely back into vertical protection; you might get a 330-350 mm belt (I profess doubts that it would be inclined at 20 degrees, as they're not Japanese), with a deck of the appropriate thickness. One also has to note that Krupp came out with studies around that time that showed that one had diminishing returns on cemented plates past 320 mm thickness, with 360 mm being the maximum before you started to lose quality.

As for your examples, I feel like I have to point out that although Denmark Strait started at 22,000 m, both sides closed the range until combat distance was around 13-14,000 metres. Renown vs. Scharnhorst and Gneisenau in the action off Norway was roughly the same distance; Bismarck's final battle can't really be counted, due to the circumstances (had she been in full control of speed and steering, for example, the British might have not been content to hold open the range), and the Battle of the North Cape has extenuating circumstances as well. I'm going to neglect your example concerning Glorious as it's not an engagement between major surface elements. It is worth remembering that radar was making gunnery more and more capable in all conditions, but you also have to bear in mind the short practical range of both British and German sets when it came to directing anti-surface fire, at least at the time, as well as the lack of real understanding surrounding the problems until later in the war when they had a chance to assess their experiences with the technology.

None of this, of course, excludes the fact that the Germans had the wrong idea about the potential engagement ranges of modern battleships. The heavy turtleback was merely their solution to their envisioned short-range combat.

[Armor Layouts and Replicas]

5 hours ago, Microscop said:

This is just wrong

First of all Turtleback can be combined with all for nothing

All for nothing is opposite of distributed armor scheme not opposite to turtleback

The Bismarck style turtleback doesn't offer better protection as the protected volume of the ship is smaller than in typical all for nothing armor scheme and with the main armored deck being much lower larger part of the ship is less protected in a result.  Also the citadel doesn't have enough buoyancy to keep the ship afloat and overall belt penetrations result in more dangerous flooding. Turtleback is also worse against plunging fire. 

All for nothing and inclined belt is the best for ww2 era ships, it would have been better for Bismarck also at ranges it fought.

This isn't exactly true. At the ranges they encountered - the ranges they expected to fight at - no normal belt can be expected to keep out shells. Using German penetration curves, you're looking at a 460 mm cemented belt to break up a 38 cm shell at 15,000 metres, with a target inclination of 20 degrees (385 mm at 30 degrees). The turtleback (böschung in the Kaiserliche Marine- I am uncertain if this designation carried over into the Reichsmarine and Kriegsmarine) of German battleships like Bayern isn't in any way comparable to - or even remotely used for the same purpose as - the turtleback on Bismarck. The former's turtleback is 30 mm strong, and at best will stop splinters from the belt or shell pieces. Anything else is wishful thinking. But Bismarck's turtleback is 110-120 mm thick: well within the realm of putting up meaningful resistance against an incoming shell, especially one that's been slowed down by first having to pierce the 320-mm-thick vertical belt. Aside from a decapping scheme like that adopted for Littorio, it's the only feasible method of ensuring that a shell doesn't enter the citadel at the short ranges they expected to fight at.

This isn't saying anything against your remarks about the protected volume (true), lower armoured deck (also true), and buoyancy (triply true). I'm simply explaining the German reasoning for why they went with that method. All or nothing is a much more viable method of protecting the armoured volume if your engagement range is expected to be longer (like, say, the Pacific). But in the confines and perpetually poor visibility of the North Sea, you have to accept that more often than not you'll be fighting an enemy at much shorter distances.

I've also included the relevant penetration table for convenience. Ranges are in hectometres (1 hm = 100 m). The left Y-axis is the range, the right Y-axis is impact velocity, the X-axis is target angle, the dark lines are for shell breakup post-penetration and the faded lines are for an intact penetration in Fit-to-Burst condition.

[Alpha-9 News Update]

3 hours ago, Steeltrap said:

Eels?

🙃

I'd have thought tentacle memes more likely from all the weebs in here.

😁

😎

Admiral Scheer wants to know your location.

[Alpha-9 News Update]

If you're talking hills to die on...

There's a joke here - Japanese 'A'-class (i.e. in excess of 7,000 tons prior to 30 May 1931) cruisers were named for mountains.

