Were the Yamato's ever really supposed to get 8" secondaries?

[Sabot_100]

I know IRL those "Yamato" mounts went to upgrade the Mogami class (instant heavy cruisers!) but my suspicion was that was the plan all along. Anyone know if it was actually an afterthought? Possibly due to production shortages.

Obviously somebody decided the mounts had to be easily interchangeable. 

Do we need an 8" secondary gunned Yamato premium? Actually a Musashi version with 8-8". Maybe change the secondaries to fire whatever your main  guns are firing (AP or HE) as a gimmick.

 

[CaptHarlock_222]

I don't remember where I read it, but I have heard at least speculation that it was briefly considered to take the 8" mounts that were intended to re-gun the Mogami-class and mount them as secondaries on the Yamato class. Assuming the information was at all accurate, the way it was worded implies that the 8" guns were meant for the Mogami-class to begin with with the 155's going to other purposes after their removal as (mostly) happened historically. That said, I cannot vouch for the accuracy when I can't remember where I learned it and it's possible that it could well be a misinterpretation, mistranslation, or outright speculative 'what-if' discussion. It does sound like the sort of thing that the IJN might consider doing, but I can also think of good reasons why they didn't, fire control issues and utility against destroyers being chief among them. Personally, I think the IJN would have been better off leaving the 155's on the Mogami-class and manufacturing more 155's for the Yamato class. To some degree, I think switching the Mogami-class to 8" cruisers might well have been a mistake, as it arguably robbed the IJN of some very nice, fairly modern high(ish) ROF cruisers that would have been very useful in some of the fights they ended up in. Just look at what the Brooklyns were capable of because of their 6" guns. Granted, the IJN 155's likely weren't able to match the ROF of the Brooklyns (5-6 RPM vs 8-10 RPM), but it would still have been close enough to stand a better chance than the old 140mm armed CLs the IJN still had kicking around.

[Sabot_100]

24 minutes ago, CaptHarlock_222 said:

I don't remember where I read it, but I have heard at least speculation that it was briefly considered to take the 8" mounts that were intended to re-gun the Mogami-class and mount them as secondaries on the Yamato class. Assuming the information was at all accurate, the way it was worded implies that the 8" guns were meant for the Mogami-class to begin with with the 155's going to other purposes after their removal as (mostly) happened historically.

My thinking (without any evidence) was putting them on (secret but known) BBs was a cover story for the plan to rearm the Mogamis (violating the Washington Treaty) in case it got out that they were building more 8" turrets. Pretty sure the world knew they were building BBs, just didn't know how big they really were. 

[HazeGrayUnderway]

I doubt it.  The Imperial Japanese Navy loved their Heavy Cruisers.  Their CA fleet was more modern overall than their Battleships.  The only more modern ship types in the IJN than their beloved CAs are their DDs and CVs.  I just don't see the IJN keeping precious 8" guns away from their CAs they were constantly building.  They were building Ibuki-class CAs, they only got cancelled and converted to CVLs because of the Battle of Midway fiasco. 

 

By the time the IJN did their major build programs post-Midway, the priority was to Carrier Flight Decks, not Battleships or even the CAs they once loved so much.  The situation was so bad that they began the Ise-class refits to make them really awkward BB-CV compromises.

[Nevermore135]

The 8” mounts produced IRL were always intended for the Mogami-class. Japan designed the cruisers from the start to be 8” CAs, they were just initially fitted with 155mm guns to pay lip service to the naval treaties Japan was still a signatory of at the time. As soon as Japan backed out, the ships were quickly converted.

The 6” triple turrets removed from the ships were not only re-used for the secondary armament of the Yamatos, but also as the main battery for Ooyodo.

[Forgotten_Void]

13 hours ago, Sabot_100 said:

I know IRL those "Yamato" mounts went to upgrade the Mogami class (instant heavy cruisers!) but my suspicion was that was the plan all along. Anyone know if it was actually an afterthought? Possibly due to production shortages.

Obviously somebody decided the mounts had to be easily interchangeable. 

Do we need an 8" secondary gunned Yamato premium? Actually a Musashi version with 8-8". Maybe change the secondaries to fire whatever your main  guns are firing (AP or HE) as a gimmick.

 

The mogami class gun swap was always the plan from the start. Documents and designs were always off to fool any spies and prevent the true nature of their plans from falling into enemy hands. Just like all designs for Yamato were 410mm cannons, which was actually the code for 460mm.

[Sabot_100]

5 minutes ago, Forgotten_Void said:

The mogami class gun swap was always the plan from the start. Documents and designs were always off to fool any spies and prevent the true nature of their plans from falling into enemy hands. Just like all designs for Yamato were 410mm cannons, which was actually the code for 460mm.

Pretty much what I was thinking.

[Forgotten_Void]

49 minutes ago, Sabot_100 said:

Pretty much what I was thinking.

I'm too lazy to go pull up references, but the mogami turrets are well known. As for the extra 203s, they could easily be passed off as spares for the Atago class

[HazeGrayUnderway]

1 hour ago, Forgotten_Void said:

I'm too lazy to go pull up references, but the mogami turrets are well known. As for the extra 203s, they could easily be passed off as spares for the Atago class

You need spare gun barrels because the guns do wear out.  In addition, the IJN transitioned all their CAs to use the same 8" gun.

