WI Japanese plans to build the Yamato class got leaked?

The USN may also choose to do nothing. Let the Japanese Navy exhaust themselves building huge ships that probably never get fully utilized. Perhaps the USN MIGHT reevaluate their torps and subs.
 
I think the whole idea behind the Yamato, was to have a Warship that the US couldn't build one of aa similar size, because it would be too big for the Panama Canal. Making sure that it would have smaller ships to engage - only problem for the IJN how to get a 'hit' with less guns, with a lower rate of fire than your opponent!?
 
I think the whole idea behind the Yamato, was to have a Warship that the US couldn't build one of aa similar size, because it would be too big for the Panama Canal. Making sure that it would have smaller ships to engage - only problem for the IJN how to get a 'hit' with less guns, with a lower rate of fire than your opponent!?
Not really. By 1937, it was pretty well known that the US was planning to build a new set of locks for the Canal that would have allowed bigger ships through. Like the Montana class.
 
Yep.. Although if the UK had reason to believe that at least some of the armour of the Yamato class might have been vulnerable to 14" shell fire that might have changed their priorities some what ?

That being said I suspect there would have been a lot of pressure within the UK to build a class of battle ships that was seen as a more effective counter to the Yamato class. This might have had some interesting ripple effects.
You don't bet on some of the armor being vulnerable to 14" shells.
 
Purple Cipher was already cracked.
The US were aware of the Yamato.
And they didn't really care because they knew that the IJN would never have enough fuel oil.
 
If nothing else I think it ensures that Britain completes Lion and Temeraire and that Vanguard is a Lion. Britain needs a counter to the Japanese ships and the Lion's are the best they can build fairly quickly.
Nah, I think the Lions get overtaken by events in European waters, just as OTL. There's simply a bigger, more urgent crisis much closer to home from June 1940.
 
I think the whole idea behind the Yamato, was to have a Warship that the US couldn't build one of aa similar size, because it would be too big for the Panama Canal. Making sure that it would have smaller ships to engage - only problem for the IJN how to get a 'hit' with less guns, with a lower rate of fire than your opponent!?
Well, it was to have a series of such 11 Warships (called the Peace Goddesses), the expectation was that the US/UK would between them build 30-40 new Battleships, and Japan could not match that in quantity, but instead to build ships to overmatch in quality. Yamato and the follow ons (5 Yamato's 2 A150, 4 post A-150), would be able to outmatch their opposite's one on one, after subs, land based air, carrier air and the nighttime torpedo action reduced enemy numbers to parity from slight superiority. They would then be able to do it again after minimal repairs when the US/UK went for round II with their Atlantic forces after the Pacific forces were defeated, and the US/UK would sue for peace

At the long range predicted effective rate of fire per gun was not really different, as you would wait until the shells landed to adjust your fire for the next salvo. Fewer guns does make a hit less likely via fewer shells, but each hit is more likely to penetrate and more likely to cause real damage if it does. They were planning on refitting the Yamato's with twin 51cm guns around '45 to outmatch US 18" designs they thought would arrive then to maintain larger size

Of course the Japanese did not figure on the US expanding Panama, and actually botched their estimates of what the US could fit through (Japanese estimate was a 63kton 23 knot ship with 10 18" guns, US estimate was 80kton 30 knot, 15 18" guns, but all designs would have lousy TDS as compromise to fit through canal), plus their QC issues and bad damage control would not help them
Purple Cipher was already cracked.
The US were aware of the Yamato.
And they didn't really care because they knew that the IJN would never have enough fuel oil.
They were aware that she existed, was 45,000 tons or larger and had guns 16" or bigger. They did not have exact details and until 1945 were describing them as 45,000 tons and 16" armed. Also they were not prepared to rely on the fuel oil thing
 
If this is 1937, the 12X16" Iowa, probably with better armor gets built, I would expect to see a far larger bomb for carrier bombers to penetrate that deck armor, and the Montana's, which probably have 18", and new Iowa's get priority over the Essex o_O for a little while until the potential of CV's is truly realized, then we spam carriers as OTL, but maybe a bit delayed
 

CalBear

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They find out about EVERYTHING(the guns, the armour, the size etc), except for the effectiveness of the Yamato class in practice.
In that case they stay with the 16"50 and superheavy AP round and build what they have. It will take several years to come up with a good 18" design, assuming one is to be had. The U.s. had looked at 18" guns several times and the strong belief was that the extra weight was not a useful trade off for a larger number of 16" guns (if one looks at the performance of the 16"/50 with the "super-heavy" AP round vs the 40cm/45 on the Yamato the difference at actual possible engagement ranges largely bears this out. It is of limited utility to have 43K yards of range if you can one engage at 34K.
 
