Midget Sub base

[ShindenKai]

Trying to find more info...been looking at Google Earth...

https://www.scmp.com/week-asia/politics ... gn=3116075

[OpanaPointer]

Frank discussed these in his book on Olympic IIRC.

[ShindenKai]

Who’s Frank? What book? Pics of the base(s) in book?

Might’ve found it...

[ShindenKai]

This island, Ha (Hajima) Island is 2.78NM south east of O island, has a similar pier and most importantly several over-grown structures...

[fontessa]

This island, Ha (Hajima) Island is 2.78NM south east of O island, has a similar pier and most importantly several over-grown structures...

I don't think so. They were 蛟龍 Koryu which had a very short cruising distance. IJN intended to use them to attack US landing convoys in Japan preparing for the Mainland Battle. So I don't think that they were sent to distant islands.

関戸 蛟龍 3.jpg (146.79 KiB) Viewed 2058 times

For example;
福島県おおい町大島 Oshima, Oi Town, Fukushima Prefecture
http://sengoshikaigi.blog.jp/archives/8449770.html

蛟龍 大島.jpg (59.91 KiB) Viewed 2058 times

P基地 P Base and Ｑ基地 Q Base near Kure (Training Bases)
http://kure-sensai.net/Iseki/P-Kiti-Q-K ... PQKiti.htm


fontessa

[ShindenKai]

This island, Ha (Hajima) Island is 2.78NM south east of O island, has a similar pier and most importantly several over-grown structures...

I don't think so. They were 蛟龍 Koryu which had a very short cruising distance. IJN intended to use them to attack US landing convoys in Japan preparing for the Mainland Battle. So I don't think that they were sent to distant islands.

fontessa

Once again, as usual, more fantastic info Fontessa, thank you. Any Japanese books about these midget sub bases?

Did the link work? It exclusively talks about an island Midget sub base off the coast of Shimane Prefecture. Ha (Hajima) Island is the only one I found that had pier structure, over-grown buildings and clearly uninhabited. This island was rediscovered by a group of Japanese researchers. The article makes no mention of the exact Midget Subs used there, I would imagine the Koryu was possibly being trained their and/or the Kairyu. The Koryu Type D actually had the longest range of all Japanese Midget Subs in WW2 with 1,000nm and the Kairyu only had a 450nm range. Its even possible it was a Kaiten training base, the article is definitely lacking in information.

[fontessa]

Any Japanese books about these midget sub bases?

I am afraid that such a book didn't published in Japan.

Did the link work? It exclusively talks about an island Midget sub base off the coast of Shimane Prefecture. Ha (Hajima) Island is the only one I found that had pier structure, over-grown buildings and clearly uninhabited. This island was rediscovered by a group of Japanese researchers. The article makes no mention of the exact Midget Subs used there, I would imagine the Koryu was possibly being trained their and/or the Kairyu. The Koryu Type D actually had the longest range of all Japanese Midget Subs in WW2 with 1,000nm and the Kairyu only had a 450nm range. Its even possible it was a Kaiten training base, the article is definitely lacking in information.

I think Hajina is 羽島 in Yamaguchi Prefecture. But, according to Japanese Wiki, no military facility was stationed there. I think Hajima is too small (Area = 0.27 km2 and Coastline = 2.0 km) for the staion. According to Japanese Wiki, all 44 people left the island en masse, leaving the island uninhabited on November 25th, 1971. We can see three hatch houses, about 20m wide.

I have never seen a Kairyus with 2 periscopes.
Two more Kairyus seems to be there,

fontessa

[fontessa]

Any Japanese books about these midget sub bases?

I am afraid that such a book didn't published in Japan.

I found the list of the assault units which were equipped with Koryus. No base was stationed in Yamaguchi prefecture including Hajima.
It seems that Koryus were rarely deployed in assault units other than those under the 10th Special Attack Unit.
15th Assault Units with 4 Koryus on papar (Shimoda, Shizuoka prefecture) / 1st special Attack Unit
25th Assault Units with 7 Koryus on paper (Saeki, Oita prefecture) / 25th special Attack Unit
21st Assault Units with 21 Koryus on paper (Tachibana Bay, Nagasaki prefecture) / 6th special Attack Unit
32nd Assault Units with 4 Koryus on paper (???, Kagoshima prefecture) / 8th special Attack Unit
101st Assault Units with 6 Koryus on paper (???, Hiroshima prefecture) / 10th special Attack Unit
Oura Assault Units with 104 Koryus on paper (Oura, Hiroshima prefecture) / 10th special Attack Unit
102nd Assault Units with 6 Koryus on paper (???, Kagawa prefecture) / 10th special Attack Unit
Shodoshima Island Assault Units with 29 Koryus on paper (Shodoshima Island, Kagawa prefecture) / 10th special Attack Unit
* Maizuru Assault Units with 6 Koryus on paper (Oshima, Fukui prefecture) / Maizuru Naval Distinct
* See my previous post
福島県おおい町大島 Oshima, Oi Town, Fukushima Prefecture
http://sengoshikaigi.blog.jp/archives/8449770.html

