Why Japanese Admirals Feared U.S. Submarines

Why Japanese Admirals Feared U.S. Submarines

At 03:17 hours on November 29, 1944, Commander Joseph Enright stood at the periscope of the submarine Archerfish, 200 ft beneath the Pacific, watching the largest warship he had ever seen. The target was moving at 18 knots, zigzagging through the darkness off the coast of Japan. Enright had been tracking her for 6 hours.

 His crew was exhausted. His submarine had never sunk a single ship in four previous patrols. And in approximately 90 seconds, he would fire six torpedoes at a vessel so secret that American intelligence did not even know it existed. The carrier was massive. Even through the green haze of the periscope lens, Enright could see the flight deck stretching hundreds of feet into the darkness.

 Three destroyer escorts flanked the giant ship, their wakes phosphorescent in the moonlight. Enright’s torpedo data computer was locked on target. His crew waited in silence. What Enright could not have known in that moment was that his target was the Shinano, a 72,000-ton supercarrier, the largest warship afloat.

 She had been commissioned only 10 days earlier. She was making her maiden voyage from Yokosuka Naval Arsenal to Kure for final fitting out, and she was about to become the largest vessel ever sunk by a submarine in the history of naval warfare. But the story of why Japanese admirals came to fear American submarines does not begin with the Shinano.

 It begins 2 years earlier, when American torpedoes did not work. American captains were considered too cautious, and the Japanese merchant fleet sailed the Pacific almost unopposed. It begins with a problem so fundamental that it nearly cost America the war in the Pacific. And it begins with one officer who refused to accept the official explanations for why his submarines kept failing.

 The morning of December 7th, 1941, changed everything for the United States Pacific Fleet. Japanese aircraft destroyed the battleship row at Pearl Harbor. They sank or damaged eight battleships. They killed more than 2,000 Americans in less than 2 hours. But they missed something critical. The submarine base at Pearl Harbor survived largely intact.

The fuel storage tanks that would power American operations across the Pacific remained undamaged. And 29 submarines of the Pacific Fleet were ready for immediate deployment against the Empire of Japan. Within hours of the attack, President Franklin Roosevelt ordered a new doctrine into effect, unrestricted submarine warfare against Japan.

 This meant sinking any warship, commercial vessel, or passenger ship in Axis-controlled waters without warning and without help to survivors. The American submarines would do to Japan what German U-boats were attempting against Britain. They would strangle an island nation by cutting its sea lanes. They would starve its factories of raw materials.

 They would sink the ships that fed its war machine. At least, that was the plan. In the first months of 1942, the American submarine campaign in the Pacific was a catastrophe. Submarines fired torpedo after torpedo at Japanese ships. The torpedoes hit their targets, and nothing happened. They did not explode.

 Lieutenant Commander Frederick Warder of the submarine Seawolf was one of the first to document the problem. During six patrols in the first year of the war, Warder recorded instance after instance where his Mark 14 torpedoes struck enemy vessels and simply bounced off. The contact reports would note a solid thud against the hull, then silence. No explosion. No damage.

 The enemy ship sailing away unharmed. In one engagement near Christmas Island, Seawolf approached a Japanese invasion force that had anchored offshore. Warder carefully positioned his submarine for an attack on the light cruiser Naka. He fired a spread of torpedoes at close range. One torpedo hit its mark.

 The rest either missed or failed to detonate. The cruiser escaped for repairs. Warder returned to port with nothing to show for his efforts. Other captains reported the same experience throughout the fleet. They would execute perfect approaches, fire at point-blank range, hear the unmistakable thud of metal striking metal through the hull, and then watch in disbelief as the enemy ship sailed away undamaged.

 The frustration was overwhelming. These men were risking their lives on every patrol. They were doing everything right, and their weapons simply did not work. The Bureau of Ordnance in Washington insisted there was nothing wrong with the torpedoes. The problem, they said, was the captains. Poor approaches, bad maintenance, human error, insufficient training.

 The Mark 14 torpedo had been designed by experts at the Naval Torpedo Station in Newport, Rhode Island. It had been tested and certified for fleet use. Any failures in combat must therefore be the fault of the men using them. But the captains knew better. They were not missing. Their torpedoes were hitting. The acoustic signatures were unmistakable.

 Something was fundamentally broken with the weapon itself, and no amount of official denial could change what they witnessed through their periscopes. When Seawolf switched to the older Mark 10 torpedoes, her success rate improved dramatically. This was damning evidence. The same crew, the same captain, the same approach techniques, but different results.

