What if no Yamato

[muttly]

What if the Japanese had not built any of the Yamato class and instead had used the time
and materials to build fleet aircraft carriers instead. What would the impact be on the war
in the Pacific.

 

[Dilandu]

Japanese admirals could not build nothing. Their battleline was elderly, and required at least some additions to stay relevant. Japanese knew that Americans and British build new battleships, presumably with 16-inch guns, and they did not like the idea of putting their old battlewagons against brand-new American units.

So, Japan would build SOME battleships, that's for sure. If nothing more but just because Fuso-class ships were nearing the end of their useful service life, and needed to be replaced. Could Japan limit the ambitions to smaller, easier to produce battleships - say, 40.000 tons with 16-inch guns? Possible. But Japan could not just "switch to the carriers"; it would seriously weaken their fleet capabilities.

P.S. Also, Japan could not just increase the number of carriers. They simply does not have enough trained pilots. Pilot training programs in IJN were... time-consuming - in no small part because the average education quality of Japanese rookies were far below American or British (Japan was still quite poor country; many recruits from rural areas literally never drive a car or even bicycle in their lives, and have zero idea how ICE actually worked). Adding new carriers with no pilots to fly from them was impractical.

 

[Justo Miranda]

The problem was not the shortage of aircraft carriers but the shortage of well-trained naval pilots. The Japanese training system was excessively slow and complicated.

 

[tomo pauk]

As noted above, some battleships ought to be built. Perhaps two, each with 6 x 16in guns (bare minimum). Leaves a lot of steel and machinery to make proper carriers, though. So there is no Shoho sent in the harms way in 1942, for the starters, but a proper carrier with the bigger air group and AA suite?

 

[CV12Hornet]

As noted above, some battleships ought to be built. Perhaps two, each with 6 x 16in guns (bare minimum). Leaves a lot of steel and machinery to make proper carriers, though. So there is no Shoho sent in the harms way in 1942, for the starters, but a proper carrier with the bigger air group and AA suite?

But it doesn't leave any building slips, which were the bigger bottleneck on carrier construction. IIRC they had maybe seven slips capable of building capital vessels in the entire country.

The United States had 19, by way of comparison.

 

[tomo pauk]

But it doesn't leave any building slips, which were the bigger bottleneck on carrier construction. IIRC they had maybe seven slips capable of building capital vessels in the entire country.

The hulls of BBs of future 40-45 thousand tons will vacate the slips faster than the hulls of BBs of future 70+- thousand tons.

 

[Dilandu]

As noted above, some battleships ought to be built. Perhaps two, each with 6 x 16in guns (bare minimum).

Most likely, there would be a pair of fast 16-inch battleships of 40.000-45.000 tons, build to replace the pair of Fuso-class ships.

But it doesn't leave any building slips, which were the bigger bottleneck on carrier construction. IIRC they had maybe seven slips capable of building capital vessels in the entire country.

Well, smaller and less... grandiose battleships could be build faster than Yamato's, and free the slips faster also.

Let's face it, without new battleships, IJN would basically have little standing power. Carriers are useless, if you need to stand and fight. And carriers without heavy hitters to fall behind, would be very limited in combat maneuvering; they would be forced to avoid any closing with enemy (and what if the wind is from enemy side? To launch or land aircraft, WW2 carriers must run into the wind - i.e. in such case, toward the enemy!)

 

[CV12Hornet]

The hulls of BBs of future 40-45 thousand tons will vacate the slips faster than the hulls of BBs of future 70+- thousand tons.

I doubt that. The construction times of the Yamatos were not out of line with how fast everyone else not named the United States built their battleships.

 

[lancer21]

This ATL occurs regularly, and while interesting it also rather simplistic imo, like others say, everybody was building new BBs, so imo a more realistic scenario in which the "aviation mafia" in IJN has more sway, is for them to build BBs more tailored to support CVs, that are smaller and faster, cheaper too.

We have the benefit of hindsight of course, but it's fun to play. So one scenario is for them to first, modernize the Nagatos with machinery like Kagas (127,000 HP) which aparently was considered OTL, to increase speed, bringing it at least equal or even more than the new american treaty BBs, thereby increasing the usefulness of these ships. As a side note, does anyone know how to calculate the speed of this ATL Nagato with 127,000 HP, standard displacement being close i assume to 40,000 tons?

