Rn vs IJN (1 Viewer)

Up until 1940 Japan had done a lot of work when it came to radar. The yagi antenna had been developed and was in use by Britain
as it's capabilities had been recognised.

By the late 1930's the first version of the Japanese built Cavity Magnetron was also working. In 1940 Britain also produced a
Cavity Magnetron which would allow high powered microwave radar to be developed.

For Japan, vital metals such as Nickel were in short supply as were the manufacturing techniques to make reliable components.

Another fork in the road was chasing the Tesla theory of using powerful microwaves to make a "death ray" which could bring
down aircraft. Work went ahead in that direction and was all destroyed just before the occupation of Japan.

The other flies in the ointment were the Bushido system and the army / navy rivalry.

Bushido put more emphasis on combat usefulness per person so technicians and developers of non combat items such as
radar were somewhat looked down on. By 1942 numbers of bright minds working on radar were ending up sitting on islands
with a rifle as that was deemed to be more useful.

As to the army and navy, both were developing their own versions of radar devices to the point where an army installation
would be built near a navy one for the same purpose. IFF development is another example as Navy IFF was different to
the army version and neither could identify the other so both arms could not recognise each others aircraft as friendly.
Somewhat bizarre all round in the end.

Japan ended up using the German VHF type plus copies of captured British and US types.

WARSPITER said:

As to the army and navy, both were developing their own versions of radar devices to the point where an army installation
would be built near a navy one for the same purpose. IFF development is another example as Navy IFF was different to
the army version and neither could identify the other so both arms could not recognise each others aircraft as friendly.

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While interservice rivalry and contesting for government funding/priorities are normal in most countries; are there other examples like Imperial Japan of a country's separate military wings demonstrating such wasteful duplication and incompatibility of effort and kit?

Would Imperial Japan have done better if the entire military was run as one organization? Sort of how today's PRC military is all People's Liberation Army, no matter if you're in the PLAAF, PLAGF, PLAN or PLARF. Japan's air force was run by the army. A single fighter aircraft, a combo of A6M and Ki-43, single twin engined bomber, combo G4M and Ki-49 might have offered benefits. Now there are deep cultural and historical barriers to making this so, but had it been done the benefits might have been notable.

Here in Canada in the late 1960s we unified all three services (Army, RCAF and RCN) into one CAF - which is more easily done when your entire organization (of today) has fewer full time personnel than seats in Wembley Stadium.

Shortround6 said:

I will note the disproportionate amount of damage the US "S" boats caused compared to the later boats and the Fleet boats, early in the war.
These used the old Mark 10 torpedoes of 1918. These were about 4ft shorter than the later Mark 14s.
By the mod 3 version they held about 497lbs of TNT and were good for 3500yds at 36 kts.

the story of the S-44 makes for interesting reading.
USS S-44 - Wikipedia

She sank 3 ships in her first 3 war patrols including the Kako returning from Salvo Island.
However the problems of operating submarines, especially old ones, are all too apparent.
The "S" boats with their old but mostly functional torpedoes in 1942 may have partially hidden how bad the Mark 14s really were.
17 S boats claimed 42 ships sunk with most of them in 1942.
There were 37 S boats out of the 112 US boats in service in Dec 1941, there were 27 older boats. Those were not used in the Pacific, most were used for training although a handful were loaned to the British and small group were used for anti-U boat work.

I think we are entitled to think about what 15-20 British subs with working torpedoes could do to Japanese invasion convoys. Not outright elimination but enough losses to slow down the ground advances. That and several divisions of well supplied, experienced troops and about 3 times the number of historical aircraft might turn the SE Asia campaign into slow motion attack that gives the British more time to reinforce and turn things into a battle of attrition.

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The 42 boats claimed by the old S class was pure fantasy. According to the Joint Army-Navy Assessment Committee post war analysis they sunk 10 ships in 1942, 4 in 1943 and 0 in 1944. The fact that they did as well was they did is a tribute to their crews.

Despite the fact that most of them didn't enter service until the second half of 1942 the most successful class were the Gatos. Using the data from JANAC I tally 57 ships sunk. The 12 Tamors/Gars which were the basis for the Gatos sank 41 while the 15 surviving Salmon/Sargos sank 39. The 10 problematic Porpoise class sunk 10 while 9 experimental so called V class sank 8.

I think defective torpedoes get more "credit" for USN failures in 1942 than is warranted. According to Clay Blair in his excellent book Silent Victory 1942 the USN submarines took an average of 8 torpedoes to sink a ship. This increased to 11.7 in 1943 and this fell to 10 in 1944. It seems that quite a few torpedoes did what they were supposed to do in 1942.

re success of the early-war USN submarines vs the mid- and late-war.

I do not know how much this skews the figures, but the 'S' class exclusively carried Mk 10 torpedoes (no magnetic influence exploder). Additionally, many of the inter-war and war-time built submarines carried the Mk 10 in the early-war due to a shortage of the Mk 14 torpedo (which had a magnetic influence exploder). It was the Mk 14 torpedo that earned a bad rep.

FWIW, when figured over the entire war, the RN fired an average of a bit over 7 torpedoes per ship sunk. The vast majority (98%+) of torpedoes fired by the RN subs were of the Mk VIII series (none of which had a magnetic influence exploder). None(?) of their war-time submarine torpedoes used a magnetic exploder.

Reluctant Poster said:

I think defective torpedoes get more "credit" for USN failures in 1942 than is warranted.

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My Uncle was a Torpedoman aboard subs during WWII (PTO) and had mentioned that they had many issues with their "fish" during the war.

One of the things he mentioned, was the torpedo not detonating (often denoted by a resounding "thud" as it struck the target's hull).

Another problem, was the occasional erratic torpedo, that would circle back. He mentioned that his boat was nearly lost to one, but the Skipper was able to crash-dive the boat fast enough to avoid being hit (they had good practice at crash-dives: B-17s attacked his boat at Midway without damage, but the B-17 crews claimed the "Cruiser" sank in 15 seconds!) however, USS Tang and USS Tullibee were not so fortunate.

There was also the problem of some torpedoes failing to run at their set depth, too.