Anyone interested in some intellectual exercise?

Thank you Mr. Prime Minister for your insightful comments. I am in full agreement with them. I would also like to than you for the quick response to the appointments of General Terauchi Hisaichi and General (Ret.) Kourei Yuushou. I am confidant that they will serve the Emperor and our country well.

 

Now we should order General Hisaichi to set up his plannings and give him the possibilities to get what he need for his job. I think that he is the right man for this task! Good luck!

 

Economy

Moving much of our industry to China to take advantage of Coal energy would be difficult in the short term, and in reguard to our ship-building well nigh impossible. Still we have several potential weapon systems who's design if far from complete such as an improved SAW, Man portable AT weapon and others. Would it be practicle to set up production in China for these new items? Any relief we can get on our homeland industry would be welcome, however small.

In selecting small auxillery warship's (Mine layer-sweeper's Light escorts and perhaps even some merchant hulls) could we accept coal fired powerplant's rather than oil to relieve some of oil shortfall? Again anything that gives us relief with reguard to oil usage seems a benefit

Sadly at this late date I see no diplomatic way out of the Western Embago as it now stands. A year or even 6 months ago perhaps there was the possibility, but not now. The actions of the previous administrations have left us no room for diplomacy.

Only the taking by force of those oil producing regions will allow us any measure of freedom for the near term. The imporatance of seizure before they can be sabotaged is such that they must be our primary focus, over and above the defeat of Anglo-Dutch military forces not directly in our path to the oil itself.

Prime Minister Belasar Tekisasu

 

Even if we dont need the oil we want Burma to cut off China and to deny it to the British. No sense leaving them a good base for operations. There are no real roads or rail connections between west Burma and India which increases the difficulty of transportation.

 

Since I've posted this here before, I will post the new version here directly:

An updated building program

Cells depicted in green represent current production which we have scheduled to proceed. Those in yellow have been subject to considerable debate. Those in red are currently scheduled for discontinuance and scrapping. Those in blue are new production specified by our council. You can clearly see that carrier and destroyer production in particular are far far more emphasized than previously.

The building way dimensions are somewhat speculative, as I cannot find maps of all, and even when I can find maps they are often hard to interpret. But the total length has been made to approximate the figures from the table found on p. 43 of the Strategic Bombing Survey. Thus even though what is on my table is not precise, it is at least close and roughly representative. I have built a yard production spreadsheet from that table.

I believe this program is much more ambitious than the previous administrations. If I am reading the numbers correctly we have the capacity to build, on average, 120 thousand tons of naval vessels and 700 thousand register tons of merchant ships. I do not personally know a good way to convert this capacity from displacement tons to register tons or back. It is my understanding that register tons represent only a fraction of the displacement, but given the greater complexity of building warships, perhaps it's not completely unfair to simply convert one for one. If anyone knows a good rule of thumb, I'd be happy to hear it. I would guess we could build an additional 570 thousand tons or so of merchant shipping.

In short this program represents:

3 Shokakus to commission in March or April of 1944, Taiho, which will commission at about the same time
and 2 Unryus to commission in November of 1943
Shinano is presently delayed, but I would guess we should be able to move her along such that she might become available about the same time as the other large carriers


We should be able to complete conversions on Chitose, Chiyoda, and Nisshin in about 1 year.

Junyo and Hiyo don't show up in the plan, as they have already launched, but they will be available in mid 1942.

We have three light cruisers underway that will be available between late next year and the middle of 1943. I have presently have no plans for other cruisers, though we could add some. We will most likely need to replace some losses and our carrier force is set to expand considerably, so some additional AA cruisers might be desirable if we can settle on a plan for them.

Additionally, this includes 50 different escorts of one kind or another: 10 Akizukis to commission in late 1942, 10 Yugumos that should be available about the middle of next year, 10 Matsus that should come online just about the same time or maybe a little quicker, and 20 Etorofus or something similar.

There are also 10 fleet submarines included.

I could easily add a couple new build APAs to that. I'd guess they would displace around 10,000 tons and take a couple of years to build. Maybe a little less.

We could (and should) add to this some work on CVE and less complex APA conversions once we have our invasion plans firmed up. Further, suggestions to convert our CLs to CLAAs merit further discussion.

I look forward to suggestions and counter-proposals.

Sincerely,
Admiral Noka

 

Domo arigato, Noka-san, for your valuable work.

We seem to have resolved the Unryu-Shokaku debate by building both. Is there a value to the mix, or it mainly to get a few ships in service sooner? Did we ever get a reading on which type puts more aircraft to sea for a given expenditure of resources?