 The variable was the torpedo itself. The man who would solve this problem and transform the American submarine force into the most devastating naval weapon of the Pacific War was Rear Admiral Charles Lockwood. In February 1943, following the death of Rear Admiral Robert English in a plane crash in California, Lockwood became Commander of Submarines Pacific Fleet.

 His call sign was ComSubPac. His sailors would come to call him Uncle Charlie. And he was about to wage a war on two fronts, one against the Japanese Empire, and one against his own Navy’s bureaucracy. Lockwood was 52 years old when he took command at Pearl Harbor. He was a career submariner who had commanded his first submarine in 1914, before the United States entered the First World War.

 He had served on submarines continuously for three decades. He understood the boats. He understood the men. He understood what it meant to go into combat beneath the waves. And he understood that when dozens of experienced captains reported the same problem independently, the problem was not the captains. Lockwood trusted his sailors.

 He believed their reports, and he was determined to find out what was wrong. The Mark 14 torpedo had been the Navy’s standard submarine weapon since 1938. It was a remarkable piece of engineering on paper, 20 ft long, weighing more than 3,000 lb, carrying a 500-lb warhead of Torpex explosive, capable of running at 46 knots for 4,500 yd, or 31 knots for 9,000 yd.

 It was designed to be the most lethal submarine weapon in the world. The torpedo featured two detonation systems. The primary was a magnetic influence exploder called the Mark 6. This device was designed to detect the magnetic field of a ship’s steel hull and detonate the warhead directly beneath the keel, where the explosion would break the ship’s back.

 The secondary was the contact exploder that would trigger the warhead upon physical impact with the target. Both systems were revolutionary. Both systems were secret, and both systems had been tested exactly twice before being issued to the fleet. Twice. The Navy had been so obsessed with secrecy around the Mark 14’s magnetic exploder that they had refused to conduct proper live-fire testing.

Budget constraints during the Depression prevented additional trials. Security concerns prohibited extensive exercises that might reveal the weapon’s capabilities to foreign observers. And so, America went to war with a torpedo that nobody actually knew worked reliably. Lockwood began his investigation before he even arrived at Pearl Harbor.

 While serving as Commander Submarines Southwest Pacific in Australia, he had heard the same complaints from his captains that were coming from every submarine force in the theater. He ordered test firings into fishing nets to measure how deep the torpedoes actually ran. The specification said the Mark 14 should run at the depth set by the captain.

 A setting of 10 ft meant the torpedo should travel at 10 ft below the surface. This was critical for the magnetic exploder to function correctly. The torpedo needed to pass beneath the target’s hull at precisely the right depth to trigger the magnetic influence feature. The tests showed something different.

 The torpedoes were running 11 ft deeper than set. A torpedo set for 10 ft was actually running at 21 ft. This meant the weapons were passing directly underneath their targets without ever coming close enough to trigger either the magnetic or contact exploder. Lockwood reported his findings to the Bureau of Ordnance. The Bureau disagreed on technical grounds.

They insisted their testing at Newport had shown proper depth keeping. They accused the fleet of improper calibration procedures. They refused to accept that their weapon was defective. Lockwood repeated the tests. The results were identical. He compiled detailed data. He submitted formal reports through the chain of command.

 He pushed and pushed and pushed. Finally, in August 1942, the Bureau confirmed through its own tests at Newport that the Mark 14 was indeed running 10 ft deeper than designed. Eight months after Pearl Harbor, the Navy finally acknowledged that its primary submarine weapon could not hit targets at the depth specified by its captains.

 The cause was embarrassingly simple. During development, the torpedo had been tested with practice warheads that were significantly lighter than the combat version. The heavier explosive warhead changed the trim of the torpedo enough to make it run deep. Additionally, the hydrostatic pressure sensor was poorly placed, giving erroneous depth readings, especially at higher speed settings.

Modifications were implemented. Captains were instructed to adjust their depth settings to compensate. The fleet believed the problem was solved. It was not. Even with corrected depth settings, torpedoes continued to fail. Some exploded prematurely, hundreds of yards from their targets. Others hit the hull and did nothing.

The magnetic exploder was malfunctioning. The contact exploder was malfunctioning. The entire weapon system was riddled with problems. On April 9th, 1943, Lieutenant Commander John Scott in the submarine Tunny found himself in an ideal position to attack Japanese aircraft carriers, including the Taiyo and Unyo.

 From only 880 yards, he fired all 10 torpedo tubes. Through the hull, his crew heard four stern shots and three bow shots explode. No enemy carrier diminished speed. None showed signs of damage. Later intelligence revealed that all seven explosions had been premature. The torpedoes had run true. The magnetic feature had triggered them too early.

