© 2005 Anthony P. Tully



By A.P. Tully

E-Mail: tullyfleet@gmail.com


(Note: All times set to Z-9, Item time.)

The struggle for the Solomons chain that was the immediate sequel to the bloody Guadalcanal campaign would prove very expensive to the Imperial Navy, especially in losses and damages to cruisers and destroyers. However, very few heavy ships were lost in 1943. A major exception that most likely deprived Japan of a successful carrier conversion later in the war was the disastrous sinking of the seaplane tender NISSHIN in summer of 1943. Though almost brand-new, the NISSHIN was already a veteran of high speed runs into enemy waters when her luck ran out off Buin. It came about when the end of June 1943 saw the American landings on New Georgia island. When this happened, it was decided to immediately reinforce the garrison at Buin. To that end, on 10 July, 1943 the NISSHIN departed Kure escorted by HAGIKAZE and ARASHI. Aboard the NISSHIN was a contingent of the South Sea No. 4 Guard Unit comprised of 630 troops, twenty-two tanks, eight artillery guns and mortars each, and reserve supplies of food and gasoline, all earmarked for the garrison at Buin. The tanks were placed in the seaplane hanger located between the uprights below decks, the food stored amidships forward of the aircraft storage, and the gasoline drums placed in the stern of the vessel. The field guns and mortars were arranged to balance the weight evenly, eight on port and starboard sides respectively.

The 11,317 ton NISSHIN was one of four purpose-built seaplane tenders. Each had four catapults with 24 seaplanes. Since then she had been converted with CHIYODA to also carry midget submarines. Like MIZUHO, it had been decided to power her with diesels only, and six diesels drove two shafts, to give 47,500 bhp. There was no stacks, the exhaust being trunked into the uprights. She was armed with 6 x 127mm and 18 x 25mm guns, 192 meters long with an assigned complement of 948 officers and men.

During the Guadalcanal operations the NISSHIN had already racked up quite an impressive record of such high-speed "Tokyo Express" runs, landing reinforcements and equipment without damage. However, her present skipper Captain Ito Jotaro had been in command only since 5 December 1942, and had not conned those operations.

Arriving at Truk on 15 July, after a four day layover departed for Rabaul, the trio now joined by heavy cruiser MOGAMI, light cruisers AGANO and OYODO, and ISOKAZE. This force arrived at Rabaul on 21 July where 250 additional soldiers boarded each of the three destroyers. There was a strong sense of urgency in the air and little time was wasted, with the force departing Rabaul for the Shortlands late in the evening that same day. Commanding the operation was ComDesRon 10 RAdm Osugi Morikazu, who had shifted his flag from AGANO to HAGIKAZE to personally lead the reinforcement dash.

Fortune appeared to desert the mission at the onset. At 2300 enemy planes were sighted in the night skies above, and it was feared that the reinfocement had been discovered. Nonetheless, there was no considering of cancellation and at 0130 course was altered to the final course that would bring the fleet straight to Bougainville. Despite concerns, the next morning brought no attack, and the NISSHIN and her destroyers pounded on at flank speed on course 140 degrees. The destroyers were arranged in an elongated inverted triangle, each 3 kilometers distant from the tender. Flagship HAGIKAZE was on NISSHIN's starboard bow, with ARASHI holding station nearly abeam to port, while ISOKAZE brought up the rear and lookouts on all four ships kept their eyes skyward on sharp watch. The weather was good, and the skies were filled with many bright cumulus clouds, which would conceal any approaching enemy aircraft. But noon came, and still no enemy had appeared. It began to seem that the force had not been detected after all. Arrival at Buin was projected to be 1630, only four hours away. A hard night's work remained ahead of course; the tanks could only be landed on the beach at the rate of two per hour, but the important thing was it looked like NISSHIN and compatriots were going to make it. Hopes rose for the mission's success.

These hopes were totally in vain. Though the late John Winton's recent work "Ultra in the Pacific" does not mention the NISSHIN affair, other works have speculated that the timing, volume, and precision of the attack that followed are typical of an "Ultra" warning and advance notice, and strongly suggest an aerial ambush had been premeditated. The author has now confirmed these speculations correct. There is now no question of this -- ULTRA records reveal that starting 19 July 1943 the Allies got wind of the NISSHIN's planned reinforcement and movement. A particularly fatal intercept of 21 July 2137 message gave numbing details of the NISSHIN convoy's estimated time of arrival and even anchorage points. The reinforcement operation, and the heretorfore fortunate veteran of many `Express Runs' was already doomed before departure from Rabaul. The NISSHIN and her precious cargo were not fated to arrive at Buin. A powerful air strike reported as comprising of twelve B-24s, eighteen Avenger TBFs, and sixteen Dauntless SBDs covered by 120 fighters had been launched to destroy them.(Note 1) They swiftly closed on their quarry, finding it just about where expected, in the Bougainville Channel.

