- 6 hours ago
A torpedo that seemed to miss its target went on to cripple a Japanese light cruiser—and change one PT boat crew’s night forever. In the darkness of Surigao Strait, Lieutenant Isadore Kovar fired from PT-137 at a destroyer. The Mark 8 torpedo ran deeper than intended, passed beneath the smaller ship, and struck the cruiser Abukuma beyond it.
This World War II military history story follows the hit, PT-137’s escape under Japanese gunfire, and Abukuma’s eventual sinking after an air attack. Discover the Surigao Strait battle, Pacific War PT boat operations, unreliable torpedo technology, and the remarkable consequences of a tiny manufacturing flaw. A narrated naval history account for viewers interested in WWII war stories, forgotten heroes, and the final battleship era.
This World War II military history story follows the hit, PT-137’s escape under Japanese gunfire, and Abukuma’s eventual sinking after an air attack. Discover the Surigao Strait battle, Pacific War PT boat operations, unreliable torpedo technology, and the remarkable consequences of a tiny manufacturing flaw. A narrated naval history account for viewers interested in WWII war stories, forgotten heroes, and the final battleship era.
Category
📚
LearningTranscript
00:00At 0335 on October 25th, 1944,
00:04Lieutenant Junior Grade Isidore Kovar stood on the bridge of PT-137
00:09watching a Japanese destroyer slice through the black waters of Surigao Strait.
00:1424 years old, seven months commanding patrol torpedo boats,
00:19zero capital ships damaged.
00:21Vice Admiral Shima's southern force had just entered the strait with two heavy cruisers,
00:26one light cruiser and four destroyers.
00:29Over 40,000 tons of Imperial Japanese Navy steel.
00:33Kovar's boat was blind.
00:35PT-137's auxiliary generator had failed three hours earlier,
00:40leaving the 80-foot Elko boat without radar or radio transmission.
00:44No way to see targets beyond visual range.
00:47No way to coordinate with the other 38 PT boats scattered along the strait.
00:52His crew of 12 sat in darkness,
00:54relying on moonlight and lightning flashes to spot enemy ships.
00:58The night belonged to the Japanese.
01:00Admiral Shima's force was racing north to support Vice Admiral Nishimura's battleships
01:06in their assault on the American beachhead at Leyte Gulf.
01:09If they broke through, 20,000 American troops would face bombardment from 14-inch naval guns at dawn.
01:17PT boats had been dying all night.
01:20Lieutenant Commander Robert Leeson's section had attacked Nishimura's force two hours earlier.
01:24PT-152 had taken a direct hit from destroyer Shigure,
01:29killing one gunner and setting the boat ablaze.
01:32PT-130's radio had been demolished by shell fire.
01:36The boats that survived reported the same problem.
01:39Japanese destroyers spotted PT boats first,
01:43illuminated them with searchlights,
01:44then destroyed them with 5-inch guns before the Americans could launch torpedoes.
01:49Kovar had already fired once tonight.
01:51At 0-115, he'd spotted two Japanese destroyers passing south of Panayon Island.
01:57He closed to 800 yards, lined up his shot, and launched one Mark VIII torpedo.
02:03The 21-inch fish ran true for 15 seconds,
02:06then porpoised, leaping out of the water like a dolphin before diving deep.
02:11The torpedo missed a stern.
02:12The destroyers never knew PT-137 existed.
02:17That was the problem with Mark VIII torpedoes.
02:20Designed in 1938,
02:22powered by a wet heater engine burning 180-proof grain alcohol mixed with compressed air,
02:27temperamental depth control.
02:29The torpedoes were supposed to run at 10 feet below the surface.
02:33Instead, they ran shallow or deep,
02:36depending on water temperature,
02:37manufacturing tolerances,
02:39and luck.
02:40PT boat crews called them swimming slot machines.
02:44The United States Navy had built 326 Elko 80-foot PT boats by October 1944.
02:51Wooden hulls made of 2-inch mahogany planks.
02:54Three Packard 12-cylinder engines producing 4,500 horsepower total.
02:59Top speed?
03:0041 knots in calm seas.
03:03Armed with four Mark VIII torpedo tubes,
03:06two twin .50 caliber machine gun turrets,
03:08one 20-millimeter Oerlikon cannon,
03:11and depth charges.
