Japanese CV Radar from Refits?

[PaxMondo]

In other words, with some German help and better direction from the higher levels of command these issues could have been resolved much sooner.

Yes, but the ARMY Junta was the government and the ARMY had little interest in the pursuit of radar technology. If you somehow address this issue, THEN yes, IJN could easily have moved forward with radar MUCH sooner than historical. I'm not sure they could have kept pace with the Brits, but they certainly could have done much better than they did.

With respect to the IJN radar procedures (turning off sets etc), there was some merit in this: the sets that they had historically were very leaky* due to poor components and design. I haven't found any specific test data, just comments from the techs about issues they had with assembly and testing. Again, these issues could have been addressed with focus.


*leaky meaning that they emitted stray frequencies in addition to those that they were supposed to. My interpretation is that these were likely harmonics not being properly filtered. Tokyo U has a stack of papers related to the magnetron invented by Kinjiro Okabe and the subsequent building and testing of various prototypes. They are NOT an easy read .... and no I have not been yet able to get through ALL of them ...

[tigercub]

Just info the Japanese were very interested in Radar the Japanese navy dove on the wreaks on POW and Repulse to retrieve Radar components.
Japan dispatched divers to the wrecks of HMS Prince of Wales and HMS Repulse in March 1942. The Operation: Shortly after the fall of Singapore in February 1942, the Imperial Japanese Army and Navy deployed the crane ship Seishu Maru carrying a team of seven divers to locate the two capital ships (which had been sunk on December 10, 1941). The Target: Japanese intelligence was keen to recover advanced British radar equipment—specifically targeting the radar fire-control sets (such as the Type 284) and surface search systems fitted aboard HMS Prince of Wales. The Result: The diving team located HMS Repulse in early March 1942, but diving on the wrecks proved largely unsuccessful due to depth, strong currents, poor visibility, and the fact that Prince of Wales had capsized and settled upside down in over 200 feet (68 meters) of water. Redirection: The recovery operation was quickly abandoned when the Imperial Japanese Army requisitioned the Seishu Maru and ordered it to Java, leaving the British radar sets mostly intact at the seabed. Japanese engineers ultimately derived much of their early technical insight into Allied radar from intact ground-based installations captured ashore in Singapore rather than from the sunken warships.

[Seacat54]

In other words, with some German help and better direction from the higher levels of command these issues could have been resolved much sooner.

Yes, but the ARMY Junta was the government and the ARMY had little interest in the pursuit of radar technology. If you somehow address this issue, THEN yes, IJN could easily have moved forward with radar MUCH sooner than historical. I'm not sure they could have kept pace with the Brits, but they certainly could have done much better than they did.

With respect to the IJN radar procedures (turning off sets etc), there was some merit in this: the sets that they had historically were very leaky* due to poor components and design. I haven't found any specific test data, just comments from the techs about issues they had with assembly and testing. Again, these issues could have been addressed with focus.


*leaky meaning that they emitted stray frequencies in addition to those that they were supposed to. My interpretation is that these were likely harmonics not being properly filtered. Tokyo U has a stack of papers related to the magnetron invented by Kinjiro Okabe and the subsequent building and testing of various prototypes. They are NOT an easy read .... and no I have not been yet able to get through ALL of them ...

The Army did have primitive radar coverage on the Home Islands and China 1941 before the start of the wider conflict, naturally those installations failed to detect the Doolittle Raid but that is another matter.

Air Cooled magnetron for 20 & 40 cm waves: Better results expected from a 6 split anode magnetron
compared to a 2 or 4 split anode. Masatsugu Kobayashi was at NEC in 1938 when research engineers
noticed during testing of a high frequency transmitter that rapid fading of the signal occurred whenever
an aircraft flew over the line between the transmitter & receiving meter. Kobayashi recognised this as
the beat-frequency interference of the direct signal & the Doppler-shifted signal reflected from the
aircraft. He suggested to the Army that this phenomenon could be used as an aircraft warning method.
In early 1941 a Doppler Interference Detector was put in operation between 4.0-7.5 Mhz involving a
number of widely spaced stations & could detect planes at up to distances of 500 km in the China
region.

https://phwl.org/assets/images/2021/11/ ... 20SWPA.pdf

[Seacat54]

yep saw several of the articles on poor performance/uptime.