Second, built a class of two quick and cheap mini-Yamatos (let's use the same names Yamato and Musashi), a japanese Vanguard if you like, about 45,000 tons, heavily armoured, 30 knots speed, using the guns left over from the Tosa and Amagi classes (24 apparently), so they could have either four twins or three triples. They should take significantly less time to build, no need to enlarge slipways etc., so both might be fully combat ready in 1941.

Third, build two new 50,000 tons heavily armoured fast BBs with nine 41cm/50 guns, these replacing the OTL Shinano and Kii but i keep the names. Because the first two take less time to to build, these two can be started and finished earlier, so they might be combat ready in 1943/1944.

Fourth, instead of the mediocre Junyos, build two proper CVs instead, say one repeat Zuikaku and one repeat Hiryu, it's a much more efficient use of that steel. They both should be operational in 1942 roughly similar to OTL Junyos, but the repeat Hiryu could be ready earlier.

Fifth, bring the auxiliary conversion programme one year early, so Zuiho is ready late 1939 rather that late 1940 with Shoho and Ryuho brought forward one year too. Same goes for the CVE, they could probably get all 3 Taiyos ready in 1941 if they start converting them early enough (that is 1940). Also they could convert the Kamakura Marus as well, so they will have 8 or 9 CVEs instead of 5.

I kinda disagree with the notion that they didn't had enough aircrew, imo the problem, at first anyway, was they didn't had enough RESERVES, so if they focus more on the carrier air airm, they could just train the additional required number of aircrew, but still with the insuficient reserves. They could also skim land based groups for more aircrew, as to the shortage of carrier aircraft, they can for instance have Nakajima build 800 D3A and B5Ns instead of the 400 G3M built OTL, but of course this is just hindsight.

 

[EwenS]

Hiyo & Junyo were ordered as passenger liners, subsidised by the IJN as part of the shadow carrier plan in the same way as the eventual CVE conversions. Laid down March and November 1939, It was October 1940 when the IJN decided to convert them, a decision formalised in Feb 1941. Being so large they were occupying slips that were also required for carriers and battleships.

Openly building two more carriers in 1939 will cause a reaction in the USA.

 

[lancer21]

That is IF the americans know about it in time to alter their own building plans... to me they didn't seem to have terribly accurate intelligence re IJN building plans, witness the whole rather silly Chichibu/Alaska story. Though possibly they could build two Hornets in 1939/40 as initially planned (40,000 tons of CVs) instead of one (with CV-9 delayed in OTL to 1941 as you know) if they find out early enough.

 

[CV12Hornet]

@lancer21

Hmm. Interesting. It looks like your plan just might be viable from a yard perspective, assuming the repeat Hiryu is built at Mitsubishi 2 and the repeat Shokaku at Kawasaki. That said, you're not going to get those two follow-on BBs early enough to be useful.

Note that the expansion of Yokosuka #2 was to allow it to build capital ships at all. Cancelling that doesn't help the situation.

 

[lancer21]

That's a great graph, i'll take my time to study it. Re Shinano, actually from japanese wiki it appears it was build in a brand new slip built specifically to handle Yamato size ships, this slip was started in 1936, so the 270m slip might actually refer to it. It looks like all that was built on that particular slip was just Shinano. So it seems it wasn't build on the same slip as Shokaku, but probably Unryu was. There is some conflicting and scarce info re japanese shipyards/ slips unfortuntely.

One may wonder then the gap between Shokaku and Unryu, i THINK that might be accounted for by the conversion of Zuiho, Shoho and Ryuho, but i'm not sure.

PS: There seem to be some errors in that graph, some launch dates seem to be mixed with comission dates, Hiryu was launched in 1937 and Unryu in 1943 for instance.
There is this very interesting graph here:

Japanese capital ship construction

This thread is something the wiking might post, but instead of about Germany it's about the Japanese capital ship building, to be more precise the organization of it or more accurately the lack of organization. In particular the panic that gripped the Japanese command after Midway which meant a...

www.alternatehistory.com

 

[CV12Hornet]

One may wonder then the gap between Shokaku and Unryu, i THINK that might be accounted for by the conversion of Zuiho, Shoho and Ryuho, but i'm not sure.