It's funny.

Laugh.

[Japanese battleship superstructures]

Yes and no? Japanese optical (i.e. rangefinders, binoculars, etc.) equipment was sufficiently advanced for its time and almost on par with German optical systems; certainly a bit ahead of Italian, British, and American optical-directed fire control systems, the former being plagued by certain details with regards to cleaning and glare treatment and the latter two for their small size. The primary problem wasn't with the optics, it was with the lack of a stable vertical and the decentralization of the fire process. You could say that - taking the two Pacific juggernauts as the example - that the Japanese had the better (optical) equipment, but the Americans had the better system, especially considering the large amounts of automation that went into the latter.

As for the visibility and targeting factors, yes, they could provide superior optical gunfighting ability. However, that didn't matter much after October 1942, when the USN began to step up its use of radar-directed fire.

[Alpha-9 News Update]

Double/triple bottoms don't seem to add oil fuel capacity and neither do the higher levels of SPS (side protection system; the fancy name for torpedo protection), so be sure to include those in your thread.

[Alpha-9 News Update]

3 hours ago, Cptbarney said:

Anyways shush. Lets just start the prediction game again, since we don't have anything better to do.

I say last week of October as i got clapped in my previous prediction, probs will in this one as well.

I also reckon the campaign won't arrive till like march next year maybe april.

As before, last Friday of November. Possibly the last Friday of December. Perhaps even the last Friday of January next year. The point is, I'm not holding out for it dropping any time soon.

[About triple (and quad) gun turrets as secondaries]

Modeling interference of shells in flight would require some incredibly complex computing, that would have to take into account a lot of real-world factors (barrel temperature, atmospheric pressure and temperature, humidity, windspeed and direction, etc.). It's much simpler and more efficient to apply an arbitrary percentage reduction, that you can modify as you like.

[Alpha-9 News Update]

On 10/18/2020 at 9:06 PM, Steeltrap said:

- Snip -

I have become extraordinarily jaded towards any and all promises of 'realism' and 'historical accuracy' from any game that promises it. We might ask for things, but ultimately, the only way to get something is to do it yourself - hence, I think, the continued insistence on mod support. If they won't give us realistic parameters, we'll just have to make them ourselves.

[Alpha-9 News Update]

2 hours ago, Fishyfish said:

So is this just turning into a "I want XYZ from WoWS" thread?

Not exactly? World of Warships bases a lot of their stuff - well, a lot of the old stuff - on actual designs and ships that existed. Now, the refits they give them (stares hard at Lyon & Normandie) are not always up to the same snuff, but that's neither here nor there. The fact is that for at least most of their lines, they have some historical basis. That's what I want, personally. More historical ships, more historical options- give me something that Wargaming can't. Give me the ability to employ ships as they were used, instead of fighting tank battles on the ocean.

And by historical ships, I mean Takao. In all of her forms. Original, Takao & Atago's rebuild and Maya-type. Mostly Maya type. Just give me Maya, really.

[Alpha-9 News Update]

1 hour ago, CapnAvont1015 said:

Ok so the Devs said that that 20inch and 19inch guns will only be available for only certain hulls most likely the the Super BB ones. So my question is should modern BB hulls be able to carry 20inch guns especially the Japanese and Germany Nations since they are the only ones (that I know of) that planned to use these guns the H-44 class and A-150 class BBs. Plz Devs I wanna make Shikishima.

I wouldn't recommend aiming for Shikishima specifically.

takes deep breath, Japanese Navy nitpick is about to begin

Shikishima emulates the final design studies for the A-150-type battleships in extremely few ways. In fact, she doesn't resemble them much at all, except in the number and calibre of the main battery - and even then, the shells are much heavier than they ought to be. What few surviving records of the A-150 that exist indicate - to point out a major difference - that she was to be armed with a homogenous dual-purpose battery of 10-cm guns, dispensing with the split LA/HA 15.5-cm/12.7-cm appropriations. She's actually closer to an up-gunned Yamato type than she is to any proposal for A-150 (and while an upgunned Yamato was the original plan for Yamato, those provisions were deleted after Fujimoto's death and his replacement with Hiraga).