The force was little more than two hours away from its destination and just southwest of the Bougainville Channel when at 1345 enemy planes were sighted in a break in the clouds. It was a large formation of aircraft, but they were not on a closing course. A gamble was taken, and the ships initially held fire, hoping to avoid detection in the event the enemy had not actually spotted the four vessels. For three minutes nothing happened, but at 1348 ARASHI suddenly warned that another group of enemy planes were only 1,000 meters distant, bearing 110 Degrees True, altitude 40 degrees and closing to the attack. All guns swung about and opened fire.

The swift NISSHIN cranked up speed to maximum, hitting 34 knots, and shifted course to 120 degrees. The enemy planes appeared to be more than ten B-17's, and their bombs were already falling. However, NISSHIN's sharp turn and speed outwitted them, and the bombs all missed, splashing into the sea some 1,000 meters off the starboard bow. Exploding and driving skyward large columns of water. All aboard felt elated relief, for Buin was only two hours away, and the enemy's strike had missed.

Suddenly, at 1353 and without warning "more than forty" enemy fighter bombers (It was actually thirty four fighter bombers involved, plus the B-24s) plunged like Kingfishers out of the clouds from 135 degrees to port, 1,000 meters. Captain Ito threw NISSHIN into a furious `maximum emergency turn' to port, causing the tender to heel sharply to starboard in her evasion. She almost made it, but one of the bombs struck the No.2 turret on the port side, tearing a twenty-meter hole in the waterline below it as well. Flooding resulted and a fire forward below was reported.

NISSHIN was still making good speed and handling well, and two minutes after the hit, at 1356, Captain Ito took the precaution of ordering the forward magazines flooded. This averted the immediate danger, but cost some trimming of the bow. The destroyers twisted and corkscrewed, firing their guns in frantic attempts to draw the enemy to themselves, but to no avail. More aircraft made steep dives, targeting the squirming seaplane tender.

In rapid succession two more bombs exploded aboard. By very bad luck, since the crew had been making preparations for unloading the tanks, the hangar was open and a bomb landed directly inside the forward end of it, causing severe internal damage deep in the vessel and starting a big fire. Great clouds of black smoke boiled forth between the uprights amidships and the fire spread rapidly below. This was bad enough, but immediately thereafter the third bomb struck the forward end of the aircraft maintenance deck to starboard of the center-line, enlarging the fire raging in the hangar and amidships.

The inferno spread from the aft engine room all the way to the forward generator room. The main panel of the electrical distribution room was knocked out, and electrical power failed. Lights went out, and communications became unuseable. Speed was more than halved, falling to 15 knots. Worse, the power failure jammed the rudder, causing the NISSHIN to swerve and circle out of control belching clouds of smoke like a snorting bull. Making matters worse, about 20 enemy fighters came in on the starboard bow, raking the packed decks with a savage strafing run. However, once they were past, the sky was momentarily clear of planes and a lull followed.

The Japanese were quick to seize the break offered, and Ito's crew went to work with commendable efficiency. The jammed rudder was reset and locked on the centerline position, and temporary steering ordered. Since the communications between the bridge and steering room were cut off, they attempted to con the ship by hand signals and flags raised from the bridge. However, the mushrooming smoke from the fire raging in the hangar foiled this as well, and steering simply had to "be done by guess". The NISSHIN could essentially steam only straight ahead, and a "slight weaving motion" the only evasion possible. Captain Ito would have to depend on his gunners and those aboard the destroyers to thwart any further attack. They were only twenty miles from Buin.

It may as well have been 200 miles. For the lull was vanishingly brief, and at 1359 enemy carrier bombers were seen boring in on a horizontal dive from 40 degrees port. One can only imagine Captain Ito's dismay, as he could do nothing to turn aside from the attack but bear on straight and pray that the enemy would over or undershoot their target. This was a vain hope, and at 1400 two bombs from the first group crashed into the tender's port side between the #4 and #6 PA mounts, penetrating the deck and exploding inside with a tremendous blast. The explosion and shocked wreaked tremendous carnage, causing heavy flooding and a full thirty-meters of the topside deck port side to collapse into a giant hole formed. Apparently the explosion vented out the starboard side, for the NISSHIN began to list noticeably to starboard and settle by the bow. Already waterlogged with the magazines flooded earlier, the tender's forepart nosed sharply down, and soon the jackstaff was cutting the water.

