Japanese Radar in WWII

[YLi]

What if the Japanese had better electronics in the Second World War, on par with American electronics?

How much longer would the war have gone on for if that was the case? I'm not saying that the Japanese will win, but it would certainly extend the war by some time.

 

[BlackWave]

Midway would certainly pan out differently, causing all sorts of butterflies. American bombing runs on the mainland would be less effective, but I'm sure it'd only be extended by a matter of months.

 

[Riain]

Radar and the Long Lance would be an awesome combination, I'd suggest even more early IJN victories in night surface fighting and perhaps a different result in the Phillipines in 1944.

 

[e of pi]

Japan's major issue in WWII was that they picked a fight (perhaps, as they thought, a fight that was in the end inevitable, but they shot first none the less) with an enemy that had a greater industrial capacity and a larger population. Simply, Japan needed to not just be on par with the Americans in technology and strategy and logistics, they needed to be better if they hoped to outwiegh the sheer quantity the US could bring to bear once it got up to speed. This POD would be a step in the right direction, but I don't know that it could have proved an effective enough force multiplier to cut the difference. However, I'm not really an expert in this area, so I defer my final opinion until somebody like pacifichistorian or CalBear wieghs in.

 

[Riain]

I think many of the assumption the Japanese made were quite reasonable in their circumstances. Years of diplomatic confrontation had led to the US cutting off Japan's lifeblood, so Japan had to act somehow. Their first move was very successful, the cut the USN down to a more manageable size and secured their territorial goals. It was the second phase of their plan which fell apart, when they failed to defeat the remainder of the USn in battle and secure their next lot of territorial objectives.

Could radar have allowed the IJN to locate and sink Sommerville's FEF?
Could radar have allowed the IJN to win Coral Sea and capture Port Moresby by sea?
Could radar have allowed the IJN to win at Midway?
Could radar have allowed the IJN to win in and around Guadalcanal, Santa Cruz and Espiritu Santu?

What would the US have done if by August 1942 the USN was a husk of its former self and with no prospect of a revival for a full year, and the Japanese holding everything they wanted?

 

[The Red]

What would the US have done if by August 1942 the USN was a husk of its former self and with no prospect of a revival for a full year, and the Japanese holding everything they wanted?

Built ten more fleets if they fancied it.FDR wouldnt even comprehend peace talks,Japans defeat is an eventuality all there needs to be is one slip up in OTL it was Midway.

 

[Riain]

I don't doubt the US has the means and the will to outmatch Japan, but I do wonder about the practicalities of fighting a sea war without a fleet for over a year.

 

[The Red]

I don't doubt the US has the means and the will to outmatch Japan, but I do wonder about the practicalities of fighting a sea war without a fleet for over a year.

Radar doesnt destroy fleets,the US had it but it still took them 3 years to properly annihilate the Japanese one.Its only a matter of time,even if they wait for a year it doesnt matter.Japan cant move anywhere theyve been stopped in Burma,trapped in a stalemate in China and cannot conceivably invade the US.The only thing they could do was maybe try an invasion of Australia or maybe Hawaii both of which would be utter disasters

 

[e of pi]

I don't doubt the US has the means and the will to outmatch Japan, but I do wonder about the practicalities of fighting a sea war without a fleet for over a year.

Even if the Japanese managed to wipe out every American fleet carrier, battleship, cruiser, destroyer, light carrier, escort carrier, and everything else afloat in the Pacific, which is unlikely in even the most offsided battle, all America has to do is play for time to keep the Japanese off balance through subs attacks and flying boats raids. Heck, they could let the Brits take up slack in the Atlantic and pull a few more decks from there to help with this stalling.

Given that there's almost certainly still some fleet (even a small one), American resolve is enough to make do with stalling until we can hit them like they hit us at Pearl. As long as carriers are taking shape on slipways and pilots are being trained and planes are rolling off assembly lines, the guys on the front have all the reason they need to make the effort required to hold the lines. And when that material arrives....there's going to be hell to pay. Radar or no radar, equal tech only wins fights if fielded in equal numbers.

 

[CalBear]

Absolute worst case: The U.S. doesn't get the Philippines back before the end of the war.