The standard game scenario and from what i can read historical refits of the Shokaku class were the first CVs to get radar installed during the mid 1942 refit---which the game accurately represents.

As well 2x BBs were given the experimental radar in early 1942 thus my reason to say they should be added to the radar list for 1942 upgrades.

So im not sure why Japanese radar on key capital ships should be none until 1943 as the key capital ships were already getting it historically from about april 1942 onwards.

The Kaga and Akagi historically were delayed the mid 1942 refit due to preparations and then the launch of midway operations during which they sunk.....so just based on the evidence available i would reason they would have been next in line for radar after the Shokaku class. Even given limited radar availability/resources the 1 month delay between each upgrade timeline should make up available the next limited set of radars.

Radar for sure would have continued to roll out to the fleet carriers had they not virtually all been sunk at midway is I think very obvious.

Now effectiveness of the radar should be shown in the game values of the radar/range and pretty sure all the radars in game have an effectiveness number which i would think the japanese radar is lower but i havent messed with or looked into it much.

The build queue,upgrades and conversions are mostly based on the historical reactions and decisions post Doolittle Raid and Midway.

The main reason the other carriers did not have radar was the operational tempo, no time, the same reason the Shokakus went to the yard and got theirs.

[Diliwitm]

That is why there is no sense that a subchaser gets an anti surface radar in 8/43 and some hvy cruisers only in 1944 and some light cruisers do not get them at all.
The idea of what is historical and should be in game and what is historical and should not be, have been ill decided in ship radars.

[Seacat54]

That is why there is no sense that a subchaser gets an anti surface radar in 8/43 and some hvy cruisers only in 1944 and some light cruisers do not get them at all.
The idea of what is historical and should be in game and what is historical and should not be, have been ill decided in ship radars.

That is why we have mods that address these issues.

[PaxMondo]

In other words, with some German help and better direction from the higher levels of command these issues could have been resolved much sooner.

Yes, but the ARMY Junta was the government and the ARMY had little interest in the pursuit of radar technology. If you somehow address this issue, THEN yes, IJN could easily have moved forward with radar MUCH sooner than historical. I'm not sure they could have kept pace with the Brits, but they certainly could have done much better than they did.

With respect to the IJN radar procedures (turning off sets etc), there was some merit in this: the sets that they had historically were very leaky* due to poor components and design. I haven't found any specific test data, just comments from the techs about issues they had with assembly and testing. Again, these issues could have been addressed with focus.


*leaky meaning that they emitted stray frequencies in addition to those that they were supposed to. My interpretation is that these were likely harmonics not being properly filtered. Tokyo U has a stack of papers related to the magnetron invented by Kinjiro Okabe and the subsequent building and testing of various prototypes. They are NOT an easy read .... and no I have not been yet able to get through ALL of them ...

The Army did have primitive radar coverage on the Home Islands and China 1941 before the start of the wider conflict, naturally those installations failed to detect the Doolittle Raid but that is another matter.

Air Cooled magnetron for 20 & 40 cm waves: Better results expected from a 6 split anode magnetron
compared to a 2 or 4 split anode. Masatsugu Kobayashi was at NEC in 1938 when research engineers
noticed during testing of a high frequency transmitter that rapid fading of the signal occurred whenever
an aircraft flew over the line between the transmitter & receiving meter. Kobayashi recognised this as
the beat-frequency interference of the direct signal & the Doppler-shifted signal reflected from the
aircraft. He suggested to the Army that this phenomenon could be used as an aircraft warning method.
In early 1941 a Doppler Interference Detector was put in operation between 4.0-7.5 Mhz involving a
number of widely spaced stations & could detect planes at up to distances of 500 km in the China
region.

https://phwl.org/assets/images/2021/11/ ... 20SWPA.pdf

Yes, a couple, but pre-war the Army was far from committed to the concept ....

