CRYPTOLOG - AFTERTHOUGHTS; The Battle of Midway

We continue the exploration of significant portions of Captain Rochefort's oral history interview conducted in 1969 by Commander Etta-Belle Kitchen. Captain Rochefort was assigned in June 1941 as OIC, Combat Intelligence Unit, Pacific Ocean Areas, located at Pearl Harbor.

The Battle of Midway followed closely on the heels of the Japanese attack on Dutch Harbor, Alaska. The devastating losses to the Japanese fleet at Midway ended the threat to the Aleutian Islands, the Alaskan mainland, and perhaps the west coast of the US. Within minutes, the Japanese lost three of its four carriers, the AKAGI, KAGA and SORYU. Several hours later, the fourth -- HIRYU -- was sunk. This total disaster to the Japanese ability to project air power and provide air cover for its fleet changed the Japanese strategy in the Pacific, indeed it changed their fate. Admiral Nimitz's decision to expose other areas in order to bring the required forces to bear at Midway, including committing his three remaining aircraft carriers -- ENTERPRISE, HORNET and YORKTOWN -- was a tremendous gamble. More importantly, this daring gamble was based solely upon Rochefort's communications intelligence. Although YORKTOWN was lost in the battle, the stunning victory vindicated Nimitz's decision and established the highest credibility for communications intelligence operations.

The setting relative to this segment of the interviews is 25 May 1942 -- Rochefort and company have decrypted and translated the entire Japanese Operation Order for the imminent attack on Dutch Harbor and Midway Island. Rochefort has been able to do his duty, as he previously defined for us, ". . . to tell his commander, his superior, today, what the Japanese are going to do tomorrow." Upon release of his warning of the planned Japanese attacks, he was called to a momentous meeting with Admiral Nimitz.

Graphic Supplements:
	[Photo (64K): USS YORKTOWN, Badly listing, nears the end of her struggle to stay afloat. She sank at 0501 on June 7, 1942. U.S. Navy Photo]
	[Map (150K): Color map of the Pacific Theater, 1942.]

The dialogue begins where Kitchen [K] homes in on Rochefort's [R] warning message of 25 May. [Please assume quotes throughout the dialogue].

[R] The May 25th message was the final translation of the Japanese operation order of May the 20th, as I recall, or thereabouts, which was the final operation order issued to all the Japanese commanders. Then on May the 25th we completely read this message including the two so-called interior ciphers or codes, one of which would be the geographical thing and the other would be the date, time and hour which was separately enciphered inside, and this presented the big problem, because we could tell them what was going to happen. The only two things we lacked were 'where and when,' and these were especially enciphered within the basic operation order by the Japanese in a separate little cipher system. Now, the 'where' was easily solved. There was no problem there at all. This was the AF [digraph used by Japanese in messages to represent Midway] and the 'where' and all that sort of thing, no problem here at all. The date, time and hours -- 'when' -- we were unable to get this because to our knowledge this [the interior code] had only been used three times -- or maybe this was the third time it had been used. I think that's more correct. This was the third time it had been used and we, of course, had the other two instances available to us which we kept studying. But unfortunately one of them was garbled, so we had nothing in which to prove or disprove our assumptions as to June 4th, or June 8th or June 10th or whether it was July the 19th. We had no way of knowing. But by concerted attack by everybody concerned we were finally able to restore or to rebuild the little system just based on these three particular little incidents and admittedly, it was rather shaky, but it was the best we could do under the circumstances because, as I say, we only had three indications of its use.

[R] We did reproduce the table, the little cipher table of months and days and hours, and we did make our assumptions then that this had to be in June and that days 'A' would be commencing, say, June 3 or whenever it was in Alaska, which was a diversion attack, June 4th and so on and so forth. Also included in this was the time of takeoff and the location of takeoff and the direction of approach.

