Admiral Yamamoto's "What Might Have Been"

[John 3rd]

Next on the list CS Nissin is listed as entering service 82 days into the war. This would be mid-to-late February. Here she comes in as a CVL. The Nisshin can come in as a Chiyoda-Class CVL and is the lead model of the conversions. We shall figure that at the 50% point the decision is to convert her from original intent to CVL.

This change would add time to the entry date of the vessel. If the change was decided upon early enough I figure six months should suffice. Instead of late-February, the ship enters service as a CVL in late-August 1942 carrying 30 planes. Normal mix of 18 Z and 12 K.

[chesmart]

Terminus once gave an explanation on the IJN shadow program which was quite interesting. He did it to rebutt EL CID in one of his RHS Scenarios. Termi where are you ?

[Kitakami]

John,

One thought I have been toying with for a while is the option to convert other IJN CA's in a manner similar to the Maya (I guess her being my current 1/350 model build in progress does not help) For those not in the know, mid-late war, loose C turret and gain 2x HAA turrets plus assorted 25mm LAA.

In your Mod the conversion could include changing HAA to 3.9 in. Although historically it was done in only one case, it is not that far-fetched.

Another thought is not to force the Japanese player to upgrade Oi and Kitakami along historical lines. What if they had stayed as torpedo cruisers, gaining LAA as the war progressed, but not loosing as many torpedo mounts (if any). I would like to see the player having the option to choose

Just a couple of thoughts.

[John 3rd]

Kitakami--The CA's secondary will upgrade to 3.9" fairly early.  This SHOULD provide a good uptick in AA Firepower.
 
Juan and I have been exchanging emails and this was his most recent note.  I am responding HERE in italics:
 
John,

The changes I mentioned are as follows;

Torpedoes - Division of submarine torpedo tubes into groups of 2 or even 1 tube, to make use of the new code in Patch 3. This is included in Scenario 46 which you're playing (almost all subs have torpedo tubes in groups of 2), but I was thinking of taking it one step further for the new versions, and work with single tubes.

LIKE this idea.  Let's put it into play.

Ship Ammo - There are several of us who are looking at ways to model ship ammo differently, to address some of the issues like ships running out of ammo mid combat which was a rarity in reality, and ships firing 90% of their ammo in bombardments when it should probably be closer to 50%. And theres light AA ammo to consider, with reports that it routinely runs out after 1 air attack. My own changes will probably see main battery ammo for big ships increase to 20-25 or so, with other numbers adjusted to reflect similar changes. Some ships, like Japanese DDs, really loose out here, as they carried rather pitiful ammo loadouts.

Watching the firing and shell expenditure in Michael and I's AAR, I completely concur with this change.

Aircraft Weapons - You may have noticed in the scenario you're playing that the aircraft weapons have been altered somewhat, with effect ratings changed compared to the official scenarios. Im working on comprehensively redoing all of them based on real data on their rates of fire, muzzle velocities and shell weights and explosive content, and then scaling this data to fit the data range of the current weapons.

Will have to see the proposal but sounds OK at the moment.

Naval Guns - There are some changes to the original data I made to the larger (6"+) naval guns in my scenarios. While the new original data is much better than it was at launch, I still felt that some of the numbers, especially penetration, for some of the large guns was off. These changes are also in the version you are playing. Theres also a number of changes to the data of smaller guns, such as the 10cm/65, which I felt the game undervalued.

I used to play the old Iron Bottom Sound board game and I remember measuring range and crossing that with the size of the gun for armor penetration!  If your revamped work makes good sense then why not!

Other Changes - There are a number of corrections to the official scenario that I made, amongst them correcting the turret types of Japanese DDs, which all have DP guns in the official scenarios when this was not the case historically. Thus, the "upgrade" of removing X turret makes no sense for most of these classes, as they loose a DP gun for some 25mms, which is not a good trade. With this change however, it is much more sensible, though for some ship classes (like the Yugumo with their Type D 12.7cm turrets), it is still not an "upgrade" in any way.