[PaxMondo]

In other words, with some German help and better direction from the higher levels of command these issues could have been resolved much sooner.

Yes, but the ARMY Junta was the government and the ARMY had little interest in the pursuit of radar technology. If you somehow address this issue, THEN yes, IJN could easily have moved forward with radar MUCH sooner than historical. I'm not sure they could have kept pace with the Brits, but they certainly could have done much better than they did.

With respect to the IJN radar procedures (turning off sets etc), there was some merit in this: the sets that they had historically were very leaky* due to poor components and design. I haven't found any specific test data, just comments from the techs about issues they had with assembly and testing. Again, these issues could have been addressed with focus.


*leaky meaning that they emitted stray frequencies in addition to those that they were supposed to. My interpretation is that these were likely harmonics not being properly filtered. Tokyo U has a stack of papers related to the magnetron invented by Kinjiro Okabe and the subsequent building and testing of various prototypes. They are NOT an easy read .... and no I have not been yet able to get through ALL of them ...

The Army did have primitive radar coverage on the Home Islands and China 1941 before the start of the wider conflict, naturally those installations failed to detect the Doolittle Raid but that is another matter.

Air Cooled magnetron for 20 & 40 cm waves: Better results expected from a 6 split anode magnetron
compared to a 2 or 4 split anode. Masatsugu Kobayashi was at NEC in 1938 when research engineers
noticed during testing of a high frequency transmitter that rapid fading of the signal occurred whenever
an aircraft flew over the line between the transmitter & receiving meter. Kobayashi recognised this as
the beat-frequency interference of the direct signal & the Doppler-shifted signal reflected from the
aircraft. He suggested to the Army that this phenomenon could be used as an aircraft warning method.
In early 1941 a Doppler Interference Detector was put in operation between 4.0-7.5 Mhz involving a
number of widely spaced stations & could detect planes at up to distances of 500 km in the China
region.

https://phwl.org/assets/images/2021/11/ ... 20SWPA.pdf

Yes, a couple, but pre-war the Army was far from committed to the concept ....

[PaxMondo]

In other words, with some German help and better direction from the higher levels of command these issues could have been resolved much sooner.

Yes, although the biggest issue in my mind was that the Military Junta in control (Army based) did not believe radar was necessary.

This is the same group that also directed aircraft design to be focused on maneuver instead of speed, 7.7mm guns instead of heavier calibers and/or cannons, and finally refused to put the country on a war economy until 1943 ...

The observation about the poor quality of Japanese vacuum tubes by war end is accurate, but a lot of that was simply due to lack of materials by then. In the early war, their tubes were on par with everyone else.

The observation about the IJ Universities is also a testament to the Junta, they controlled and limited the university syllabuses.

The observation about the IJN not being able to recruit candidates before the war is also correct and again very much due to Army being in control; smart kids went where the power, money, and probable promotions were.

There is a common theme here ...

[Seacat54]

In other words, with some German help and better direction from the higher levels of command these issues could have been resolved much sooner.

Yes, although the biggest issue in my mind was that the Military Junta in control (Army based) did not believe radar was necessary.

This is the same group that also directed aircraft design to be focused on maneuver instead of speed, 7.7mm guns instead of heavier calibers and/or cannons, and finally refused to put the country on a war economy until 1943 ...

The observation about the poor quality of Japanese vacuum tubes by war end is accurate, but a lot of that was simply due to lack of materials by then. In the early war, their tubes were on par with everyone else.

The observation about the IJ Universities is also a testament to the Junta, they controlled and limited the university syllabuses.

The observation about the IJN not being able to recruit candidates before the war is also correct and again very much due to Army being in control; smart kids went where the power, money, and probable promotions were.

There is a common theme here ...

Hardly a monolithic organisation when Ki-44 requirements for speed + climb = Energy where given in 1939?

Their politics and internal ideological factions where just different degrees of crazy but they had also capable thinkers and planners.