...Instead, you should shoot even higher and go for the original A-150 design, which called for nine 51 cm guns and sufficient protection against those shells from the expected combat distance of 25,000 to 30,000 metres (implying a 46 cm belt and a 25 cm deck, with a known turret face thickness of 80 centimetres). Obviously, this plan was rejected as it was simply outside of the capabilities of Imperial Japan to construct- even the notoriously shoot-for-the-moon (and in this case, hypocritical considering their other life choices) Imperial Japanese Naval General Staff rejected it out of hand because it was "too big and too expensive." But those choices don't apply to a video game, so don't just copy Wargaming. Go one better.

[Alpha-9 News Update]

2 minutes ago, Cptbarney said:

Cus i want Charlemagne which is basically a bigger jean bart with 3 quad 431mm guns at front lol. 

But what about Super Alsace No.2 with a standard arrangement of 3x3 431mm instead?

[Alpha-9 News Update]

2 minutes ago, CapnAvont1015 said:

A French Modern Battleship of 45,000 to 65,000 tons, which can faithfully recreate the historical Battleship Richelieu.

French BB Alsace your in my sights, soon you'll be MINE.

That's only if we're able to place guns on the rear, which it doesn't look like we'll be able to. Judging from the way it was presented, if we had been offered an Alsace-type hull as well, it would have been shown off along with the all-forward Richelieu model.

[Alpha-9 News Update]

Well, we have Yamato, Iowa/South Dakota/North Carolina, Bismarck, and now Richelieu... that leaves just King George V, Sovetskii Soyuz, and Littorio for our cadre of modern battleships.

[Alpha-9 News Update]

1 hour ago, Nick Thomadis said:

Triple and Quad Guns are distinctively heavier: Making ships with many heavy guns will need more trade offs. This was especially needed now, that we added quad guns and the huge guns of 19-inch and 20-inch caliber.

I hope that the weight increase isn't by too much, as the primary historical advantages of the concentration of the armament was that it didn't weigh as much as something like four or five twin turrets, since one could shorten the length of the armoured citadel drastically.

[Alpha-9 in Progress]

I'll say the last Friday of next month.

[Japanese 20inch (510mm) guns]

1 hour ago, ReefKip said:

 

A tactical opinion that is short sighted in the context of the war they were planning to fight. reasons for that i already explained. 

and i am arguing that its best to go for what is practical. if what is feasable is not going to give you any considerable advantage, then logically what is practical takes the upperhand. 18 inch was the practical caliber here,

Which they would not have had if carriers were not sucking up that same steel resource pool. apparantly i have to say this for the second time. Steel which could be put into the Super BB program instead.you keep referencing the original time line here while what we are discussing happens in a scenario Where america acts differently in how it builds its navy. also the steelshortage argument works both ways. japan was suffering from this considerably as well. slowing their own production time even more as time went on,

So the picture is inaccurate then. so why use it as a support for your initial argument? whats to say many other examples layed out in that graph are not inaccurate as well?
How complex a ship is matters ofcourse. but reality and your graph also shows that if a country has the resources and facilities, design difficulties matter less in the overall production progress thern when  a country with fewer production facilities and less resources has to deal with it.. which fit  America and japan perfectly. So America working on a Super BB facing design difficulties will still Finish it much faster then japan designing the same class of BB. Missouri was finished in 3,5 years  in our original time line with Steelshortage and the focus being put on carriers. this already beats Musashi with 10 months and Yamato with  8 months. the Americans were already significantly faster then the Japs in their first attempt. What makes you so sure that this production process would not have been streamlined in a Naval industry totally focused on producing those kind of Ships? like it was with CV,s in the original time line?

1. It is not a shortsighted tactical consideration in the context of a short war fought with on-hand resources, centred on a single decisive outcome between surface fleets.

2. It is both practical and feasible to go for the larger calibres in the case of the Japanese. As you've pointed out before, Japan's industrial base and resources aren't as sufficiently advanced as the Americans (the product of going from medieval to modern in the span of a decade) so they need the calibre gap to make up the disparity. Additionally, you never once mentioned 46 cm / 18 in. You said explicitly to go to a 56 cm / 22 in calibre in two years flat, which is ridiculous.