03:13Crew complement?
03:14Three officers,
03:1514 enlisted men,
03:17though most boats operated with 12 to 14 total.
03:20But the torpedoes were the weapons that mattered.
03:23Each Mark VIII weighed 2,215 pounds
03:26and carried 466 pounds of Torpex explosive,
03:3150% more powerful than TNT.
03:33A single hit could cripple a cruiser or sink a destroyer.
03:37The problem was getting hits.
03:40Mark VIII torpedoes had a documented failure rate of 30%.
03:43Some ran circular.
03:45Some sank to the bottom.
03:47Some exploded prematurely.
03:49The ones that worked had to be launched from less than 1,000 yards,
03:53close enough that Japanese searchlights could blind PT boat crews
03:56and 5-inch shells could tear wooden hulls apart.
04:00Kovar watched the destroyer's silhouette sharpen against the darkness.
04:03The Japanese ship was heading south,
04:06running at 20 knots,
04:07no zigzag pattern.
04:09Probably damaged or separated from Admiral Shima's main force,
04:13a straggler.
04:14If you want to see how Kovar's blind torpedo shot turned out,
04:17please hit that like button.
04:18It helps us share these forgotten stories with more people.
04:21And please subscribe.
04:23Back to Kovar.
04:24He had three torpedoes remaining,
04:27range closing to 900 yards.
04:29The destroyer hadn't spotted PT-137 yet.
04:32Kovar's boat sat low in the water,
04:34painted dark gray,
04:35with its engines throttled down to reduce wake.
04:38The Japanese lookouts were scanning north,
04:40watching for threats from Admiral Oldendorf's battle line.
04:43Kovar made his decision.
04:45He ordered his crew to battle stations without speaking,
04:48using hand signals in the darkness.
04:50Torpedo Man 2nd Class checked the tubes.
04:52Gunners swung their .50 caliber turrets
04:54to cover the destroyer's searchlights.
04:56Enginemen stood ready to run the Packards
04:58to full power for the escape.
05:00900 yards.
05:02Kovar centered the destroyer in his sight.
05:04His thumb moved to the torpedo launch trigger.
05:06He had one shot.
05:08If the Mark VIII ran true,
05:10he might damage a destroyer.
05:12If it ran deep or shallow,
05:13he'd launched $1,500 worth of explosives into empty water.
05:17And if the destroyer spotted PT-137's torpedo wake,
05:21searchlights and shells would follow within seconds.
05:24Kovar pressed the trigger.
05:25The Mark VIII tube fired with a pneumatic hiss.
05:28The torpedo dropped into the water
05:30and its wet heater engine ignited,
05:32leaving a phosphorescent wake
05:34that glowed green in the darkness.
05:36Kovar counted seconds.
05:37At 41 knots,
05:39the Mark VIII would reach the destroyer
05:41in 23 seconds if it ran straight.
05:43If it ran at all.
05:44The torpedo disappeared beneath the surface.
05:47No porpoising.
05:48No circular run.
05:49The wake tracked true toward the destroyer's midship section.
05:53Kovar kept his eyes on the target,
05:55waiting for the flash of torpex detonating against steel.
05:58Nothing happened.
05:59The destroyer steamed past the torpedo's track without slowing.
06:02No explosion.
06:04No fire.
06:05No damage.
06:06Kovar had missed.
06:08Another Mark VIII had failed.
06:09His crew stood silent on the deck,
06:11watching $1,500 of American ordnance
06:14vanish into Surigao Strait.
06:17Then the night erupted behind the destroyer.
06:20A massive explosion lit the water
06:22800 yards beyond the Japanese ship.
06:25Yellow-orange flames shot 200 feet into the air.
06:28The concussion wave hit PT-137 three seconds later,
06:32a physical blow that rattled the boat's wooden hull
06:35and knocked one gunner off his feet.
06:38Kovar grabbed the windscreen to stay upright.
06:40Something big had just died.
06:43The destroyer's searchlight snapped on,
06:46sweeping across the water toward PT-137.
06:49The beam caught the PT boat in its glare.
06:52Kovar shouted for full power.
06:54His enginemen slammed the three Packard engines
06:57to maximum throttle.
06:584,500 horsepower roared to life.
07:01Star shells burst overhead.