By the 10th of August 1945 Japan is being starved and burned to the ground, has eaten two nuclear weapons.

Let's say that Japan wipes out the USN at Midway (something we have discussed in the forum in the past) thanks to Radar (BTW: this would not have had this result, nevertheless...) and then, even more unlikely, manages to take the Island with the woefully undersized and ill prepared force it was sending. What has Japan gained? A REALLY good place for the USN to whittle the IJN down in a war of attrition by air and submarine attack, more or less Guadalcanal in better surroundings and with a better tactical position for the U.S.

IOTL there was a serious pause in fleet operations outside of the Solomons for nearly a full year while both sides tried to reconstitute forces. Much the same happens here except the Japanese now have to fight nearly constantly to defend Midway. At the end of 1943 what happens? The USN, rebuilt and reequipped with far better aircraft than the IJN possessed meets and destroys the IJN, probably somewhere near Wake. The U.S. then takes Midway back, followed by Tarawa and probably Wake before heading into the Mandates, with the war proceeding pretty much the same in macro.

The idea that radar would be a wonder weapon for the Japanese ignores several basic facts.

1) Japan HAD radar, possibly even at Midway (John Prados notes that post-war interviews with a senior office on-board Hiryu indicate that that ship has radar as soon as the IO Raid, other sources dispute this)

2) Radar is of VERY little use if your fighters do not carry radios. IJN pilots routinely removed the radios from their Zero fighters to save weight and improve maneuverability

3) It was the lack of radios, not lack of warning, along with the constant penny packet attacks against the Kido Butai that made the critical difference during the dive bomber attacks on June 4. IJN carrier had been unable to replace CAP fighter due to the necessity of constantly evading attack, leaving the fighters in the air short of 20mm ammunition. Zeros without 20mm ammo were woefully ineffective against U.S. aircraft.

4) Japan was almost never taken completely by surprise in the naval war. In the air attacks against the various island bases warning was going to be of very little help thanks to the general inferiority of the IJN aircraft by that time and the lower mission capable rates if IJN/IJA designs.

5) From early 1943 onward IJN task forces had radar. They lost every single engagement.

5) Japan HAD radar raid warning for the B-29 attacks. It just lacked sufficient quality interceptors to matter.

Radar wasn't the key. The key was fighting an enemy who could, with less than half of its industrial output, outproduce Japan nearly 10 to 1 and produce increasingly superior aircraft that had high reliability and superior naval vessels in quantities beyond Tokyo's wildest dreams.

 

[Bill Cameron]

I think many of the assumption the Japanese made were quite reasonable in their circumstances.

Riain,

Reasonable? More like blinkered, if not actually psychotic.

Years of diplomatic confrontation had led to the US cutting off Japan's lifeblood, so Japan had to act somehow.

And they could have acted without involving the US at all.

In November of '41, Congress reauthorized the draft by one vote and FDR's rearmament plans, plus the undeclared ASW war in the Atlantic, were troubling to a lot of people. In repeated polls, over half the population opposed entry into the war.

Making matters worse, on December 8th the Chicago Tribune was set to print what might have been the Pentagon Papers of the 1940s; the War Department's plans for a 100 division army designed to fight overseas. When you remember that FDR campaigned for his third term with the promise "Your boys won't die overseas" you'll begin to sense just how unlikely war was.

And then the Japanese attacked. Absolutely brilliant on their part, wasn't it?

Actual historians, and not amateurs like us, believe that, if Japan had left US territory alone during her "Lunge To The South", the US would have done nothing. Japan could have grabbed all the resources they needed without sparking a war with the US.

Their first move was very successful, the cut the USN down to a more manageable size and secured their territorial goals.

Their first move did nothing of the sort because it left intact the same forces that gutted the Kido Butai only seven months later at Midway.

It was the second phase of their plan which fell apart, when they failed to defeat the remainder of the USn in battle and secure their next lot of territorial objectives.

To the contrary, they secured all of their pre-war objectives and many of the other objectives their amazing run of success allowed them to add to the list.

While they defeated the USN several times, they failed to attrit it in the manner their pre-war plans envisioned and a large part of that failure had to do with US industrial might.

