Bonin islands garrisons?

[KASHANKA]

Well, the Iwo Jima orbat is real easy to get. However I am interested in the japanese garrisons on other Bonin islands, especially Chichi Jima. Anyoen has any info on that?

[Akira Takizawa]

Chichi Jima
109th Division HQ - Lt. Gen. Yoshio Tachibana, 496 men
17th Independent Mix Regiment (less 3rd Battalion), 1,136 men
304th Independent Infantry Battalion, 614 men
306th Independent Infantry Battalion, 578 men
307th Independent Infantry Battalion, 958 men
308th Independent Infantry Battalion, 680 men
Engineer unit of 1st Mix Brigade, 50 men
Artillery unit of 1st Mix Brigade, 66 men
Detachment of 9th Heavy Artillery Regiment, 776 men
Detachment of 17th Shipping Engineer Regiment, 704 men
45th Special Machine Cannon Unit, 81 men
46th Special Machine Cannon Unit, 79 men
Signal unit of 109th Division, 227 men
Chichi Jima Army Hospital, 179 men
Chichi Jima MP, 10 men
Chichi Jima detachment of 59th Anchorage HQ, 480 men
2nd Independent Sea Transport Company, 84 men
Intendance Dep. of 109th Division, 111 men
Special Field Ordnance Depot
Special Field Munitions Dump

Haha Jima
1st Mixed Regiment (less 3rd Battalion) - Col. Hitoshi Masaki, 2,146 men
305th Independent Infantry Battalion, 713 men
274th Independent Infantry Battalion, 563 men
276th Independent Infantry Battalion, 404 men
303th Independent Infantry Battalion, 565 men

Ani Jima
275th Independent Infantry Battalion - Lt. Col. Naoji Takenaka, 549 men

[KASHANKA]

Wow, thanks for the speedy reply, much appreciated.

[cstunts]

Hello,

The senior Japanese oficer at Chichijima was VADM Mori Kunizo of the IJN. I don't know offhand what units he had under his command there. Here is a link to the story of Japanese forces at Chichijima with a very rare photo of Tachibana & Mori together at the end of the war. (It's on page 13 of the issue) http://www.leatherneckmagazine-digital. ... 0807/?pg=6

[Akira Takizawa]

IJN on Bonin Islands in 1945

- Chichi Jima (3,566 men)
Chichi Jima Special Base Force - Rear Admiral Kunizo Mori
209th, 303rd Construction Units
2nd Torpedo Boat Unit
1st, 2nd, 5th Shiyo Units
Chichi Jima Signal Unit
Chichi Jima Air Unit
Chichi Jima Naval Hospital

- Haha Jima (2,040 men)
Haha Jima Guard Unit
304th, 309th Construction Units
3rd, 4th Shiyo Units

- Kita Iwo Jima (67 men)
Kita Iwo Jima Detachment

Taki

[john whitman]

Taki:

Your information about the Bonins is great.
Can you tell me when the 1st Independent Mixed Regiment (less 3rd Battalion) travelled from Japan to Haha Jima? As you might remember, I am trying identify which units sailed with which convoys/marus.
I have found a few Japanese web sites that give some information about independent mixed brigades. Are there any sites about independent mixed regiments?
Thanks for your help.

John

[Akira Takizawa]

> Can you tell me when the 1st Independent Mixed Regiment (less 3rd Battalion) travelled from Japan to Haha Jima?

1st Mixed Regiment (1st Independent Mixed Regiment is my error) was reorganized from fortress units on Haha Jima.

> Are there any sites about independent mixed regiments?

It is only a simple list, but no other site.

http://ja.wikipedia.org/wiki/%E5%A4%A7% ... 0%E8%A6%A7

Taki

[Sewer King]

From United States Pacific Fleet and Pacific Ocean Area, “Field Survey of Japanese Defenses on Chichi Jima Retto, Part One – the Report,” CINCPAC-CINCPOA Bulletin No. 2-46, 15 February 1946, pages 6-7

• Total Japanese order-of-battle, Bonin Islands, by island location and service:
  
  
  
  
  Army orbat by unit and unit strength:
  
  
  
  
  Navy orbat by unit and unit strength, with arrival dates:
  
  
  Hadn't the shinyo squadrons arrived around September 1944?

Apologies for the small print, it was a third-generation microfilm copy and scan

====================================

Taki,

These figures may have been supplied to the US Marine occupation force by Major Horie Yoshitaka around the time of surrender, even early in the surrender arrangements. But, except for the Navy figures, there is no precise date of information in these tables.

• Would the slight differences in unit strength from your list result from movements over time, and maybe casualties? Would including the gunzoku also have made some difference as well?
  
  Was the small military police section necesssarily Kempeitai, though they are not named as such?
  
