CDR Alden is a WWII submarine veteran and has conducted significant research on US WWII submarine actions. Results of those researches have been reported in his previous articles in these pages.
Sixty-six years late, a previously unclaimed US submarine victim has come to light! The sinking of the Japanese KAIBOKAN (Coast Defense Vessel) CD 219 has until now been attributed to U.S. carrier aircraft, but a recently translated report by a sister ship makes it clear that one of our submarines was the real killer. I am indebted to Erich Muelthaler, a German researcher, for translating the Japanese document and providing the essential information that follows.
On 12 July 1945 a hunter-killer group consisting of CD 219, CD 65, and minesweeper W 24 left Ominato to sweep the eastern approaches to Tsugaru Strait in a southern direction, starting from Erima-misaki on the Hokkaido side and continuing toward Shiraya-zaki on Honshu. The three ships formed a horizontal line covering a span of five nautical miles with CD 65 in the center, CD 219 on the eastern end, and W 24 on the western end. While working their way southward, CD 65 discovered and avoided two torpedo wakes at 2030 Tokyo time. Two hours later it heard two heavy explosions to the eastward and closed the range to investigate when CD 219 failed to respond to a call. A search revealed only some floating debris but no sign of CD 219 or any survivors. The KAIBOKAN had vanished together with its entire crew of 193 men.
A search of US records shows that the only submarine firing torpedoes at the time and location in question was CARP (SS 338) under Lieutenant Commander James L. Hunnicutt, USNR. CARP was a new Balao-class boat fresh out of the building yard at the Electric Boat Company in Groton, CT and on its first and only war patrol. It was also Hunnicutt’s first command, which was noteworthy because he was the third of only seven reservists to command fleet boats during the war. The deployment got off to an inauspicious start when the executive officer was hospitalized after a fall on deck while the boat was undergoing training at Balboa, and had to be replaced. The patrol report shows that of 83 men on board at the start of the patrol, 45 were not qualified; 38 of these were making their first war patrol. Of the nine officers, five had made no previous patrols. This was a remarkably inexperienced crew even at that late stage of the war. None-the-less, the report describes an aggressive and successful patrol.
The attack that downed CD 219 is of particular interest because of its circumstances as well as the difficulties involved in resolving its outcome. It started early on 12 July when radar contact was made on two ships whose tracks indicated that they were patrolling back and forth off Todo Saki light in Tsugaru Strait and whose pinging identified them as anti-submarine vessels. A third more distant target appeared on the radar screen about two hours later. The two closer ships were tracked throughout the day and identified as a minesweeper and a PC, but several attempts to reach a firing position were unsuccessful. Shortly before midnight Hunnicutt surfaced, made an end-around approach, and at 0115 on the 13th fired two Mk 18-2 torpedoes from tubes #3 and 4 at the larger target. At this point in the narrative the words See special report are inserted. Then at 0121 an unidentified explosion was heard, followed by another that was believed to be a depth charge. However, both targets remained in contact, so at 033 7 a single Mk 18-1 was fired from tube # 1. This one was seen to premature ahead of the target, which continued on course. (Although both CARP and CD 219 were reportedly using Tokyo time, they seem to have been several hours out of agreement. Such discrepancies between U.S. and Japanese accounts are unfortunately very common.) Before contact was lost, the minesweeper was seen to be signaling to the PC by searchlight, so the torpedoes had obviously missed the target.
The key to this case lies in the special report. Such reports were required for highly secret operations such as the employment of an experimental weapon. They were normally classified Top Secret or Secret and handled separately from the regular patrol reports. Even today they are not readily accessible to researchers.
However, enough information is available from other available records to provide a spare outline of the special operations- four in all-noted in CARP’s patrol report. The first clue appears in ComSubPac’s third endorsement to the patrol report, which credits CARP with nine ships sunk-three by torpedo, four by gunfire, and two by separate report-and six damaged by gunfire. Most were sea trucks or other small craft; those attributed to the separate report were a PC and a lugger.
The second source is the Submarine Operations Research Group’s comprehensive list of submarine attacks. This indicates that during the patrol Hunnicutt fired 11 Mk 18-2s for four claimed hits, two Mk 18-ls for one hit, three CUTYs for 2 hits, and one DOGY for no hit. CUTY (or Cutie) was the code name for the Mk 27, an undersized swim-out torpedo with a passive sonar homing head. The less well-known DOGY was the Mk 28, also a homer but a full-sized weapon that had to be ejected by air. Both types became available only very late in the war and were subjected to extreme security measures in order to prevent the Japanese from learning of their existence. They were typically carried aft in order to be fired from the stem tubes against pursuing anti-submarine vessels. The DOGY was the special torpedo fired by CARP at the presumed minesweeper on 13 July in between the MK 18s. Since none of the four torpedoes hit their intended target, which was CD 65, it would have been pure luck for one of the straight-running MK 18-2s to continue on and hit a distant, unseen third ship. It appears much more likely that the homing DOGY could have been attracted to a new target, so it was probably the torpedo that accounted for CD 219.
Despite the positive evaluations by ComSubPac, no ships at all were credited to CARP in the Joint Army-Navy Assessment Committee’s official postwar tally. The sea trucks, luggers, and probably some other victims as well were too small to meet JANAC’s cutoff limit of 500 gross tons. Japanese records available to JANAC for the final months of the war were- and still are- notably fragmentary or contradictory if not entirely missing. However, previous postwar disclosures have provided evidence that the 1,535-ton cargo ship KOGA MARU and the 135-ton auxiliary subchaser CHA 59 were probably sunk by CARP. The 745-ton CD 219 is a significant addition to that record. It was one of a large class of anti-submarine ships built under war emergency programs, and in size and appearance it closely resembled the Japanese pre-war minesweepers illustrated in naval recognition manuals. So to CARP’s surviving wartime crewmen, a belated but hearty “Well done!”