Taking your questions in order and assuming the IJN had the same radar capabilities that the Allies do at the time of each event:

Could radar have allowed the IJN to locate and sink Sommerville's FEF?

No. There were no carrier-borne, radar-equipped, search aircraft at the time and no IJN surface vessel came within sighting distance, radar or otherwise of the FEF.

Could radar have allowed the IJN to win Coral Sea and capture Port Moresby by sea?

Probably not. First, see the search issues above. Second, radar directed CAP intercepts as part of task force defense were still being worked out. The USN would still have an edge in this however do to the radios available for her planes.

Could radar have allowed the IJN to win at Midway?

Probably not. See both issues above. Radar may have detected the inbound USN dive bomber squadrons in time to prevent all the defending IJN Zeros from chasing the USN torpedo plane strike, but those Zeros would have then been split between defending against both strikes.

Could radar have allowed the IJN to win in and around Guadalcanal, Santa Cruz and Espiritu Santu?

First, the IJN won more of those battles than you seem to believe. Second, the US surface search radars of the period were routinely bested by IJN eyeballs and confused by clouds, islands, and other natural formations. Towards the end of the period, USN radar and radar techniques did improve enough for them begin ambushing the IJN effectively. By Vella Gulf in August of '43, the USN could stalk and defeat IJN ships at night with near impunity. Which leads us to the other thing you've completely overlooked.

Toys do not equate techniques. The Allies developed radar equipment and then had to develop the means in which it was best used. Simply giving the IJN radar equal to that of the USN doesn't magically tip the scales somehow.

What would the US have done if by August 1942 the USN was a husk of its former self and with no prospect of a revival for a full year, and the Japanese holding everything they wanted?

Go to http://www.combinedfleet.com/economic.html and read the why your question is moot. The economic war, the only war that actually mattered, was over the instant the first Japanese bomb fell on Pearl Harbor. Japan lost her war in that instant. All that remained after that was to see how long it took her to lose.


Bill

 

[Riain]

CalBear, I was thinking more of accumulative advantage starting from Coral Sea through to Espiritu Santu, rather than an anihilation in a single battle.

Bill, there are lots of issues there, but I would like to say that countries sue for peace all the time, France did in 1940 because they knew that the jig was up while only a theird or so had been actually conquered. It is not impossible to conceive that after losing most of their fleet in a series of battles the US decides to cut its losses and call for an armistice rather than lose the rest of the fleet. Also radar doesn't just control fighters, it also is used for surface search and gunnery control, which could be very handy for the IJN in places like the slot. Doctrine and toys go hand in hand, you can't have blitzkrieg without tanks and torpedo tactics without Long Lances.

 

[CalBear]

CalBear, I was thinking more of accumulative advantage starting from Coral Sea through to Espiritu Santu, rather than an anihilation in a single battle.

Bill, there are lots of issues there, but I would like to say that countries sue for peace all the time, France did in 1940 because they knew that the jig was up while only a theird or so had been actually conquered. It is not impossible to conceive that after losing most of their fleet in a series of battles the US decides to cut its losses and call for an armistice rather than lose the rest of the fleet. Also radar doesn't just control fighters, it also is used for surface search and gunnery control, which could be very handy for the IJN in places like the slot. Doctrine and toys go hand in hand, you can't have blitzkrieg without tanks and torpedo tactics without Long Lances.

I used a single battle at Midway to illustrate matters. Bill went into more detail on your specific questions but the answer doesn't vary. Radar was a useful addition, but it wasn't a wonder weapon (I would note that during several of the early action in the Solomons, American force commanders either ignored or misinterpreted radar to the point of it cause their defeat).


Japan had nary a prayer.

 

[CalBear]

...



And they could have acted without involving the US at all.

In November of '41, Congress reauthorized the draft by one vote and FDR's rearmament plans, plus the undeclared ASW war in the Atlantic, were troubling to a lot of people. In repeated polls, over half the population opposed entry into the war.

Making matters worse, on December 8th the Chicago Tribune was set to print what might have been the Pentagon Papers of the 1940s; the War Department's plans for a 100 division army designed to fight overseas. When you remember that FDR campaigned for his third term with the promise "Your boys won't die overseas" you'll begin to sense just how unlikely war was.

