The Sho Operation plans that the Imperial Japanese Empire drew up for the defense of the Philippines in 1944 were ambitious and desperate. Their implementation called for massive reinforcements of troops and supplies to reach the islands, which in turn called for large convoys to carry them in. Such a convoy, designated HI-71, began loading and forming in Japan in the early part of August 1944. The grim saga of it's struggle against the many United States Navy submarines which sought to block its passage -- and its connection to the demise of one of the greatest of them -- has heretofore gone untold.
HI-71 comprised many large and valuable ships, all loaded to the gunwales with soldiers, munitions, and the many other necessary implements of war-making. Among them were new fleet tanker HAYASUI (18,300 tons), food-supply ship IRAKO (9,570), tankers TEIYO MARU (9,845) and EIYO MARU (8,672), transports TEIA MARU (17,537), AWA MARU (11,249), NOTO MARU (7,191), HOKKAI MARU (8,416), TAMATSU MARU (9,589), NOSHIRO MARU (7,184), and MAYASAN MARU (9,433). Screen for the convoy would be provided by 6th Escort Convoy, under overall convoy-commander Rear Admiral Kajioka Sadamichi, scapegoat-***-victor at Wake Island in the war's earliest days. His escorting forces comprised two destroyers, the modern and well-equipped FUJINAMI (presumably serving as Kajioka's flagship, though the record is unclear) and much older (1920s-vintage) YUNAGI, the five smaller kaibokan (coast-defense vessels, or CDs) HIRATO, KURAHASHI, MIKURA, SHONAN, and No. 11, and last but certainly not least the escort carrier TAIYO. Other groups of vessels joining or leaving the convoy during its voyage would eventually confuse the total number of ships assigned it, but the above 19 certainly represented its core.
Neither TAIYO nor her Captain Sugino Shuichi were strangers either to convoy duties or to the hazards of war, and both had proven fortunate in such situations before. TAIYO had thrice been attacked by American submarines and twice hit and repaired, while Sugino had already survived the sinkings of two previous commands, destroyer SHIRAYUKI (in the Bismarck Sea convoy disaster) and cruiser KUMA (to a submarine). It could only be hoped that while covering this big convoy with TAIYO's 931st Air Group detachment of a dozen B5N "Kate" attack planes, their luck would continue to hold.
Admiral Kajioka led his ships away from Moji on 8 August 1944, bound eventually for Manila and Singapore but with a first stopover at Mako in the Pescadores. There the convoy's first "shape-shifting" took place, with five ships separating from it and another joining. [1] And as HI-71 sortied again from Mako for Manila on the 17th Kajioka's escort forces were further strengthened by five more warships sent from Takao on the orders of 1st Surface Escort Division: old destroyer ASAKAZE (sister-ship to YUNAGI) and kaibokan SADO, ETOROFU, MATSUWA and HIBURI.
Thus bolstered, Kajioka steamed south for Luzon Straits and Manila -- and almost immediately into his first encounter with enemy submarines. For at 0524 on the 18th USS REDFISH (SS-395) put a torpedo into EIYO MARU, damaging but not sinking her. Either the transport or her cargo must have been deemed valuable indeed for Kajioka detached both destroyers ASAKAZE and YUNAGI to shepherd the cripple back to Takao. This would seem a most generous if unwise detachment of strength at the very outset of what all had to know would be a bitterly-fought battle ahead.
Both destroyers would be heard from again before HI-71's story had ended.
Thus depleted but with tightened formation and vigilance increased to the maximum, the convoy pressed on south. But as the day wore on the seas rose, and by the time HI-71 was well into Luzon Straits a typhoon was raging. Off northwest Luzon gale winds reached Force 12 from the southeast and aided the onset of evening in shutting down visibility. Kajioka's convoy began to become increasingly scattered and disorganized as the ships rolled and pitched in the stormy seas and pitch black night of 18/19 August.
Under such conditions did the onslaught of the American submarines against Kajioka begin in earnest, opened by one of the most daring, determined and deadly of all: USS RASHER (SS-269).