 

20 cm/50 (7.9") 3rd Year Type No. 2

Official Designation: 50 caliber 3rd Year Type 20 cm Gun 2 GÔ (No. 2)

Actual Size 20.3 cm (8.0")

http://www.navweaps.com/Weapons/WNJAP_8-50_3ns.php

Ships using the guns:

As Completed     Takao and Tone classes 

As Rearmed     Furutaka, Aoba, Myôkô and Mogami classes 

As Planned     Ibuki

 

That's a lot of CAs between 7 CA classes requiring guns.  The IJN laid down 2 hulls for the Ibuki-class in 1942, so that's 20 more 8" guns needed just to fit them, never mind spare guns for replacement.  Even in peace time there will be wear and need for replacement because the crews need their training.

[Forgotten_Void]

1 hour ago, HazeGrayUnderway said:

You need spare gun barrels because the guns do wear out.  In addition, the IJN transitioned all their CAs to use the same 8" gun.

 

20 cm/50 (7.9") 3rd Year Type No. 2

Official Designation: 50 caliber 3rd Year Type 20 cm Gun 2 GÔ (No. 2)

Actual Size 20.3 cm (8.0")

http://www.navweaps.com/Weapons/WNJAP_8-50_3ns.php

Ships using the guns:

As Completed     Takao and Tone classes 

As Rearmed     Furutaka, Aoba, Myôkô and Mogami classes 

As Planned     Ibuki

 

That's a lot of CAs between 7 CA classes requiring guns.  The IJN laid down 2 hulls for the Ibuki-class in 1942, so that's 20 more 8" guns needed just to fit them, never mind spare guns for replacement.  Even in peace time there will be wear and need for replacement because the crews need their training.

I was talking during the washington treaty days, but including aoba and furutaka class ships, 40 extra barrels are easy to hide among the spares.

[Royeaux]

18 hours ago, Sabot_100 said:

Do we need an 8" secondary gunned Yamato premium?

That would probably be a bad idea.  Generally in gunnery the sweet spot for getting accurate shots at range is having at least 8 barrels committed to a target at a time.  With the 6" triples, they could get a 9 gun broadside with the original Yamato design, downgraded to 6 guns once Yamato got refitted.  That would give them decent anti-destroyer, anti-submarine firepower.  With just a 6 gun 8" broadside later downgraded to a 4 gun 8" broadside would have made those secondaries ineffective.  The 8" guns ironically might have had less of an effective range than the 6" guns if they only had 4 guns to work with to get the range.

[CaptHarlock_222]

3 hours ago, Royeaux said:

That would probably be a bad idea.  Generally in gunnery the sweet spot for getting accurate shots at range is having at least 8 barrels committed to a target at a time.  With the 6" triples, they could get a 9 gun broadside with the original Yamato design, downgraded to 6 guns once Yamato got refitted.  That would give them decent anti-destroyer, anti-submarine firepower.  With just a 6 gun 8" broadside later downgraded to a 4 gun 8" broadside would have made those secondaries ineffective.  The 8" guns ironically might have had less of an effective range than the 6" guns if they only had 4 guns to work with to get the range.

Not to mention we do have Satsuma which does have that same 4 gun 8" secondary broadside backed up by a bunch of nerfed 100mm mounts that are twice as numerous as Shikishima's, but only half as effective individually because WG doesn't want me to run my usual secondary build on the ship. (I do anyway.) I can report from running said secondary build that the 8" guns are actually slightly more effective than I'd hoped, having a surprisingly good reload for IJN 8" guns, and are decent fire-starters when they hit, but the low number of them does let them down a fair bit, which would be better compensated for by the 100mm guns if they weren't nerfed as badly. (Seriously, they don't even work as well for AA as Shikishima's mounts of the same guns and the reload is about twice as long as it should be.)

[SgtBeltfed]

12 hours ago, Forgotten_Void said:

The mogami class gun swap was always the plan from the start. Documents and designs were always off to fool any spies and prevent the true nature of their plans from falling into enemy hands. Just like all designs for Yamato were 410mm cannons, which was actually the code for 460mm.

Nagato and Mutsu carried 41 cm (16.1 inch) guns. Which were redesignated as 40cm weapons in 1922. They always had 410 mm bores.

Yamato's guns were designated as 40 cm guns, or 40.6cm guns (16 inch) weapons for deception purposes. Interestingly enough, 16 inch is also a caliber the IJN never used.

There was no "code", The Japanese were trying to (and for a long time did) trick everyone into believing that Yamato simply carried an improved model of Nagato's guns

[Royeaux]

1 hour ago, SgtBeltfed said:

There was no "code", The Japanese were trying to (and for a long time did) trick everyone into believing that Yamato simply carried an improved model of Nagato's guns

What's funny is nations usually built Battleships to show their strength, not hide it.

[Forgotten_Void]

14 hours ago, SgtBeltfed said:

There was no "code", The Japanese were trying to (and for a long time did) trick everyone into believing that Yamato simply carried an improved model of Nagato's guns

That....is a form of code. 

But also mogami class were listed as 8500 ton cruisers even though the actual design was 9500. Listing as one thing and doing something similar but off is a form of counter intelligence and a very simple form of code 

[SgtBeltfed]

15 hours ago, Royeaux said:

What's funny is nations usually built Battleships to show their strength, not hide it.

Actually, creative reporting of displacement was pretty common on treaty battleships.

There was a lot of running the ships on trials with no ammunition on board, partial fuel loads, lacking some armament, ect...

I think the Germans held the record leaving the secondary armament off, and the fire control system.

[ElCuervoJones]