07:03Japanese illumination rounds hung suspended on parachutes,
07:07turning night into day.
07:09Kovar could see his entire boat lit up like a target
07:12at a shooting range.
07:13He ordered hard starboard,
07:15throwing PT-137 into a violent turn.
07:18The first 5-inch shell hit the water 30 yards to port.
07:22The second shell hit 50 yards astern.
07:24The destroyer was firing blind,
07:27trying to bracket the PT boat with high-explosive rounds.
07:30Each shell displaced two tons of water when it detonated,
07:34creating geysers that drenched Kovar's crew.
07:37PT-137 reached 40 knots.
07:40The wooden hull pounded across the waves,
07:43vibrating so hard that instruments shook loose from their mounts.
07:47Kovar steered toward a thick bank of smoke that hung over the strait,
07:51residue from the night's earlier battles.
07:53If he could reach the smoke before the destroyer's guns found their range,
07:57his boat might survive.
07:59The third shell missed by 20 yards,
08:02the fourth by 15.
08:04The Japanese gunners were walking their fire closer.
08:07Kovar counted the seconds until the fifth shell would land directly on his boat.
08:12PT-137 hit the smoke bank at 41 knots and disappeared.
08:16The star shell still burned overhead,
08:18but the thick black smoke concealed the wooden boat from Japanese gunners.
08:23Kovar maintained full speed for two minutes,
08:26then throttled back and changed course to northeast.
08:29The destroyer's guns fell silent.
08:32Either they'd lost a target,
08:33or they'd moved on to other threats.
08:36Kovar's radio man worked frantically to restore the auxiliary generator.
08:41After ten minutes of rewiring connections in the dark,
08:44power returned.
08:46The radar screen flickered to life.
08:48The radio crackled with traffic from other PT boats.
08:51The explosion Kovar had witnessed wasn't his imagination.
08:55Someone had transmitted a contact report.
08:58Light cruiser hit.
08:59Dead in water.
09:01Listing to port.
09:02Location.
09:03Southern entrance to Surrigal Strait.
09:05Time.
09:06O-3-36.
09:08One minute after Kovar had fired his torpedo.
09:11But Kovar had shot at a destroyer.
09:14His Mark VIII had missed.
09:16He'd watched the torpedo pass harmlessly astern of the Japanese ship.
09:20There was no cruiser in his firing solution.
09:23No secondary target beyond the destroyer.
09:26Unless the torpedo hadn't missed.
09:28Unless it had run deep.
09:30Deeper than the destroyer's five-foot draft.
09:33And continued traveling through the water until it found a larger ship with a deeper hull.
09:38Radio traffic confirmed details.
09:41The cruiser was Abukuma.
09:42Flagship of Destroyer Squadron 1.
09:45Nagara-class light cruiser.
09:475,570 tons.
09:50Hit in the number one boiler room.
09:5237 crew dead.
09:54Speed reduced to 10 knots.
09:56The cruiser had fallen out of Admiral Shima's formation and was attempting to retreat south.
10:02Kovar's torpedo hadn't failed.
10:04It had run exactly as designed.
10:06At depth.
10:08Too deep for the destroyer, which drew only 5 feet of water.
10:11But perfect for Abukuma, which drew 16 feet.
10:15The Mark VIII had passed under the destroyer and struck the cruiser 900 yards beyond.
10:20A failed shot had become the most significant hit by an American PT boat in the entire Pacific War.
10:27But Abukuma was still afloat.
10:29Still armed with seven 5-inch guns and eight torpedo tubes.
10:33Still capable of 20 knots if her engineers could contain the flooding.
10:38And Kovar's PT-137 sat in Japanese-controlled waters with two torpedoes remaining and a generator that had already failed
10:46once tonight.
10:47Dawn was three hours away.
10:49Admiral Shima's force continued north into the killing zone that Rear Admiral Jesse Oldendorf had prepared.
10:55Six American battleships waded across the northern exit of Surigao Strait,
10:59with their main batteries loaded and gun directors locked on radar contacts.
11:04Eight cruisers flanked the battleships.
11:0626 destroyers prowled the flanks, ready for torpedo runs.
11:11Vice Admiral Nishimura's force had already been destroyed.
11:14Battleship Yamashiro had taken multiple torpedo hits and capsized at 04-19,
11:19taking 1,636 crew to the bottom.
