Operation Storm: Japan's Top Secret Submarines and Its Plan to Change the Course of World War II

by John Geoghegan

  “What the hell are you doing?” he yelled.

  The I-400 crewman smiled and bowed, making Hiatt realize he just wanted to help. Still, Hiatt had come so close to shooting the man, he was shaken. The Japanese crewman had only been offering to hold the rifle while Hiatt squeezed through the deck hatch. Azuma was right. The Americans were nervous.25

  Hiatt did his best to keep watch over the engines, but he found them distracting. They were the biggest things he’d ever seen. Additionally, instead of being placed in two sequential compartments, they were located side by side with a hatch between them. Hiatt began to relax though when he realized the Japanese motor machinist’s mates were more curious than hostile. In fact, they were downright friendly. Using an impromptu form of sign language, they happily answered his questions about how the engines functioned. But as Hiatt familiarized himself with their workings, he noticed a rat crawling along a bulkhead. There weren’t any rats aboard a U.S. sub, and this one seemed in no hurry to escape. Hiatt had never seen anything like it.26

  After radio communication was established with the Blue, Lieutenant Rowan ordered a weapons search. Swords and small arms were collected and locked inside Kusaka’s cabin. Once the sub was secure, Rowan radioed the Blue, and the two vessels got under way for Sagami Bay, near Yokosuka.27

  Surprisingly, the Blue wasn’t the only one interested in capturing the I-400. Capt. Lew S. Parks of the 20th Submarine Squadron wanted to claim her as well. When Parks intercepted Lieutenant Mahoney’s first message, he immediately contacted the USS Proteus (AS-19) about assembling a prize crew to take the sub. When word came back from Admiral Halsey to “go fetch,” Parks assigned Cdr. Hiram H. Cassedy to form a boarding party.28

  “Hi” Cassedy was an experienced sub captain who’d served aboard the USS Sailfish (SS 192), Searaven (SS 196), and Tigrone (SS 419).29 Overweight, overbearing, and prone to outbursts, he was every bit as gruff as Ariizumi. One thing was for certain—Cassedy had no problem taking risks. As captain of the Searaven, he’d distinguished himself by rescuing 31 Royal Australian Air Force personnel from enemy-held Timor.30 More recently, he’d rescued 31 B-29 airmen downed off the coast of Japan. Since “lifeguarding” wasn’t a sub captain’s favorite duty, Cassedy might have been itching for glory, or he might have simply been reverting to type. Either way, he wasn’t going to let anyone prevent him from “capturing” the I-400.

  Cassedy had no trouble finding officers to join him. There was so much demand, he had to deal a poker hand to decide the winners.31 But persuading enlisted men to volunteer was problematic. The Proteus was loaded with experienced submariners, many of whom just wanted to go home. There was no point risking one’s life now that the war was over, especially since the navy had ceased being a long-term career.32 Furthermore, Cassedy wanted men who not only had an intimate knowledge of how subs operated but were familiar with Japanese tactics. Forty men were eventually chosen; still, the operation was hurried and their briefing limited.33

  Harry Arvidson was one of the men selected for Cassedy’s boarding party. A baker by training, and ship’s cook third class, Arvidson soon found himself along with Cassedy aboard the USS Weaver (DE-741). The Weaver had been escorting the Proteus from Guam to Tokyo when she was assigned to transport Cassedy’s prize crew. Now the Cannon-class destroyer escort steamed at high speed to reach Mahoney’s last reported coordinates.

  JUST AFTER NIGHTFALL on the evening of August 27, a large black object appeared on the horizon. Cassedy’s spirits must have soared when the object turned out to be a huge Jap sub. His heart sank though when he realized the sub was already being escorted by a U.S. destroyer. His prize had been claimed. The captured sub was the I-14, however, which Mahoney had spotted shortly before finding the I-400.34 Since the USS Murray had the sub under control, the Weaver continued through the night toward Kusaka’s sub.35 When Cassedy reached the I-400 early the next morning, he was thrilled.