3. I am referencing the only timeline there is. If you want to talk ahistorical scenarios, we can go on about illogical and unreasonable things all day. Tillmans, for example. This leads into the crux of the argument that America wouldn't act differently: if they lost their aging Standard fleet in the Marianas - as your ahistorical scenario might go, I don't know - and then needed to rebuild it quickly to counter a supposed 510-mm-gun-armed Japanese battleship, they would rather produce a large number of modern 406-mm-gun fast battleships than a small number of 558-mm-gun 'super battleships.'

4. The graph isn't inaccurate. That was the time they spent on the slips. However, of the time that they spend building, only part of that time was when construction was actually being done. There's a difference between being labeled as 'under construction' and actually 'building.'

5. Design difficulties factor into production immensely. The Iowa-class ships were a result of wartime expediency and the yards building them had already had experience building previous modern warships with a high efficiency rate; the two Yamatos were unlike anything Japan had attempted previously, with their last battleships having been built in the early 1920s. They had to dig into a hillside in order to extend the reach of the slip at Nagasaki.

6. Because even without a carrier fleet slowing you down, you don't just get to produce 'more battleships.' There is a hard upper limit to armour production capacity and naval ordnance; carriers require comparatively nothing in terms of armour plate, so they can be assembled relatively rapidly. But light surface elements still take priority for surface construction; unless you want to cut the production of all heavy and light cruisers, which you cannot do without dooming your fleet to destruction at the hands of torpedo-armed Japanese fleet elements, your production will still be bottlenecked. Even the industrial might of the U.S. wasn't enough to produce more than the ten battleships they did build.

Finally, I'm going to retire from the discussion. I've already said everything I wanted to say. I hope this has been informative.

[Japanese 20inch (510mm) guns]

1 hour ago, ReefKip said:

I am not speaking from the benefit of Hindsight. i am speaking from Knowing American industrial Might. which was already very well known in the 1930,s are you denying this was known?even yamamoto refered to this i am also speaking from a grand Startegic perspective. while you are speaking from a tactical perspective.  even if everything went according to plan and they could have destroyed most of the american fighting fleet. What could they do with that Short window of naval dominance?

-they could not reach and destroy American industrial centre,s. those were on the mainland for ever outside Japanese reach. a land invasion is out of the question.

-they could not cut off America from any vital resource, because Again. those were on the mainland which caused America to be self sufficient. not depending on trade. which Japan was. so a blockade is out of the question as well,

so what is stopping America to just take those losses. and rebuild their fleet? absolutely nothing. so yes the plan was Short sighted because your dealing with America here. Not Germany for instance. which is a country that relies  on Import of Resources to fight a prolonged war. that is the Mistake you are making.Which japan also made.Counting on the Moral Blow after Pearl Harbour to force the Americans into Submission was not going to happen, unconditional surrender was the focus by then. The entire plan relies on America Wimping out on losses. how is this not Short sighted?

America making Super BB,s in 2 years or less is plausible. The Iowa class battleships were constructed  over 2,5 years as well. and this while America was also focussing their Naval efforts on Building Aircraft Carrier,s at the same time. Now considering we are discussing a situation in which America refrained from Building those carriers and choose to Compete with the japanese on Making Super BB,s. this would have taken them much less amount of time to produce such BB,s. America would both produce them faster and in larger quantities then the Japanese. That picture you have is totally irrelevant to the hypothetical situation we are discussing. because it shows American BB production while being held back by Carrier production. but for something else it is useable. for example it shows Ships like Littorio being produced in a way slower time then Iowa while having less displacement and overall resources needed. Because italy just like japan had a smaller Resource source and industrial base to put into the building of those ships. America did not face this leading them to completing Much heavier designs much quicker then italy completed lighter designs. this can be extended to japan as well.

I'm not attempting to argue whether or not the Japanese were doomed as a result of their decision to go to war with the United States - that's a subject that's been beaten to death and beyond, right into Asphodel. However, the concept of their plan - which you're saying is short-sighted - is a tactical opinion. Unless you've switched tack from the 'decisive battle' to the overall conduct of the war, grand strategy is not in the purview of the discussion. The entire point is, from a technical and tactical point of view, there's no reason to not go for the larger calibre gun if it's feasible.