At 2225 the TAIYO, traveling at the back of the convoy as per standard procedure, suddenly exploded in a shocking concussion and 1,000-foot-high mushroom of flames. The "Great Hawk's" luck had run out when two RASHER torpedoes crashed into her starboard side. Facts about the flattop's final fate -- how long she remained afloat and whether she took even another hit to port -- became obscured in the resulting mayhem. His lucky star proving more faithful than TAIYO's, Captain Sugino survived her sinking. But as TAIYO burned and exploded, the rest of the convoy fell apart and into chaos as all ships accelerated to maximum speed and sought escape individually, losing contact with one another in the driving rain and fire-seared night.[2]
Meanwhile RASHER continued her relentless attack, and at 2310 torpedoes exploded along the starboard side of the huge transport TEIA MARU. The ex-French liner caught fire and staggered out of formation, mortally wounded. On her crowded decks men vied for lifeboats as the ship's distinctive square funnels tipped toward the sea. Escorts approached but could do little but attempt to rescue survivors when TEIA MARU slipped under. She was the second-largest merchant ship sunk by U.S. submarines in the war.
As if TAIYO and TEIA MARU were not enough, RASHER claimed two more hits on a "very long" vessel and one hit on another. Though records don't seem to bear this out, there would occur at least one anonymous sinking and two other ships damaged at unknown times that night.[3]
And still RASHER was not done, but relentlessly pressed her attack against the disintegrating HI-71. By now the convoy had split into at least two distinct groups and probably more as it broke apart in flight. Just past midnight of the 19th RASHER closed in on an eastbound group of three large ships with one escort (probably ETOROFU), and at 0033 torpedoes blew open the port sides of armed merchant cruiser NOSHIRO MARU and transport AWA MARU. RASHER later reported one target blown up and sunk and hits on two others. But in fact both vessels were able to make it to shore, there to beach themselves near Port Curimao to avoid sinking. RASHER pursued, but at 0510 with dawn breaking and an escort approaching, she finally had to break off. RASHER's final satisfaction before turning away came from observing a big armed cripple (probably NOSHIRO MARU) open fire on the escort, apparently having mistaken it for the hated submarine.
Even as RASHER chased her victims ashore, all Hell continued breaking around and amongst Kajioka's other ships to her rear. For REDFISH had kept up with him after hitting EIYO MARU, and was now joined in the attack by USS BLUEFISH (SS-222) and USS SPADEFISH (SS-411) as well. Such were the conditions and ferocity of their ongoing assaults that proper crediting of results was and remains difficult to determine. At 0320 HAYASUI took two or three hits, and the big fleet tanker burst into flames and went down stern first. At 0510 tanker TEIYO MARU was also hit and went to the bottom. To top off the ignominy, the TAMATSU MARU simply vanished: her "whereabouts became unknown." She never responded to Kajioka's calls, and was never seen again.
Admiral Kajioka realized that if something wasn't done his convoy would soon become extinct, and the riddled HI-71 was ordered to make for the temporary haven of San Fernando. To hold down the enemy submarines and perhaps exact some revenge, as well as doing what they could for cripples and/or survivors, the SADO, MATSUWA and HIBURI were ordered to stay in the attack zone and cover the convoy's flight with aggressive antisubmarine sweeps.
Although the embattled Japanese could not know it, the worst of the nightmare was past. Kajioka's abrupt course-change apparently succeeded in throwing off his attackers: the American submarines had -- temporarily -- shot their bolt. HI-71 gradually reformed off San Fernando, then successfully made the short run from there to Manila without further molestation, arriving on 21 August.
As it did so U.S. codebreakers were busily tracking a flurry of ULTRA intercepts and trying to determine just what damage the submarines had inflicted to date. According to these the AWA MARU had at first been temporarily grounded, then with "small damage" was reported to be under tow; she would in fact arrive in Manila on the 21st not long after the main body of the convoy. The EISHIN MARU was also "hung on a reef near Port Curimao," while the TAKATORI MARU "was aground and in great distress." The NOSHIRO MARU was also beached with "medium damage." But that damage proved sufficient to immobilize her, and NOSHIRO MARU was still there when finally destroyed by Halsey's TF 38 on 21 September.[4]
With HI-71 safe at Manila, and his three detached escorts frustrated after two days of unsuccessful submarine-hunting, Admiral Kajioka on the 21st ordered SADO, MATSUWA and HIBURI to suspend their actions and proceed to Manila. They were just approaching the entrance to the bay early on 22 August when further catastrophe struck. For awaiting them was the dread "destroyer-killer," Commander Sam Dealey's USS HARDER (SS-257), and consort USS HADDO (SS-255).