  The boat was at least a football field long, with a sail that rose from the port side like the leaning tower of Pisa. On deck, a humongous housing ran more than 100 feet before ending in a mysterious bulge.36

  Cassedy knew he’d bagged “something special.”37 However, the USS Blue already had a prize crew on board and was escorting the sub to Tokyo Bay. But Cassedy was not about to let the Blue steal his thunder. Insisting that his orders took precedence, he bullied his way into the situation by claiming the Blue’s prize crew had no submarine experience. Though this wasn’t true, the Blue’s captain gave way. The photographer Cassedy had brought to record the historic capture probably added some incentive.38

  As Cassedy assembled his prize crew, the Blue’s boarding party assembled on the I-400. Lieutenant Rowan clearly had the situation in hand, but reality was not going to stand in Cassedy’s way. Ordering the Weaver to lower two whaleboats,39 he hurried to claim his prize.

  Harry Arvidson was in one of Cassedy’s boats as they made their way toward the I-400. The sea was choppy, and spray came off the bow. Arvidson used a tarp to keep dry, while Cassedy got wet. A less than heroic photograph shows him boarding the I-400, his shirt and pants completely soaked.

  Arvidson wore a life belt but had no helmet or weapon, as those were reserved for officers. By the time Cassedy boarded the I-400, however, a weapon wasn’t needed.40 The only tension that existed was between Cassedy and Lieutenant Rowan.

  As the I-400’s surrender flag flapped violently in the wind, Cassedy relieved Rowan of command, then went about doing everything Rowan had already done. Rowan’s boarding party was not as ill prepared to manage the sub as Cassedy contended. For example, Cassedy thought well enough of Gordon Hiatt and several of his colleagues to keep them aboard during the trip to Tokyo.

  Rowan wasn’t the only person perturbed by Cassedy’s power play. Kusaka was irritated as well. Now the Japanese sub captain found himself having to deal with an entirely new officer. From the pained expression on Kusaka’s face captured by Cassedy’s photographer,41 it’s evident he didn’t enjoy having yet another American tell him Japan had lost and that his sub was now a U.S. war prize.42

  Cassedy’s translator tried sweetening the pill by telling Kusaka, “We promise to treat you as gentlemen, so please cooperate and obey our commander.”43 Undoubtedly, it was politer than anything Cassedy would have said. Still, it hardly softened the blow.

  Cassedy later claimed Kusaka opened up to him once he noticed the dolphins on his shirt. As Cassedy recalled, “When I told [Kusaka] that I and my … men were veteran submariners … he bowed deeply and from then on was most cooperative.”44 Polite would probably be a more accurate description, because Kusaka remained evasive under questioning. It would have been typical of Cassedy to assume he was smarter than the enemy. For example, he assumed the I-400’s size meant she was a cargo carrier.45 He was wrong, of course, and Kusaka did nothing to disabuse him of this notion. As for his claim that Kusaka was talkative,46 it seems self-aggrandizing given that Kusaka was not known for his eloquence either in English or Japanese. The idea that Kusaka, a battle-hardened commander, would pour his heart out just because they were fellow sub captains stretches credulity, especially when you consider that Cassedy never even bothered to learn Kusaka’s name.

  While Cassedy interrogated Kusaka, his prize crew checked for torpedoes. When they found they’d been disposed of, they chained the hatches open to prevent the sub from diving.47

  Takahashi was impressed by the courtesy of the prize crew, especially Cassedy’s translator.

  “We’re submariners too,” the interpreter told him. “We know what you’ve been through.”

  “So this is democracy,” Takahashi thought.48 It was certainly better than he’d expected.

  There were communication problems though. Cassedy’s translator may have won the crew’s sympathy, but Kusaka found his Japanese so poor as to be humorous.49 When a prize crew member left guarding the I-400’s wardroom gave in to temptation and lit a cigarette, he was scolded by a Japanese officer for smokin
g. In other words, it wasn’t always clear who was guarding whom.50

  At noon a ceremony was staged on the I-400’s bridge for the benefit of the navy photographer. Cassedy looked on as Japan’s battle ensign was lowered and replaced with the Stars and Stripes. Kusaka also observed the proceedings. Hoping no one would notice, he quietly wiped a tear from his eye.51 Cassedy saw the emotion and was uncharacteristically sympathetic.52 Even the gruff commander could feel the pain of a fellow sub captain surrendering his command.