As far as American industrial capacity, there is still no method by which the United States can construct a super-battleship in two years or less, especially if it's armed with guns larger than 45.7 cm. The largest calibre that they seriously considered and had actual experience building was 45.7 cm, after all: you can still see the 18in/48 at the Dahlgren Naval Surface Warfare Center in Virginia today. Beyond that calibre - especially jumping to 22in/56 cm - is a completely new field that you have to design, test, and produce an entirely new weapon for. There are basic sketch profiles for twin and triple 457 mm gunhouses, but nothing for anything beyond that, because the USN's surface warfare experts came to the conclusion that - with the known limitations of naval gunnery for the time - that that was the largest calibre you would need.

Going further into this, while one can produce an Essex in around 24 months, one also has to consider that you need so much less to build an Essex than a battleship of comparable displacement. Even the fastest battleship time, Indiana at 29 months, is only possible with the complete mobilization of the American workforce to a war footing - and Indiana is less than half the standard displacement of any potential American super-battleship with guns of that size. Considering that the US had a steel shortage starting in 1943 and had completely maxed out their armour production capacity by that point in time with their construction programmes, it's not unrealistic to say that any super-battleships would have been the first to be axed (the fate of Montana). If anything, the U.S. would have been tapped out for production earlier with anything on that scale - even if you axe the carriers entirely, armour production capacity as well as the speed of creating large-calibre naval guns are a hard cap on how quickly you can produce a battleship. Carriers require significantly less armour than battleships, after all. This goes without going into the other logistical infeasibilities of such ships, like their inability to use the Panama Canal (which would kill them before they made it out of sketch stage), the massive infrastructure overhaul required to transport the materials for their building (their gun turrets would be as heavy as a WWI-era light cruiser), or the requirement to build new slips and dredge anchorages to handle them.

Finally, Littorio and Vittorio Veneto's building times are inflated in that the first pair didn't actually start construction until about 5 months after they were initially laid down. Their actual building times were on the order of 27 and 26 months, respectively - and their displacements were nearly the size of those afforded to Iowa by the time they were finished, despite their nominal '35,560-metric ton' designation.

Basically, this entire conversation boils down to me trying to explain that: "You're right that Japan would lose, but for all the wrong reasons."

[Japanese 20inch (510mm) guns]

24 minutes ago, madham82 said:

Very good post, but this part has me intrigued. Just comparing the ranges of the Nagato and North Carolina (which the NC was built in response too), their ranges are very close (40K vs 37K yds). Yamato was more like 45K yrds. Iowa ended up just over 41K. Where exactly did the Japanese envision a range advantage? A couple of thousand yards isn't going to be a qualitative advantage. My guess here is they were thinking the US would not build anything more advanced than the Colorados (which was like 34K) and the like, which IMO is short-sighted thinking. Could be the reality behind their thinking, but I had always heard the idea behind Yamato was to build a ship that could carry the firepower and armor to make up for numerical inferiority, not that range was a real factor. 

Also I find it hard to understand their thinking on range fighting when you have to observe the shell splashes. That means your ability to see the splashes is the deciding factor (i.e. the visible horizon and your own optics), not the range of the guns. Since they did not invest in radar for "blind" firing, or utilize seaplanes for spotting. 

The range advantage they calculated they had was based on the superiority of their optical equipment and the known ranges of the American Standard-type battleships, which they had been able to observe discreetly during the USN's 'Fleet Problems' of the 1930s. Colorado was the basis of their assumptions, since at that time the North Carolina hadn't been constructed yet (and even during the earliest phases of her design process, was slated to receive 356 mm rather than 406 mm). Even if the U.S. decided to construct new 406-mm-armed battleships - which they knew would become a reality as soon as the naval treaties were allowed to lapse without renewal - the range advantage of the Japanese 460 mm over the North Carolina's 406 mm would be enough to ensure at least a temporary superiority. Yamato was, after all, designed not to completely surpass all American future construction - an impossibility, one that the designers were very well aware of - but rather to overwhelm existing older 406-mm-gun battleships. Practically speaking, Yamato is pretty well meant to slug it out with however many Colorados or Nelsons you want to send her way. She's invulnerable to their gunfire at all reasonable ranges (invulnerable to most gunfire period at all reasonable ranges) whilst they simultaneously have no protection against her guns at all.