Of these, I would only suggest you consider including the torpedo changes, and the corrections to data such as for the Japanese DDs. If you are interested in the other changes, let me know.

I think your approach to doing it area by area is a good one, as it helps prevent confusion over whats done and what isnt.

Lastly, two things I'd like to comment on from your thread;

1) You list the BC Ikoma/Kawachi class as having 12.9" (32.7cm) guns - is this a mistake and you meant 12.1" (31cm), or is this a "what if" upgunned B65?

I meant 12.1" Guns.  I believe you have already Modded this ship out. 

2) Regarding Hiyo and Junyo, I would think that more work on them is not worth the materials and delays incurred because of it. Even at 25 knots, their cruise speed is enough to keep up with the rest of KB as long as you do not "sprint", and even sprinting they can still keep up with most of your BBs. Given thaT 56,000shp got them to 25 knots, I would hazard a guess that it would take ~90,000shp to get them to 30 knots. This would mean increased space and weight for machinery, which would affect the design in other ways, possibly through a reduced airgroup (to say ~45 or 48).

We've already made the decision here.  They stay as is.
 

[JuanG]

I suppose I might as well respond here directly in future, since my emails tend to end up here regardless. [:D][:D]

I've finished the preliminary work on the aircraft weapons, so if you'd like I can send it to you (in a spreadsheet comparing old values to new) by email. However, I'm not sure its a good idea to include it as some of it is changed significantly from stock and I have yet to run tests lasting more than a month ingame with it.

Im working on the ammo figures, I can post an update here with some of the likely loadouts for key ship classes (Fletcher, Iowa, Lexington, Shokaku, etc) in a few days once I get the formula's down.

Submarine changes are straightforward, but time consuming. In light of this I might suggest you consider using the Da Babes scenario (#26) as a base for your mod, rather than Scenario 1, as that scenario includes submarine torpedo changes (into groups of 2) like my scenarios do, along with some further OOB detail to small craft.

You did not comment on my suggestions for ship class corrections like the Japanese DDs - would be interested to know your take on it.

Juan

Edit - Regarding Nisshin, if the conversion is started while she is building, I do agree it is reasonable to reduce the conversion time to ~6 months, meaning she would be due in August-September '42.

[John 3rd]

Sorry Juan--YES I have been placing your emails here. Guilty. It is just that they are SOOOO juicy with good thinking and ideas. (Sucking up now)

Is there a reasonably SHORT description of what is in the 'Da Babes' Mod? Be happy to look at it before we roll up the sleeves as it were.

[JuanG]

Well, I thought I could have saved you the trouble of copying everything here had I done it in the first place. [;)]

This is from the Da Babes Readme, probably the best description I've found for it;

Da Babes is an effort by several people to enhance the logistical, support, and infrastructure aspects of the basic AE campaign scenario. Japan has about 300 additional ships from many new classes; the Allies have about 500.

Both Japan and the Allies have new classes, especially in the smaller models, that might be best described as ‘workhorses’; auxiliary subchasers, coastal patrol boats, coastal minesweepers, sea-trucks, vessels that protect and defend bases and local waters, as well as provide an enhanced replenishment infrastructure.

As said, it also includes the submarine torpedo changes, which should save you a good 3-5 hours of work. However, if you decide not to use it, I can merge those changes to Scenario 1 for you easily enough.

[bklooste]

4 CLAA (Oyodo-Class) 1943/1944
Bring in as pairs in early-1943 and late-1943. Configured as ‘Ring-Defense’ Leaders in the CV TF mounting 8-10 3.9” Turrets. These would be TOUGH little ships!
 
I cant see any advantage of these over just building more Akizuki , which were ordered , more shared components , should be at  least 2:1 , more ships  = more targets and more flexible , destroyer power plants , no armour etc. The concept of a cruiser mounting a 4" guns is just not likely , even the US atlantas were quickly discontinued as it will be facing oponents with 6 and more prob 8".
 
