Tactical Defeat of US marines at Iwo Jima?

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Takao
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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Takao » 13 Jun 2012 11:53

I haven't either. Although considering the utmost secrecy surrounding the Atomic Bomb, I doubt that it would be mentioned in most primary sources. Still, Iwo did serve as an emergency strip for the primary bombing aircraft, with one B-29 waiting at the airfield in case the primary aircraft could not continue on to target.

However, I believe that the primary reason for capturing Iwo Jima was to provide a base for B-29 fighter escorts. When the fighter escort effort failed(well, was not successful as hoped), the you see the other "explanations" begin to make their rounds.

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Junglemike » 13 Jun 2012 15:47

I appreciate and understand the reason for supporting sources and documentation. Unrestrained speculation accomplishes little if anything in historical study. It would be difficult to imagine that the nuclear strikes would have occurred from Saipan/Tinian had Iwo remained in japanese hands.

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by sonofsamphm1c » 13 Jun 2012 17:16

Takao wrote:I haven't either. Although considering the utmost secrecy surrounding the Atomic Bomb, I doubt that it would be mentioned in most primary sources. Still, Iwo did serve as an emergency strip for the primary bombing aircraft, with one B-29 waiting at the airfield in case the primary aircraft could not continue on to target.

However, I believe that the primary reason for capturing Iwo Jima was to provide a base for B-29 fighter escorts. When the fighter escort effort failed(well, was not successful as hoped), the you see the other "explanations" begin to make their rounds.
I don't even think they hoped fighter cover would be successful. I think they knew it would not be successful. They told General Arnold it would not be successful.

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Carl Schwamberger » 13 Jun 2012 23:11

Junglemike wrote:I appreciate and understand the reason for supporting sources and documentation. Unrestrained speculation accomplishes little if anything in historical study. It would be difficult to imagine that the nuclear strikes would have occurred from Saipan/Tinian had Iwo remained in japanese hands.
There may be something about that in the books. Tibbets & the others involved in figuring out how the "devices" would be delivered must have discussed interceptors at some point. Unlikely a group of experienced bomber pilots would have 'forgotten' about that. We do have to recall at this point the actual delivery missions were run without fighter escort, in daylight, so at some point the problem/probability of fighter interception from the main islands airfields must have been dismissed.

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Carl Schwamberger » 13 Jun 2012 23:13

sonofsamphm1c wrote:
I don't even think they hoped fighter cover would be successful. I think they knew it would not be successful. They told General Arnold it would not be successful.
Still the effort was made. I'd have to review the size of that effort before dismissing it as a reason.

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Takao » 14 Jun 2012 03:09

Given the very poor results of the Japanese very high altitude interceptors, the fact that the B-29s flew over Japan proper at 31,000 feet, the fact that the "Silverplate" B-29s were stripped of most of their armament to save weight, and the very few aircraft involved...I think that interception would have been very remote. Also, pertaining to the "few" aircraft involved in the actual "bombings", the Japanese would have most likely left them alone, as they did the numerous weather & photo recon B-29s(the Japanese were waiting for the mass flights of B-29s to intercept).

Had Iwo not been in American hands, the missions probably would not have been changed(although I have not crunched the numbers). However, the mission would have had to have been "perfect", Sweeney's Nagasaki mission would have resulted in an abort or the loss of the aircraft.

Still, the Americans went to a lot of trouble for something
... they knew it would not be successful. They told General Arnold it would not be successful.
See http://www.506thfightergroup.org/mustangsofiwo.asp

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Carl Schwamberger » 14 Jun 2012 03:36

Reading that item reminded me of something I'd suspected but not followed up on. That is as the US closed in on Japan the B29 heavy weights were not the only aircraft attacking targets in the main islands. Fire bombing the cities did not serve all requirements for preparing the way for the intended invasion and the smaller aircraft were starting to ramp up the sort of missions the US 9th AF or the Brit tactical air forces performed in NW Europe. The painting of the P51 & the railroad engine coveys the idea.