[Seacat54]

Yes, but the ARMY Junta was the government and the ARMY had little interest in the pursuit of radar technology. If you somehow address this issue, THEN yes, IJN could easily have moved forward with radar MUCH sooner than historical. I'm not sure they could have kept pace with the Brits, but they certainly could have done much better than they did.

With respect to the IJN radar procedures (turning off sets etc), there was some merit in this: the sets that they had historically were very leaky* due to poor components and design. I haven't found any specific test data, just comments from the techs about issues they had with assembly and testing. Again, these issues could have been addressed with focus.


*leaky meaning that they emitted stray frequencies in addition to those that they were supposed to. My interpretation is that these were likely harmonics not being properly filtered. Tokyo U has a stack of papers related to the magnetron invented by Kinjiro Okabe and the subsequent building and testing of various prototypes. They are NOT an easy read .... and no I have not been yet able to get through ALL of them ...

The Army did have primitive radar coverage on the Home Islands and China 1941 before the start of the wider conflict, naturally those installations failed to detect the Doolittle Raid but that is another matter.

Air Cooled magnetron for 20 & 40 cm waves: Better results expected from a 6 split anode magnetron
compared to a 2 or 4 split anode. Masatsugu Kobayashi was at NEC in 1938 when research engineers
noticed during testing of a high frequency transmitter that rapid fading of the signal occurred whenever
an aircraft flew over the line between the transmitter & receiving meter. Kobayashi recognised this as
the beat-frequency interference of the direct signal & the Doppler-shifted signal reflected from the
aircraft. He suggested to the Army that this phenomenon could be used as an aircraft warning method.
In early 1941 a Doppler Interference Detector was put in operation between 4.0-7.5 Mhz involving a
number of widely spaced stations & could detect planes at up to distances of 500 km in the China
region.

https://phwl.org/assets/images/2021/11/ ... 20SWPA.pdf

Yes, a couple, but pre-war the Army was far from committed to the concept ....

Short Survey of Japanese Radar

https://analysis.williamdoneil.com/Hist ... kinson.pdf

[PaxMondo]

Hardly a monolithic organisation when Ki-44 requirements for speed + climb = Energy where given in 1939?

Their politics and internal ideological factions where just different degrees of crazy but they had also capable thinkers and planners.

360mph and 3000fpm were hardly defining in 1939. The Tojo was ok through '42 in the Pacific as long as it didn't encounter any of the few Spit V's that were around. In Europe, it was obsolete when introduced. It did well only because the allies did NOT send many of their best aircraft to Asia until '45.

The K-44 was intended as an interceptor, and the Army had a hard time admitting that they needed one. Production was heavily skewed to the Oscar, which was an "offensive" fighter with range, but lacked both speed and firepower.

The IJN got their A6M which was a far superior fighter compared to the Oscar, but they couldn't get their A7M until the war end because it lacked an engine. (The first test flight was actually in '42). For whatever reason, and I have read several and was told others, they could not get a stable multi-stage engine to work reliably. Multi-speed super charger? No problem. Multi-stage (like a twin charger)? Nope. Nada. Nothing. Not until it was too late. This was in spite of the fact that all of the other world powers had this figured out, even the Italians, in the late 30's and were in production in the very early 40's. The devs gave a HUGE easter egg to the IJ players with the Helen; IRL the plane never left the hangar because it used a twin-charged Ha-34 engine. Engine lifetimes were measured in minutes and very rarely ever got to triple digits. Hence the Sally was produced the entire war and was the IJA bomber for most of it until the Ki-67 arrived.

[Sardaukar]

We have to remember, that Japan had started to industrialize only 50 years before WW II started.

So, while often brilliant, their science & engineering lacked massive manpower.

[PaxMondo]

We have to remember, that Japan had started to industrialize only 50 years before WW II started.

So, while often brilliant, their science & engineering lacked massive manpower.

This is accurate, but not completely true. Japan had the world's highest literacy rate in 1938. Education was emphasized by both the government and the family. On a per capita basis, yes they trailed the US in industrialization (1939 numbers), but not by as much as is often thought in these forums.