And then the Japanese attacked. Absolutely brilliant on their part, wasn't it?

...

It is true that the U.S. would not, in all likelihood have acted against Japan any further than it already had without Pearl Harbor. The Japanese, however, had to work based on the enemy's capabilities not hope that the U.S. would act in a certain manner.

In Japan's eyes the U.S. was already more or less at war with them. The American economic attacks against Japan (which went far beyond the oil and steel embargoes everyone believes to be the last straw) had crushed her economy and would, even if the capture of the Southern Resource Area had been completed without a hitch, have left Japan as a near bankrupt state with no capacity to trade internationally or to import badly needed industrial materials. This being the case, leaving the Philippines, Wake, Guam, and the U.S. battle fleet intact and a clear and present danger to the vital supply lines between the new resource areas and home would have been strategic madness.

The Japanese also had almost no understanding of the American political landscape or American beliefs. Those who did understand the U.S. were both ignored and, when any part of their information was heard, it was taken to mean that the American people were not capable of sufficient sacrifice to engage in a war with the Yamato people. This was a dreadful combination and it virtually guaranteed that armed conflict would seem a reasonable choice. It is noteworthy that the Japanese High Command sincerely believed that it would be possible to arrange a negotiated peace with the U.S., possibly with payment for damages incurred, within a year of the initial engagement.

Lastly, the Japanese did what most nations would have done, including the U.S., they projected their values and thought process onto the enemy after applying their prejudices regarding the opponent. This is a process that is common to this day (the current disaster in Iraq is a textbook example of this sort of projection of values and desires) and it fatally shaped Japan's decision process.

Japan attacked the U.S. because it both assumed that the U.S. would react as Japan would in similar circumstances and that the U.S. had no belly for the fight that would follow. Both assumptions were incorrect, to Japan's sorrow.

 

[Bill Cameron]

Bill, there are lots of issues there...

Riain,

Few of which you seem grasp.

... but I would like to say that countries sue for peace all the time, France did in 1940 because they knew that the jig was up while only a theird or so had been actually conquered.

So the US, which has been attacked, which has only lost the Pacific portion of it's navy and which has no foreign troops on it's soil, let alone marching through it's capital, would somehow give up? With a deeper POD perhaps, one that changes the US politically, but solely due to improved IJN radar? Never.

Also radar doesn't just control fighters, it also is used for surface search and gunnery control, which could be very handy for the IJN in places like the slot.

Which I mentioned in my responses to your specific questions and which you've evidently ignored; i.e. no IJN surface vessel came within sighting distance, radar or otherwise of the FEF. and the US surface search radars of the period were routinely bested by IJN eyeballs and confused by clouds, islands, and other natural formations.

Radar's surface search and gunnery roles helped the USN very little during 1942 and early 1943. The failure's associated with radar, both in equipment and in its use, even left USN commanders cool towards relying on it for a period.

Doctrine and toys go hand in hand, you can't have blitzkrieg without tanks and torpedo tactics without Long Lances.

No they do not. You're confusing, again, the ability to make weapons with the ability to use them correctly. You want to believe that doctrine and toys go hand in hand? Then tell us why did the French in 1940, who had better tanks than the Germans, failed to use those tanks correctly. You can even have the proper doctrine only to see it spoiled by a lousy weapon, such as with the USN and the torpedoes available to it early in the war.

There is more at work than just inventing radar here.


Bill

 

[CalBear]

Apropos of nothing in the original POD, but since it has been brought up several times the Long Lance (more properly the Type 93 Torpedo) wasn't the almighty terror sometimes presented. Savo Island, while a brilliant victory, was also something of a fluke.


It had a lower overall success rate than it generally understood (well below 10%) and was mainly effective thanks to the evolutionary advantage it possessed in both speed and range more than any tactical breakthrough by the IJN. Once the properties of the weapon became known it was actually less effective than the much disparaged U.S. MK 15 (as shown at Samar Island where USN DD and DE crippled part of the IJN cruiser force with hits on at least three ships and forced much of the remaining force out of pursuit while IJN torpedoes did no damage at ail despite the presence of 19 ships (6 CA, 2 CL, 11 DD) equipped with Type 93).