 Every single weapon had detonated before reaching its target. The next day, the submarine Pompano attacked the aircraft carrier Shokaku with six torpedoes. At least three exploded prematurely. The carrier sailed on undamaged. Submarine captains estimated that 10% of their torpedoes were exploding prematurely. The Bureau of Ordnance statistics claimed the number was 2%.

 Neither figure was acceptable. These men were risking their lives on weapons that worked less than half the time. Ships that should have been sunk escaped to fight again. Japanese troops that should have drowned at sea landed safely on Pacific islands. The war continued longer than it should have. In the summer of 1943, Lockwood flew to Washington and confronted the Bureau directly.

At a conference with fellow admirals, he made his frustration absolutely clear. “If the Bureau of Ordnance cannot provide us with torpedoes that will hit and explode,” he said, “then for God’s sake, get the Bureau of Ships to design a boat hook with which we can rip the plates off a target’s side.

” The Bureau chief, Rear Admiral William Blandy, was furious. He accused Lockwood of trying to discredit his organization. The confrontation was heated. Blandy demanded to know whether undermining the Bureau of Ordnance was part of Lockwood’s mission. Lockwood replied that if anything he said got the Bureau off its duff and produced action, he would consider his trip worthwhile.

 By June 1943, Lockwood had seen enough. He officially ordered what many of his captains were already doing secretly, “Deactivate the magnetic exploder entirely. Rely only on contact detonation.” The magnetic feature was too unreliable to trust. But even this did not solve the problem. were still hitting targets and failing to explode.

 The breakthrough came from the submarine Tinosa in July 1943. Commander Dan Daspit spotted a 19,000-ton Japanese whale factory ship called the Tonan Maru number three. This was a massive target, dead in the water, with no escorts in sight. A perfect opportunity. Daspit fired four torpedoes from 4,000 yards. Two hit and stopped the ship dead in the water.

 He fired two more. Both hit. The target was stationary. Daspit had all the time in the world. He maneuvered carefully into a textbook firing position, 875 yards off the target’s beam. The range was perfect. The angle was perfect. There was no way to miss. He fired nine more Mark 14 torpedoes. All nine were duds. Daspit watched through his periscope as each torpedo struck the motionless vessel and failed to explode.

 Some produced small bursts when their air flasks ruptured on impact. None detonated their warheads. The Japanese ship remained afloat. Daspit, suspicious that he was working with a faulty production run, made a decision that would change the course of the submarine war. He saved his last remaining torpedo and brought it back to Pearl Harbor for analysis.

 The torpedo was examined at the submarine base. What they found was damning. The contact exploder’s firing pin was too weak. It was designed to strike the target at a perpendicular angle and trigger the detonator. But when a torpedo hit a ship dead on, the impact force was so great that the firing pin crumpled before it could initiate the explosive chain.

Ironically, a perfect shot was almost guaranteed to fail. The more accurate the attack, the more likely the torpedo would be a dud. The Navy’s premier submarine weapon had been designed without adequate testing, built without proper quality control, and deployed without understanding its fundamental flaws.

 Three separate defects had crippled American submarine operations for nearly two years. The machine shops at Pearl Harbor went to work immediately. They designed a reinforced firing pin using stronger materials. Legend has it that engineers studied the propeller blades from downed Japanese aircraft captured at Pearl Harbor and found a lightweight metal perfect for the application.

 By late September 1943, the submarine Barb departed on patrol with 20 torpedoes equipped with the new design. By mid-October, every submarine leaving Pearl Harbor carried the modified weapons. Uncle Charlie had won his war against the Bureau of Ordnance. His sailors finally had torpedoes that worked, 21 months after Pearl Harbor. 21 months of frustration.

 21 months of watching good men die because their weapons did not function. 21 months of official denial and bureaucratic resistance. And then, when the torpedoes finally worked, the American submarine force became the most devastating naval weapon in the Pacific. The transformation was immediate and stunning.

 In 1942, American submarines had sunk approximately 109 Japanese ships totaling around 42,000 tons. The numbers were disappointing given the resources invested. Too many patrols returned with empty bags. Too many targets escaped. Too many opportunities were squandered by defective weapons. In 1943, with the torpedo problems gradually being solved, the totals increased.

 But the real devastation came in 1944. That year, American submarines sank 603 Japanese merchant ships totaling approximately 2.7 million tons, more tonnage than in the first 25 months of the war combined. The Japanese merchant marine was being systematically annihilated. But Lockwood understood that sinking random freighters was not enough.

 He needed to target the ships that mattered most to Japan’s war effort. In late 1943, he issued new orders. Tankers were now the top priority for every submarine patrol. Japan had gone to war precisely because of oil. The American embargo of July 1941 had left the Imperial Navy with approximately 12 months of fuel reserves for the army and 18 months for the Navy.