  But Cassedy’s sympathy didn’t extend to the crew’s personal effects. Before relieving Lieutenant Rowan of command, Cassedy ordered him to leave all Japanese swords and small arms behind. Even though an officer’s sword was considered part of his uniform,53 Cassedy wanted them for war trophies.54 In one photograph, he can even be seen with the hint of a smile as the swords are stacked like cordwood on the I-400’s catapult track.55 Cassedy made sure the Blue’s boarding party left empty-handed, saying the swords would be turned over to the proper authorities. It was a promise unlikely to be kept.

  Cassedy wasn’t the only one to show interest in war booty. While walking through the I-400’s officers’ quarters, Harry Arvidson spotted a short sword dangling from a bunk with a man lying next to it. Undeterred, Arvidson released the belt clip and calmly walked away with the prize.56 Another enlisted man was so eager for souvenirs, he “liberated” the I-400’s bridge compass. Unsatisfied with his haul, he stripped insignia from a Seiran crewman’s uniform, including the buttons, and took several sets of hashi from the galley. In fact, by the time the I-400 arrived in Tokyo, the U.S. prize crew had taken pretty much anything that caught their eye, including personal letters and New Year’s greeting cards. When Takahashi lost his sword, he consoled himself by saying, “It’s all just worthless trash anyway.”57 Even so, it must have stung.

  As the I-400 got under way, however, Kusaka let some information slip. There was another sub at large just like the I-400, with the squadron commander on board. This was news to Cassedy, but what Kusaka said next was even more disconcerting. Kusaka told him he knew the commander personally and didn’t believe he’d surrender without a fight.58

  Unfortunately, Kusaka was too late. The I-401 was already locked in a showdown with the USS Segundo, a showdown that Commander Ariizumi had no intention of losing. No intention, that is, unless Nambu could stop him.

  CHAPTER 37

  RECKONING

  NAMBU KNEW ARIIZUMI MIGHT SCUTTLE THE I-401, BUT HE WAS still shocked when the commander ordered the Kingston valves opened. Nambu was captain; he alone had authority to issue such a command. But Ariizumi was commander, and though there was no squadron left for him to command, he naturally had a proprietary feeling toward his flagship. It was debatable whether scuttling the sub was his call to make. Unfortunately, Ariizumi decided it was, and since he was the highest-ranking officer, there was no one to stand in his way except Nambu.

  Neither man had been given suicide orders.1 This meant it was a matter of choice—killing themselves was left to their discretion. Ariizumi believed death was preferable to dishonor, while Nambu felt his responsibility was to return his crew safely to Japan. The two were so opposed that Nambu went to talk to Ariizumi in his cabin.*

  Ariizumi’s quarters-cum-office was small but private, with a bed, a desk, and a clock on the bulkhead. The two men could have a confidential conversation so long as they didn’t raise their voices. But their relationship was beyond strained at this point. Despite both officers being products of the Imperial Japanese Navy, their personalities were so different, it only bred antagonism.

  “Our duty is done,” Nambu began. “I’d like to return the precious lives of my 204 crewmen to Japan.”

  Ariizumi was unmoved. “Please give those lives to me.”

  Nambu held firm. “I would like us to return to Japan and will gladly take responsibility for the decision.”

  But Ariizumi refused to budge.2

  It’s impossible to know exactly what Ariizumi thought, since he left no written record and never spoke of the meeting. Nevertheless, a few things can be surmised. First, Ariizumi considered Nambu impertinent if not downright mutinous for questioning his authority. Though Nambu had asked for the lives of his crew in the most formal and polite way, it didn’t take much to trigger Ariizumi’s temper.

  Additionally, Ariizumi was under tremendous strain. Japan had lost the war, the Imperial Navy was in disgrace, and his special attack force had been scattered without firing a shot. What was supposed to be the pinnacle of his naval career had become its darkest hour.

  As if that weren’t enough, Ariizumi was the kind of commander to whom honor meant everything. Though he had favorites among his men, their lives were his for the taking. Nambu wanted to return to Japan, but as far as Ariizumi was concerned, it wasn’t his decision to make. And though not everyone aboard the I-401 shared Ariizumi’s refined sense of honor, it was incomprehensible that the commander would surrender his flagship to an enemy he despised. These feelings contributed to Ariizumi’s agitated state. He’d been wracked by depression ever since the emperor’s speech, and the sweltering conditions inside the sub only exacerbated matters.

