Naval powers at the start of WW2

pikeshot1600

Ad Honoris
Jul 2009
10,084
Article about USN radio intelligence intercepts of IJN Fleet Exercises in the 1930s:

National Security Agency | Central Security Service > About Us > Cryptologic Heritage > Center for Cryptologic History > Pearl Harbor Review > Following the Fleets

There is a PDF, declassified NCA document 3362395, which goes into this in greater depth, but I couldn't make it copy and paste.
Intelligence and radio intercepts are not as sexy as propaganda films of battleships firing big guns and of airplanes (aeroplanes) taking off from carriers. However, such intelligence became something of a force multiplier during the years when navies were restricted by treaty in what ships and weapons they could add to their fleets.
 
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Jan 2019
21
Kent, England
In regard to posts #226 and 227, none of the European Treaty powers (Britain, France, Italy) really developed a "carrier doctrine."
Err...the British invented all the carrier doctrine used in WWII. From about 1931 onwards they carried out a series of exercises in massing carriers to launch combined strikes, and this was well ahead of either the USN or IJN. In terms of defensive doctrine the RN pioneered the idea of carrier groups relying on radar-directed fighters to intercept hostile aircraft during the Norwegian campaign of 1939-1940. The USN then copied these ideas.

Additionally, according to David Brown's book Carrier Fighters, the RN developed the idea of 'delousing' - using fighters to inspect returning aircraft to prevent enemy planes launching sneak-attacks - during Operation Pedestal, and again this was imitated by the USN to deal with kamikazes.
 
May 2013
117
there
Err...the British invented all the carrier doctrine used in WWII. From about 1931 onwards they carried out a series of exercises in massing carriers to launch combined strikes, and this was well ahead of either the USN or IJN. In terms of defensive doctrine the RN pioneered the idea of carrier groups relying on radar-directed fighters to intercept hostile aircraft during the Norwegian campaign of 1939-1940. The USN then copied these ideas.

Additionally, according to David Brown's book Carrier Fighters, the RN developed the idea of 'delousing' - using fighters to inspect returning aircraft to prevent enemy planes launching sneak-attacks - during Operation Pedestal, and again this was imitated by the USN to deal with kamikazes.
I've noticed over the years that the British have a tendancy to embelish an already great naval history. However the UK did not invent all carrier doctrine as you state. The USN first theorized about effectiness of multiple carriers in 1920 and was practicing in excercises by 1929 . The US also theorized early on that the best way to protect a carrier was with a large versitile air group that could gain air superiority, vastly different than the British approach . Also the use of a deck park and naval dive bombing are a couple others off the top of my head that the UK did not create.
 
Aug 2014
304
New York, USA
In addition, IJN and USN had different carrier doctrines to begin with (both developed in the 1920s), both in how airplane complements on carriers are used (IJN assigned their pilots to a specific carrier as a unit vs USN mixing planes between ships) to how the planes are supposed to be launched (USN emphasized the importance of first strike vs IJN that emphasized the importance of a cohesive strike), etc. Just looking at it at face value, the British certainly couldn't have practiced two completely different doctrines at the same time...
 
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pikeshot1600

Ad Honoris
Jul 2009
10,084
The Fourth Fleet Incident, which too place during the IJN 1935 Fleet Exercises:

Naval War in China
The issues of IJN ships in the mid 1930s were of course a combination of trying to "beat the Treaty," and also of attempting to cram more weaponry and other equipment onto some hulls that became top heavy. Trying to disguise a destroyer as a torpedo boat to circumvent limitations of the 1930 London treaty led to the mistake of the Chidori class torpedo boat, one of which (the Tomozuru) capsized while on exercise in heavy seas.

This was because of far too much top weight. These small 580 ton ships carried turrets with three 5" guns, and their bridge structure was too high. Of 20 ships planned, 16 were cancelled and 8 redesigned with smaller superstructures and lighter armament. These ships were not successful in their intended roles and all were relegated to escort duty.

The comments in the Fourth Fleet article, on electric welding of hull structure, show another attempt to save weight in order to over stuff ships with weaponry and equipment. The IJN was cutting corners that resulted in new ships that had great difficulty in withstanding the heavy seas of the northern Pacific. In the typhoon mentioned, structural damage - and structural failure - was widespread enough to cause the reconstruction of many existing ships and the redesign of others yet to join the fleet.

Electric welding at that time had its place in marine engineering - the use in turbines and other machinery - but it was still an undeveloped technology for naval architecture and construction. The hulls of warships must be constructed to serve in the sea conditions where they operate.
 
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Oct 2015
999
Virginia
There was also the instance of the Mogami class ships which were supposedly 8500 tons (the Royal Navy Director of Naval Construction said they were either made of cardboard or lying). During trials they were found to have stability problems, and had welded seams open up when the main armament was tested. The ships had to be returned to the shipyard for major reconstruction and emerged at over 13000 tons and an. 8" main armament.
 
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pikeshot1600

Ad Honoris
Jul 2009
10,084
There was also the instance of the Mogami class ships which were supposedly 8500 tons (the Royal Navy Director of Naval Construction said they were either made of cardboard or lying). During trials they were found to have stability problems, and had welded seams open up when the main armament was tested. The ships had to be returned to the shipyard for major reconstruction and emerged at over 13000 tons and an. 8" main armament.
IIRC this class was intended to be upgraded from 6.1" guns to 8" guns at some point. Being designed around 1930 it becomes pretty obvious that Japan was already planning to leave the treaty restrictions behind at the earliest opportunity.
 
Oct 2015
999
Virginia
That's right. The turret rings on the Mogami and Tone Classes were designed to be easily converted.