Japan’s entire strategic calculation depended on seizing the oil fields of the Dutch East Indies and shipping that petroleum home to feed the factories, fuel the ships, and power the aircraft of its war machine. The distance from the East Indies oil fields to Japan was roughly 6,000 km. Every barrel of oil, every gallon of aviation fuel, every drop of diesel had to travel by sea.

There was no alternative. There were no pipelines. There were no overland routes. The tanker convoys were Japan’s lifeline. And Lockwood intended to cut that lifeline completely. American cryptographers had broken the Japanese merchant shipping codes. Intelligence officers at Fleet Radio Unit Pacific could track the movements of tankers across the ocean.

 They knew which ships were sailing, what cargoes they carried, which routes they would take, and when they would arrive at their destinations. Lockwood positioned his submarines accordingly. The submarines waited along the shipping lanes. They lurked at the choke points where convoys had to pass. They patrolled the waters around Singapore and the Philippines.

 They haunted the approaches to the Japanese home islands. And when the tankers came, they struck. The results were catastrophic for Japan. Of the 43 tankers lost in the first 6 months of 1944, 27 were sunk by American submarines. Japanese High Command took the extraordinary step of reallocating steel designated for warship construction to build new tankers.

This was a desperate measure. Japan needed every available resource for its naval building program. But without oil, the existing fleet could not operate. Even with every available resource committed to tanker construction, losses exceeded production. The shipyards could not build fast enough.

 The submarines sank faster than Japan could replace. By the end of 1944, American forces had destroyed two-thirds of the Japanese tanker fleet. Japanese oil imports from the Southern Resource Zone peaked at approximately 1.4 million barrels per month. Although production in Japanese-controlled areas reached nearly 4 million barrels monthly in 1943, most of that oil never reached the home islands.

American submarines made certain of it. The strategic consequences cascaded through every aspect of Japanese military operations. Admiral Tokusaburo Ozawa commanded the Japanese carrier fleet. After returning from Rabaul in late 1943 to replace aircraft losses and train new pilots, Ozawa discovered that the oil shortage was so severe that he could not remain in home waters.

 There was not enough fuel to conduct training operations near Japan. He was forced to relocate his entire fleet to Singapore, closer to the oil sources of Borneo and Sumatra. This way, his ships could refuel directly from local sources without depending on the vulnerable tanker convoys. But moving the fleet south meant moving it thousands of miles away from the decisive battles in the Central Pacific.

 Japan’s carrier force would have to sail from Singapore to contest American advances in the Marianas. The crews would have limited time to train. The pilots would be green. The ships would arrive at battle with the minimum fuel necessary for combat operations. The consequences became apparent in June 1944 at the Battle of the Philippine Sea.

 American forces had invaded Saipan, threatening the inner defense perimeter of the Japanese Empire. The Japanese fleet sorted from Singapore to contest the landing. Ozawa’s carriers launched wave after wave of aircraft against the American fleet, but the Japanese pilots were poorly trained. Many had fewer than 100 hours of flight time.

They had practiced over the calm waters near Singapore. They had never faced the massed anti-aircraft fire of an American task force. They had never fought experienced American pilots flying the new Hellcat fighter. The result was slaughter. American fighters shot down Japanese aircraft faster than they could reach their targets.

 Dive bombers and torpedo planes fell from the sky by the dozen. The battle became known as the Great Marianas Turkey Shoot. In a single day, Japan lost approximately 270 aircraft. Over the course of the battle, Japanese naval aviation lost nearly 500 planes and most of its trained pilots. The submarine Albacore torpedoed the fleet carrier Taiho.

 The submarine Cavalla sank the fleet carrier Shokaku. Japanese naval aviation never recovered. And still, the submarines kept killing tankers. By early 1945, the situation was desperate. Oil imports had slowed to a trickle. Japanese warships could not leave port for lack of fuel. Aircraft sat grounded on airfields because there was no aviation gasoline.

 The last tanker from Southeast Asia reached Japan in March 1945. After that, nothing. The pipeline was closed. Japan’s lifeline had been severed. But the submarines did more than sink tankers and carriers. They systematically destroyed Japan’s ability to reinforce its island garrisons. American submarines sank an estimated 44 Japanese troop ships during the war.

In 33 of those sinkings, the death toll surpassed 1,000 soldiers. Entire army divisions disappeared beneath the waves before they could reach their destinations. The troop transports sailed from Japan packed with reinforcements for the Pacific islands. They carried soldiers, equipment, ammunition, and supplies.

