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

by John Geoghegan

  With three torpedoes remaining in the bow and a full nest aft, Fulp made for the convoy. As dawn broke, the Segundo was still 4,100 yards away. Since the transports would soon reach the safety of a nearby island, he had to act fast. Unfortunately, one of the escorts, sensing the Segundo’s presence, closed to within 2,400 yards, forcing Fulp to break off the attack.

  Two weeks later the Segundo was ordered to Pearl for refit.

  THE SEGUNDO LEFT on her fourth war patrol on April 26, 1945.15 When she arrived in Saipan on May 8, a dinner was held to celebrate her one-year anniversary. Germany’s recent surrender must have contributed to the good cheer. Certainly, the newly installed ice cream freezer didn’t hurt. U.S. forces continued to face a daunting enemy though. Germany had been defeated, but the Japanese showed no inclination to surrender. And though enemy targets were in decline, the Segundo was still in danger from sea mines or a Japanese destroyer bearing a grudge.

  Once again Fulp headed for the East China Sea. It was his eleventh war patrol, fourth as captain of the Segundo. Though eleven patrols were a lot for a submariner, Fulp showed no sign of fatigue. He’d worked these waters before, and even though he knew they were dangerous, he was eager for action.

  As proof, a crewman spotted an untethered mine bobbing on the surface. The sub’s 40mm guns quickly dispatched it.16 On May 18 they passed two cadavers floating in the sea, “one Jap, one Yank.”17 It was a grim reminder of the war’s toll on both sides.

  On the afternoon of May 29, Fulp encountered six Chinese junks destined for Korea.18 Junks (also called sampans) were small wooden sailboats used for coastal transport. They had a large mast aft, a smaller one forward, and a jib. The Japanese had come to rely on them as their merchant fleet was destroyed. There was something suspicious about an identical fleet of junks all heading in the same direction, so Fulp surfaced for a closer look.

  As the Segundo passed the first vessel, Fulp reduced speed and ordered the .50 caliber machine guns manned. After closing to within 50 yards, he looked each junk over, then let them pass—until somebody noticed a Japanese insignia on one of the last boats. Fulp ordered a warning shot, intending to sink the vessel, but instead of abandoning the sampan, her crew scurried below deck. It was strange behavior, which didn’t deter Fulp. He sank the ship anyway.

  The Segundo inspected 14 junks that afternoon.19 It wasn’t difficult to guess which ones were the enemy. As the Segundo approached, the Korean crews bowed and smiled at the passing sub. The Japanese crews, however, changed course, trying to hide their bow markings. As the Segundo’s patrol report noted, the enemy crews appeared “stalwart, surly and unbending as you would expect Japanese to be.”20

  Ens. Vic Horgan was topside when a Segundo crewman charged up on deck waving a .45-caliber sidearm. When the man began shooting at the Japanese crews, Horgan felt disgust. He could understand blowing a ship out of the water. But shooting individuals? That wasn’t what they were about.21

  A total of 60 junks appeared that afternoon,22 which must have given Fulp pause, since he was outnumbered. He still managed to sink seven of them though, demonstrating just how granular the Pacific war had become.

  As the days passed, the Segundo continued reaping small rewards. On June 3 she encountered a four-masted schooner from an earlier age. Over 200 feet long, she was fully rigged with great billowing sails and classic lines.23 Fulp launched two torpedoes at 500 yards, both with zero angles and a 90-degree port track. Thirty seconds later the explosion from the first torpedo broke the schooner in two. The second torpedo missed due to a bad gyro angle, but it didn’t matter. The ship was destroyed.24

  The only significant opposition Fulp encountered on the Segundo’s fourth war patrol came late on the evening of Friday, June 8. Near Port Arthur, China, the sub spotted a good-size tug. Fulp suspected a trap, since the Japanese were known to use heavily armed Q-boats disguised as freighters to lure U.S. submarines to their doom. The tug appeared to have a ship in tow, but it was pitch black, and Fulp wasn’t sure what he was seeing. He prepared to attack anyway.25

  The Segundo closed to within 600 yards before letting two torpedoes go. The target immediately turned to confront them. It might have been a tug, or it might not; Fulp had no way of knowing.* Unfortunately, both torpedoes missed, and whatever it was set course to ram them. Fulp ordered full speed ahead to avoid a collision. Even then the “tug” missed by only 100 yards. Fulp was in no mood for retreat, so he called for a “down the throat” shot, the most difficult kind to make. He slowed the Segundo to ten knots before letting loose with a torpedo from his aft nest. Even at a “kissing distance” of 580 yards, it somehow missed.