  As their voices rose in heated confrontation, sweat rolled down Nambu’s face. The I-401’s captain probably stood in the presence of his commander, making his six-foot frame intimidating. Their yelling eventually crescendoed to the point that it was heard outside the cabin. Though their words were unclear, the crew could easily tell the men were angry. Both were insistent; neither would back down. Finally Ariizumi boiled over. Refusing to accept Nambu’s insubordination, he struck him in anger.3

  It wasn’t the first time Nambu had been hit. Corporal punishment was de rigueur in the Imperial Japanese Navy. But Nambu was stunned by the action. Being struck like a midshipman was the worst kind of insult. It also meant Ariizumi had lost control.

  Turning on his heel, Nambu exited the cabin. His pride might have been stung, but Ariizumi’s behavior had only steeled his resolve.

  It’s a testament to both men’s stubbornness that neither could be dissuaded. Nambu planned on saving his crew, while Ariizumi intended on sinking the sub. It was a standoff comparable to the one they faced with the Segundo. There was a complicating factor though. A pro-Ariizumi faction existed aboard the sub. The commander embodied the Imperial Japanese Navy, and plenty of crewmen supported him. Asamura was one of them. He deeply respected Ariizumi and shared his belief in an honorable death. And Asamura wasn’t the only one.

  Many of the I-401’s officers were loyal to Nambu, however. After all, a navy’s command and control structure was sacrosanct. If Ariizumi wanted the I-401 to do something, he had to work through her commanding officer to do it. He couldn’t just issue orders over his head.

  There was another wild card, though. Everyone knew what Ariizumi was capable of. They’d all heard about the I-8 massacres. One of Nambu’s officers even called Ariizumi “Gyangu” or “gangster” behind his back.4 When Ariizumi ordered the I-401 scuttled, no one doubted he meant what he said.

  The Kingston valves were located on the bottom of the I-401’s hull. When they opened, seawater flooded the boat’s ballast tanks, allowing her to submerge. But for Ariizumi to scuttle the boat, the bridge hatch would also have to remain open. The moment the sub dipped below the waves, the ocean would flood in, sinking her in minutes.

  It’s no fun drowning this way. The force of water would hit like an explosion, knocking many of the crew unconscious. Those who survived the impact would find themselves looking for air pockets. As the sub sank deeper, the increased pressure would expel the remaining air, and the men would drown quickly. Undoubtedly, a few crew members would follow their instinct and try escaping. It would be impossible to fight the torrent of flood water though. If they succeeded in closing their compartment’s watertight hatches, they might last until the boat passed her safety depth, but then the sub would implode, crushing them like paper. Trapped in the cold, dark confines o
f a sub plummeting out of control, you wouldn’t have more than a few minutes to realize you were a goner. A bullet to the brain would have been faster and a lot less horrifying.

  The commander might have been a god who rarely descended from heaven, but Nambu was the I-401’s captain; the crew took orders from him. Add to this the human will to live, and it was anyone’s guess what would happen when Ariizumi ordered the Kingston valves opened.

  When Ariizumi gave the order, most of Nambu’s officers froze. The commander was a powerful personality. It was impossible to ignore him. But his order to open the sea cocks only caused confusion among the crew.5 Enough officers sympathized with Nambu that they refused to take action. In fact, a few of them had already commandeered pistols to make sure no one complied with Ariizumi’s order.6 As the commander raged on, they pretended not to hear him.

  When Ariizumi realized he was being ignored, it was as if his legs were cut out from under him. He’d played his hand and lost; Nambu retained the conn. It was a milestone of sorts. What could have been a tragic end to the world’s largest submarine had become a humiliating defeat for her squadron commander. The war, and everything the Imperial Japanese Navy stood for, was over. It was a bitter defeat for Ariizumi, but Nambu finally had a chance to save his crew.

  AS NAMBU AND Ariizumi struggled to control the I-401, Johnson continued pressing Bando for concessions. He wanted his officers to board the Jap sub,7 after which the Segundo would escort her to Yokosuka. Johnson was unaware of Ariizumi’s resistance to his plan. Nor did he realize the commander wanted to scuttle his boat. If anything, Johnson wanted to avoid a mass suicide. It’s doubtful Bando relayed Ariizumi’s message asking Johnson to torpedo them. If he did, Johnson either ignored or dismissed it as too bizarre for consideration.

  After 20 minutes of negotiation, Bando finally agreed to carry Johnson’s terms to the I-401.8