 Each ship was desperately needed at the front lines. Each ship ran the gauntlet of American submarines. At the critical stages of the Guadalcanal, Saipan, and later campaigns, thousands of Japanese troops were killed in transit or diverted before they arrived where they were needed. Reinforcements that the Japanese high command counted on simply never materialized.

 Island garrisons that should have been strengthened remained at partial strength. Counterattacks that should have had overwhelming numbers faced American forces with equality or inferiority. Japanese military planners eventually issued a circular in January 1945 titled “How to deal with maritime emergencies.

” The document acknowledged that the density of troops packed into each transport ship had soared during the war. Soldiers were crammed into cargo holds on tiered bunks called silkworm shelves. The ships were floating death traps. When submarines found them, the casualties were catastrophic. Some historians estimate that American submarines killed more than 97,000 Japanese soldiers at sea.

This number is derived from detailed analysis of Japanese records compiled after the war. But even researchers acknowledge that their figures represent a floor, not a ceiling. Japanese records did not comprehensively track troop losses on torpedoed transports. Many sinkings went unrecorded. Many casualty figures were lost or destroyed.

The true number may be significantly higher. The psychological impact on Japanese commanders was profound. Admiral Mineichi Koga, who succeeded Yamamoto as commander of the Combined Fleet, knew that every convoy sailing from Japan to the southern resource zone faced submarine attack. Every tanker bound for Singapore risked destruction.

Every troop ship heading to reinforce the Philippines might never arrive. Japanese admirals had built their careers on the doctrine of the decisive fleet battle. They studied the Battle of Tsushima, where the Imperial Navy had annihilated the Russian Baltic Fleet in 1905. They believed that war would be decided by great ships engaging in epic combat.

Instead, they found themselves fighting an enemy they could not see. American submarines operated beneath the surface. They struck without warning. They disappeared before escorts could respond. They were everywhere and nowhere. And their torpedoes, once the Mark 14 was fixed, rarely missed. The Japanese tried to counter the threat.

They developed escort groups modeled on British anti-submarine forces. They instituted convoy procedures. They deployed anti-submarine aircraft along the shipping lanes. They increased depth charge production. They developed new detection technologies including radar and improved sonar. But Japan lacked the industrial capacity to build enough escort vessels to protect its merchant fleet.

 The nation that had focused its entire naval strategy on building battleships and carriers had neglected the humble destroyer escorts that could have saved its shipping. Japan commissioned approximately 250 destroyers and escort vessels during the war. America lost only 52 submarines to all causes.

 Japanese anti-submarine tactics improved, particularly after the introduction of radar in late 1943. American submarines reported more dangerous patrols in 1944 than in previous years. Depth charge attacks became more accurate. Japanese escort commanders learned to predict submarine movements. The hunting became harder. 52 American submarines were lost during the war, along with more than 3,500 men.

 The casualty rate of approximately 22% was the highest of any American military branch. Submarine service was extraordinarily dangerous. The boats that did not return simply vanished, lost with all hands, their crews entombed forever in their steel coffins on the ocean floor. But the ratio of ships sunk to submarines lost continued to favor the Americans.

 For every American submarine destroyed, the Japanese lost dozens of merchant ships and thousands of soldiers. The mathematics were inexorable. The Japanese were losing the war beneath the waves. This brings us back to Commander Joseph Enright and the Shinano. Enright had served in submarines since before the war.

 He had watched captains struggle with defective torpedoes in 1942. He had seen patrols fail through no fault of the men involved. He understood the frustration of attacking enemy ships and watching the weapons malfunction. He had been given command of the submarine Dace early in the war and had a disappointing first patrol. Later, he took command of Archerfish.

Four patrols produced no confirmed sinkings. By the standards of the aggressive submarine force, his record was mediocre. But by November 1944, everything had changed. The torpedoes were reliable. The intelligence was accurate. Submarine tactics had been refined through three years of combat experience.

 And Enright was about to get the opportunity of a lifetime. Archerfish was on her fifth war patrol, stationed off the coast of Japan to rescue downed bomber crews during B-29 raids on the home islands. On the evening of November 28th, with no bombing mission scheduled due to weather, Archerfish was free to hunt. At 20:48 hours, radar operators detected a large contact leaving Tokyo Bay.

 The target was moving fast, at least 18 knots, accompanied by three smaller vessels. Enright ordered pursuit. For six hours, Archerfish tracked the mystery ship on the surface, maintaining parallel course and waiting for an opportunity. The target was zigzagging, changing course unpredictably to throw off submarine attacks, standard anti-submarine procedure.

 But Captain Toshio Abe aboard the Japanese vessel made a critical error. He believed he was being tracked by a pack of submarines rather than a single boat. He thought Archerfish was a decoy meant to lure away his escorts while other submarines positioned for attack. He ordered his destroyer screen to maintain formation rather than pursuing the contact.