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by sonofsamphm1c » 14 Jun 2012 19:13

Carl Schwamberger wrote:
sonofsamphm1c wrote:
I don't even think they hoped fighter cover would be successful. I think they knew it would not be successful. They told General Arnold it would not be successful.
Still the effort was made. I'd have to review the size of that effort before dismissing it as a reason.
I'm not dismissing fighter cover as the reason for taking Iwo Jima. I think it was the main reason.

Once they decided to do it, the fighters would be based in sufficient numbers to fail at a mission known to be implausible. The military never does that sort of thing?

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by donsor » 14 Jun 2012 21:34

Without sounding like an expert tactician, I think that even if the US could have provided the b-29s with the most sophisticated fighter escorts in great numbers, I still think that the unescorted high altitude option used was the best choice, much like, in a lesser degree, the option chosen in Dolittle's bombing of Tokyo earlier in the war. BTW, what type of high altitude fighters did Japan have that they could have used to intercept the B-29s?

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by LWD » 14 Jun 2012 21:40

donsor wrote:..., I still think that the unescorted high altitude option used was the best choice,..
Actually the USAAF decided that low level unescorted night raids were the best bet at lest of firebombing. They even pulled guns from the planes (and their associated gunners).

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Carl Schwamberger » 15 Jun 2012 00:25

donsor wrote:... BTW, what type of high altitude fighters did Japan have that they could have used to intercept the B-29s?
I dont have my books at hand, but will risk censure by linking to Wiki. You can search up other better descriptions of these, and perhaps better books than I have.

Note that all were used to one degree or another to attack the low flying B29 attacking at night. Sucess at that had everything to do with pilot skill & aircraft features like speed or gun weight coming in second.

Twin engine J1N. Modified anti bomber versions used a bank of 20mm cannon. Despite the lack of radar skilled pilots had spectacular sucess with it. Fortunatly there were few of these and fewer pilots with the skill or instinct required.

http://en.wikipedia.org/wiki/Nakajima_J1N

J2M served as a fast point defense interceptor with a noteable climb rate.

http://en.wikipedia.org/wiki/Mitsubishi_J2M

A Few of the Ki43 were left in 1945 & had the bare speed to reach a Superfort

http://en.wikipedia.org/wiki/Nakajima_Ki-43

Ki-44 was another point defense interceptor this one was a bit aged but still had the climb and speed, plus a pair of cannons
http://en.wikipedia.org/wiki/Nakajima_Ki-44

IIRC this one (Ki-61) was used for ramming attacks, or as it translates from a freqent Japanese description 'body slamming techniques'. If what I read was accurate many of the pilots body slamming the B29 survived & made repeated sorties.
http://en.wikipedia.org/wiki/Kawasaki_Ki-61

Ki-84 Common aircraft in late war but lacked high altitude performance.
http://en.wikipedia.org/wiki/Nakajima_Ki-84

Designed for range & manuverability the Ki100 lacked high altitude performance
http://en.wikipedia.org/wiki/Kawasaki_Ki-100

The Shinden was a brute of a entirely different class from the other Japanese fighter planes. Robust and capable of asorbing damage it was claimed to be the equal of US types like the corsair and Hellcat. Only a few hundred were built. I dont remember if any actually intercepted B29s but it had the speed and fire power, and did not fall apart from a few 50 cal MG hits.
http://en.wikipedia.org/wiki/Kawanishi_N1K

Late war variant of the Zero had a robust 1500 hp engine & IIRC alcohol injection for speed burst. Wiki give a climb capability of 29,000 feet in nine minutes. Which fits the claims from elsewhere.
http://en.wikipedia.org/wiki/Mitsubishi_A6M_Zero

Hope this answers the question

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by donsor » 15 Jun 2012 02:36

How many of the above listed Japanese aircraft were effective enough to harass the B-29s bombing mainland Japan to the point were sorties were cancelled or tactics changed in response. Further, if there were enough Japanese interceptors to harass the B-29s, why didn't the US adopt the escort tactics predominantly used in the European air campaign? Certainly we had enough long range fighters such as the P-38s and P-51s in addition to the carrier borne aircraft that could baby sit the B-29s. BTW, I've heard much about the B24/B17 casualties we had in Europe but do you have any statistics on how many B-29s were shot down by Japanese interceptors during bombing runs to Japan?

