StarDestroyer.Net BBS

Does anyone know if the Japanese navy had anything that could have potentially sank the American carriers?

While obviously this wouldn't have led to an eventual Japanese victory, what would be some of the long term consequences? My guess is that US Naval aviation would be significantly delayed in becoming effective as they would presumably be less willing to take risks after that point. Another even larger loss would have been the core of officers in naval aviation that were present there, including the obvious of Halsey and the less obvious of Marc Mitscher.

The takeoffs commenced at a range of around 650nm off Tokyo. The plan had been 500nm but detection by the previously unknown Japanese patrol line thwarted that. But Japan had the patrol line where it was to provide useful warning against a conventional carrier based raid, which had a realistic radius of no more then about 200nm. By leaving its destroyers behind the US task force could operate at sustained high speed in the final phase of the operation, and upon launching so far offshore, simply turn around and flee laughing at 25 knots. At that kind of distance even had Japan had say, a carrier group to send after them, overtaking them in a stern chase would never happen. They'd run out of fuel trying.

As it was though Japan's only ready naval forces were a couple old battleships in the Inland Sea and very small numbers of patrol planes and fighters. Japan was conducting a masterful economy of force operation in the Pacific, and one place they super economized was on leaving anything in the Home Islands. The battleships were all the older slower ones they simply had no use for anywhere else. Only handfuls of modern fighters, and not even many obsolete ones were present. I don't believe Japan had any modern bombers in operational units in the home islands, though they did have some modern patrol planes. Exactly Japanese patrol plane was seen on US radar during the retirement but it never spotted the US force.

The main Japanese carrier force at the time was near the Luzon Strait returning from the Indian Ocean Raid, and while several carriers were ordered to intercept the US ships they were utterly incapable of actually doing so at that kind of distance. The chase was called off within a day due to lack of actual contact with the US force after it cleared the patrol line.

Had the US force been sunk by magic though, that would mean no Midway and Japan would attempt to launch even vastly more stupid operations into the south west Pacific.

Meant to put this in, official track chart of Enterprise. Straight in at 20 knots, straight out at 25 knots. A surface intercept was impossible, and while the final phase had no destroyer escort the reality is that WW2 submarines had great difficulty intercepting fast task groups on the open sea under any circumstances. It really only worked when large numbers of subs could be predeployed into the known path of enemy forces.

All those markings on the chart are all the converted fishing boats and small freighters the task force sighted and attacked (with epic bad gunnery and bombing accuracy) forcing the early launch. Japan had a huge number of craft in this patrol system, but it didn't last far into the war because USN submarines began sinking them with gunfire and Japan became able to field more and some radar equipped patrol planes. They also simply needed the shipping for even more vital tasks.

Thanks. That is more or less what I suspected, though as usual with far more detail.

Yeah its kinda just dead simple in this case. Raid meant nothing, but Japan couldn't stop it. The US knew its main carrier force was away to the south too, though it probably would have launched the operation either way. BUt as happened, once spotted the task force had only two options, launch at once, in this case at much greater then planned range, or jettison the B-25s to clear the flight deck of USS Hornet for combat operations by her own planes.

Japan meanwhile also couldn't launch its own raids, because the war was simply always being fought on the Japanese side of the international date line. Only on the original Oahu strike and to a much less degree during the Aleutians operation did they move east of it. The US much feared return attacks to Oahu, steadily expanding the defenses right until the end of the war, and even some really insane level fears about Alaska (given its own secret oil refinery in case it was isolated!) and California but Japan simply never actually had such long range capabilities.

Could they maybe have shot down the aircraft before they got to the islands?

Purple wrote:Could they maybe have shot down the aircraft before they got to the islands?

The B-25s went in at treetop level and weren't even spotted until the bombs started dropping. The Japanese scrambled whatever air defenses they had but they were basically caught completely by surprise.

Yeah, the Japanese didn't know a thing specifically until the first plane was near Tokyo. A couple of the bombers that had to strike targets further east or came over Tokyo last were intercepted by fighters, one had to dump its bombs to evade but none was shot down. Three Japanese fighters were shot down by bomber gunners. It took about 1 hour to launch all the bombers, so the resulting attack was not exactly a single sudden event.

The bombers flew a couple hundred feet off the deck for the approach and departure when they could, but the actual bombing runs were flown at anything from 600ft to 2,400ft depending on the crew and target, each plane had multiple targets assigned and dropped only one or two bombs on each. The bombs in use at the time could not be safely dropped very low, nor realistically could the crews have effectively aimed with the equipment in use at the time. Japan actually had barrage balloons up in some areas to deter low level attacks, but not enough of them to matter against such a small raid.

However because Japan did know an American task force was approaching with several hours warning they were not totally unprepared. They had expected the US force to get much closer and then launch a normal carrier strike though, so they didn't actually have every plane in the air as they could have had had they known of the B-25s.

Most of the handfuls fighters that took off to oppose the raids were from Japanese training units, many being Ki-27s with barely any speed advantage over the B-25. Though over Yokohama the Kawasaki factory actually launched several Ki-61 prototype fighters that managed to make an ineffective intercept. While Japan was very weak on actual defensive assets, they did have a prewar ground observer-sound locator based air defense warning network that did something in terms of getting stuff into action. After the Doolittle Raid several complete fighter groups were brought back to Japan to give this system more teeth; which was then completely irrelevant until the first B-29 raid from China in 1944.

Prewar Japan was super paranoid about air attacks and engaged in large scale programs of bunkering of key military facilities and active protection and elaborate air raid drills; the Soviets being the main threat on that front, but they had to strip away all the teeth to support the strike south in 1941-42. Well, everything that wasn't already sent to China.

Interestingly all the B-25 crews reported sighting multiple Japanese fishing boats and merchant ships as much as several hundred miles offshore (different then the patrol line vessels) but it appears none of them issued a warning to the Japanese military. I would suspect because the crews just naturally assumed any plane they might see so close to home was Japanese and thought nothing more of it.

What were overall Home Island defenses like?

What if the raid had been a full speed run to 200 miles out and an all out carrier plane attack on some important coastal target in Japan?

Sea Skimmer mentions that a lot of japanese people saw the airplanes and assumed they were Japanese. This "Mis-conception" might have been helped along by the National Marking the planes were carrying at the time - a star & bar with a red dot in the center: easily mistaken for the Japanese National Insignia. Which is also why it was later removed a little while later: too many cases of mistaken identity by US pilots attacking their own airplanes when they saw a big read Meatball on it!
Just my 2 cents worth.

Necro much? Although I can certainly see that being a contributing factor to misidentification; while the two insignia don't really look much alike, stress or inattention could easily change that.

Esquire wrote:Necro much? Although I can certainly see that being a contributing factor to misidentification; while the two insignia don't really look much alike, stress or inattention could easily change that.

Especially if it's just random fishermen or merchantmen looking at the planes, not trained aircraft spotters. To the great majority of civilians, one military plane will look much like another, especially without higher magnification (binox, telescopes, etc) to pick out details at a great distance/height.