  Embarrassed at having wasted three good torpedoes, Fulp took a moment to consider his options. The night was too dark for effective gun action, and the water too shallow to dive. His only choice was to risk a high-speed surface attack.26 Hiding in front of an island’s black silhouette, he gave his gun crew 20 minutes to adjust their eyes to the darkness. Then, at 22 minutes past midnight, he began his charge.

  The Segundo raced at flank speed, maintaining a small angle on the bow to keep her profile at minimum.27 At first Electrician’s Mate Bud Quam, the pointer on the five-inch gun, found it so dark, he couldn’t see what he was shooting at. The target was out there though because whatever it was, was firing back at him.28 Once the Segundo’s deck guns opened up,29 their tracer ammunition provided all the illumination Quam needed.30 Twenty-four minutes later both targets were destroyed.

  Naturally, a crew wanted to celebrate an enemy being sunk, but nothing was supposed to be “dryer” than a sub on war patrol. Fortunately, this wasn’t always the case. Fulp kept a shower filled with Greasy Dick, a Pittsburgh-brewed beer. It was broken out only with the captain’s permission, usually on Sundays to and from war patrols, or after a successful enemy engagement. Crewmen were limited to one can each, which they could drink off duty and never during battle stations.31 No one recalls whether they drank a Greasy Dick that night. It wouldn’t have been surprising if they had. A seaman and his booze aren’t easily parted, and sinking two ships was reason to celebrate.

  FULP PRIDED HIMSELF on taking calculated risks. He knew how to analyze a situation, finding the right balance between aggression and winding up dead at the bottom of the sea. Some sub captains wouldn’t attack in less than 180 feet of water. Fulp wasn’t one of them. The Segundo spent a lot of time in shallow depths, since that was where coastal shipping was found. He wasn’t foolish, though. When the sun came up, he knew to head for deep water.32

  You couldn’t always depend on Fulp’s brand of courage, however. One of the few times Fulp’s instincts let him down came in the Yellow Sea. He’d just sunk a Japanese freighter and was being pursued by her escorts into shallow water when the enemy inexplicably broke off their attack. Fulp couldn’t understand why until he realized they’d chased him into the middle of a minefield.33

  Unable to see what lay in his path, Fulp had to maneuver with tremendous care. It was all too easy for the sub’s bow or stern planes to snag a cable pulling the attached mine against the hull where it would explode. And at that close range it only took a single mine to sink a sub.

  Fulp spent the better part of a day working his way through the obstacle course.34 Once or twice his crew heard the terrifying sound of a steel cable scrape the length of the Segundo’s hull.35 The noise alone was enough to make your knees buckle. But Fulp managed to shimmy his way out of trouble. It wasn’t an episode he wanted to repeat, however. Perhaps that’s why his patrol report never mentioned it.

  The final attack of the Segundo’s fourth war patrol turned out to be Fulp’s last. It began on Sunday, June 10, while the sub was still in the Yellow Sea. Once again Fulp found himself in only 90 feet of water. It was 10:35 in the evening when SJ radar picked up a contact at 14,000 yards. The target proved to be the Fukui Maru No. 2, a Japanese freighter accompanied by two escorts.

  It was a poor night for an attack. Fog reduced visibility to 500 yards,
and the sub’s radar wasn’t working properly. A submerged approach would be preferable. Unfortunately, it was out of the question. But a surface attack was also dangerous, especially if the escorts had radar.

  The night was so dark, Fulp couldn’t see the freighter at 600 yards. Using target bearing transmitter bearings to make his calculation, he launched four torpedoes shortly after midnight. Forty seconds later three explosions could be heard. Three minutes after that the Fukui Maru was gone.

  The next day the Segundo was ordered to Midway. Her fourth war patrol was over.

  THE SUB’S REFIT lasted more than a month. There were problems with the main motors, and rust was found in the torpedo tubes.36 Nobody was disappointed, though. The Segundo had won her fourth battle star and added ten more enemy ships to her battle flag.