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by sonofsamphm1c » 15 Jun 2012 04:24

I found this on another site:

"Here's a table agreeing with that total with a few more details, from the USAAF Statistical Digest, "Very Heavy Bomber" meaning B-29. Of enemy action losses 74 were to fighters, 54 to AAA, and 19 to a combination. ..."

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Takao » 15 Jun 2012 06:58

sonofsamphm1c,
you forgot to add that that the majority(267) of B-29 losses fell into the category of "other", which is military lingo for "damned if we know."

If you wish to peruse the statistical Digests, they can be found here: http://www.afhso.af.mil/usafstatistics/index.asp
the "web friendly" one you are talking about is this one: http://www.usaaf.net/digest/t165.htm


Carl Schwamberger,

I didn't see the Ki-45 Toryu/Nick on your list, that was probably one of the best Japanese aircraft used against the B-29s. The Japanese also modified the Ki-46 Dinah, a high speed, high altitude recon aircraft, to be a fairly decent B-29 Hunter. The IJN also experimented with modifying the D4Y "Judy" & the C6N "Myrt" with obliquely mounted cannon to combat the B-29s, AFAIK, neither were very successful.

Also, Japanese quality was varied at best and while one J2M(for example) might perform well at altitude, another may perform miserably. Further, the "low" octane & quality AvGas used by the Japanese aircraft was considerably detrimental to their performance, Japanese aircraft performed much better when captured models were tested with the higher octane US AvGas.

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Re: Tactical Defeat of US marines at Iwo Jima?

Post by Carl Schwamberger » 15 Jun 2012 14:18

donsor wrote:How many of the above listed Japanese aircraft were effective enough to harass the B-29s bombing mainland Japan to the point were sorties were cancelled or tactics changed in response. Further, if there were enough Japanese interceptors to harass the B-29s, why didn't the US adopt the escort tactics predominantly used in the European air campaign? Certainly we had enough long range fighters such as the P-38s and P-51s in addition to the carrier borne aircraft that could baby sit the B-29s.


Bottom line is the B29 raids originated long before the airfields were close enough for effective escort. You need to look up the range of these missions, originally from China & later from the Marinas islands.
donsor wrote:BTW, I've heard much about the B24/B17 casualties we had in Europe but do you have any statistics on how many B-29s were shot down by Japanese interceptors during bombing runs to Japan?
Like Takao wrote the numbers are complex. Only where the crew survived was there a clear indication why the aircraft was lost. Japanese records are not definative as many of their pilots were lost before proper reports were made re:"Body Slamming Techiniques", and the effectiveness of the anti aircraft artillery is not definative. The losses from interceptors, AAA, weather, and mechanical failure are difficult to interpret in any but a broad way.

Le Mays biography has some numbers. If I get time this weekend I'll look them up. Perhaps the most telling indicator is the ratio of aircraft and aircrew permanetly lost vs those hit but returning to friendly airfields on Iwo. With those landing strips the number of aircrew survivng increased dramatically, as did the number of damaged aircraft salvage vs those which crashed at sea.

A unrelated but more important problem was the weather, particularly the wind, was very different from that of the US or Europe. Aside from unexpectedly strong high altitude wind - the jet stream, there were stronger than anticipated cross winds as altitude dropped. As the bombs fell 8,000+ meters they passed through multiple changes in wind direction with net changes in wind speed of 100+ kilometers per hour. This was beyond the optical wind observation equipment and analog or mechanical computers/bomb sights of the era. The cloud patterns were very changable and altitude and density difficult to predict, further degrading accuracy. The result was the bomb runs at eight kilometers or five miles altitude were not accurate enough, by a wide margin. Gen. Le Mays decision to attack from lower altitude - below 3,000 meters or 10,000 feet got around much the weather/wind problem and attacking at night negated much of the interceptor problem. That of course exposed the bombers to more effective AAA fires.

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