11:23Battleship Fuso had broken in half and sank.
11:26Only destroyer Shigure survived from Nishimura's seven-ship force.
11:30Admiral Shima never reached the American battle line.
11:33At 04-25, his flagship Nachi collided with the burning wreck of cruiser Mogami in the smoke and darkness.
11:40The collision tore a 40-foot gash in Nachi's bow and jammed her starboard propeller shaft.
11:46Speed reduced to 18 knots.
11:49Admiral Shima ordered his entire force to retreat south.
11:52The Japanese were running, but Abukuma couldn't run with them.
11:56The torpedo hit had flooded Abukuma's forward boiler room.
11:59Salt water poured through the 16-foot hole in her portside hull.
12:03Damage control teams sealed the watertight doors, containing the flooding to two compartments.
12:08But the cruiser had lost one of her four boiler rooms.
12:12One quarter of her power plant was gone.
12:14Her bow settled four feet deeper in the water, creating drag that further reduced speed.
12:20Captain Hanada Takuo fought to save his ship.
12:23His engineers rerouted steam from the three remaining boilers.
12:26Pumps worked continuously to control flooding.
12:29Repair crews welded steel plates over smaller hull fractures.
12:33By 0445, 90 minutes after the torpedo hit, Abukuma's speed had increased from 10 knots to 20 knots.
12:41Not enough to keep pace with Admiral Shima's heavy cruisers, but enough to escape Surigao Strait
12:46before American battleships could range her with their 14-inch guns.
12:51Abukuma turned south at 0500, following destroyer Ushio through the smoke-filled strait.
12:57The cruiser was down at the bow, listing three degrees to port, but she was under her own power.
13:02Captain Hanada ordered his crew to jettison unnecessary weight.
13:06.50 caliber machine gun ammunition went overboard.
13:10Spare parts followed.
13:11Anything that wasn't essential for keeping Abukuma afloat and armed.
13:16PT boats shadowed the retreating Japanese ships.
13:19Lieutenant Commander Robert Leeson's PT-134 reported Abukuma's position at 0600.
13:25The cruiser was making 20 knots south, trailing oil, but still dangerous.
13:31Her seven 5.5-inch guns remained operational.
13:34Her torpedo tubes were loaded.
13:37American PT boats that attempted close approaches were driven off by accurate defensive fire.
13:42By 0630, Abukuma had cleared Surigao Strait and entered the Mindanao Sea.
13:48The cruiser turned west toward Dapitan, a small port on Mindanao's northern coast where emergency repairs could be attempted.
13:56Captain Hanada calculated arrival time at 1400 hours.
14:01Eight hours to reach safety.
14:03Eight hours to keep his ship from sinking.
14:05The Battle of Surigao Strait ended at 0700 on October 25th.
14:10The Imperial Japanese Navy had lost two battleships, three destroyers, and suffered heavy damage to three cruisers.
14:18American losses, one PT boat sunk, several damaged.
14:22It was the last battleship engagement in naval history and a complete American victory.
14:27But the battle wasn't finished for Abukuma.
14:30The cruiser had survived the torpedo hit.
14:33She'd escaped the strait.
14:34She'd maintained enough speed to run south ahead of American pursuit.
14:38Captain Hanada had kept his crew disciplined and his ship functional, despite catastrophic damage.
14:44Abukuma reached Dapitan Harbor at 1430 hours on October 25th.
14:49Repair crews went to work immediately, welding steel patches over the torpedo hole and pumping out flooded compartments.
14:56The cruiser would need three days of emergency repairs before attempting the run back to Japan.
15:01Three days anchored in Philippine waters.
15:04Vice Admiral Thomas Kincaid, commander of the U.S. 7th Fleet, received contact reports on Abukuma throughout October 25th.
15:13The damaged cruiser represented unfinished business.
15:16Kincaid ordered Rear Admiral Thomas Sprague to locate and destroy all retreating Japanese ships from the Battle of Surigao Strait.
15:24Sprague commanded 18 escort carriers operating east of Leyte Gulf.
15:28His air groups had been fighting Vice Admiral Takeo Kurita's center force all morning in the desperate battle off Samar.
15:36But by afternoon, Kurita had retreated.
15:39Sprague's aircraft were available for search and strike missions.