Shinano - are we considering an armored deck (historical) configuration, or is possible to investigate a dual-hangar option like our existing carriers? It appears that the single hangar would allow her to operate around 42-47 aircraft, plus spares. This is roughly consistent with ships like Kaga or Shokaku which operated about 72 aircraft, 36 per hangar, plus spares. It suggests that a dual-hangar Shinano might have an air group of around 84. She should also be able to have at least three elevators, and her beam might allow the midships one to be far enough to one side that aircraft could be moved around it. If we go forward with her as a carrier, I suggest we see if the game system can accommodate the dual-hangar configuration.

Fast transports are an intriguing concept, but it seems a waste of assets to convert 28-29-knot seaplane carriers, which already have fuel and ordnance storage for ~24 aircraft, to anything except full-fledged carriers.

One candidate for fast APA conversion is the 20-knot submarine support ship Taigei. Adaptation for the APA role would require minimal work and seems far more practical than expending greater effort, including complete replacement of her engineering plant, to make her into a mediocre carrier (Ryuho).

I too would like to see more cruisers, especially since current American plans call for over forty of them, but I think we are correct in giving priority to carriers, destroyers, and escorts. Rather than new-construction AA cruisers, I would invest in more Akizukis - which were thought of as AA cruisers early in the design process.

I think we had general agreement to convert the twelve Nagara, Kuma, and Sendai class cruisers (less Oi and Kitakami) to AA ships as we have opportunities to cycle them through the shipyards. Any not needed as destroyer squadron flagships could be assigned to the carrier force for additional AA firepower. Incidentally I would expect the new Agano class cruisers to replace some of the older ships in the destroyer leader role.

I though we had also agreed to focus on the Type C/D kaibokan for our escort force, with a few of the larger Mikura or Etorofu types to serve as escort group flagships (this seems to have been a historical practice; several US submarines were sunk by such groups). The main difference between C and D was the propulsion plant, diesel or steam; there might be an opportunity for a coal-fired variant.

I second suggestions to use coal power and wooden construction where possible, particularly for escorts or minesweepers operating in home or coastal waters. Escorts and minesweepers are quite similar, so a common hull could be used, like the British Empire Bangor or Bathurst classes.

We haven't had much discussion of the Matsu class destroyer. It's an intriguing concept, though it would be more so with a top-of-the-line AA gunfire control system. The speed and torpedos are more than needed for most escort missions, but inferior to our or the enemies' fleet destroyers. Are we better off with the "in-between" ship or with the resources invested in more cheaper escorts and few more Yugumos? Bobimoto-san and I had also proposed an AA escort around Etorofu or Matsu size. I think we are the point where we need to start saying definitive yeas or nays to all of these ideas.

 

Admiral Karonada,

The decision to start 2 Unryu's is meant as an insurance policy should our efforts to keep America neutral for an acceptable period of time fail or if we find ourselves suffering greater than hoped for losses in our Carrier Fleet before our new Shokaku's can be launched. They (Unryu's) are still decent ships at a economical price. If we have the success we anticipate, we build only Shokaku's there after, if not, we launch as many Unryu's as we need to keep us as close to the American's as possible.

My support for Shinano to be finished as a CV Is solely contingent on our ability to fit her with two (2) hangers and a air group of 75+ aircrft. Otherwise we must clear the slipway and undertake a 3rd Shokaku.

I can live with trading Ryuho as a APA for Nisshin as a CVL if all can agree.

Prime Minister Belasar Tekisasu

 

APAs and CVLs

Admiral Karonada's observations about Nisshin and Taigei seem quite correct. We can plan to convert Nisshin to a CVL and consider converting Taigei to an APA. I think I would lean toward new build APAs over converting Taigei, simply because we don't have much surplus on submarine tenders. We currently have 7 split among 4 fleets with an 8th scheduled to become available late next month. Further, I'd like to increase the size of our submarine fleet, so I could easily envision needing more tenders rather than less.

Fleet CVs

The carrier program is something of a compromise between those who favored better, more survivable carriers and were willing to sacrifice some capacity over those who favored the largest possible aircraft compliment above all else. I believe Prime Minister Belasar is correct. The Unryus are a contingency plan. Certainly they will provide more aircraft capacity for less money slightly more quickly. But I feel that their vulnerability offsets some of that, and I have thus advocated building the Shokakus anyway. The current plan perhaps sacrifices a little efficiency, but not very much. It's not as though we're producing many major components centrally and distributing them to satellite yards. (Though we could and should consider ways that we could do this at least on our smaller vessels.)

Production Question

Could we use the same machinery for all of our destroyers? Would we be able to produce more turbines if we produced them centrally and then shipped them complete to the smaller yards? Would it require too much shipping to do that? But with large capital ships we won't be producing them in so many places, nor will we be building so many. Further, we would be ill served by using machinery deigned for smaller ships. (Though obviously we can in a pinch.)