As far as fighting at range, the practical limit for naval gunnery is 35,000 metres, no matter the era or what kind of optical or radar-directed fire control equipment you happen to be using. The Japanese did not invest extensively into radar until after the Sea Battle off Savo Island, what is known in Western media as the Battle of Cape Esperance (11-12 October 1942), but they did drill with aircraft spotting throughout the 1930s (as did every other major navy). That may have been short-sighted on their part, but like most things, their lack of natural resources (the entire reason they went to war in the first place) and the poor base quality of those that were available precluded their adoption of quite a few advanced technologies.

I have also included a rather decisive comparison of a modern battleship of inferior calibre (often-noted to have guns as powerful as 406 mm) vs. Yamato.

[Japanese 20inch (510mm) guns]

5 hours ago, ReefKip said:

Another mistake the japanese made is that even if the Americans would have build their own Super BB,s instead of going the carrier route, they still would be able to produce more of them with higher technological advancements compared to the japs. so still this quality above quantity aproach was extremely short sighted. and thus their perspective was flawed from the start. even  from a 1930,s perspective.   but looking at the japanese Plan for the pacific war against the US. it was short sighted overall. The plan was to bait the American Fleet into a decisive battle, which the Japs would win. after which they Hoped the Americans would surrender. this aproach was extremely Naive and optimistic as Japan was in no way capable of preventing the US to wage war by destroying it,s production and Resource Facilities. Which was needed to decisively put the US out of the war,

except that the American reply would come alot faster then the japanese counter-reply. Japanese industry did roughly 4 years producing the yamato and Musashi i believe? US industry would have those ships ready in atleast half the time. if not even less then that. look at US carrier Production for reference.So japs produce 20 Inch Ship. Americans spot them and have a 22 Inch ship ready in less then 2 Years, which is entirely plausible with all Industry which was focused on carriers now put into Super BB,s.  with which the Americans have  atleast 3-4 years  of Dominance until the Next generation of Japanese 24 Inch gun Battleships  are ready and on it goes like that. it gives no advantage at all to the japs.except at the start of the War in which the Americans have yet to reply to the first Super BB.

For our time line 18 Inch was enough to counter what the Americans put out in the war. 20 inch even if the war went according like Japan had planned, defeating most of The US's Pacific fleet in the first year, would have no advantage.

The  Japanese plan for bigger calibre  for every  new Generation Battleship sounds alot like the German Plan for their Tanks in WW2. in which the plan was to release a new Generation of Tanks every year with heavier armor and firepower. but atleast that made sense as the Germans could guarantee a technological and quality edge over their enemies. unlike Japan which used outdated equipment when Mid-War aproached. combined with a much lesser developed industrial base which did not allow them to keep the edge they had Early war. and you get a japanese dream instead of a plan.

You're speaking from the benefit of hindsight, which isn't a good place to start when you're trying to say "from the perspective of the 1930s." In 1936, when the initial requirements for the Yamato class were drafted, the Japanese plan was in no way shortsighted or flawed. The 'decisive combat between surface fleets' was the fundamental doctrine of every major navy going into the late 1930s and early 1940s- and it's worth noting that, had the Americans followed War Plan Orange as they had intended prior to the destruction of their major surface elements at Pearl Harbour, we might well have seen a battleship gun duel in the western Marianas - just as the Japanese had planned for. They were counting on the morale shock of losing the majority of the American fighting fleet and even the temporary inability for the Americans to replace them in order to, if not win a short war, then at least gain a negotiated settlement with terms at least mostly favorable to the Japanese.

