Forum: Rumors
Topic: Rumors - Part 6
started by: Larry Jewell

Posted by Larry Jewell on May 01 2001,9:00
I'm currently working on a 13 page "summary" of pre-war reports from Military Attaches all around the globe, prepared in 1944.  This one item floated to the surface:

"The MA in Mexico forwarded a report that the Japanese were constructing special small submarines for attacking the American fleet in Pearl Harbor, and that a training program then under way included towing them from Japan to positions off the Hawaiian Islands, where they practiced surfacing and submerging."

Now we all know that you don't need to go to Hawaii to "practice surfacing and submerging."  But otherwise it was a "hot" piece of info, IF you apply 20-20 hindsight.  Unfortunately I'm sure that it got lost in the cacophony of intell that was then blizzarding in on the War Dept.

My question, oh founts of knowledge, is when did the midget training program start?  AND is there anyway MEXICO would have info on the program?  (Other than the usual diplomatic party talk, of course.)

Posted by Ken Hackler on May 01 2001,11:06

According to all the books I have read, including Sakamaki's, the training went on all summer. But that was general training without a specific target, which all navies do all the time. The decision to use the midgets in the Pearl Harbor attack came in the fall, and training kicked in hard and heavy in October.

Since there was a lot of talk bandied about in 1941 by various diplomats, I would say it's possible one of them chattered too much at a party in Mexico, although I have no proof of that. Where are you finding these messages?

Posted by Larry Jewell on May 01 2001,11:31


Explanatory Notes.

The summaries which follow are based solely on information relating to Japan's war potential and intentions included in reports from U. S. Military Attaches and Military Observers during the period beginning 1 January 1937 and ending 7 December 1941. These intelligence documents, a descriptive catalogue of which follows the yearly summaries, are reproduced in Far Eastern Documents, Volumes I-XV. In most cases marginal lines have been added to the documents to indicate sections pertinent to the subject.
Marginal references in the yearly summaries indicate the documents from which the information is extracted. For instance, "FE 1" refers to the first Far Eastern document. Where several sources contain essentially the same information, they are indicated in the margins but not always referred to


specifically in the text of the summaries. When the source of any statement is desired, the marginal references should be compared with the annexed table of contents of the documentary file.
The following abbreviations have been used:

MA Military Attaché or Assistant Military Attaché
MO Military Observer

Expressions such as "Tokyo reported" or "Singapore reported" refer to reports from War Department intelligence personnel stationed at those places. Reports are included from Military Attaches or Assistant Military Attaches on duty at embassies or legations in Japan, China, Thailand, Australia, Portugal, Great Britain, and Mexico, and from Military Observers in India, Malaya, and Netherlands Indies, where no diplomatic representation was maintained.

I'll have a fresh copy of the Clarke Investigation online this week, reformatted for easier reading.  The old one (vanilla text format) is still online at

That (Far Eastern Documents, Volumes I-XV) has me drooling.  Anybody know if they've been published?

Posted by ben e fox on May 01 2001,12:57
Could you provide a specific, precise, useable citation for the quote?


Could you provide contexual information such as date, document, etc.?

(Edited by Ken Hackler at 3:11 pm on Oct. 13, 2001)

Posted by Larry Jewell on May 01 2001,3:33
The quote is from

CONGRESSIONAL INVESTIGATION INTO THE ATTACK ON PEARL HARBOR, PT. 34, PROCEEDINGS OF THE CLARKE INVESTIGATION,  page 209.  The post at 10:31 am on May 1st explains the context of the report.

If you need more than that I would direct you to the full text on

I'm a few pages shy of having the reformatted version ready to go online, but the current copy has the same text, just not as pretty.

Posted by Ken Hackler on May 01 2001,4:11

I'd be curious to know which Japanese diplomats and attaches were at the Mexico embassy, since I've heard more than one rumor come out of Mexico before the war.