fontessa

[ShindenKai]

Just highlighting the double periscopes and sail sizes of the training Kairyu.

[fontessa]

Just highlighting the double periscopes and sail sizes of the training Kairyu.

Thanks. Were these photos taken at Tokosuka Naval Yard? Japanese wiki says 20 Kairyu with 2 periscopes were made there.

水防眼鏡2型改5
Periscope Type 1 Improvement 5

潜望鏡.jpg (110.32 KiB) Viewed 836 times

fontedda

[ShindenKai]

I found the list of the assault units which were equipped with Koryus. No base was stationed in Yamaguchi prefecture including Hajima.
It seems that Koryus were rarely deployed in assault units other than those under the 10th Special Attack Unit.
15th Assault Units with 4 Koryus on papar (Shimoda, Shizuoka prefecture) / 1st special Attack Unit
25th Assault Units with 7 Koryus on paper (Saeki, Oita prefecture) / 25th special Attack Unit
21st Assault Units with 21 Koryus on paper (Tachibana Bay, Nagasaki prefecture) / 6th special Attack Unit
32nd Assault Units with 4 Koryus on paper (???, Kagoshima prefecture) / 8th special Attack Unit
101st Assault Units with 6 Koryus on paper (???, Hiroshima prefecture) / 10th special Attack Unit
Oura Assault Units with 104 Koryus on paper (Oura, Hiroshima prefecture) / 10th special Attack Unit
102nd Assault Units with 6 Koryus on paper (???, Kagawa prefecture) / 10th special Attack Unit
Shodoshima Island Assault Units with 29 Koryus on paper (Shodoshima Island, Kagawa prefecture) / 10th special Attack Unit
* Maizuru Assault Units with 6 Koryus on paper (Oshima, Fukui prefecture) / Maizuru Naval Distinct
fontessa

Fantastic info, again. Thank you Fontessa!

Yes, those pics were taken at Yokosuka. Photos from US Navy site.

[ShindenKai]

水防眼鏡2型改5
Periscope Type 1 Improvement 5
fontedda

I'm slightly confused, Google translate says that it's a Type 2 Modified 5 periscope for a Type 1 Kaiten...

Did the Kairyu use a longer version of the Kaiten periscope? Thank you Fontessa.

[fontessa]

水防眼鏡2型改5
Periscope Type 1 Improvement 5
fontedda

I'm slightly confused, Google translate says that it's a Type 2 Modified 5 periscope for a Type 1 Kaiten...

Did the Kairyu use a longer version of the Kaiten periscope?

Sorry for the lack of explanation. Periscope Type 1 Improvement 5 was used in both Kaiten and Kairyu.
On the other hand, Koryu which was the modification of 甲標的丙 Ko-target Mod.C used 九七式特眼鏡改二 Type 97 Special periscope Improvement 2.

The 1st and the 2nd figures show the Kairyu prototype No.3 which was used at Yokosuka Assault Unit for teaching materials (cut model) and is kept at the JMSDF 1st Technical School now.
The 3rd figure shows the cockpit model of 甲標的甲 Ko-target Mod.A which is displayed at Yamato Museum. It used 九七式特眼鏡改一 Type 97 special periscope Improvement 1.

潜望鏡 海龍.jpg (71.57 KiB) Viewed 789 times

潜望鏡 甲標的.jpg (83.35 KiB) Viewed 789 times

fontessa

[ShindenKai]

So, the "cut-away" Kairyu was actually used for training purposes during the war? I had always assumed it was done afterwards just to display the inner workings of the sub. Very interesting. Thank you Fontessa.

[ROLAND1369]

How did this cutaway survive the postwar allied demilitarization of Japan?