You're also seriously overestimating American industrial capacity. Even if we assume that they can build a so-called 'super battleship' in two years or less - which they can't, not then, not now, and not ever - the design and testing process, not to mention the massive lead times necessary to construct 51-56 cm guns and their turrets, would preclude their installation on any such warship. Even if you started in 1939, you would not have those ships ready before 1944-45, as an extraordinarily generous estimate. You'd be better off building larger numbers of modern, fast 406-mm-gun combatants (which is what the USN did, for those very reasons listed among others). One can't look at carrier construction and compare it to battleship construction because battleships require significantly more extra weight that has to be produced with major lead times (armour plate - which even the industrially-giant US had maxed out its capacity for by 1943 - and heavy artillery).

As far as the 'calibre race' of 406-457-506 mm (or 410-460-510 mm if you're Japanese) goes, it's a simple logic of being able to 'outrange the enemy.' If there was a real, serious threat to the American battle fleet from their Japanese counterparts, it was their fighting range. The Japanese extensively drilled to open fire from a longer range than their American counterparts - on the order of 6,000 metres or more. A larger, heavier shell keeps its stability in flight better and retains more kinetic energy on impact, losing less 'punch' over distance. It's a fault, perhaps, that the Japanese didn't develop anything like the 'super heavy' shell, but even then, Japanese shells were generally heavier than their comparable American counterparts until just prior to the war (1,020 kg for Nagato's 41 cm vs. Colorado's original 957 kg for its 16in Mk.1).

Ultimately, the point I'm trying to make is this: it wasn't an unreasonable assumption to continue the pursuit of ever-larger battleships and larger artillery while they continued to be the ultimate arbiters of naval combat. You do not plan to lose a war, you plan to win one.

To quote Bagnasco's The Littorio Class:

• From the doctrinal point of view, battleships continued to be the fundamental and indispensable part of every fleet;
• From the technical standpoint, only a large displacement could offer assurance from threats of guns, torpedoes, and bombs and it would have been a mistake to abandon building battleships as long as other ships with these characteristics existed or could be built, given the uncertain outcome of the conferences on the limitation of naval armaments.

If you want to learn about Japanese naval doctrines and planning prior to the war, I recommend Kaigun. It's an incredibly good English-language source on the subject. If you can read Japanese, I can offer several other titles, but they're a bit pricey (one I would like goes for over $650 USD in its used condition).

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19 minutes ago, Friedrich said:

That's not actually true. I think it was against Bismarck where a British ship evaded her fire by making slight course corrections into the splashes of the last salvo. The result was that Bismarck would fire her guns, and the shells would land pretty much right on top of where her target would've been had those adjustments not been made.

I think the term you're looking for is 'chasing salvoes', a method to frustrate accurate shooting in the days of analogue fire control. As nearly as I remember, it works on the principle that most mechanical FC tables used 'Up' or 'Down' rates, based on visual spotting of the fall of shot; the manoeuvring target would therefore 'chase' the last salvo fired, turning in that direction. If the salvo landed beyond the target, a 'Down' spot would be applied: the ship would then close with the last salvo fired, causing the next salvo to be short and an 'Up' spot applied, and then so on and so forth.

Of course, this all goes out with the advent of more sophisticated radar fire control and remote-power controlled mountings. By the time of the 1940s, ships could both manoeuvre and fight, rather than just one or the other.

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1 hour ago, IronKaputt said:

Source? I only heard about 780 kg Long Lance variant.

Six-tube launcher also would be nice.

Streamlined shells (I absolutely adore boat-tails), filler % (1,5-3% for AP, up to 15% for HE), dye (and perhaps tracers) color, fuzes (especially for torps).

For guns and mounts: damn RoF and traverse speed, reliability for both cases, barrel life (chrome plating and wear reduce additives), weight reducing tech, base accuracy of course, gain-twist and gradual rifling (dunno if it worked together, but I'm a greedy perfectionist).

Would be sad, if I'll have to simply mod meself some fancy stuff, for it is kinda unsporty.

Lacroix & Wells mention it under "Torpedo Ordnance" in Appendix H of Japanese Cruisers of the Pacific War, p.779-780.

As for your other suggestions... yes, I want all of those things too. I'm also a perfectionist and I want everything to be as minutely detailed as possible so that I can build ships the way I want to, right down to the number of lands and twists in a gun barrel.