It would be something of a challenge (but possibly worthwhile) to see if the source of the information can be pinpointed, and working backwards from there, to see where he got that information.

Perhaps I'll take that on as a new project now that the midget submarine project has about run its course. Six months on any one project is plenty of time I think. Thanks for the idea!

Posted by Larry Jewell on May 01 2001,5:15
All I have is the summary of these document.

Magic shows messages addressed to "Miura" and "Koshi" in Mexico.

Posted by Ken Hackler on May 01 2001,5:53

I think it should be easy enough for me to get an embassy staff roster from the Japanese government or the local newspapers in Mexico City. Since most of the rumors came back to the U.S. through the liason or attache I will also look at the U.S. embassy staff.

Will make a nice little project to dig into once I finish typing up the midget submarine manuscript.

I grabbed my copy of Sakakamaki's book this afternoon and looked up a few things for you by the way.  He says that they began training in late April 1941, 24 single men, and that they were not volunteers as some have written in the past. Sakamaki says that they were selected, and that was that.

He mentions training in June 1941 near the village of Mitsukuye, on the Inland Sea. Their training was completed by the end of September 1941, although they had no specific target, nor does he say that there was even any mention of war yet.

On page 34 of his book he mentions war for the first time in context of the midget submarines being used specifically. He says "during October," without giving a date, "I gathered from the words of our superiors that something serious was in the air. Our maneuvers shifted from a mid-ocean encounter * to an inside harbor tactic. Captain Harada showed us maps of Hong Kong, Singapore, Sidney, San Francisco, and Pearl Harbor."

The submarine crews were told to learn the harbors.

* Note that prior to this point their training had been in the form of open ocean fighting against a fleet, as that was the original intent of the midget submarines.

A few things to note about his comments overall are that no one knew in June 41 about the midgets being used at Pearl, although there may have been some talk within the Navy. Also, their training did not shift from the original purpose of open ocean fleet engagements to harbor attack until October.

He goes on to say the middle of October 1941 they were stationed on the  north coast of Shikoku facing the Inland Sea. They practiced navigation in narrow inlets at night, something that could have meant the use of the midgets in any of the previously mentioned ports.

Sakamaki says that they were finally told of the attack on Pearl Harbor on November 16, not long before sailing from Kure.

The source of this information is Kazuo Sakamaki's book, "I Attacked Pearl harbor." The U.S. copy was published in 1949 by the Association Press in New York. It was published in Japan in 1947.

Posted by Larry Jewell on May 01 2001,6:15
A footnote on page 271 of "The Pearl Harbor Papers", by Goldstein and Dillon, says, "...At the end of October, 1941, the commander in chief of the Combined Fleet decided to use midgets in the Pearl Harbor Operation.-Eds."

BTW, the NHC website has bunches of midget pictures.  (And none of them are captioned, "The Plane! The Plane!)

Posted by Ken Hackler on Jul. 06 2002,12:25

The rumor about the small Japanese submarines was passed to Navy Intelligence via the Military Attache (i.e., Army) in Mexico, but originated elsewhere.  The documentation on this rumor is contained in the Clausen Investigation of the Pearl Harbor Attack Hearings, with several pages of notes. Also, many senior Navy officers discussed this item during their testimony before the various attack hearings.

The Army's memo to the Navy that went with the report said that the informant was not reliable, and that the information probably came from him (the informant) learning something of the "pygmy" submarines being built by the Japanese, and that the guy's imagination did the rest.

In other words, it was not something that carried a great deal of weight with anyone. In hindsight, they were right to be skeptical of this guy. The Japanese never had such a plan as he envisioned.

However, ADM Kimmel did order searches along the coast of Molokai, where these submarines were reportedly hiding out. This was in late summer or early fall 1941, several months before the Pearl Harbor attack.

The Army memo to the Navy was sent out again a few months after the Pearl Harbor attack, with a note that said "perhaps this information should be reviewed again in light of recent events."

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