[R] Of the planes. So, as an example, this May 25th dispatch of ours, which was the final dispatch bearing directly on the operation -- the Japanese operation -- contained such things as where the Japanese aircraft carriers would be when they launched their planes, degrees and distance from Midway, and the hour and the minutes. Then, of course, the rest of the dispatch would be the strength of the attack and the composition of the attack forces and so on. This was perhaps the major problem, and this was the dispatch we sent, as I recall, on May the 25th, and that was the morning that Admiral Nimitz had sent for me to arrive at a certain time at his headquarters and I was late. The reason I was late was that we were still working on the final aspects of this dispatch and when I say that we were working on it, I mean that this would involve an agreement among the senior people at station Hypo [his unit at Pearl Harbor] and would probably have included Dyer, Wright, Finnegan, the translator, Huckins, the radio intelligence officer and possibly Jack Williams, also radio intelligence officer, and this message that went out then was our consensus of what the dispatch meant and what the dispatch said and our reasons for it. Like everything else in station Hypo, any major decision of this nature would be the result of, and you might want to call it, the staff conference. We never did call it things like that. We just said that we all agree with this. When I saw 'we' I am always referring to the people who were most experienced and the most knowledgeable. It might or might not have included Jasper Holmes. I would doubt that, because he would not be familiar to that extent with the things Japanese.

At this, point, Kitchen probed Rochefort about Nimitz's reaction to Rochefort's tardiness, the attendees and the general atmosphere of the meeting. She continued with a line of questioning in an effort to document Nimitz's personality, demeanor and leadership traits. It is here that I found a gem of a tale where the cunning and sense of humor of Admiral Nimitz is exposed. It is a story that is also relevant to the Battle of Midway and exemplary of the unquestioned superiority of Navy over Army.

[K] You started this by saying in the meeting [Nimitz] was -- or someone said he was -- a compromiser. Were you thinking of a specific incident in the meeting?

[R] Not at this particular meeting , no. I don't know if I mentioned it before or not, but to me this [other] little incident explains quite a bit about Admiral Nimitz and his relationship with other segments of the Armed Forces. As I recall -- and I'll try to make this very simple -- this, I think, was the meeting after Midway and the question arose as to the situation within the Japanese forces. What were they doing? Had they actually retired and given up the idea of occupying Midway and so on and so forth? As I recall, during the course of this thing, the suggestion was made by someone present to send out some additional planes to Midway as a precautionary measure. Admiral Nimitz spoke to the Army Air Corps man who told him he had X number of planes that were suitable for use around Midway. However, he was very reluctant to send these planes out there, because these were all the planes the Army had on Oahu. You take these planes off Oahu -- they were B-17s, as I recall -- if they take these planes off Oahu, this is all we've got on Oahu. The Navy had nothing. This would take everything the Army had, and Oahu would be completely defenseless. The Admiral reminded him that within the next 30 minutes or an hour or something the SARATOGA [aircraft carrier] was coming in from San Diego with a load of planes as well as its own Air Group and he volunteered that if the Army Air Corps would send out all of their B-17s from Oahu for use in the Midway area, then he would turn over the operational control of the SARATOGA planes during their entire period of stay in Pearl Harbor.

[R] He would transfer the operational control to the Army Air Corps, at which point the Army Air Corps brightened up and agreed to send these planes. Admiral Nimitz asked him to get the order under way then. I noticed at the time that the Navy Air man -- who I think was Admiral Bellinger [Rear Admiral Patrick N. Bellinger, USN, Commander Patrol Wing Two] -- I thought he looked a little bit surprised at the moment, but he said nothing and the conversation went on. They discussed other things. Then at some later period, perhaps 45 minutes or so later, the Army Air Corps man said, "By the way, Admiral, you say that the SARATOGA is due in today at Pearl?" and he said, "Yes, it should be in at any moment now." The Air Corps man said, "How long may we expect the SARATOGA to be here?" The Admiral said, "Long enough to fuel, and then she will proceed to sea and load up the planes again." But, by this time, the B-17s were on the way to Midway. . . [Gotcha! GO NAVY!]

Copies of this memoir and that of codebreaker Thomas Dyer are available for sale, or readers may rent copies through the lending lilbrary of the United States Naval Institute. The fee for a one-month rental is $12 for Naval Instutute members, $15 for non-members.

For orders or further information please contact Ms. Ann Hassinger, History Division, U.S. Naval Institute, 118 Maryland Avenue, Annapolis, Maryland 21402-5035; telephone 410-268-6110.

AFTERTHOUGHTS

Rochefort on: The Battle of Midway -- June 1942

Rochefort on:
The Battle of Midway -- June 1942