During World War II there was only one confirmed instance of a U. S. submarine firing on another U. S. submarine

Since 12-27-03
 

This article is printed as it appeared in the U. S. Submarine Veterans of WWII magazine Polaris vol. 43, No. 6 December 1999.  The Raton version is by RADM J. W. Davis, USN Ret who was the Commanding Officer of the Raton at the time of the incident.  The Lapon version is by CAPT R. C. Gillette, USN Ret who was the Executive Officer and Navigator at the time of the incident. 
 
RATON VERSION

During World War II there was only one confirmed instance of a U. S. submarine firing on another U. S. submarine.  It happened on the morning of 27 May 1944 in the South China Sea.  The two submarines involved were Lapon (Cdr L.T. "Steamie" Stone '29) and Raton on which I was the skipper.  At the time Raton was patrolling in an area adjacent to Lapon and Gunnel (Cdr. John S. McCain, Jr. '31) areas.  Since I never kept a diary or have war patrol reports available for reference, what I am now writing is from memory and must be accepted in that light.  After all this incident occurred almost 50 years ago.
 
A day or two before the incident we had received a "ultra" message (we used to refer to them as "burn before reading messages."  As I recall it started off "For Jim Davis eyes onl."  At that point the decoding officer stopped and brought the message and decoding machine to me and I finished decoding the message.  The message reported a small Japanese RO class submarine en route from Singapore to Japan.  It gave the routes, dates, times, and positions.  I made notes and then burned the decoded message in the ash tray on the wardroom table.  Next I passed this info to the Exec. who was also at the time Navigator, on a "need to know" basis.  He was the only other person on board who was privy to this info.  We then plotted it on a chart and set a course to intercept as I considered this message to me was for Raton's action only.  It meant that we would have to enter Lapon's area and I assumed that she was either on her way home or at least had been alerted to our probable entry into her area.  As I recall I never gave it any further thought other than the normal lookout for her when we entered her area.
 
On the morning of the incident I had told the navigator that we would delay our normal early dawn trim dive in order that he could obtain a good fix as we were approaching the projected tract of RO submarine.  Later on we were still on the surface when he called down from the conning tower and said he had a good fix and requested permission to change course 30 degrees to the right.  It was granted and I started to the bridge.  At the time I believe we were on course almost due west.  I had just started up the ladder in the Control Room and I could feel the ship turning when the ship was shakened by two strong underwater explosions.  My first reaction was we had been caught on the surface by a plane.  I hurried to the bridge and was surprised that the bridge personnel had not felt the explosions, but the J.O.O.D. did say he thought he might have seen a thin oil or air bubble slick about 1000 yards on the port beam.  Anyway we continued on and dove on the projected track of the RO submarine and commenced a periscope watch.
 
Early in the afternoon we made contact with the RO submarine and started an attack approach.  However, just before we were ready to fire she made a large turn away and we did not fire.  We surfaced later and started an end-around for a night surface attack.  Again we were not successful.  As we were going in for an attack the sub turned sharply away and dove.  We broke off contact and resumed our normal patrol.  We were also very close to the southern edge of Gunnel's area.
 
A little while later I was down in the wardroom preparing a message to headquarters in Australia about our day's activities when the Communications Officer handed me a message.  It was from Lapon and as I recall it started off "Oh my God X Missed repeated missed possible Uncle Sugar submarine etc."  A quick check of her position and the mystery of the two early morning explosions was solved.  I couldn't believe it, and as I recall I was a little upset.  I started my message to Headquarters "Poor shot X Missed repeat missed Japanese Ro submarine, etc."  After I had sent the message I realized that I might have violated coding instructions.  Six months later, while I was on duty in Pearl Harbor, the Director of Naval Communications informed me in no uncertain terms that I had indeed violated coding instructions.
 
After we returned to Australia I don't recall ever discussing the incident either with Adm. Christie or any member of his staff.  Neither did I ever discuss it in detail with "Steamie" Stone whom I had known only slightly up to that time.  However we became good friends and continued so even after his retirement and up to the time of his death.  I am sure that the reason that there were no searching discussions of the incident was the "very nature of the beast" - "ultra."  It was strictly taboo subject for discussions - an on a "need to know basis" only.  No reference or hints of "ultra" would ever be made in the war patrol report.
 
The reason I am writing this account after so many years is that in a recent book (1989) and account of the incident is recorded in which it is stated that Raton "went into her (Lapon) area" with no explanation why.  It further stated that Raton was "moving along underwater" when the attack occurred, when in fact Raton was cruising on the surface.  In none of the post war reports I have read has the reason why Raton was in Lapon's area been thoroughly recorded.  In fact in all of the reports there is a strong inference that Raton was at fault.  On the basis of that "ultra" message to me I believed that we were required to enter Lapon's area in order to carry out orders.  I further believe that the chief cause of this unfortunate incident probably had its birth in the Staff Headquarters back in Australia.
 
 
LAPON VERSION

RADM Jim Davis's, USN Ret interesting recollection of the Lapon vs Raton incident in the South China Sea on 27 May 1944 as reported in the January 1992 of Shipmate brought back similar memories that will remain forever etched in my memory bank.
 