I don't think that's an explanation; Zuiho is already listed, and Shoho and Ryuho were converted in drydock.

 

[publiusr]

Yamato was built for high speed…no ramming of subs and such, IIRC

 

[muttly]

I have always wondered this question, now I have a clearer answer. I always thought
the Japanese decided air power was king and the battleships were of little use.

 

[Dilandu]

I have always wondered this question, now I have a clearer answer. I always thought
the Japanese decided air power was king and the battleships were of little use.

It's wrong assumption. Using carriers without battleships was very dangerous during WW2. Carriers have no standing power, in case of enemy advancing they could only strike & run - and running may actually block them from implementing aviation. So-called "deck aviation weather gauge".

 

[muttly]

I understand more and more from reading this forum, thanks to all.

 

[kaiserd]

I have always wondered this question, now I have a clearer answer. I always thought
the Japanese decided air power was king and the battleships were of little use.

It's wrong assumption. Using carriers without battleships was very dangerous during WW2. Carriers have no standing power, in case of enemy advancing they could only strike & run - and running may actually block them from implementing aviation. So-called "deck aviation weather gauge".

But this is really one of those views that was overtaken by WW2 experience (and with scenarios made far less likely with the wide spread adoption of radar, catapults etc.).
Hence the extinction of battleships and the continuing evolution of aircraft carriers and their air wings.

The major naval powers planning and building battleships pre-war and early in the war (like Japan and the Yamato class) still made sense from decision makers perspectives when the relevant decisions were made.
But the decisive switch over of priority to aircraft carriers during the war is quite clear and the very late battleships like HMS Vanguard and Jean Beart completed post war were just a waste of resources that really should have been recognised as such at the time by decision makers. Arguably something similar is true of the Yamato’s; the resources involved would have clearly been better directed towards carriers and War experience has that comprehensively proven. But that clearness and clarity is a product of a perspective it’s not fair to demand or expect of the relevant Japanese decisions at the time.

 

[uk 75]

Battleships remained an important part of a naval task force

Battle of Leyte Gulf - Wikipedia

en.m.wikipedia.org

After World War 2 the arrival of jet aircraft on carriers armed with nuclear weapons is the decisive shift. Similarly submarines come into their own with nuclear power.
But until 1945 battleships do have a role.

 

[T. A. Gardner]

You don't just need carriers, you need pilots and planes. The problem(s) for the IJN were not just in carriers.

First, you need pilots. The IJN training cycle pre-war washed out something close to 50% of the candidates mostly for niggling reasons. That is, they didn't meet some exacting and overly high standard. So, you have a shortage of pilots.

Next, you need planes. The IJN going into the Pacific War, couldn't even ensure every squadron had the up-to-date aircraft in service. Many of the secondary and smaller carriers were still using A5M fighters and other obsolescent aircraft due to shortages in production.

Thus, more carriers don't help unless you also ensure more aircraft production and more pilots getting trained. It didn't help that the IJN also custom fit each air wing to its carrier meaning that transferring pilots between carriers was a difficult and convoluted process.

As for the USN, they still overwhelm the IJN by 1943 and completely dominate them by 1944. Japan simply cannot match the prodigious production America is capable of.

 

[T. A. Gardner]

Hiyo & Junyo were ordered as passenger liners, subsidised by the IJN as part of the shadow carrier plan in the same way as the eventual CVE conversions. Laid down March and November 1939, It was October 1940 when the IJN decided to convert them, a decision formalised in Feb 1941. Being so large they were occupying slips that were also required for carriers and battleships.

Openly building two more carriers in 1939 will cause a reaction in the USA.

Hiyo and Junyo were simply liner conversions. The USN had plans and even had a hand in designing the liners to be used, to convert up to a dozen such ships into carriers. The reason this wasn't done was by 1942 the USN realized that doing so was going to be as costly and less successful than just building from scratch.

Hiyo and Junyo were never really successful carriers for Japan, and that in a way confirms what the US conclusions about such conversions were.