 Instead of running in a straight line at maximum speed, which would have left Archerfish behind, Abe continued zigzagging. And each zigzag brought the target closer to the submarine. At 02:56 hours, Archerfish submerged while turning east to find the optimal attack position. Enright ordered his torpedoes set for 10 ft, hoping to hit the target higher on its hull where the damage would be most difficult to control.

 He also wanted to increase the chances of a hit in case the torpedoes ran deeper than set, echoes of the earlier problems that Lockwood had solved. At 0317 hours, the carrier turned to the south as part of her zigzag pattern. This brought her entire broadside perpendicular to Archerfish. The range was 1,400 yd. The angle was perfect.

 Enright could not have asked for a better setup. He fired six torpedoes. Four struck the ship between the anti-torpedo bulge and the waterline. The explosions were tremendous, felt throughout the submarine. Archerfish immediately dove to 400 ft to evade the expected depth charge attack. The crew heard loud breaking up noises from the target for 47 minutes.

 The carrier was the Shinano, largest aircraft carrier ever built up to that time. She had been laid down in May 1940 as the third Yamato class battleship, sister to the Yamato and Musashi, the most powerful battleships in the world. After the disaster at Midway in June 1942, where Japan lost four fleet carriers in a single day, the Japanese navy ordered Shinano’s conversion to an aircraft carrier.

 Her construction had been so secret that American intelligence had no record of her existence. A B-29 reconnaissance aircraft had photographed her during sea trials on November 1st, but analysts did not recognize what they were seeing. The ship was unknown to the Americans until after the war. Shinano displaced 72,000 tons. Her armored flight deck was designed to withstand 1,000-lb bomb hits.

 She was intended to support other carriers, operating as a floating supply ship carrying fuel, ammunition, and replacement aircraft. The Japanese had pinned enormous hopes on this vessel. She sank in less than 7 hours. The crew could not contain the flooding. Shinano had been rushed to completion with watertight doors that were not finished.

 Pumps were missing from critical locations. Many compartments were not properly sealed. The construction workers had labored around the clock to meet the deadline, but quality had suffered. Her crew was inexperienced. Many had never served on an aircraft carrier. They did not know the ship’s layout. They did not understand her damage control systems.

When the torpedoes hit, they did not respond effectively. The four torpedo strikes exposed fundamental design flaws in the joint between Shinano’s armor belt and her underwater protection system. This was a weakness shared by all Yamato class vessels. Water flooded through the damaged sections faster than the pumps could remove it.

 Captain Abe attempted to beach his ship on the Japanese coast. He ordered flooding of portside tanks to counter the growing list, but the damage was too extensive. The flooding could not be controlled. At 10:18 hours, Captain Abe ordered abandon ship. 45 minutes later, Shinano rolled completely over and sank by the stern.

Captain Abe chose to go down with his ship. He was subsequently promoted posthumously to rear admiral. 1,435 men died with him. Approximately 1,000 crew and civilian workers were rescued. Archerfish returned to Guam on December 15th, having sunk more tonnage in a single attack than any submarine in history. But Enright did not know exactly what he had hit.

 He sketched the target from memory during the patrol report. Based on his observations, he estimated the carrier displaced approximately 28,000 tons, consistent with a Hayatake class vessel. American intelligence initially credited Archerfish with sinking a cruiser, then upgraded the assessment to a carrier based on Enright’s drawings.

 Only after the war, when American investigators examined Japanese naval records, did the true identity of the victim become clear. Archerfish had sunk the Shinano, the largest warship ever destroyed by a submarine. Enright received the Navy Cross for his achievement. Archerfish received a presidential unit citation. The record still stands, but the Shinano was only the most dramatic example of what American submarines accomplished against the Imperial Japanese Navy.

 The battleship Kongo, one of the great capital ships that had served Japan since before the First World War, was sunk by the submarine Sealion on November 21st, 1944. Kongo was returning to Japan after the Battle of Leyte Gulf when Sealion caught her in the Formosa Strait. Two torpedo hits ignited her magazines.

She sank with the loss of over 1,200 men. No Japanese battleship had ever been lost to a submarine. The psychological impact was enormous. These were the great ships, the pride of the Imperial Navy, the weapons that Japanese admirals had trained their entire careers to command, and they were being sunk by underwater boats that displaced less than 3% of their tonnage.

American submarines sank eight Japanese aircraft carriers during the war, including Shinano. They sank the fleet carriers Shokaku and Taiho, the escort carriers Taiyo, Unyo, and Shinyo, and the fleet carrier Unryu. Each loss represented not only the vessel, but the trained air crews and aircraft aboard her.