The incident, from Lapan's vantage point, is very similar to that described by RADM Jim Davis, but is a variance on a few significant points.  I was the Executive Officer and navigator of Lapon and my recollection is as follows:
 
Lapon had been patrolling an area in the South China Sea, north of Raton, from about 13 May to 23 May 1944 without having made any contacts.  Lapon entered her South China Sea area through Balabac Strait North of Borneo and concentrated on the Palawan Passage area which had been fruitful in the past.  Finally, nearing the end of our patrol, with no results we decided to proceed west and look for targets near the Singapore - Tokyo route and then return home via Kaimata Strat west of Borneo via the Java Sea.  Fortunately, as we traveled west on 23 May smoke was sighted and the chase was on.  Lapon, succeeded in attacking a two-ship convoy on 23-24 May in a series of night surface attacks expending 20 torpedoes.  These all night attacks resulted in sinking the two large AKAs and seeing the escorts retire.  The next day, 24 May Lapon received an "ultra" message concerning a Japanese submarine, type unspecified, enroute from Singapore to Tokyo which would take her through Lapon's area.  This message, unlike the Raton message, was not addressed to "Eyes only Jim Davis" so Lapon immediately set course and speed to intercept the Japanese submarine.  We set up our attack plan on the assumption that the target would probably be running on the surface at night and submerged during the day.  This assumption was based on the fact that she was carrying very important German radar scientists/technicians and valuable spare parts.  To run the gauntlet of the great number of U. S. submarines between him and Tokyo on the surface during daylight didn't seem logical.  In any event we assumed he would be making a trim dive in the dawning hours after an all night run.
 
The Lapon strategy was to compute his estimated down diving position from the information in the "ultra" and patrol submerged at that point at shallow depth across his projected track using the periscope and sweeping with the SJ radar in quick bursts.  The possibility that the friendly submarine in the area to South would respond to the "Ultra" was not considered as it was beyond belief that Headquarters would send a submarine into a submarine occupied area without first telling the incumbent to pull clear.  Further, Lapon had informed Headquarters the day before that she had sunk two ships, had four torpedoes left and her position at the time of the attacks.  This position should have made it obvious to Headquarters that Lapon was in a position to intercept and would attack the Japanese submarine.
 
The foregoing is developed in some detail as it confirms in my mind that the Operations Department in Pearth really were asleep and couldn't have done a better job of setting up a potential catastrophic event as if that had been their intention.
 
As to the details of the attack, at about 0500 the periscope watch sighted what he thought was a sailboat.  I immediately went to the conning tower from the chart desk in the control room and identified the target, which was appearing out of the first light of dawn as a submarine.  After further observation, I identified it as Japanese when I saw what I believe were portholes.  Unlike US submarines, many Japanese submarines had portholes installed in the bridge structure.  Raton had a cut down bridge which was new and unfamiliar to the operating Perth boats.  The effect was that what appeared to be portholes were openings through the bridge structure which the light of the false dawn was showing through.  The identification was reinforced by the fact that the target was sighted on time, on the projected track, and at the expected dawn diving position as computed from the "ultra" message.
 
Lapon was immediately swung right to bring the four stern tubes to bear and an estimated set up put in the torpedo data computer (TDC).  Range, speed and angle on the bow were all estimated and the tubes made ready.  A four-shot speed was to be used.  The attack was developing rapidly.  At this time the Skipper "Steamie" Stone, took over the scope and made ready to fire.  He agreed with the identification and adjusted the set up slightly and fired the first two torpedoes of the spread of four at which time he ordered "checkfire".  I remonstrated saying that he was running the spread to which he replied "I think it's one of own."  There was an immediate silence through the boat and sonar was told to keep on the torpedoes in the water.  Our estimates had indicated that the torpedo run to target should take a little over two minutes.  At about four minutes we heard two explosions which checked out as end of run.  "Steamie" said he could still see the target and his screws were also heard.  The target changed course radically and went off at high speed.  Lapon then went deep at silent running to reconstruct what had happened.  The Japanese submarine could still be in the vicinity, and if so, would certainly be alerted by the explosions.  When about one hour had passed the decision was made to go to periscope depth and search with radar, surface when all clear, and clear the area.
 
Upon regaining periscope depth and getting ready to surface a periscope was sighted on the starboard beam.  Lapon immediately went deep, set silent running, changed course and continued a sonar search.  The question of course, was the periscope sighting for real?  If so, was it the Jap or was it the friendly sub?  
 
Obviously, there was no answer to these possibilities.  Lapon then attempted to contact the unknown submarine by sonar including plain language, referencing nick names that only a U S submarine skipper would recognize.  No responses were received so the decision was made that we would battle surface and quickly clear the area.  This was accomplished with no complications or contacts.  We proceeded towards Perth, as we only had two torpedoes and had informed Headquarters of the episode by sending a message which stated "missed, repeat missed a possible friendly submarine with two torpedoes."
 
The days events were not quite over yet as Lapon headed South towards Perth via Karimata Strait.  The high scope picked up a US Submarine approaching, the two of us approached like sniffing dogs with many changes of course to ensure eyeball recognition.  The approaching submarine was USS Gunnel commanded by Jack McCain.  When we got within hailing distance we told him we had fired two torpedoes possibly at Jim Davis in Raton whereupon Jack said, I hope you didn't sink him as I'm supposed to meet him later."
 
Upon arrival in Perth the Raton sailors maintained that we had hit them with a dud, as a large dent in the hull was found when she was in dry dock and that they had been really shaken up by the end of run explosions.
 
The memory of the deathly silence that prevailed on Lapon during the four-minute torpedo run will never be forgotten.  The episode was one that all wanted to forget and to my knowledge, other than Roscoe's book Submarine, had never been reported until Jim Davis's fine article in Shipmate.