  The crew loved Midway. A nineteenth-century coaling station about a third of the way between Hawaii and Japan, the island was a welcome break. The monk seals were so tame, you could walk right up and scratch their belly, and the gooney birds provided hours of entertainment.

  Fulp was awarded a Gold Star in lieu of a second Silver Star for conspicuous gallantry in his penetration of “shallow enemy-controlled waters and … skillfully executed gun and torpedo attacks which resulted in the sinking of 14,000 tons of enemy shipping.”37 But the glow didn’t last.

  On June 29, in a brief formal ceremony, Cdr. James Douglas Fulp, Jr., in accordance with Commander Submarine Force Pacific Fleet, Subordinate Command, Navy No. 1504, Serial 403, was relieved as commanding officer of the USS Segundo. Having completed his duty as sub captain, Fulp was returning to Pearl Harbor, for a staff job. In other words, he was being kicked upstairs.

  The Segundo’s crew were sorry to lose their captain.38 Fulp had proven both capable and reliable, attributes they’d come to appreciate. Importantly, he’d shaped them into a fighting machine that could handle just about anything thrown their way.

  Unfortunately, their new captain, Lt. Cdr. Stephen L. Johnson, didn’t make the same impression. Instead of coming across as calm, cool, and collected, Johnson seemed young, arrogant, and impetuous. It was not a good combination.

  What kind of skipper have we got now? the crew wondered.

  They would soon find out.

  * Some of the Segundo’s crew suggest it was two Japanese “whale killers,” patrol craft similar to a PT boat.

  CHAPTER 25

  NANAO BAY

  THE DAY AFTER THE SEGUNDO SANK ITS SECOND FOUR-MASTED schooner, Nambu’s I-401 arrived in Nanao Bay. The I-13 and I-14 were already there waiting. The I-400 was due to follow the next day.1 Finally, all four submarines would be together, with a full complement of Seiran to practice attacking the canal. Considering that three of the four subs had been commissioned by early January 1945, it was late in the game to be fully operational.

  Nanao Bay is located in the crux of the Noto Peninsula. Extending into the Sea of Japan like a curled index finger, the peninsula stands halfway up the west coast of Honshu opposite Korea. Noto was sparsely populated in comparison with Kure. Except for the town of Anamizu, there was hardly anyone about. It was perfect for secret training.

  Ariizumi’s hope was that the region’s deep water and hidden coves would protect them against enemy air raids. Still, the trip there had been discouraging. Everywhere they looked, they’d found America’s handiwork. Sunken ships littered Japan’s shoreline, and what traffic continued to ply the waters hugged the coast. The enemy had never seemed closer.

  They didn’t have to look far for an explanation. Once Germany surrendered, America no longer had to split her forces between the European and Pacific theaters. Japan could now expect the full force of the United States military focused against her. If the Sen-toku subs didn’t close the Panama Canal, tens of thousands of men and countless tons of ships, planes, tanks, bombs, and ammunition would flow uncontrollably into the Pacific. Ariizumi had to put a stop to these reinforcements, otherwise Japan would be invaded before the year was out. Destroying the Panama Canal was the only action left that could prevent defeat.

  After successfully refueling at Chinkai, the I-13 and I-14 had arrived at Nanao. It was June 1, 1945, and the bay was covered in fog, forcing them to wait for it to clear.2 Three days later, while the rest of the fleet was still in transit, the I-14 craned her two Seiran on board. It was the first time Captain Shimizu had his full complement of aircraft.3 The I-14 was finally fully operational.

  The 631st air group had already established a new base. While Nambu had been making his way up Japan’s west coast, the Seiran pilots had settled into their headquarters. They didn’t have long to wait. Joint training began on June 6.4 The subs practiced rapid surfacing and Seiran assembly, followed by a swift catapult launch and crash-diving to escape detection. When the drill was complete, the subs resurfaced; the Seiran landed in their wake, taxied up their port side, and were craned on board, where the process was repeated all over again.

  Perhaps the most labor-intensive part of Seiran assembly was attaching the floats. Everyone knew when the time came that the Seiran would launch without them. They needed them for training though. There was no way for a seaplane to land safely and be retrieved without them. Securing the floats took a ten-man team at least two and a half minutes5—one reason Seiran launchings didn’t go as quickly as Nambu would have liked. Of course, eliminating the floats would reduce precious launch time, but that was reserved for the mission.