15:42At 1500 hours on October 25th, Sprague dispatched scout aircraft to locate Admiral Shima's retreating force.
15:50The search pattern covered waters from Surigao Strait west to the Sulu Sea.
15:55Priority target? Damaged cruisers attempting to reach safe harbors.
16:00Abukuma sat in Dapitan Harbor with her engines shut down for repairs.
16:04No air cover.
16:06No destroyer screen.
16:07Just one escort.
16:08Destroyer Ushio.
16:10And repair crews working frantically to patch a 16-foot hole below the waterline.
16:15October 26th dawned clear.
16:18Perfect weather for carrier aircraft.
16:20Perfect hunting conditions for American dive bombers searching for crippled Japanese ships.
16:2617 Grumman TBM Avenger torpedo bombers from rear Admiral Sprague's escort carriers
16:32found Admiral Shima's force at 0900 on October 26th.
16:36The American aircraft spotted heavy cruisers Natchi and Ashigata steaming west at 25 knots, screened by four destroyers.
16:45The cruisers were undamaged and combat capable, defending themselves with concentrated anti-aircraft fire.
16:52The Avengers attacked but scored no hits.
16:55Shima's main force would escape.
16:57But the scout aircraft had also spotted something else.
17:15The cruiser sat dead in the water with visible damage to her bow section.
17:20The 13th Air Force received the contact report at Clark Field on Luzon.
17:24The 5th Air Force received it at Morotai.
17:27Both commands had B-24 Liberator heavy bombers available for immediate strikes.
17:33The consolidated B-24 was America's most produced heavy bomber.
17:3718,500 aircraft built by October 1944.
17:42Four Pratt and Whitney engines.
17:44Maximum speed 300 miles per hour.
17:47Combat radius 1,000 miles.
17:49Bomb load 8,000 pounds.
17:5144 B-24 Liberators launched from Philippine and Morotai airbases at 1,100 hours on October 26th.
18:00Their mission?
18:00Sink the damaged cruiser before she could complete repairs and escape to Japan.
18:05The bombers formed up in flights of four to six aircraft and headed for Daputan.
18:09Abukuma's lookouts spotted the first flight of B-24s at 1,200 hours.
18:15Six four-engine bombers approaching from the northeast at 12,000 feet.
18:20Captain Hanada ordered his crew to battle stations.
18:23The cruiser's anti-aircraft batteries consisted of four twin-mount Type 96 25-millimeter guns
18:30and 10 single-mount 25-millimeter guns, 38 barrels total.
18:35Effective range, 3,000 feet.
18:38The guns were designed to defend against dive bombers attacking from 6,000 feet or below.
18:43They were nearly useless against level bombers attacking from 12,000 feet.
18:47Destroyer Ushio added her anti-aircraft fire.
18:50Another four twin-mount and four single-mount 25-millimeter guns.
18:55But Ushio was a Fubuki-class destroyer built in 1929.
19:00Her anti-aircraft armament was inadequate for 1944 aerial warfare.
19:05The first flight of B-24s approached from the northeast.
19:09Each bomber carried 12,500-pound general-purpose bombs, 72 bombs falling from 12,000 feet.
19:17The bombardiers used Norden bomb sights, calculating for wind speed, altitude, and target motion.
19:23Abukuma couldn't maneuver.
19:25The cruiser sat anchored with her engines offline for repairs.
19:28The first bombs fell at 12,07.
19:32Captain Hanada watched them drop, small black dots growing larger as they accelerated downward.
19:38The bombs took 22 seconds to fall from 12,000 feet, 22 seconds to track their trajectory and realize his
19:46ship had no escape.
19:47Three bombs hit Abukuma.
19:49The first struck near the stern, penetrating the deck and detonating inside the after-engine room.
19:55The explosion killed 14 engineers and destroyed the cruiser's starboard propeller shaft.
20:01The second bomb hit amid ships, blowing a 20-foot hole through the main deck and igniting aviation fuel stored
20:08for Abukuma's Type 94 reconnaissance float plane.
20:11Fire spread through three compartments.
20:13The third bomb struck forward, detonating in the crew quarters and killing 31 sailors.
20:19Abukuma was dying.
20:21Three direct hits from 500-pound bombs had opened her hull in multiple locations.
20:27The fires couldn't be controlled.