 They sank two heavy cruisers and seven light cruisers. They sank dozens of destroyers and escort vessels. They sank transports, tankers, cargo ships, and freighters by the thousand. Vice Admiral Charles Lockwood, who had fought for reliable torpedoes and aggressive tactics when others counseled caution, watched his command achieve results beyond his expectations.

 Over 1,000 enemy ships totaling more than 5 million tons were sunk by submarines under his direction. His force accounted for approximately 55% of all Japanese vessels lost during the war. The men who served under Uncle Charlie never forgot what he had done for them. He had trusted their reports when the Bureau of Ordnance insisted they were wrong.

 He had fought for weapons that worked. He had pushed tactics that put submarines in the most dangerous waters. And when his sailors came home from patrol, he made certain they were cared for. Lockwood established rest camps for returning crews. He arranged for submarines returning from patrol to be greeted with ice cream and fresh vegetables.

He secured the Royal Hawaiian Hotel in Waikiki as a rest facility for submariners. These were small gestures, but they mattered enormously to men who had spent weeks in cramped steel tubes beneath the ocean. By early 1945, Japan’s oil supply had collapsed entirely. The tanker routes that had sustained the empire were now killing zones patrolled by American submarines.

So desperate was Japan’s need for fuel that the government mobilized millions of civilians to produce substitutes. Entire classes of schoolchildren were sent to dig up pine roots for distillation into low-grade oil. 37,000 improvised distillation units were constructed across the country. They produced approximately 70,000 barrels of pine oil, from which only 3,000 barrels of aviation fuel could be refined.

 The fuel was so contaminated with impurities that American jeeps, which used captured stocks during the occupation, quickly suffered engine failure. The pine oil clogged injectors and corroded engine components. It was barely functional as a fuel source, but Japan had nothing else. By August 1945, most Japanese warships had been sunk or immobilized by lack of fuel.

The operational fleet had been reduced to perhaps 20 destroyers and 40 submarines. Even these could remain at sea for only days before their fuel ran out. The Japanese admirals who had planned for decisive fleet battles in the tradition of Tsushima found themselves commanding ships that could not leave port.

 The carriers that survived the submarine attacks could not launch aircraft because there was no aviation gasoline. The battleships that remained afloat could not sail because their tanks were dry. American submarines had accomplished what no surface fleet or air armada could have achieved alone. They had severed Japan’s arteries.

 They had starved the empire of the resources it needed to fight. They had killed its soldiers before they could reach the battlefield. They had sunk its carriers before they could launch their aircraft. They had destroyed its tankers before they could deliver their cargoes. The men who achieved this victory paid a terrible price.

 The submarines that never returned took their crews with them. Nearly one in five boats that saw combat was lost. Commander Dudley Morton of the submarine Wahoo became one of the war’s legendary figures. His aggressive tactics inspired a generation of submariners. He took Wahoo into waters that other captains considered too dangerous.

 He attacked convoys with a ferocity that earned him the nickname Moosh. In five patrols under his command, Wahoo sank 19 ships totaling approximately 55,000 tons. On October 11th, 1943, Wahoo was lost with all hands in the Sea of Japan, caught by Japanese aircraft while attempting to exit through La Perouse Strait.

 Morton and all 79 members of his crew were killed. His body was never recovered. Morton’s executive officer, Lieutenant Richard O’Kane, went on to command the submarine Tang. O’Kane became the top scoring submarine commander of the war, sinking 33 ships in five patrols. Tang was credited with more ships sunk than any other American submarine.

 On October 24th, 1944, during a night surface attack in the Formosa Strait, Tang fired her final torpedo at a damaged transport. The torpedo malfunctioned, made a circular run, and struck Tang’s stern. The submarine sank in 180 ft of water. 78 men were killed. O’Kane and eight others survived, escaping through the flooded submarine using Momsen lungs, and were captured by Japanese forces.

O’Kane spent the last 10 months of the war as a prisoner in Japanese camps. After liberation, he received the Medal of Honor for his actions during Tang’s final patrol. His citation noted that he sank two convoys totaling 13 ships in less than 24 hours. Lockwood survived the war and continued to advocate for his sailors.

He documented their achievements in several books that became classics of submarine literature. He testified at war crimes trials. He served as Inspector General of the Navy after the war. He fought to ensure that the submarine force received the recognition it deserved. The official statistics tell the story.

American submarines, constituting less than 2% of United States Navy personnel, accounted for more than 55% of all Japanese shipping losses. They sank more than 1,100 merchant ships and 200 warships. They killed tens of thousands of Japanese soldiers and sailors. They rescued more than 500 downed American airmen from the waters of the Pacific.

