Naval Ships and Technologies without the Arms Treaties

[Just a Rube]

I think the whole fortification issue is probably the most major change than a no WNT world would see - can you imagine a Pacific war where every island is a fortress?



Well, the effects of American policy basically destroyed the credibility of the existing government policy. With a hostile US (and consequently hostile Britain) and world trade being balkanized and fractured, the plan of becoming an eastern Britain looked plainly silly. So yes, there were serious problems in Japan, but they were the same serious problems that plagued most of the world - i.e. that the great depression had left the government looking completely out of touch. So the irrationality of the Japanese army and navy is much the same as the irrationality of the German electorate when lots of people were saying this Hitler guy was saying some smart stuff. It was irrational because according to the information people had at the time, crazy looked like good policy (or at least better policy than the idiots who were already running the country). So, change the information available, and you change what the army and the navy do. Maybe not enough to change Japanese policy very much, but Japanese policy changes should not, in my view, simply be dismissed because "they were irrational".

fasquardon

Sure, didn't mean to imply that Japanese people are uniquely insane, but I did want to argue that the Japanese political system (both formal and informal), as it existed in the 1930s and '40s, is designed in such a way as to encourage certain policies. I expect that many of the OTL fault lines will emerge anyway, treaty or no treaty.

Sure, the specific policies that take place may change, but Japan isn't going to be content to play second fiddle to anyone, and is going to want a piece of the pie. The Navy and Army in Japan had a great deal of political leverage (both legal and illegal) and sufficient autonomy to lobby for their own policies. And the IJN not only will insist on Japan building an enormous navy (for the same reason that e.g. the USN of today keeps building more aircraft carriers despite the fact that we already have vastly more and better than anyone else), but has the means to enforce their will. So we can expect that Japan will continue trying to push the envelope in its naval buildup, despite the economic challenges they face. How well they succeed is a different matter, but we can expect them to try.

 

[fasquardon]

The other possible result of Japan seeing that the US can easily out-build them is for them to go to war earlier. Say in the 1920s.

On the bright side, this does mean that the USN won't have radar... On the less bright side, the Japanese wouldn't have the carriers that gave them their 1940s naval victories...

fasquardon

 

[Delta Force]

The other possible result of Japan seeing that the US can easily out-build them is for them to go to war earlier. Say in the 1920s.

On the bright side, this does mean that the USN won't have radar... On the less bright side, the Japanese wouldn't have the carriers that gave them their 1940s naval victories...

fasquardon

The IJN also won't have the Long Lance torpedo, which could be a good or bad thing for them. Good in that Long Lance torpedo explosions resulted in several cruisers being severely damaged or lost. Bad in that they won't have that torpedo, and torpedoes would play a major role in any naval conflict well into the 1930s.

Also, I think the IJN would actually have a gunnery advantage early on. Japanese optics were considered better than those produced in the United States, and many USN ships used Japanese optics at the start of World War II.

 

[Riain]

There is actually no comparison between even the 13.5" Queen Mary and 14" KGV gun. The 14" gun has 25% more armor penetration at 10,000 yards, and 90% of the 13.5" gun's 10,000 yard penetration at 20K. Interesting, the 15"/42 on the Queen Elizabeth/Hood had only a 5.7% advantage over the later 14"/45 at 10K and virtually identical side armor performance at 20k and even deck penetration difference is less dramatic than might be expected.

The 16/45 on the Nelson class is also surprising close to the 14/45 at practical combat ranges, although deck penetration is considerably better it would not be sufficient to handle the deck armor of later super drednought designs at anything under 30K.

Where you see dramatic differences is when you compare the USN 16/45 or 16/50 using the 2,700 pound super heavy AP shell, with the 16/50 having better side armor penetration at 35k than the RN guns at 20K and 75% greater (20.04" v. 12") at 20k.

Modern guns perform better than older guns. Bigger modern guns literally blow older guns out of the water.

Do your figures for the British guns include the later 15" 1938lb shells with 'supercharge' that the Vanguard used, and the later 2375lb 16" shells that the Nelsons used?

 

[CalBear]

Do your figures for the British guns include the later 15" 1938lb shells with 'supercharge' that the Vanguard used, and the later 2375lb 16" shells that the Nelsons used?

The data on the Nelson is from Navweaps are refer to the 2,038 pound AP shell. Vanguard used the same 15"/42 that was used on the Queen Elizabeth class and the data used, again from Navweaps is for the 1,938 pound shell at 2,400 FPS velocity.

 

[Riain]

The data on the Nelson is from Navweaps are refer to the 2,038 pound AP shell. Vanguard used the same 15"/42 that was used on the Queen Elizabeth class and the data used, again from Navweaps is for the 1,938 pound shell at 2,400 FPS velocity.

During WW2 supercharges increased the muzzle velocity from 2400fps to 2600fps, giving the 1938lb round an extra 4km range at 30 degrees elevation. I'd imagine this would improve the 15" guns stats.

Similarly the 2375lb shells in the Nelsons would improve the 16" guns stats.

 

[jsb]

The other possible result of Japan seeing that the US can easily out-build them is for them to go to war earlier. Say in the 1920s.

When will the Japanese realise they are being easily out built ? I don't think that it will be obvious till its to late, I think that the IJN will plan ships (8-8 plan) to keep 60-70% ratio and will think its tight but ok until the great Kanto earthquake hits and they run out of cash. At that point they will rapidly be overwhelmed by US ships within a couple of years.
They will not go to war as,
1) they will not be ready immediately.(but they will see lots of US ships laid down that they will be finished soon so would need to go to war immediately )
2) they are not into china yet so not already in a war mentality.
3)No US sanctions etc so they can survive by just accepting a smaller ship ratio.(it will be easy to say IJN is better than USN divine Yamato spirit etc so 50% is ok, then 49% is still ok, as its only 1% etc )
4) 1920 Japanese government is still mainly run by the genrō + civilians who are at least a bit more sane and competent than the 1940's lot !
5) War in 1920's is JAPAN v USA + GB + FR + anybody else who wants to jump on the wining band wagon, China, USSR ?

JSB

 

[Tentrees]

What is Springsharp?

 

[Delta Force]

What is Springsharp?

Springsharp is a free program you can use to simulate ships between 1850 and 1950.

 

[edgeworthy]

I think the jump to 16 inch guns for the Nelsons was inspired by the fact that everyone else was doing it. The RN designed the guns and turrets initially for the G3s but when they were canned they put them on the Nelsons all be it with the turrets altered to be lighter. The RN kind of went crazy trying to ensure the Nelsons were treaty compliant whilst Japan and America both cheated to some degree.

The result was that the new turrets were quite unreliable when introduced (them being the RNs first foray into tripple turret designs) and the sheer number of safety features to prevent turret flashes reaching magazines were far cry from the more simple designs of WW1 vessels.
The big thing was that the RN went and copied what the Germans did in WW1, trying a lighter shell than everyone elses 16 inch designs to increase muzzle velocity for greater armour penetration. The 16 inch of the Nelson could have fired a heavier, lower velocity shell which probably would have been more effective and its probably what the G3 would have fired. But the Nelsons in a search for higher muzzle velocity AND to save weight had a lighter shell which was not that great a performer.

I think this might help
http://www.navweaps.com/index_tech/tech-059.htm