The resulting execution was reminiscent of the triple-sinkings of British armored cruisers ABOUKIR, CRESSY and HOGUE by German submarine U-9 in World War I. But in that first war the sub's quarry had been big, slow, and ungainly relics that had no place sharing the same seas with stealthy underwater marauders. This time around the victims were much more modern and nimble craft, actually designed to confront submarines. And yet the result was the same. Never before or after would the kaibokan's shortcomings vis-a-vis their American fleet submarine counterparts be more eloquently or dramatically showcased.
Without warning, at 0456 both MATSUWA and HIBURI were torpedoed in their port sides by HARDER and stopped dead in the water . SADO signaled for assistance, then gamely stood by her stricken consorts. Then at 0524 SADO herself was torpedoed and immobilized, this time by HADDO. It is a testament to their sturdy design that all three little warriors initially remained afloat. But their fate was sealed nonetheless, for no help was forthcoming from Manila -- so near and yet so far. Drifting helplessly, their crews could only watch and wait their turn as one by one the ax fell upon them. At 0649 MATSUWA was blasted under the waves by HARDER. At 0720 HADDO fired three torpedoes at the two remaining derelicts: one missed but the others hit SADO squarely and sank her as well. HIBURI's torment ended at 0755 when she rocked violently and plunged under the waves bow first, another -- and, unbeknownst to all, the last --victim of the deadly HARDER. Whether or not the luckless kaibokan yielded up any survivors is unknown.
Admiral Kajioka received and digested this latest distressing news as his ships at Manila off-loaded cargo marked for Luzon and steeled themselves to resume the voyage to Singapore. But he also received orders to await the arrival of further vessels before proceeding. For back at Takao lay the brand-new tankers HAKKO MARU No. 2 (10,023 tons)and NIYO MARU (10,022). HI-71's earlier loss of ASAKAZE and YUNAGI now became their gain, for the two destroyers were ordered to get the tankers down to Manila to join Kajioka for the run to Singapore. The little convoy, under the command of YUNAGI's Lieutenant Commander Iwabuchi Goro, departed Takao at 0900 on the 21st.[5]
Iwabuchi's headaches began with the new tankers' repeated engine breakdowns and machinery mishaps. But worse was to come, for at 1455 on the 22nd they ran into yet another undersea ambush. It was off Cape Bojeador, where TAIYO had gone down four days earlier, that HAKKO MARU No. 2 was struck by two torpedoes, fired by USS SPADEFISH, in the port bow and amidships. The tanker's keel was buckled and the bow sagged, but the well-built vessel remained afloat and maneuverable. Iwabuchi ordered his other ships to accompany her to nearby Besarang Bay while he remained behind in YUNAGI to hold down the sub. This accomplished, Iwabuchi rejoined them there, then directed ASAKAZE to proceed with NIYO MARU to Manila while his YUNAGI remained to assist and protect the beached cripple.
It was well that YUNAGI did so, for SPADEFISH's Commander Gordon Underwood was not a quitter, and coolly resolved to take his boat into the glassy waters of the shallow bay, sink the destroyer, and finish off HAKKO MARU No. 2. Gliding in, SPADEFISH began a wearying game of cat-and-mouse, finally settling for a shot from his stern tubes. At 1430 SPADEFISH fired off all four of these, only to have them detonate in the shallow bottom short of the tanker. Thus alerted, YUNAGI began dropping depth charges, but brought up only "dead fish." As Iwabuchi continued random depth-charging, SPADEFISH prudently decided to let this game go, and headed back out to sea. This round had gone to YUNAGI.
But further south, Lieutenant Yamaguchi Osamu's ASAKAZE could not claim the same. The subsea demons were far from finished, and at 0800 on 23 August, as she escorted NIYO MARU off Lingayen Gulf, the destroyer suddenly had her bow blown off by a torpedo fired from the ubiquitous HADDO. Fortunately for NIYO MARU it was HADDO's last torpedo, and the submarine had to withdraw while calling for help from packmates. Sorely-stricken ASAKAZE initially remained afloat, and the tanker took her in tow for Dasol Bay. But as flooding gained and the destroyer's shattered bow nosed further under, Lieutenant Yamaguchi and his crew were taken aboard the tanker. ASAKAZE finally rolled over and sank, while NIYO MARU proceeded disconsolately but safely into Dasol Bay.