Speaking of the Akizuki , you can use the same hull , use some Yamato sheduled 6.1" guns and build a Tromp like Destroyer leader with 3*2*6.1" and a float plane this will really help Japanese destroyers in the gunnery department and would be cheap.
 
Lastly on the 100/65 i really dont think the gun is suitable for other ships that the Akizuki. For cruisers as mentioned the gun is too big and heavy for secondary arnament and doesnt have enough punch for a primary weapon. For AA I like the scaled down 80mm version they put in the Aganos ( which is still usefull against Destroyers and smaller ships) in theory you could have 30-50% more of these.
For battleships a secondary weapon must be able to deal with destroyers quickly to prevent them torpedoing your capital ships the  100/65 doesnt have the firepower.
 
That being said if Japan realy wanted a DP weapon they would have just upscaled the 100/65 ( just like they down scaled it for the Aganos) , the 5"/40 is decent and available from 1932. An upscaled 100/65 would prob be a hybrid of the 5"/40 and could be 120/65 and could be carried by all ships as a secondary weapon ( or primary for destroyers) .  127/65  is certainly possible but would be a very heavy gun for destroyers to carry in 3 duel turrets.
 
Compare shell weight
5"/38    25kg
5"/50    23kg or 28kg (existing destroyer)
100/65  13Kg
80/60     8kg ( scaled down 100/65)
127/40  23kg
Some quick calcs
120/65?   ~24kg
127/65    ~30kg
 
If Japan did do this they would forget about 40mm weapons relying on 25mm light and heavy weapons.
 
 
 
 
 
 
 
 

 

[JuanG]

ORIGINAL: bklooste

That being said if Japan realy wanted a DP weapon they would have just upscaled the 100/65 ( just like they down scaled it for the Aganos) , the 5"/40 is decent and available from 1932. An upscaled 100/65 would prob be a hybrid of the 5"/40 and could be 120/65 and could be carried by all ships as a secondary weapon ( or primary for destroyers) .  127/65  is certainly possible but would be a very heavy gun for destroyers to carry in 3 duel turrets.

Compare shell weight
5"/38    25kg
5"/50    23kg or 28kg (existing destroyer)
100/65  13Kg
80/60     8kg ( scaled down 100/65)
127/40  23kg
Some quick calcs
120/65?   ~24kg
127/65    ~30kg

If Japan did do this they would forget about 40mm weapons relying on 25mm light and heavy weapons.

This is exactly what I did for my CV Variant, with the weapon developed being a 12cm/60 firing a 20kg shell (same weight as the old 12cm/45).

However, I disagree that the 10cm/65 is not powerful enough to handle destroyers - even though its shell is lighter, its high ROF and good ballistics make it a useful weapon. The only downside is barrel life.

[bklooste]

ORIGINAL: JuanG

ORIGINAL: bklooste

That being said if Japan realy wanted a DP weapon they would have just upscaled the 100/65 ( just like they down scaled it for the Aganos) , the 5"/40 is decent and available from 1932. An upscaled 100/65 would prob be a hybrid of the 5"/40 and could be 120/65 and could be carried by all ships as a secondary weapon ( or primary for destroyers) .  127/65  is certainly possible but would be a very heavy gun for destroyers to carry in 3 duel turrets.

Compare shell weight
5"/38    25kg
5"/50    23kg or 28kg (existing destroyer)
100/65  13Kg
80/60     8kg ( scaled down 100/65)
127/40  23kg
Some quick calcs
120/65?   ~24kg
127/65    ~30kg

If Japan did do this they would forget about 40mm weapons relying on 25mm light and heavy weapons.

This is exactly what I did for my CV Variant, with the weapon developed being a 12cm/60 firing a 20kg shell (same weight as the old 12cm/45).

However, I disagree that the 10cm/65 is not powerful enough to handle destroyers - even though its shell is lighter, its high ROF and good ballistics make it a useful weapon. The only downside is barrel life.