Their real issue was much more obvious: they had only about 1/3 the population of the US, so even if they had been on par with the US, their economy would still have been only 1/3 the size. It was actually a bit under 1/3, but saying that should make you pause. Why would you pick on someone who is 3x bigger?

Then we have the next big ooops. The US went onto a war economy Dec 8, 1941 ... the IJ didn't do that until Q2 1943 ... over a year later. So while the US economy essentially doubled every 9 months or so, the IJ economy grew at a 5% - 8% rate ... by mid-43 the US economy was basically 10x the size of the IJ economy ... could the IJ have matched the US growth? Who knows, academic argument for sure, but they certainly could have kept the 10x disadvantage lower.

Compare this to Europe where Germany went on a war economy sometime in the mid-30's ... by 1939 their economy had recovered from WWI to the point where it was the largest in Europe ... IJ did not do this ...

Anyway, a lot of this is behind the drive of my mod that I may restart again sometime and delve into all of these little economic woes ...

[Seacat54]

We have to remember, that Japan had started to industrialize only 50 years before WW II started.

So, while often brilliant, their science & engineering lacked massive manpower.

This is accurate, but not completely true. Japan had the world's highest literacy rate in 1938. Education was emphasized by both the government and the family. On a per capita basis, yes they trailed the US in industrialization (1939 numbers), but not by as much as is often thought in these forums.

Their real issue was much more obvious: they had only about 1/3 the population of the US, so even if they had been on par with the US, their economy would still have been only 1/3 the size. It was actually a bit under 1/3, but saying that should make you pause. Why would you pick on someone who is 3x bigger?

Then we have the next big ooops. The US went onto a war economy Dec 8, 1941 ... the IJ didn't do that until Q2 1943 ... over a year later. So while the US economy essentially doubled every 9 months or so, the IJ economy grew at a 5% - 8% rate ... by mid-43 the US economy was basically 10x the size of the IJ economy ... could the IJ have matched the US growth? Who knows, academic argument for sure, but they certainly could have kept the 10x disadvantage lower.

Compare this to Europe where Germany went on a war economy sometime in the mid-30's ... by 1939 their economy had recovered from WWI to the point where it was the largest in Europe ... IJ did not do this ...

Anyway, a lot of this is behind the drive of my mod that I may restart again sometime and delve into all of these little economic woes ...

Germany went on full war economy starting from 42-43, arms production breaking over 20% of the GDP for the first time and part of this is occupied Czech industry.


Two Ocean Navy Act in 1940 for the rest of the world would look like war economy, for USA economy it was possible in peace time.

[chaos45]

when speaking of economy---all the main Axis powers had the same critical weakness when it comes to the modern/mechanized/air war that WW2 was going to be- a lack of easily accessible oil that was near infinite for the purposes of waging war.

The USA alone could effectively power the entire allied war effort in oil supplies and US oil production wouldnt start to drop off until awhile after the war.

That economically speaking is the massive reason the allies outproduced and gained overwhelming force vs the Axis powers.

Even other raw materials were issue for the Axis powers both Germany and Japan struggled with steel production and required large amount of imports that became increasingly difficult as the war went on.....The allied war effort was just massive in comparison esp with the amount of the globe the allies had to effectively supply its war needs. Germany effectively had no sea power most of the war meaning allied naval dominance could with some effort supply all its war needs via imports from basically anywhere in the world.

The amount of just stuff the USA built alone dwarfed the entire Axis powers war effort. Other allied powers were extra added on top. Even Germany couldn't compete really when u look at the numbers.

[RangerJoe]

when speaking of economy---all the main Axis powers had the same critical weakness when it comes to the modern/mechanized/air war that WW2 was going to be- a lack of easily accessible oil that was near infinite for the purposes of waging war.

The USA alone could effectively power the entire allied war effort in oil supplies and US oil production wouldnt start to drop off until awhile after the war.

That economically speaking is the massive reason the allies outproduced and gained overwhelming force vs the Axis powers.