20:29The flooding couldn't be stopped.
20:31Captain Hanada knew his ship had minutes remaining.
20:33More B-24s appeared.
20:36Second flight.
20:37Third flight.
20:38The American bombers circled Dapitan Harbor, lining up for follow-up attacks.
20:43They could see Abukuma burning and listing.
20:46They could see crew abandoning ship.
20:48But the mission called for confirmation of sinking, not just damage.
20:53The second wave dropped 48 more bombs.
20:56Four additional hits struck the doomed cruiser.
20:59One bomb detonated in the Ford magazine, where Type 93 long-lance torpedoes were stored.
21:04The torpedo warheads contained 1,080 pounds of explosives.
21:08When the bomb hit triggered a sympathetic detonation, the explosion tore Abukuma's bow completely off.
21:15The cruiser lurched forward, her severed bow section sinking immediately.
21:19The stern section rose out of the water, propellers exposed to air.
21:23Abukuma's hull broke in half amid ships.
21:25Both sections began their final plunge.
21:28Captain Hanada gave the order to abandon ship at 12.25.
21:32The crew had 18 minutes to get off a ship that was breaking apart and sinking.
21:36330 men remained alive.
21:39They jumped into Dapitan Harbor and swam toward destroyer Ushio, which maneuvered to pick up survivors.
21:45Abukuma disappeared at 12.42 on October 26, 1944.
21:50One day and nine hours after Lieutenant Junior Grade Isidore Kovar's torpedo had struck her in the darkness of Surigao
21:56Strait.
21:57250 crew died.
21:59250 crew died.
22:0037 in the torpedo hit.
22:01The rest in the bombing.
22:03Destroyer Ushio rescued 283 survivors, including Captain Hanada.
22:07The B-24s returned to their bases, reporting one Nagara-class cruiser sunk.
22:12Lieutenant Junior Grade Isidore Kovar returned to base at Tacloban, Leyte, on October 26.
22:18His after-action report documented one torpedo fired at a Japanese destroyer at 03.35 on October 25.
22:27Target?
22:28Destroyer.
22:29Estimated 1,500 tons.
22:31Result?
22:32Miss a stern.
22:33No observed hits.
22:35No confirmed damage.
22:36Kovar didn't claim to have struck Abukuma.
22:39He'd watched his torpedo pass under the destroyer.
22:42He'd seen no explosion on his intended target.
22:45The massive blast 800 yards beyond the destroyer had occurred in smoke and darkness.
22:51Kovar couldn't confirm what his torpedo had hit, if anything.
22:5539 PT boats had operated in Surigao Strait that night.
22:59They'd launched dozens of torpedoes at Japanese ships.
23:02Multiple boats reported explosions.
23:05Multiple boats claimed possible hits.
23:07The chaos of night combat, with radar failures, radio failures, smoke, and Japanese star shells,
23:14made accurate observation nearly impossible.
23:17Commander Selman Bowling commanded Motor Torpedo Boat Squadron 21.
23:22He faced a puzzle when reviewing after-action reports from the Battle of Surigao Strait.
23:26Several PT boat crews claimed hits on Japanese warships.
23:30Some claims overlapped.
23:32Some contradicted each other.
23:34The darkness, rain squalls, and confusion caused by enemy gunfire made precise observation impossible.
23:41Bowling noted that stated times in the action reports might be wrong by 15 to 30 minutes.
23:47Estimated numbers and types of enemy ships weren't considered accurate.
23:51But someone had hit Abukuma.
23:53Japanese records recovered after the war confirmed the light cruiser had taken a torpedo hit at 0325 on October 25.
24:02Location, southern entrance to Surigao Strait, near Bennett Point on Panaan Island.
24:08The torpedo struck Abukuma's port side near the number one boiler room.
24:1237 crew killed instantly.
24:14American naval intelligence began cross-referencing PT boat positions with Japanese damage reports.
24:20Only three PT boats had been operating near Bennett Point at 0325.
24:25PT-134, PT-132, and PT-137.
24:31Lieutenant Commander Leeson's PT-134 had fired its last torpedo earlier, missing a destroyer.
24:37Ensign Jones's PT-132 had expended four torpedoes against another destroyer, all missing.
24:44That left PT-137.
24:45PT-137.