I think its ok for destroyer vs destroyers ( not good since the 5"/38 has a higher ROF a betetr director and double the shell weight) but esp bad in BB vs destroyers where secondary arnament is often 6" and you need to destroy the destroyers quickly. It would take a lot of shots to make up ie 56Kg vs 13kg ie prob 5 shells if you include the effect fo armour this is even worse if the attackers are light cruisers with armour. .

[bklooste]

ORIGINAL: JuanG
This is exactly what I did for my CV Variant, with the weapon developed being a 12cm/60 firing a 20kg shell (same weight as the old 12cm/45).

It would certainly fire this shell for AA until a new one is developed , though against ships a larger shell would be used straight away. No point building such a long barrel with its extra weight unless your going to fire a bigger shell and at higher velocity.

Speaking of the 5"/38 one major issue is there is a single device representing
1) 1941 5"/38 with an earlier director
2) 1944 radar controlled 5"/38
3) guns on carriers with local storage of shells or pedastal mounts.

This is why the 100/65 seem under rated . IMHO it is not when compared to a 1944 5"/38.

3) is prob the most critical since you Kates and Vals take double the histroical AA from the carrier.

[castor troy]

ORIGINAL: John 3rd


4. There are no diversions into other Fighter Airframes---the Zero is the fighter for the war. There is no Jack. The Zero design team focuses its entire energy to improving their superb opening version of the plane.

while there were other frames, the Zero already was the fighter for the war and they did everything to improve it, the problem was that you couldn´t improve this design far enough to match Allied second generation fighters, nor making the Zero competitive enough to really harm Allied bomber types. The only way for the IJNAF to match Allied second generation fighters was to develop new fighter(s) as the improvement of the Zero was an improvement but by far not enough to keep pace with the Allied developments. A late war Zeke won´t match Allied fighters, not even if it would be available a couple of months earlier IMO.

[FatR]

ORIGINAL: John 3rd

4. There are no diversions into other Fighter Airframes---the Zero is the fighter for the war. There is no Jack. The Zero design team focuses its entire energy to improving their superb opening version of the plane.

In this case, an interceptor version of Zero, branching off A6M3 and focusing on armament and armor, at the expense of fuel load, probably should be introduced.

[John 3rd]

Good Comments.

Three Topics for conversation:

1. I thought the Agano, Taiho, and Oyodo carried the 3.9" DP Guns as their heavy AA. By some of the comments posted, am I in error about that?

Specific Points/Questions:
A. Is the 3.9" too heavy as a secondary for placement (as an upgrade) on BBs, BCs, Carriers, and CAs?
B. If so, then what would be the better choice as a heavy AA Gun? There was some serious chatter on Page One regarding this. How about we have people make their case and we'll see where the discussion goes?

2. My original supposition was to work out to the final models of the Zero for use in the Mod. Perhaps this is a bad idea and we display more forethought but going ina new direction. How about The Japanese build the M2, M3, and M3a and END Zero production while researching the Jack and a CV-BASED version of it for the duration? Would that be NUTS?

3. As to the Oyodo's coming out as AA Cruisers, the point made about just building more Moon-Class DD makes solid sense. We could make the Oyodo's into the follow-on Agano DD Leaders and place 9 6" guns on them instead of the 6 carried by Agano and her sisters. This would create 4 good CLs that might be fairly effective.


I plan to put together a comprehensive list of the Shadow Fleet conversions with their release dates and any relevant changes to them. Will then shift to the CVLs and the two new Shokaku sisters. Taiho and her pair of sisters will follow after that. All other CVs remain as after Circle Four construction.

EDIT: Need names for the two Shokaku and two Taiho. There were three Taiho planned and so perhaps their names were selected and can be found?

[JuanG]

ORIGINAL: John 3rd

Good Comments.

Three Topics for conversation:

1. I thought the Agano, Taiho, and Oyodo carried the 3.9" DP Guns as their heavy AA. By some of the comments posted, am I in error about that?