The NISSHIN was clearly doomed, and the order to abandon ship was given. Heroically, the NISSHIN's crew gave first priority to aiding the escape of the soldiers aboard, giving little thought to their own safety. The gunners remained at their machine guns till they were actually washed away from them, seeking to lay down cover fire for the evacuees as enemy planes returned to assault the sinking vessel. Army men ill-suited to escape and swim from a sinking ship frantically clambered over the sides with sailors helping as best they could. Nor did the danger from above relent: at 1403 the sixth and last bomb blasted the tender between the #3 and #5 PA mounts, roughtly opposite from where bombs #4 and #5 had hit to port. But this was redundant; the NISSHIN was already settling rapidly by the bow now and heeling further to starboard.

A mere fraction of troops and crew had had time to clear the ship when at 1405 the NISSHIN lurched sharply to starboard and plunged under the waves, bow first. The rush of the sea at last extinguishing the raging fire in the hangar as she slid under. Senior survivor was LtCdr Tsurumaru Hirotsugu, washed from the bridge as it plunged under, but Captain Ito Jotaro, his XO Commander Tanaka Eichu, First Lt. LtCdr. Aizawa Kitakazu, and Chief Engineer Commander Terada Terao all were killed or went down with the ship. The position was 06-33'S, 156-10'E.

As noted before, by cruel stroke of fate, the escorting destroyers were already loaded with troops -- 746 between all three ---- and hardly in a position to risk them or attempt to take on more survivors. Nevertheless, since the enemy withdrew, the risk was taken to see if at least some lives could be plucked from the sea before sunset. But due to the speed of sinking, the pickings were slim, and time to linger too short. At 1625 the destroyers were bombed by seventeen B-17's . No damage was suffered, but they dared tarry no longer. The three ships simply had to leave the scene to land their own forces, and hope to send out help later. Flank speed was rung up to leave the B-17s and the scene of disaster behind. The men in the water would have to hold on till darkness fell. At 1830 the heartbroken remnants arrived at Buin. They wasted no time, unloading as swiftly as possible, putting back out to sea at 2000 and arriving at the scene of the disaster two hours later. Yet even the dark of night offered little protection: the rescue had been underway for only an hour when enemy planes attacked the three destroyers. As the disastrous sinking of destroyer YUGURE and damage to cruiser KUMANO after midnight just three days prior warned, the enemy's night capability was not to be underestimated. Nor was the fate of YUGURE's would-be rescuer, KIYONAMI, sunk the next morning, forgotten either. Returning by day would not be an option. After enduring the attacks for a few more minutes the three rescue ships cleared out, and with heavy heart, fled the scene and headed back, not to Buin, but to Rabaul. Regrettably left behind also, was one three of their rescue cutters with a total of two officers and 30 men aboard. It is unclear if they made their way safely to Buin or elsewhere subsequent to the report.

It was not a large naval action, and the reinforcement run and its destruction was termed by S.E. Morison as "routine". But the fact is the loss of the NISSHIN proved to be one of the Imperial Navy's greatest disasters. Between the rapidity of the sinking and the delay in rescue, the casualty toll was tragically heavy. Of the 630 hapless soldiers aboard - despite the valiant efforts of the crew -- only 91 survived. NISSHIN's toll reflected their hard efforts as well: only seven officers and eighty men of the seaplane tender's crew escaped. A grim total of 1,085 lives had been sent to the bottom of the Bougainville Strait. The 178 numbed survivors, the soldiers among them, were simply returned to Rabaul on 23 July on the same destroyers that had come with them. (But see Note 2). Captain Ito was duly promoted posthumously.


Note 1: Comairsols - 221224 bulletin.

Note 2: There is some ambiguity on the exact loss, as the reading of the microfilm of the Action Report appears to be different from the loss figure quoted here from Senshi Sosho. Caution is advised.


Thanks go to Mr. Jean-Francois of Canada for providing crucial details of officers and assignments.


Taken during an earlier attack, on 13 October 1942, this picture strongly suggests how NISSHIN may have looked like during her final action as well. Ironically, on this occasion, she was also at Bougainville, having delivered supplies to Guadalcanal two days previously. She would perish later less than 20 miles from this same island.

Copies/info on this photo can be obtained at:

This is from material from my unpublished manuscript on the last battles of the IJN.

E-Mail: tullyfleet@gmail.com

  • NISSHIN - Detailed Action Report July 1943
  • Signal log and Daily activity record, DesRon 2 War Diary, December 1944
  • Signal log and monthly summary of action, 5th Fleet War Diary, December 1944
  • Total Eclipse, Last Battles of the IJN, 1944-45 Unpublished manuscript by Anthony Tully, 1996.
  • Japanese Cruisers of the Pacific War , by Eric Lacroix and Linton Wells, USNI Press, 1997, pp 351-352

    15 July 2005