Even other raw materials were issue for the Axis powers both Germany and Japan struggled with steel production and required large amount of imports that became increasingly difficult as the war went on.....The allied war effort was just massive in comparison esp with the amount of the globe the allies had to effectively supply its war needs. Germany effectively had no sea power most of the war meaning allied naval dominance could with some effort supply all its war needs via imports from basically anywhere in the world.

The amount of just stuff the USA built alone dwarfed the entire Axis powers war effort. Other allied powers were extra added on top. Even Germany couldn't compete really when u look at the numbers.

I believe that one state in the USA shipped out enough ore to make 20% of the entire world's steel production in 1942. It mined about 10 million tons less so there was a rather large stockpile and to be sent to the mills. There were also other states mining iron ore as well.

[Seacat54]

when speaking of economy---all the main Axis powers had the same critical weakness when it comes to the modern/mechanized/air war that WW2 was going to be- a lack of easily accessible oil that was near infinite for the purposes of waging war.

The USA alone could effectively power the entire allied war effort in oil supplies and US oil production wouldnt start to drop off until awhile after the war.

That economically speaking is the massive reason the allies outproduced and gained overwhelming force vs the Axis powers.

Even other raw materials were issue for the Axis powers both Germany and Japan struggled with steel production and required large amount of imports that became increasingly difficult as the war went on.....The allied war effort was just massive in comparison esp with the amount of the globe the allies had to effectively supply its war needs. Germany effectively had no sea power most of the war meaning allied naval dominance could with some effort supply all its war needs via imports from basically anywhere in the world.

The amount of just stuff the USA built alone dwarfed the entire Axis powers war effort. Other allied powers were extra added on top. Even Germany couldn't compete really when u look at the numbers.

Bingo! But this battle for access to oil started already with the World War I and culminated in World War II.

And it seems to be the same as we are going towards the third but let not go current here.

[PaxMondo]

Germany went on full war economy starting from 42-43, arms production breaking over 20% of the GDP for the first time and part of this is occupied Czech industry.


Two Ocean Navy Act in 1940 for the rest of the world would look like war economy, for USA economy it was possible in peace time.

So, not the generally accepted definition of a "war economy". % of GDP going to arms is only one aspect, and the 2 Ocean Act was done on a peacetime economy.

My AI results are (not perfect, but not terrible either) as follows covering the 5 major aspects of a War Economy*:

Code: Select all

Key Characteristics

• State Intervention and Control: Governments take a much more centralized role, guiding or directly managing industries, supply chains, and labor forces to ensure quotas are met.
• The "Guns Versus Butter" Trade-off: Nations shift factories away from making consumer and luxury goods ("butter") and convert them into manufacturing weapons, ammunition, vehicles, and military technology ("guns").
• Rationing and Price Controls: To prevent shortages of vital goods, governments often ration food, fuel, and raw materials (such as rubber, oil, and metals) for the general public.
• Financing the War: Governments fund military operations by raising civilian taxes, selling war bonds, borrowing heavily, or expanding the money supply—which often carries a high risk of inflation.
• Workforce Shifts: As large portions of the population are conscripted or volunteer for military service, civilian labor shortages emerge, frequently leading to major shifts in workforce demographics (such as increased employment of women in heavy industry).

Germany went into a war economy when Hitler was elected. By 1939 they were something like 40 Billion Marks in debt. US started Dec 8 when Roosevelt declared war and enacted the War Powers act. In both cases it wasn't (initially) about % of GDP making arms, but rather the Government intervention into the economy with respect to controls, finance (borrowing), and rationing. The next steps were the Guns v Butter and the Workforce Shifts, in the US that starts to happen in late '42 ... it took almost a year for the tooling and factory expansions to happen to then need all the workers. Then in '43 is when the women started to replace men in the factories as the 3rd shift was added and the men were called up for service ....

*Wikipedia has a decent writeup on what a "War Economy" is as well. Rand has a really good write-up in a modern context located here:
https://www.rand.org/content/dam/rand/p ... nglish.pdf