No, you are correct. The B65 Super Cruiser was to carry this weapon as well.

ORIGINAL: John 3rd
Specific Points/Questions:
A. Is the 3.9" too heavy as a secondary for placement (as an upgrade) on BBs, BCs, Carriers, and CAs?
B. If so, then what would be the better choice as a heavy AA Gun? There was some serious chatter on Page One regarding this. How about we have people make their case and we'll see where the discussion goes?

While the 3.9in/65 mount was slightly heavier than the 12.7cm/40 (34tons vs ~27tons), replacing the guns on existing ships is not impossible. However, I am not certain that it is worth the time required for such an upgrade (probably 30-45 days?).

The 12cm/45 was a good weapon, and the 12.7cm/50 in Type D mounts was also a good weapon, though the adoption of cartridge based ammo instead of the bag ammo would help in further improving this weapon.

ORIGINAL: John 3rd
2. My original supposition was to work out to the final models of the Zero for use in the Mod. Perhaps this is a bad idea and we display more forethought but going ina new direction. How about The Japanese build the M2, M3, and M3a and END Zero production while researching the Jack and a CV-BASED version of it for the duration? Would that be NUTS?

I dont think the Jack is suited to CV operations, because of its shorter range. However, if you're going in this direction, what about working with the Zero until the early A6M5 models, and then introduce a carrier based N1K? This could then either serve for the rest of the war, or get phased out in '44-45 for the A7M.

ORIGINAL: John 3rd
3. As to the Oyodo's coming out as AA Cruisers, the point made about just building more Moon-Class DD makes solid sense. We could make the Oyodo's into the follow-on Agano DD Leaders and place 9 6" guns on them instead of the 6 carried by Agano and her sisters. This would create 4 good CLs that might be fairly effective.

There were plans for a follow on of the Agano class powered by the high-pressure powerplant of the Shimakaze's and mounting 8 x 15.2cm/50s, intended as DD Leaders for the Shimakaze's.

However, there were also plans for a CLAA mounting 24 x 10cm/65, and this is what the CLAAs in my scenarios are based on. I think the design was designated C44 but I need to check that.

ORIGINAL: John 3rd
I plan to put together a comprehensive list of the Shadow Fleet conversions with their release dates and any relevant changes to them. Will then shift to the CVLs and the two new Shokaku sisters. Taiho and her pair of sisters will follow after that. All other CVs remain as after Circle Four construction.

EDIT: Need names for the two Shokaku and two Taiho. There were three Taiho planned and so perhaps their names were selected and can be found?

The 3 planned Taiho were to be of the modified Taiho-Kai (G15) design, and included an extra pair of 10cm/65 guns and improved DC systems. No names were officially assigned to these hulls (like with the later Yamato's) as far as I know, only serial numbers.

[FatR]

ORIGINAL: John 3rd

I've got some time before going to Caucus Training this morning so I thought I'd begin the work by examining some of the CVs to be worked with in the Mod.  The pair that vex me is Junyo and Hiyo.  The Mod assumes an acceleration of conversion and/or work on the Shadow Fleet.  All of us know the marginal use of these two large passenger liner converts. 

Let me throw out proposed thoughts for them within this scenario:

1.  They enter service as built (about 25 Kts with a marginally decent air group of 51 planes) but slightly earlier.  The ships enter service in January and March 1942 respectively.

or

2.  Their engines are re-tooled and made USEFUL.  This change would raise their speed to 28 or 30 Knots so they could better keep up with the Fleet Carriers.  If that route is chosen then they enter on their historic dates in May and July 1942 but with real engines.

Remaking engines is a huge change. Probably not effective, cost-wise. Considering overall and significant expansion of Japanese fleet for this scenario, I think that their pre-war conversion could be put on hold, to save funds for other programs (primarily real carriers), if the mod is supposed to stay roughly within the realm of historically possible. They can be present at the start as passenger liners, but with the conversion option.
  