 They altered the outcome of the war. The Japanese admirals who began the conflict confident in their battle fleet ended it without ships, without fuel, without hope. The submarines they had dismissed as auxiliary vessels, useful only for reconnaissance and coastal defense, had become the decisive weapon. The underwater boats they had failed to counter had strangled their empire.

 The transformation began with one officer who refused to accept that his torpedoes were working when they clearly were not. Charles Lockwood fought his own bureaucracy as fiercely as he fought the enemy. He demanded tests when the Bureau of Ordnance insisted none were needed. He modified weapons when regulations prohibited unauthorized changes.

He pushed aggressive tactics when doctrine called for caution. And when the torpedoes finally worked, when the submarines finally had the weapons they needed, they became unstoppable. Japanese admirals learned to fear what they could not see. Their tankers vanished. Their troop transports disappeared.

 Their carriers sank without warning. The American submarines operated in their waters, along their shipping lanes, even in the Sea of Japan itself, and they could not be stopped. By the summer of 1945, the submarine campaign had achieved its ultimate objective. Japan was isolated. Japan was starving. Japan was beaten.

 The war beneath the waves was over. If you found this story as compelling as we did, please take a moment to like this video. It helps us share more untold stories from the Second World War. Subscribe to stay connected with these histories. Each one matters. Each one deserves to be remembered. We would love to hear from you.

 Leave a comment below telling us where you are watching from. Our community spans the globe, from veterans and their families to history enthusiasts around the world. You are part of something special here. Thank you for watching, and thank you for keeping these stories alive. There is a postscript to this story that deserves telling.

 In the decades after the war, historians and researchers began to piece together the full scope of what American submarines had accomplished. The wartime statistics, carefully compiled by the Joint Army Navy Assessment Committee, revealed that United States submarines had sunk 540,000 tons of Japanese naval vessels and nearly 4.

8 million tons of merchant shipping combined. This represented over 54% of all Japanese vessel losses during the conflict, but the numbers only tell part of the story. The submarines did not merely sink ships. They broke the back of an empire. They demonstrated that an island nation dependent on sea transport could be choked into submission by a relatively small force of underwater vessels.

 They proved that modern submarines, when properly equipped and aggressively commanded, could alter the strategic balance of an entire theater of war. The lessons were not lost on military planners. In the decades after 1945, submarine warfare became central to the naval strategies of every major power. The nuclear submarines that followed inherited the legacy of the fleet boats that had stalked the Pacific.

 The tactics evolved. The weapons became more sophisticated. But the fundamental principle remained unchanged. Control the seas beneath the surface, and you control the seas. Charles Lockwood retired from the Navy in 1947 with the rank of vice admiral. He spent his remaining years writing about the submarine force he had commanded.

 His books, including Sink ‘Em All and Down to the Sea in Subs, preserved the stories of the men who had served under him. He died in 1967 at the age of 77. He is buried at Golden Gate National Cemetery in San Bruno, California, alongside his fellow admirals Chester Nimitz, Raymond Spruance, and Richmond Kelly Turner. The destroyer escort Lockwood, commissioned in 1970, was named in his honor.

 The Naval Submarine League continues to present the Vice Admiral Charles Lockwood Award annually to recognize excellence in submarine operations. Richard O’Kane retired as a rear admiral. He wrote two books about his experiences, Wahoo and Clear the Bridge, both considered classics of submarine literature.

 He died in 1994 at the age of 83. The guided missile destroyer O’Kane, commissioned in 1999, bears his name. The wreck of the Wahoo was discovered in 2006 in the La Perouse Strait, resting in over 200 ft of water. Dudley Morton and his 79 crewmen remain entombed in their submarine, a war grave honored by the nations that once fought over those waters.

 The Shinano lies somewhere in the deep waters off the coast of Japan, the largest warship ever sunk by a submarine, a monument to the devastating effectiveness of the American undersea campaign. And in the quiet depths of the Pacific, scattered across thousands of miles of ocean floor, rest the submarines that never returned home.

 Their crews made the ultimate sacrifice in the silent service of their country. They deserve to be remembered. That is how a small force of submarines changed the course of a world war, not through a single decisive battle, but through relentless grinding attrition. Not through brilliant fleet actions, but through patient stalking and precise attacks.

Not through overwhelming numbers, but through skill, courage, and weapons that finally worked. The Japanese admirals who dismissed submarine warfare as secondary to the grand fleet engagement learned their error too late. By the time they understood the threat, their tankers were on the bottom, their armies were stranded, and their empire was dying of starvation.

 The submarines had won.