 

[Dilandu]

But this is really one of those views that was overtaken by WW2 experience (and with scenarios made far less likely with the wide spread adoption of radar, catapults etc.).
Hence the extinction of battleships and the continuing evolution of aircraft carriers and their air wings.

To be exact, three factors brought the demise of battleships:

* Carrier aviation - which outranged them
* Guided missiles - which allowed much smaller ships (even MTB's) to carry a battleship-grade weaponry with much greater chances to hit
* Advances in weaponry (nukes, shaped charges) - which made armor protection useless

 

[kaiserd]

With respect battleships have a role up to the end of the war but essentially it is as cover against other battleships and bombardment duties, roles largely done as well or better (and a lot more efficiently at much further distance) by mid and late carrier air wings (with a lot of their other carrier supporting roles done as well by much cheaper cruisers).
While I may greatly admire an Iowa class battleships pound for pound such late war battleships were not as powerful or as useful as an Essex class carrier and it’s air wing.
And the evidence that the US and the UK largely recognised this reality can be seen by their cancelling of battleships constructions and prioritising of carriers instead (with the Vanguard being an exemption that proved the rule). The effective obsolescence of the battleship came before shaped charges, anti-ship missiles and nuclear weapons were particularly immediate factors (for example if my memory is correct there is approx. 5 years between the cancelling of the US of their last new build battleships and the US “loosing” their nuclear monopoly - late 1944 and late 1949 - a large amount of time in a period of rapidly advancing technology).
While I’m as much a fan of battleships as the next person I think some of the revisionist enthusiasm for them strays well beyond what was actually true and creates a false historical narrative around when, how and why they actually became obsolete.

 

[EwenS]

While the US may have cancelled the Montanas in 1943, it still had an interest in more Battleships right up to the end of the war and beyond. They recommenced work on Kentucky and Illinois, the 5th and 6th Iowas in late 1944/early 1945 having previously stopped it in 1942. Illinois wasn’t finally cancelled until 11 Aug 1945 when 22% complete. Kentucky was even further advanced. While work on her slowed after the end of WW2 it didn’t cease until at least late 1947 by which time she was 73% complete.

 

[T. A. Gardner]

The only reason Kentucky saw some continued work was the USN really didn't know where they would end up with the move to guided and ballistic missiles. Having a large hull for a potential missile ship was seen as having some value. Kentucky had no potential for completion as a gun armed battleship.

 

[muttly]

Dilandu's comment on the danger of using carriers without the battleships
would explain the U.S. building battleships that could keep up with the carriers.

 

[kaiserd]

There was a limited window were that was really true (i.e. between when the primary intended purpose of the fast US battleships was to chase down fast Japanese battleships like the rebuilt Kongo’s and when having built them the US used these fast battleships to escort carriers because apart from some limited advantages in that role there wasn’t really that much else for them to do).

The fact of how quickly battleships were dropped as carrier escorts post-war (seen as excessively resource intensive in that role versus cruisers) indicates the degree carriers actually needed battleship escorts at that stage (i.e they didn’t).
The fate of the Yamato and other battleships overwhelmed by the striking power of carrier air wings long before they got next to near the relevant launching carrier (or these carriers escorting fast battleships) shows where the balance of power and need now decidedly lay.

 

[EwenS]

Contrary to the popular view carriers did not spend much time operating above 25 knots in WW2.

The USN had standard procedures that meant the carrier groups would operate at speeds between 15 and 25 knots depending on what the tactical plan called for. If an individual carrier found it needed to operate its aircraft independently of the rest of the carriers in the TF, such that it required a speed faster than that of the TF itself or a different course, then procedures called for it to position itself as far downwind as possible, while remaining within the escort screen. It would then run into the wind, launch/recover what it needed, and then return to its previous position.

There were many reasons for the speed limitation other than that of usually, but not always, operating with 27 knot BB. These included:-

Minimising fuel burn, particularly important for the destroyer escorts.
WW2 ASDIC/sonar only operated effectively up to around 20 knots. It was only from 1944 that sets became available that could be used at faster speeds, but not all ships had them.
Speed did not guarantee safety. The IJN Taiho and Shokaku were both torpedoed at a speed estimated at 25-26 knots.