On the other side of the ledger, the Long Lance was directly responsible for the loss of several IJN ships when otherwise minor hits set off the compressed oxygen used as fuel with secondary detonation of the torpedo warheads.

 

[Riain]

CalBear, I'm organising the concept of 'accumulative advantage' in my head and think the first 9-12 months of the Pacific war is a good place to test it. I've read that for the IJN torpedo tactics to work they needed a 15% hit rate but only got about 10%, however in the first year of the war their hit rate was up around 12%. Could radar have gotten their hit rate in these torp engagements up to a consistent 15% in the first year of the war, keeping in mind the quality of their training etc.

Bill, French tanks were crap. Despite thick armour, decent sized gun and good performance they had a single man turret. Since they couldn't organise how to get the best out of a single tank I'm not surprised they couldn't get the best out of a thousand of them.

 

[Bill Cameron]

Since they couldn't organise how to get the best out of a single tank I'm not surprised they couldn't get the best out of a thousand of them.

Riain,

Exactly. France's possession of better tanks than Germany didn't automatically equate a better use of those tanks. I'm glad you understand that and can now, hopefully, apply the same understanding to the question of IJN radar.

As for your idea of "accumulative advantage", please pay attention to what CalBear tells you about the Long Lance. It was not the wonder weapon you seem it to believe it to be.

I'll repeat my belief that the US of the OTL is not going to forced into an armistice through major naval losses in the Pacific. The actions of an ATL US is another question entirely, but the OP's question had to do with radar only and nothing to do with weakening the US.


Bill

 

[CalBear]

CalBear, I'm organising the concept of 'accumulative advantage' in my head and think the first 9-12 months of the Pacific war is a good place to test it. I've read that for the IJN torpedo tactics to work they needed a 15% hit rate but only got about 10%, however in the first year of the war their hit rate was up around 12%. Could radar have gotten their hit rate in these torp engagements up to a consistent 15% in the first year of the war, keeping in mind the quality of their training etc.

...

Probably not. The key to training is that you have to have both doctrine to support it and experience with the systems. Even if you give the IJN the exact same systems as the U.S. they would barely have gotten them installed at the start of the war on a few of their capital ships and a very few new construction lighter forces. That isn't enough time to integrate the new tool into the old doctrine (again, the USN experience in the Solomons and even with fighter direction in the first six months of the war is instructive in this area) with any reliabilty.

Use of torpedoes with radar is especially tricky, especially the early surface search sets since aiming a torpedo is more a matter of prediction than precision and radar would sometimes provide a target at a longer range than the Mark 1 eyeball, but with a less percision regarding speed and exact course. The longer the range a unguided weapon is fired from the less likey it is to hit. As the war progressed, radar became much more precise so by late 1942 it was the best method of aiming guns, but even then the number of hits was extremely low, and that was for a weapon that had a travel time measured in seconds, not minutes.

What WOULD have greatly increased the effectiveness of the Type 93 would have been wake following or wire guidance. Both of these technologies were well into the future, although the Germans and the U.S. did field passive wake following weapons that could be used against low speed targets before the end of the war (with mixed success).

 

[xchen08]

Another question would be how the Japanese are able to get radars. They are less than a century removed from being a medieval backwater. They were massively deficient of trained engineers, scientists, and technicians. Japanese fighters went into the war equipped with American made radios and gunsights. How could they possibly get radars as good as the Americans? The US had the resources needed to invest in everything, and then reap from those efforts that meet up with success. Consider the Manhattan project, where the Americans simultaneously pursued two totally different weapon designs and ended up getting both. The Japanese simply didn't have the resources for this. They decided to invest everything into high quality optics, which they got. Had they decided to go for radar instead, they would most likely have failed due to their electronics deficiency, but had they succeeded, they would have radar but no high quality optics. Early on, when both radar and tactics for its use were primitive, this would have led to greater losses. And considering that Japan has not the industrial capability to replace losses, they would never have recovered enough to further develop the technology or its use.