Outside the bay, though HADDO had withdrawn, her place was soon taken by none other than the fearsome USS HARDER, now accompanied by USS HAKE (SS-256). Unaware that ASAKAZE had sunk, the two packmates conceived a plan to finish her off. HARDER would guard the entrance while HAKE went in at floodtide the next morning to destroy the cripple.
But as the two subs closed Dasol Bay at 0630 on 24 August, they picked up pinging approaching from the southeast. Responding to Yamaguchi's calls for assistance, Patrol Boat No. 102 and CD No. 22, assisted by a depth charge-equipped plane flying overhead, had put to sea to destroy ASAKAZE's attacker.
As the two American submarines came in for their attack, HAKE's skipper found that he didn't like the setup, so broke off. Commander Dealey, however, continued in towards Dasol Bay: the "destroyer killer" was apparently intent on adding to his score. But this time the cards would fall the other way.
Aboard Patrol Boat No. 102, Lt. Tomoyoshi Yoshima supervised the run as his ship closed for the attack, and when the aircraft detected submarine activity below, No. 102 proceeded with deadly thoroughness. Japanese reports indicate that HARDER let fly three torpedoes at CD No. 22, but for once missed. The airplane then dropped a depth charge, apparently forcing HARDER deeper and, more importantly, indicating her position. At that point No. 102 charged in to seize the advantage. At 0828 she commenced a lethal series of depth charge runs, each charge set to detonate at a depth greater than the last. Somewhere below, the gallant HARDER was firmly bracketed, and the fifth salvo touched off explosions that finally ended the lives and career of HARDER and her entire crew. The patrol boat recorded that that fifth salvo brought oil, wood splinters, and cork bubbling to the surface, and a sounding confirmed that this time at least, the Imperial Navy had won a resounding victory in its undersea war.[6]
Adding grim irony to this Japanese triumph and American tragedy was the fact that Patrol Boat No. 102 was none other than the ex-American destroyer USS STEWART (DD-224). Japan had captured her in a damaged condition in a Surabaya drydock early in 1942, then repaired and rebuilt her as the humble patrol boat that would deprive ComSubPac of one of its most celebrated boats. Truly a ghost coming back to haunt those who had abandoned her, and in a manner worthy of the most demonic of spirits.[7]
One final Japanese loss, though technically no longer Kajioka's, also deserves mention here. For on 25 August, the day after HARDER's sinking, the northbound Japanese convoy MA-TA 48 passed by Besarang Bay, where YUNAGI and HAKKO MARU No. 2 still sheltered. The convoy detached CD No. 25 to take over the tanker's guard, and YUNAGI came out to take her place in the convoy's screen. Not even an hour later, KOTOKU MARU (1,943) was struck to starboard by a torpedo from USS PICUDA (SS-382) and sank immediately. Spinning to the counterattack, YUNAGI then herself fell victim to a "down-the-throat" salvo of three torpedoes from the same sub. Her back broken by one of them, veteran YUNAGI remained afloat only ten minutes before sinking with 38 of her crew. Lieutenant Commander Iwabuchi, along with 202 others, was rescued by CD No. 35. But, having had ships torpedoed out from under his protection three times in one week, including in the end his own, his despair is probably better imagined than described.
On 26 August the reformed HI-71, now reduced to twelve marus, set forth again from Manila, bound for Singapore. Of 6th Escort Convoy, only FUJINAMI, HIRATO, KURAHASHI and MIKURA remained of the warships that had accompanied it from Japan and Taiwan. (Losses aside, SHONAN, ETOROFU and CD No. 11 were replaced in the screen for this last leg of the voyage by CD No. 2 and Subchaser No. 28.)
As if impressed by their tenacity, the fates finally relented. Not even the seemingly-omnipotent U.S. Navy could have its wolfpacks in all places at all times, and Admiral Kajioka's shrunken convoy reached Singapore on 1 September 1944 without further incident.