  The 45th and 46th Special Machine Cannon units seem to be mistaken in the CINCPOA bulletin as “MG.” Maybe there are other errors in the table? Would these be the AA troops mentioned as sent from Tokyo in the following quote

  Second Lieutenant Kato [IJA] in command of the radar squad which had been expanded on August 2 [1944] with the arrival of advance units of [AA] gunners of the Tokyo Air Defense Regiment. [They had actually] been en route to Iwo Jima ... but American air attacks on the convoy carrying them forced a retreat to Chichi Jima. The several hundred members of the Tokyo Air Defense Regiment were dispersed to various mountaintop anti-aircraft batteries on the island...

  {from Robert Stinett's military biography, George Bush: his World War II Years (Pictorial Histories Publishing Co, 1991), page 127 and 139)

It has been said that despite the bombardment of the Bonins, many of their fortifications still stood and remain there today. Because they were built over a longer time with less enemy interference, and were closer to mainland Japan, they were in fact stronger than those of Iwo Jima. Some, I think, have been used in modern times for earthquake monitoring instruments.

• Although it would be in Japanese only, is there any guide to (or diagrams and photographs of) the Chichi Jima fortifications? Even if only for visitor interest?
  
  What became of the strange copper-lined vaults at Kiyose on Chichi Jima, after the Bonins were returned to Japan? In the 1950s the US Navy reportedly used them to store Regulus sub-launched missiles or their warheads.

====================================

Here is a link to the story of Japanese forces at Chichijima with a very rare photo of Tachibana & Mori together at the end of the war. (It's on page 13 of the issue) http://www.leatherneckmagazine-digital. ... 0807/?pg=6

This link did not allow reading the pages unless logged in as a member. There are extant photos of Tachibana at his sentencing for war crimes and execution by hanging at Guam in 1947, along with Major Matoba Sueo.

====================================

… I am interested in the japanese garrisons on other Bonin islands, especially Chichi Jima.

I too am interested in the history of the Bonins, military and otherwise. Maybe you have also seen Major Horie‘s original typewritten report of defensive plans and general strength in the Bonins? I have some of the JICPOA diagrams of Chichi's fortifications and can post them if wanted.

From his explanation it seemed that the 109th Division fully expected Chichi Jima to be invaded at or around the same time as Iwo Jima. Susaki airfield had been mined against the possibility of airborne attack.

-- Alan

[Akira Takizawa]

> Hadn't the shinyo squadrons arrived around September 1944?[/list]

First Shiyo unit arrived at Chichi Jima on Sep. 13th, 1944. Others arrived until the end of 1944.

> Would the slight differences in unit strength from your list result from movements over time, and maybe casualties? Would including the gunzoku also have made some difference as well?

My data on the army forces is in April 1945. I also have numbers of soldiers returned from Bonin islands after the war. They are siightly different. There was a communication between Bonin islands and Honshu until the end of the war. So, there would be movements of soldiers.

> Was the small military police section necesssarily Kempeitai, though they are not named as such?

I cannot understand your question well. But, Kempeitai is a general term meaning MP in Japanese. So. all MP is called Kempeitai in Japanese.

> Maybe there are other errors in the table?

There are some small errors in translation of unit names.

> Although it would be in Japanese only, is there any guide to (or diagrams and photographs of) the Chichi Jima fortifications? Even if only for visitor interest?

http://www17.big.or.jp/~father/aab/ogas ... awara.html

Taki

[Sewer King]

Many thanks as always Taki.

I thought there might also be some limited air connection to Chichi Jima, although Susaki airfield was repeatedly bombed and repaired, then finally mined. Wasn't all air and sea connection to the Bonins run through the Izu Islands, though they too were bombed? I think Major Horie said he wanted not to be made chief-of-staff to General Tachibana, but he could not leave even if the connection was open -- it must have been a unpleasant change from General Kuribayashi. Indeed he feared for his life up to the arrest of the war criminals.

From several of the published accounts of the Bonins' occupation, there is some mention of demobilized soldiers who were returned to Japan from Chichi Jima. Some of them had let it be known that atrocities had been committed there against US prisoners-of-war. Some of the officers seeking to cover those up had arranged for return of the witnesses who might know best about them. One of them, an IJN lieutenant, committed suicide when he learned he was being sought by US investigators in connection with this.

My apologies, I was mistaken partly in expecting the JICPOA bulletin to explicitly call the very small MP section as Kempeitai rather than just military police. It seemed to me that on Chichi Jima MPs would have ordinary garrison duties rather than the security police work for which they were feared in occupied Asia (my parents remember them well in the Philippines). So, I had thought they were different, but now understand that the term means all IJA police. It had also seemed so small a police unit (15 men) for so large an Army garrison (more than 12,000), although they could detail other troops to work for them as needed.

Thank you especially for the chart, an extremely few kanji of which I can read, especially while knowing the basic geography of Chichi Jima. Some modern-day visitors and former US Navy veterans of the 1950s-60s have posted photos of the wartime fortifications. Even some ex-Marines remember the copper-lined vaults at Kiyose left by the Japanese, for it was their job to guard the missile warheads stored in them. I thought that some of Japan's space tracking and communication stations might also be on or near some of the higher-up fortifications today.

-- Alan