ASW escorts

The Etorofus may be simply a mistake on my part. Upon further reflection I think I would advocate building B types. The Cs and Ds are a little slow. We could begin building them as an economy measure if losses become unmanageable, but since we should not have to fight the American submarine force initially we will have some time to build up a more capable ASW force and work to develop doctrine. I think we would be better served by building the most capable ships we can before we need to economize.

Matsus

I envision these serving as escort leaders in our general rear area convoys or as primary escorts to our more forward and more sensitive convoys and our 20-25 knot APA-CVE/A task forces. Think of them as economy fleet destroyers for shipping of slightly less speed than Kido Butai, but still with a quite high value. Also, it will be useful to have one or two ships in most of our convoys that could hope to run down a fleet submarine on the surface. Our PGs could not do that.

Build Program

I found a clerical error in a previous post. If we substitute Type Bs for the Etorofus the total proposed new construction, exclusive of conversions and cruisers and destroyers from the previous program would come to 242,000 tons. That's a little deceptive, though, since the capital ships are really spread over two or more years construction. If we double the escort production and divide by two that gives us a better idea of the single year proposal. This comes to 178,500 tons, which seems quite manageable and still leaves room for conversions and completing the previous program.

CLAAs, APAs, and Torpedo cruisers

I'm curious what we might do with Kitakami, Oi. I very much like the idea of greeting our foes with shoals of torpedoes from ranges vastly beyond their own, but the two torpedo cruisers seem like odd ducks in our fleet. (And may not contribute all that much to this vision simply because they are but two in a fleet of seven hundred ships and boats There is no other combatant type we have in such small numbers.) It had been suggested that we might convert them to APAs. The Tenryus present a similar problem. They are small and old. We could use them as training cruisers, of course, but they are fast and could prove otherwise useful.

I await your thoughts and suggestions.

Sincerely,
Admiral Noka

Addendum: Yes. My support for conversion of Shinano is also contingent upon fitting her with sufficient hangar capacity for 70 or so aircraft. (Or a hundred or so if we decide to use a permanent deck park.)

 

A question. Is Taigei in a yard currently undergoing conversion to CVL/E?

 

Could we use the same machinery for all of our destroyers?

The Yugumo and Akizuki classes both have twin-shaft, three-boiler, 52,000hp plants, so I think we have that covered.

Side note, the third and fifth Unryu class ships used 104,000hp plants, two sets of destroyer machinery, for a speed of 32 knots. The standard Unryu arrangement was the 152,000hp plant used in the last few heavy cruisers.

Oi, Kitakami - since we have them, I would use them in their intended role, especially if we have an early engagement with the American fleet. We might consider whether they should be attached to the battle fleet for a decisive battle or used for a preliminary torpedo attack. Not to be callous, but I wouldn't mind risking them if there was a chance of inflicting significant damage. If there are no opportunities to use them in torpedo attacks, the large sponsons might serve for launching or loading landing craft.

Tenryu, Tatsuta - I would use them as is as flagships and gunfire support for amphibious operations.

Is Taigei in a yard currently undergoing conversion to CVL/E?

What's today's date? Conversion started in December, or possibly November, 1941. As Noka-san noted, we could retain her as a submarine support ship if our sub force needs her; after all, we can't convert everything to something else

 

We can also use the smaller and older ships in the Indian as guard against the British.

 

Would it be possible to convert Ryuho into an effective CVL?, Other than the current re-design. Otherwise keep her as she is as a Submarine Tender

 

Admiral Karonado,

Yes. I've seen the plans for using destroyer machinery in Unryus, and the result is not unsatisfactory, but I believe it would push the machinery quite hard to achieve that design speed of 32 knots. I have some concerns about reliability. We could do it. But I don't know that we should if we can avoid it. The extra 50,000 shp should provide a much needed margin of error, lest we end up with problems like those we fear with the Junyos.

Prime Minister Belasar,

To my knowledge the only ships that have begun conversion according to the plans of the previous administration are Hiyo, and Junyo. Both are nearing completion. Several other conversions were planned, but none started, so far as I am aware. We have the luxury of either accelerating them or canceling them if we wish. So far as I know the plan I have proffered has not been put into effect. I am attempting to formalize ideas the council has suggested in the past and to my knowledge we can still safely revise it.

Col. Bobimoto,

I am beginning work on a formal merchant ship building program. We will no doubt need additional auxiliaries not detailed in the main program: repair ships, floating drydocks, distilling ships, stores ships, troop ships, assault ships, and of course escort carriers for instance. New build auxiliaries could be added to this program. Do you have your notes from previous suggestions handy? I can work them into the merchant program. (I'll go back and see if I can't find them in the totality of our discourse, but it will take me time to find them thus.

