Okinawa Battle: Japanese unit

[Wellgunde]

hello Marek:
I have looked at Senshi Sosho vol 17, Nippon Kaigun Hensei Jiten (Japanese Navy Order of Battle Encyclopedia) and several other resources. I can find no mention of a 187th Naval Attack Force Rifle Battalion. Also, it does not match any IJN unit numbering scheme that I am aware of. Generally, these ad hoc types of emergency defense units were numbered starting with "one." The highest number that I know of is "ten." If anyone else has more information, please feel free to jump in.

[Wellgunde]

Hello Fontessa,

Do you have any JCAR references for 沖縄方面根拠地隊?

Thank you,
Wellgunde

[hisashi]

沖縄方面根拠地隊 Okinawa-ward BF and 第四海上護衛隊 4th sea escort force was a nimai-kanban (dual capacity) unit. As Okinawa-ward BF it reported to Sasebo chinjufu and as 4th sea escort force it reported to sea escort GHQ. With a handful of weak, converted ships, seaplanes and small ground units, it defended Okinawa and Amami as well as the sealane to them.

In Apr 1944 they began their business with the first commander RAdm Nippa Teizo (新葉亭造), succeeded by Ota in Feb 1945.

Navy RADAR crews at Kumejima Island was infamous in that they killed at least 22 civilians, for example because the civilian passed them an allied message to surrender. But because this team has been well documented, we know only 27 crew worked for Kumejima RADAR site. So it is diffecult to find RADAR sites in IJN order of battle of the day.

Fortunately Okinawa-ward BF/4th sea escort force wartime log (JACAR C08030144200) gives a list of navy RADAR sites in this unit, Apr 1945.
久米島 与那国島 口永良部島 宝島 沖永良部島 南大東島 曽津高崎 口之島 北大東島 沖大東島
Kumejima Is. Yonakunijima Is. Takarajima Is. Okinoerabujima Is. Minami-Daitojima Is.
Sotsukozaki Cliff(west end of Amami Oshima Is.) Kuchinoshima Is. Kita-Daitojima Is. Oki-Daitojima Is.

[Wellgunde]

Hello Hisashi.

The concept of nimai kanban (kanji?) is very well understood in the U.S. Navy and the Royal Navy and has been used by both from World War II up until the present. Not much has been known about the use of nimai kanban in the IJN. Thanks for helping to clarify one aspect. Itsumo osewa ni narimasu.

[Mil-tech Bard]

Hisashi,

Outstanding!

Thank you for your research.

The following are bits on Japanese radars on Kume Jima and in the Northern Ryukus chain from American primary source Wartime and Occupation documents.

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http://kumejima.warwickhi.com/Marinestakekume.html

Company "A", 1st Battalion, 7th Marines,
1st Marine Division(1)
30 July, 1945

July 2, 1945

At approximately 0330 the 81-mm fired a harassing mission and the enemy returned the fire by spraying the bivouac area and defensive perimeter with two 13.2-mm dual-purpose MG's. The 81-mm fired two missions and neutralized the enemy machine guns. One strecher bearer was critically wounded and died as a result of wounds received from enemy fire.

A coordinated attack was launched at 0730 on the enemy position on the peak at TA 7390-0 by Company "A", Amph Recon Bn. moving south from road at TA 7391R and south. Company "A", 7th Marines, moved west along the ridge from hill at TA 7591-U. Company "B", Amph Recon Bn., was deployed with combat groups on a line generally from TA's 7290-Y-5 to 7290-N. The attack was preceded by preparatory fire from two 75-mm howitzers (LVT(A)'s) and the 60-mm and 81-mm sections. The attack progressed against inaccurate enemy rifle fire; movement was across extreemly steep and rugged terrain where thick vegetation hindered both movement and observation. By 1400 the enemy positions were completely overrun. The bulk of the ememy holding force is believed to have withdrawn and scattered in the wooded area in TA's 7489, 7589, and 7689. Two heavy MG's, caliber 13.2-mm were captured intact by Able Company, 7th Marines. The enemy is estimated to only have one MG, and it has been removed from a crashed plane, probably 7.7-mm.

Enemy radar equipment was destroyed by Able Company, 7th Marines. All troops returned to initial beachhead and occupied their original defensive positions.

The US Army Intelligence Report No. 30 Northern Ryukus, dated 1 July 1946, reports the following regards Japanese radars --

Page 75

Anami-o-shima Two radars destroyed by Tenth Army Task Force in October 1945. There was an observation that the Kikia Jima radar was moved to Amani Oshima for orderly destruction.

Page 103 Tokuno

JNAF operated a Radar for the Army on the Island (30 men)

Page 106 Okino-erabu

Japanese radar station on Okino-erabu-shima w/ one warrent officer and six enlisted men. Located on the south west coast facing China. It was damaged by American bombs in April 1945.
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My research says this claimed Apr 1945 destruction date mentioned above for the Okino-erabu radar is post war white wash.

USMC radio countermeasures TBF's were picking up signals from Okino-erabu in June 1945. This was published in the USAAF RADAR magazine as well as a reprint of the same article in the US Navy's "CIC" magazine in the immediate post-war.

Also, as I mentioned previously, my research shows the JNAF was operating an Army radar on Tokuno while a Army radar (Tachi-6) with a navy crew was on Kume Jima suggests a local deal between the General of 32nd Army and the Okinawa Base Force commander.

What is notable to me are the JNAF radars not mentioned as destroyed.