[bklooste]

ORIGINAL: John 3rd

Good Comments.

Three Topics for conversation:

1. I thought the Agano, Taiho, and Oyodo carried the 3.9" DP Guns as their heavy AA. By some of the comments posted, am I in error about that?

Yes they did . For the Oyodo and Taiho and Agano carried the scaled down 80/60 . Note partly because these DP guns are heavy Oyodo ended up carrying very little primary arnament for their size 6 *6" for 8000 tons . By heavy i mean about the same as a 4.7 gun.

Specific Points/Questions:
A. Is the 3.9" too heavy as a secondary for placement (as an upgrade) on BBs, BCs, Carriers, and CAs?
B. If so, then what would be the better choice as a heavy AA Gun? There was some serious chatter on Page One regarding this. How about we have people make their case and we'll see where the discussion goes?

2. My original supposition was to work out to the final models of the Zero for use in the Mod. Perhaps this is a bad idea and we display more forethought but going ina new direction. How about The Japanese build the M2, M3, and M3a and END Zero production while researching the Jack and a CV-BASED version of it for the duration? Would that be NUTS?

A. No its not too heavy for these BBs carried 6" secondaries. The only question is can they kill a destroyer fast enough before the torpeods are launched since teh main arnament will be busy. For CAs this is not the case as the main arnament is expected to fight destroyers its just a question of weight note the Ibukis mounted 8 × 127 mm (5 in) dual-purpose guns , not sure what these were intended to be ... prob the 127/40s.

B. If the Japanese were serious about air they would have upgraded the 120 or 127 guns to prob be 120 or 127/60 using some of the features of teh 100/65 with a shell about 23 to 30kg. WHile these would be a bit heavier they are much more usefull as a secondary arnament on Capital ships vs ships which is important to black shoes. For pure AA the 80mm/60 has a lot of merit as it is smaller yet still effective.

Note even if a 127/60 or 127/65 gun is adopted and mounted on destroyers as 3*2 the 4*2* 100/65 would still be better at AA.

2. No . Its a natural evolution as the war went on put a chutai of interceptors with armour which has the CAP roll these become more and more usefull so they build more. I cant remember the detials but im sure the IJN trialed some heavier fighter planes on CVs maybe even the Jack but the pilots disliked the large engines for landings.

3. As to the Oyodo's coming out as AA Cruisers, the point made about just building more Moon-Class DD makes solid sense. We could make the Oyodo's into the follow-on Agano DD Leaders and place 9 6" guns on them instead of the 6 carried by Agano and her sisters. This would create 4 good CLs that might be fairly effective.

I plan to put together a comprehensive list of the Shadow Fleet conversions with their release dates and any relevant changes to them. Will then shift to the CVLs and the two new Shokaku sisters. Taiho and her pair of sisters will follow after that. All other CVs remain as after Circle Four construction.

EDIT: Need names for the two Shokaku and two Taiho. There were three Taiho planned and so perhaps their names were selected and can be found?

3. I would ditch all CLs. They cant face US CAs and are no better than destroyer leaders vs destroyers. I would put every resource into the Moon-class DDs or build 15K tons Soryus If i had to build any cruisers i would build the Ibukis.
Options
- Copy the Tromp design put 3*Twin 6.1" (from the Mogamis) on a Moon class hull ( almost the same size as Tromp) a bit top heavy but its doable since the tromp did it . Add a float and you have an excelent cheap ship at 1/3 the cost and more importantly build time of a CL.
- Build faster 37-40 knot Super Moon class these were also planned. They planned 42-45 knots versions but this is not doable . Basic idea is to make them very fast with a small turning circle making them very difficult targets.

Regarding the Taiho if they stuck with the original design instead of arguing she would be there 2 years earlier , but what was the design ???