If the USN knows the size and capabilities of the Yamatos will be in 1937....well let's just say the new set of locks that were to be built for the Panama canal get started 2 years earlier and thus are probably finished which eliminates the restrictions on USN capital ship design imposed by the original locks and the Iowas are going to be basically a 30 knot Montana design
 
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Problem is Yamato's plate is so @#$% inconsistent. You had one plate tested post war that was thickness for thickness the best the US had ever seen, right next to another at risk from being penetrated by 12" guns. Japanese QC had real issues

Super Heavy shells were already in the pipeline, and given desire for a somewhat balanced ship plus the realities of US obstructionist, 18" gun probably has to wait until BB-65 anyways
The United States would make its samples using American quality control, getting results better than the ones on the ships.
Considering Yamato's cost, might simply building more very fine ships--South Dakotas and Iowas--suffice? If, for each Yamato, there's three Iowas and a piar of Essex class carriers...
Japan was limited by what it could build--the USA prewar was limited by what it would build--and that can change in a heartbeat. The only reason that thre wasn't a three or four ocean navy bill is that there were only two oceans of importance.
A Panama Canal with wider locks will have butterfly effects worldwide...
 
The United States would make its samples using American quality control, getting results better than the ones on the ships.
Considering Yamato's cost, might simply building more very fine ships--South Dakotas and Iowas--suffice? If, for each Yamato, there's three Iowas and a piar of Essex class carriers...
Japan was limited by what it could build--the USA prewar was limited by what it would build--and that can change in a heartbeat. The only reason that thre wasn't a three or four ocean navy bill is that there were only two oceans of importance.
A Panama Canal with wider locks will have butterfly effects worldwide...
It would get more consistent samples, not neccesarily better better, fewer bad ones, but no "best plate thickness for thickness ever tested", as if they could they would have. Of course the US is just likely to test using their own armor, at what they assume is an equivalent thickness, adding or subtracting as needed

Building more ships would suffice, but the US wants quality as much as quantity, as in 1937 it does not know, war in late '41, end of the BB as a real warship rather than oversized monitor by '46. Yamato is going to set the bar, and the US will have to assume that everybody will be building ships that powerful, ergo they have to as soon as they can without disrupting the existing program
 
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Twin 18's can be a good option, especially if ships are designed carefully to allow the triple 16's to be replaced with twin 18's. Not "easily," as no job like that is easy, but have such things as the overhead rails for moving shells from turret to turret designed accordingly, shell loading hatches, and all the myriad little details set up.
 
What a 12 x 18 in. response might look like, courtesy of Ultimate Admiral: Dreadnoughts Alpha 3 (never mind the Spanish Flag - its 'merican):

USS Michigan.jpg


The smaller twins are a blast shield version of 3 in. .50 cal. The singles are a ATL super 50 mm Bofors. No aircraft, from lessons learned in Solomons with cruiser float planes and fires, and plentiful other air assets. Torps are standard U.S. 21 inch - negative comments on open deck mounts in 3, 2, 1, and go.

I'm inclined to start a thread for UAD in Chat:Non-Political, with all the naval expertise here that I trust, interested in opinions of this if there are any - in that thread mind.
 
The Americans let them and when the Japanese throw ten Yamato’s or successors at the DECISIVE BATTLE, theyre met by the aircraft of thirty to forty fleet carriers and the survivors sunk by gunfire from the American gunline.
 
The Americans let them and when the Japanese throw ten Yamato’s or successors at the DECISIVE BATTLE, theyre met by the aircraft of thirty to forty fleet carriers and the survivors sunk by gunfire from the American gunline.
Thirty to forty fleet carriers with nuclear bombers, even. The fifth Yamato wouldn't be done until at least 1947 and the successors even later.
 
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