My humble thanks to my fellows on our council. I feel certain we can meet our needs and that our work will meet with success, difficult though it be. And I eagerly await any and all suggestions for revising the program. (Particularly as it applies to ASW escorts.)

Sincerely,
Admiral Noka

 

According to Lt. Wiki in the construction department "The Ryūhō started life as the submarine depot ship Taigei, and [will be] taken out of service in December 1941 for conversion into a light aircraft carrier." so we should be able to cancel that.

He also informs us that "Between 25 November 1941 and 31 May 1942, Yawata Maru [will be]rebuilt in Kure to be an auxiliary aircraft carrier." (Unyo) which I think we are in agreement to let go forward. Sister Nitta Maru (Chuyo) is also available; historically "After the Battle of Midway, it was decided to convert her to an escort carrier. The conversion took place in Kure between 20 August and 25 November 1942.", note how rapidly the conversion could be accomplished. These are sisters of Taiyo, already in service as a carrier.

 

Ah, the redoubtable Lt. Wiki, what would we do without him!

After re-reading one of his previous memorandum's reguarding the Taigei I see this vessel has several flaws (weak hull, powerplant and poor subdivisions) that would make her a poor selection for a Carrier conversion in my humble opinion. These same flaws would seem to make her conversion to an assault transport (APA) questionable also. As Admiral Noka points out we have little excess submarine tender assets as it is, and since no work has yet begun to convert her, I feel she should be left as she is.

I think we all aggree the Shinsu Maru is the optimal design APA, so other than conversion of our CX's into APA's we should concentrate on this one common design to meet our needs. I suspect we will need to start a new hull of this type as soon as resource's and space will allow.

Prime Minister Belasar Tekisasu

 

I would make at least one significant change to the Shinshu Maru design.Rather than a flight deck she has been supplied with a "taking off deck" of the sort we recently dispensed with on Akagi and Kaga. I would modify her superstructure such that we could giver her a full length flight deck with arresting gear and at least a small hangar. (No need for a full hangar. She doesn't need to operate as a true carrier. But one for repairs would be good.)

Apart from that and some armament, sensor, and command and control changes to standardize with the fleet and give her better flag facilities I think she's a quite solid design.

Which reminds me: it has been noted elsewhere that the flag facilities on our carriers are notably deficient. (Perhaps because the carriers were conceived as subsidiary to the battle fleet until quite recently.) Thus our cruisers and battleships all have better flag facilities and communications suites. Since our fleets are built around the carriers, and we will most likely wish to control at least air operations from these anyway, would it not be wise to expand the islands on our carriers as we have the chance and thus improve the C and C arrangements to make them better suited to flag roles?

Sincerely,
Noka Shijin

 

Even if we need a 'repair carrier', I respectfully suggest it might be a bit much to try to add that capability to Shinshu Maru. It also appears

File:ShinshuMaru-1938.jpg - Wikipedia, the free encyclopedia

that she carries her smaller landing craft, Shohatsu type, atop the superstructure and launches them by davits, so adding a flight deck would be complicated at best. As I understand it, she launches aircraft by catapult, to land on shore bases (I'd be fascinated to see interior plans of this ship and how well deck, hangar, and troop quarters all fit in).

Flag facilities for carriers is a very forward-looking thought; we only started putting islands on carriers in 1935 (Kaga, reconstructed). The islands are sponsoned out so as not to encroach on the flight deck, which may limit their size; but it should be feasible at least to add a deck level and separate fleet and ship command functions (I wonder if WITP can incorporate this level of detail, in ship design and in improved C&C in combat).

Converting our auxiliary cruisers to APAs should be relatively easy since they were originally passenger-cargo ships. If their existing cranes can handle a few 14m Daihatsu carried on deck we're basically in business.

 

The modest improvements you suggest for the Shinsu Maru follow-on's seem reasonable as long as they do not impair her primary duties.

With all do respect to our fleet commanders, they must station themselves where they can best control all the vessals at their command, and where they can best communicate with other supporting commands. Their ego must be seperated from their duties in this reguard. If a Battleship or Cruiser has the better command facilities, then that is where they must fly their flag.

I would not favor withdrawing one of our fleet carriers to simply improve her command facilities. However as they undergo any major refit or repair, and if such improvements do not greatly delay her return to service, then by all means make the alterations.

If we do finish Shinano as a carrier could she not have these improvements incorporated within her?

Can we make the neccasary changes to the Shokaku's we will soon be laying down?

 

Maybe you can get some informations from here to the Shinshu Maru our former IJA ship.

View attachment 16753

 

Thanks, General! One thing a bit puzzing, looks like the funnel uptake goes through one of the stored Daihatsu. I don't even want to imagine how cramped quarters for 2000 troops must have been!