[bklooste]

ORIGINAL: FatR

ORIGINAL: John 3rd

I've got some time before going to Caucus Training this morning so I thought I'd begin the work by examining some of the CVs to be worked with in the Mod.  The pair that vex me is Junyo and Hiyo.  The Mod assumes an acceleration of conversion and/or work on the Shadow Fleet.  All of us know the marginal use of these two large passenger liner converts. 

Let me throw out proposed thoughts for them within this scenario:

1.  They enter service as built (about 25 Kts with a marginally decent air group of 51 planes) but slightly earlier.  The ships enter service in January and March 1942 respectively.

or

2.  Their engines are re-tooled and made USEFUL.  This change would raise their speed to 28 or 30 Knots so they could better keep up with the Fleet Carriers.  If that route is chosen then they enter on their historic dates in May and July 1942 but with real engines.

Remaking engines is a huge change. Probably not effective, cost-wise. Considering overall and significant expansion of Japanese fleet for this scenario, I think that their pre-war conversion could be put on hold, to save funds for other programs (primarily real carriers), if the mod is supposed to stay roughly within the realm of historically possible. They can be present at the start as passenger liners, but with the conversion option.
  

Agree here redoing engines is very expensive (cost wise) , and not really practical due to lack of room etc it would prob triple the conversion time. Still converting non war ships into escort carriers is fine but fleet carriers and be expected to be exposed to hits ?... Instead of all these time consuming conversions they could leave them as AO , AP and AS ( which are all pretty usefull) and build some 15-18K Soryu style ships. Note a lot of conversions such as Ibuki were wartime necesities after Midway but without Midway are unlikely to have been done , still the option should be there.

Its probably worth considering the conversions vs new ships here.

New ships
Require lots of steel and armour , which was used mainly on the Yamato program so in short supply just before the war.
Can be build to the latests standard
Can be built to purpose so far higher plane count for the tonnage for CVs
Far More survivable
Uses slips

Conversions
Cheap in Material
Time consuming
May need to tie up Dry docks.

[bklooste]

Anyone got more accurate figures on Agano and Oyoda costs ?
 
The way i see it
 
4 Katori *5890  + 4 Agano * 6600 + 2 Oyoda * 8100 =
= 24 Akitsuki at 2700 tons  if you include mass productions , the cost of not building 3 designs , cheaper destroyer power plants , no armour plate you can prob get 30 for those light cruisers and a lot earlier.
 
You could say
+12 Akitzuki
+6  Destroyer leader Akitzuki ( free guns)
+12  Fast Akitzuki.
 
Use AS or Merchant converted AV   for your subs ..
I know what i would take ... who needs the advantages of a light cruiser in 43-45 ie spotting plane , extra range more reliable engines and 1" belt armour.
 
 
 
 
 
 

[Whisper]

It all depends on what kind of scenario you want to have. If you just want the Japs to have more and better ships then that’s cool you can do what you want. But if you want something historically plausible, you have some problems.

Naval construction does not go ton by ton it goes volume by volume. Japan did not have the cability to increase their naval yard size to any great degree. Japan is a small country with much of the skilled labor force in a few places. It is mountainous and has no beaches and the water is deep up to the shore. Shipyards are constructed in heavily populated areas and cannot be expanded to any degree so what you see is what you get.

There is some room to move in Okayama Province, but the land/water interface does not allow anything bigger than DE/DDs. The costs to make a capital ship yard are about 4 times the cost of the ship itself. So it is just not possible.

And DD power plants are not ‘cheaper’ than CL power plants. Power plants depended on the technical specifications of temperature and pressure. Japan could not get even close to where the US got. Apart from that it was scale, it was not cost. A hi-T, hi-P plant for a DD could transfer over by tonnage scale to a CL on a Deadweight ton percentage. But hi-t, hi-p engines used trunk and turbine materials not available in Japan so those are useless for guesses. And it is totally worse for anything bigger, so there go your fast CVLs down the dumper.

So if you want to work up and play a scenario that has a cool poop ton more Japanese ships, I think that’s great, but please don’t attempt to historically justify it. It just couldn’t happen.