IJA Radar

[Mil-tech Bard]

>>I think they reported to Okinawa Base Force via 43rd Minesweeper Division.

Humm...that implies they (43rd Minesweeper Division) were based elsewhere than Okinawa.

Was the 43rd Minesweeper Division HQ on Amani Oshima?

Sasebo?

Somewhere else?

[fontessa]

Hello Mil-tech Bard,

The 43rd Minesweeper Division HQ was located at Naha, Okinawa.

fonressa

[Mil-tech Bard]

So after Naha and the associated Naval Base force fell to the US Marines...

...the IJN radar stations at Kume Jima, Miyako Jima, Ishigaki Jima, Yonakuni Jima were cut off from rreporting to any Imperial Japanese Navy higher headquarters?

[fontessa]

Hello Mil-tech Bard,

I think so.

fontessa

[Mil-tech Bard]

fontessa ,

You said over on the Amami Oshima topic that the Imperial Japanese Army placed the cut off from 32nd Army IJA units on Miyako, Yaeyama, and Daito islands under the 10th Area Army.

Would the radars on those islands be under 10th Area Army or 8th Air Division (in Taiwan) after 32nd Army HQ was over run?

Also, in the same area, Who did the IJN radar stations at Miyako Jima, Ishigaki Jima, Yonakuni Jima report to after Naha and the Okinawa Area Base Force HQ was over run?

Since 2nd Air Fleet in Taiwan was disbanded on 8 January, 1945, who was left for them to forward reports to in Taiwan?

4th Escort Fleet or Sasebo Naval Distinct on Kyushu seems to be out of daylight radio range for high frequency broadcast reports from Miyako Jima, Ishigaki Jima, or Yonakuni Jima.

[Wellgunde]

Also, in the same area, Who did the IJN radar stations at Miyako Jima, Ishigaki Jima, Yonakuni Jima report to after Naha and the Okinawa Area Base Force HQ was over run?

Almost certainly the Sasebo Naval District.

4th Escort Fleet or Sasebo Naval Distinct on Kyushu seems to be out of daylight radio range for high frequency broadcast reports from Miyako Jima, Ishigaki Jima, or Yonakuni Jima.

From personal experience, it is possible to communicate in the daytime between Okinawa and Sasebo using HF. How well depends on the frequency, transmitter power, type of antenna, and a host of other factors. Please also consider that Okinawa, the islands between Okinawa and Kyushu, Formosa, and Kyushu were all connected by submarine telegraph cable.

[fontessa]

Hello Mil-tech Bard,

You said over on the Amami Oshima topic that the Imperial Japanese Army placed the cut off from 32nd Army IJA units on Miyako, Yaeyama, and Daito islands under the 10th Area Army.
Would the radars on those islands be under 10th Area Army or 8th Air Division (in Taiwan) after 32nd Army HQ was over run?

I think radar stations were transferred to the 10th Area Army Air Intelligence Unit.

Since 2nd Air Fleet in Taiwan was disbanded on 8 January, 1945,

I have overlooked the 1st Air Fleet. It moved from the Philippines to Taiwan at the end of 1944 and was disbanded on 15 June 1945.

fontessa

[Mil-tech Bard]

So...2nd Air Fleet IJNAF was disbanded on 8 January, 1945 in Taiwan.

And 1st Air Fleet IJNAF was disbanded on 15 June 1945 in Taiwan.

What was left for those three radar stations to report too?

5th Air Fleet IJNAF (in Kyushu)?

[fontessa]

Hello Mil-tech Bard,

I don't think specially established lookout stations reported to any air fleet directly.

Although I can't find the evidence, I guess Navy radar stations reported to Ohshima Coast Defense Unit after Okinawa Campaign.

fontessa

[Mil-tech Bard]

Didn't the Imperial Japanese Navy have a Coast Defense Unit or command for Formosa?

They certanly had enough air fields.

[Wellgunde]

Didn't the Imperial Japanese Navy have a Coast Defense Unit or command for Formosa?

They certanly had enough air fields.

Briefly,

Takao Guard Force
Takao Minor Naval Station
Takao Base Force
Takao Naval Air Group

Takao is modern day Kaohsiung, Taiwan
Information in greater detail would be appreciated.

[Mil-tech Bard]

IIRC, Wellgunde. none of the following radar stations -- Miyako Jima, Ishigaki Jima, Yonakuni Jima -- were listed in the USN NAVTECHJAP report nor the British report on Japanese countermeasures for Operation Olympic on the Sasebo Naval District radar network.

Also, in the same area, Who did the IJN radar stations at Miyako Jima, Ishigaki Jima, Yonakuni Jima report to after Naha and the Okinawa Area Base Force HQ was over run?

Almost certainly the Sasebo Naval District.

4th Escort Fleet or Sasebo Naval Distinct on Kyushu seems to be out of daylight radio range for high frequency broadcast reports from Miyako Jima, Ishigaki Jima, or Yonakuni Jima.

From personal experience, it is possible to communicate in the daytime between Okinawa and Sasebo using HF. How well depends on the frequency, transmitter power, type of antenna, and a host of other factors. Please also consider that Okinawa, the islands between Okinawa and Kyushu, Formosa, and Kyushu were all connected by submarine telegraph cable.

[Wellgunde]

IIRC, Wellgunde. none of the following radar stations -- Miyako Jima, Ishigaki Jima, Yonakuni Jima -- were listed in the USN NAVTECHJAP report nor the British report on Japanese countermeasures for Operation Olympic on the Sasebo Naval District radar network.

Some things to consider.
1. There is an operational chain of command as well as an administrative chain of command. The island lookout stations could have been reporting to two different commanders.
2. Logically, it would make sense to have them reporting operationally to a HQ on Kyushu since the potential air and naval threat was directed towards Kyushu and not Formosa. Of course, what seems logical to us in hindsight may not have been the actual practice.
3. It is entirely possible that they didn't report to anyone operationally. Japanese air defense tended to be local in nature. In that respect, they were way behind advances in other countries. With regards to Japanese defenses, the term "network" may be an overstatement.

Can you provide more complete citations for the two references you listed? I'm interested in trying to find them. Are they primarily function/location oriented or do they also speculate on network "wiring?"

[Mil-tech Bard]

>>Can you provide more complete citations for the two references you listed? I'm interested in trying to find them.

See this Report link and specifically page 68 of 78 in the PDF you find there:


0-56(N) Japanese Field and Amphibious Equipment Kyushu Defense Systems

http://www.fischer-tropsch.org/primary_ ... MJ_toc.htm

The British report has identical data on the Radar stations reporting to Sasebo Air Defense Center.

[Mil-tech Bard]

What I have found interesting is the way that the Kume Jima radar seems to have been wipped out in terms of US Navy reporting to the War Department in Washington DC.

The following picture is from:

JAPANESE RADAR LOCATIONS,
RATEL No.11
July 1945
Military Intelligence Division
War Department
Washington DC.

Japanese Okinawa Area Map July 1945

Based upon this and the OSRD Division 15 report on Radio Countermeasures, it sure looks like the Navy Department was trying to hide the existence of the IJN Kume Jima Radar and the implications of it for the post-war reputations of the USA Navy brass involved in running the Okinawa campaign.