As they were directed to their berths and dropped anchors, the ships' weary crews can only have breathed profound sighs of relief, and counted themselves singularly fortunate. For behind them, strewn along the seabed and beaches of Luzon's western littoral, lay the remains of an aircraft carrier, two destroyers, three kaibokan, and over a half-dozen tankers and transports -- all priceless to the Empire and utterly irreplaceable by this stage of the war. And of course one American submarine, equally irreplaceable in her own unique and storied way. Not to mention the corpses of hundreds, if not thousands, of brave seamen and warriors. These losses, the many dramatic and deadly battles which led to them, and the dogged courage and perseverance of both sides in continuing to press forward despite them: all combined to make HI-71's story one of the epic convoy sagas of World War II.

(Note 1) Author's Note: Translation uncertain here, but seems to indicate that five of the twenty marus of the the convoy separated from it at Mako. If so, it might explain the discrepancy contained in some sources that say the convoy was fourteen ships that night. On the other hand, this might refer to the *joining* of five separate ships, ie, a reference to the ASAKAZE and the four frigates.
(Note 2) None of the U.S. accounts really agree on which of RASHER's attack runs the TAIYO met her end. Some claim she was the first to explode, which finds support in the 1st Surface Escort Division's War Diary. Others say she is the second long ship struck in the second attack which sank TEIA MARU, while still others suggest she is one of the vessels hit in the third attack. Similar confusion persists about the times TEIA MARU and TEIYO MARU were torpedoed. The Japanese sources themselves confuse the issue with TAIYO's TROM, which indicates the carrier survived one hit, only to be sunk in a second attack, while the War Diary implies sudden destruction by equating her with the first ship that RASHER stated blew apart. Further research is needed before this point can be clarified; perhaps TAIYO crew members still alive will contact me and provide some answers.
(Note 3) The heretofore most accurate English language account appears to be in W.J. Holmes' Underseas Victory. Holmes mentions typhoon weather and clearly states that TAIYO was the first ship hit and exploded in an eruption of flame, which checks with the 1st Surface Escort Division's version. However, he gives a vastly abbreviated roster for the screen, listing only TAIYO, YUNAGI, SADO, MATSUWA, HIBURI, and MIKURA, while adding Special Subchaser #39, which was apparently not even present at all. For convoy composition, Holmes gives "ten marus, mostly fast tankers". His source for this incomplete account is not known, and it would be interesting to learn its origin. If separate from the 1st Surface Escort Division's War Diary, it could provide independent confirmation of the time of TAIYO's explosion. As it is, it is impossible to account for his inclusion of Subchaser #39, nor the smaller scale of the screen.
(Note 4) Most U.S. accounts of HI-71 list the EISHIN and TAKATORI MARUs among the victims of the night of the 18/19th. Further, they claim EISHIN MARU, a mere 542 tons, was the first ship hit and exploded by RASHER's attack. However, the EISHIN MARU was hung on a reef on 21 August, and so could not have been the first ship hit. Further, it seems quite possible that EISHIN and TAKATORI MARU were not even part of HI-71 in the first place, though it may be true of the latter. The list of HI-71's marus is incomplete, but only by one or two vessels.
(Note 5) The story of the YUNAGI and ASAKAZE escort mission and the YUNAGI's subsequent loss are not found in the 1st Surface Escort Division War Diary's account of HI-71 as quoted in BKS No. 46. Instead, the details are in the YUNAGI's Detailed Action Report for 21-25 August 1944, which by a stroke of fortune survives and was translated by the author. The DARs preface and summary when mated with the Diary's account make clear that YUNAGI and ASAKAZE were both part of HI-71, only to be temporarily detached when EIYO MARU was damaged and returned to Takao.
(Note 6) The real connection and relation between HI-71 and the HARDER's last action and loss has not previously been recognized. That ASAKAZE was part of the ill-fated convoy and thus HARDER's quarry involved in it, was not revealed by the published sources to date. Thus the tale of the HARDER's last fight is appropriately part of the greater tapestry of one of Japan's worst convoy disasters.
(Note 7) The Story of PATROL BOAT No. 102's destruction of USS HARDER was translated by Edwin P. Hoyt and published in his Submarines At War (Jan 1992) page 255. The source was an article written by a No. 102 officer, Tomoyoshi Yoshima, that appeared in the Sept. 1981 issue of Rekishi to Jinbutsu (History and People). However, Mr. Hoyt did not discover or mention the connection to HI-71.