  While the floats were being attached, the rest of the team swarmed over the planes completing their prep work. As soon as the first Seiran launched, its rail cart was removed, the surrounding area was cleaned up, and the second plane maneuvered into launch position. The real problem came after the second plane was catapulted into the sky. The I-400 subs had originally been designed to accommodate only two aircraft. When the third Seiran was added, the resulting design changes did not allow for the same kind of smooth launch process as the first two planes. One reason was that the sub’s deck could only accommodate two planes at a time, leaving the last plane stranded in the hangar. This meant both planes had to be in the air before the launch crew could turn their attention to prepping the third. Considerable time was lost.*

  Ariizumi made his sub captains drive their crews relentlessly. He had to. The Sen-toku subs were so far behind schedule and Japan was so badly losing the war, there was little time left. This meant training was around the clock. The subs left port every day between two and three in the morning and often didn’t return until ten that night.6 Training in darkness was critical, since it simulated the conditions under which the Seiran would launch. Still, the schedule was grueling. The mechanics had the most difficult time. Up all night launching planes, they’d spend the morning performing maintenance to make sure the Seiran were ready for the next practice. They got little sleep, no time off, and even less sympathy, since they were under pressure to speed up the launch process. At one point, the stress became so great, Nambu heard a maintenance man shout, “I will never be a mechanic on a submarine again!”7 Maybe he was kidding—Nambu wasn’t sure. Either way, he admired their determination.

  At first it took the better part of a day to launch three planes.8 But as aircrews became more adept, they managed to get it down to 45 minutes, then a half hour. Finally, after six weeks of training, they were able to catapult the first two planes in as little as four minutes.† 9

  The problem was the third plane, which took up to 20 minutes to launch.‡ 10 That was nearly three times longer than the first two planes combined. They may have cut total launch time to 28 minutes, but that was a lifetime in enemy waters.

  Despite the complaints of a few mechanics, the Sen-toku crew were in high spirits.11 After so many delays, they were finally training without interruption. Nambu felt proud to lead these men. They’d been called upon to save their country and would selflessly heed that call. But he harbored no illusions. He knew their chances of survival, let alone success, were shrinking by the day. Still, he’d overc
ome any obstacle, suffer any deprivation, in order to succeed. The mission was everything.

  And so the Sen-toku squadron practiced over and over again. As Nambu reduced launch times, a symphony of coordination began to take shape. Despite his best efforts though, the Seiran continued to be plagued by problems.12 Sometimes an aircraft’s wing would be damaged during launch preparation, leaving the pilot to fume while repairs were made. Other times the engine didn’t work as designed. Seiran engines tended to overheat at full throttle, and there were still many oil leaks.13

  One day shortly after takeoff, Asamura was surprised by hot oil geysering into his cockpit.14 The Seiran’s canopy was so obscured by the viscous black liquid that he was forced to make an emergency landing near his sub. Asamura’s piloting skills saved him from disaster, but he was lucky. Some Seiran pilots were forced down so far from their sub that precious time was lost retrieving them.

  Not every mishap was easily remedied. It was bad enough that the maintenance crews had to operate in darkness, sometimes the sub’s pitching and rolling threw them overboard. Timing the catapult launch was also a challenge. A Seiran had to be launched into the wind to ensure enough lift for it to climb. Nambu did his best to steer accordingly, but wind and wave direction could change without notice, putting the Seiran in jeopardy.15 Furthermore, Seiran pilots needed to see the horizon when launching, which was difficult at night.16 It was easy to get disoriented and crash upon takeoff, which was one reason the pilots received six-yen hazard pay each time they launched.§ 17

  Taking off from a sub was always dramatic. The catapult was noisy,18 but the actual launch was smoother than what Asamura was used to.19 Its concussive force still slammed him into his seat back though. As the Seiran hurled down its track toward the tapering bow, the giant sub must have seemed not quite long enough to successfully launch an airplane. There was a sickening dip at the end, when the Seiran shot over the water and its engine clawed hungrily for altitude. An experienced pilot knew to gun the throttle for the lift he needed. For Asamura, it was the greatest ride he’d ever experienced.