24:46Kovar's report documented firing one torpedo at 0335, 10 minutes after the Japanese recorded Abukuma's torpedo hit.
24:54But Kovar had noted that his boat's chronometer might be inaccurate.
24:59Without functioning radar or radio, PT-137 had relied on a mechanical clock for time references.
25:05The 10-minute discrepancy fell within normal clock error.
25:08The firing position matched.
25:11PT-137 had been 900 yards from a destroyer heading south near Panaan Island.
25:16Japanese records showed Abukuma had been steaming south at that location, screened by destroyers.
25:22The geometry aligned perfectly.
25:25Kovar's torpedo had been aimed at a destroyer in the foreground.
25:28It ran deep, passed under the destroyer's shallow draft, and continued until it struck Abukuma's deeper hull 900 yards beyond.
25:36The United States Navy officially credited Lieutenant Junior Grade, Isidore Michael Kovar, and PT-137 with sinking IJN Abukuma.
25:46The confirmation came months after the battle, following detailed analysis of American action reports and captured Japanese records.
25:54Abukuma became the largest warship whose destruction was credited primarily to an American PT boat.
26:00The 5,570-ton cruiser displaced more than any other capital ship sunk by PT boat torpedo attack in the
26:08Pacific War.
26:10Previous PT boat successes had been against destroyers, destroyer escorts, and smaller craft.
26:16No American PT boat had ever destroyed a light cruiser before Kovar's accidental hit.
26:21The Navy Cross was awarded to Lieutenant Junior Grade, Isidore Michael Kovar, for extraordinary heroism during the Battle of Surigao
26:29Strait.
26:30The citation recognized his aggressive attack against superior enemy forces under intense fire.
26:35Kovar had closed to 900 yards of Japanese warships without radar or radio, launched a torpedo under starshell illumination, and
26:44escaped under 5-inch gunfire.
26:46The accidental nature of his hit wasn't mentioned in the citation.
26:49The Navy Cross recognized courage and tactical execution, not luck.
26:55326 Elko 80-foot PT boats served in World War II.
26:59They conducted thousands of patrols in the Pacific and European theaters.
27:03They rescued downed pilots.
27:05They raided enemy supply lines.
27:07They fought Japanese destroyers and German E-boats.
27:10They evacuated General Douglas MacArthur from Corregidor.
27:13They carried Army Rangers on covert raids.
27:16They sank enemy barges, sampans, and small craft by the hundreds.
27:21But only one PT boat destroyed a 5,000-ton cruiser.
27:25Only one PT boat fired a torpedo that ran under the intended target and struck a capital ship beyond.
27:31Only one PT boat commander earned a Navy Cross for a shot he believed had missed.
27:37PT-137 survived the war.
27:39The boat continued combat operations in the Philippines through early 1945, conducting 53 more patrols after the Battle of Surigao
27:48Strait.
27:48Lieutenant Junior Grade Kovar remained in command through March 1945, before rotating back to the United States.
27:55The Mark VIII torpedo that struck Abu Kuma represented manufacturing lot 237, produced at the Naval Torpedo Station in Newport,
28:04Rhode Island, in August 1944.
28:07Serial number 11847, cost to manufacture $1,500, value of the target destroyed, estimated $40 million in 1944 currency.
28:19That torpedo had a problem.
28:21It ran deep.
28:22The Mark VIII torpedo had been designed to run at 10 feet below the surface.
28:27Depth control was managed by a hydrostatic valve connected to horizontal rudders.
28:31As the torpedo traveled through water, pressure sensors measured depth and adjusted the rudders to maintain the preset running depth.
28:39In theory, the system was reliable.
28:41In practice, water temperature variations, manufacturing tolerances, and mechanical wear caused depth control failures in 30% of Mark VIII
28:51torpedoes.
28:52Cold water increased density, making torpedoes run shallow.
28:56Warm water decreased density, making them run deep.
29:00The tropical waters of Surigal Strait registered 78 degrees Fahrenheit on October 25, 1944, warm enough to affect torpedo buoyancy
29:10by 2 to 3 feet.
29:11Manufacturing variations added another layer of unpredictability.
29:15Each Mark VIII torpedo contained 2,827 individual parts machined to tolerances measured in thousandths of an inch.
29:24A hydrostatic valve spring compressed .005 inches too much would cause the torpedo to run 3 feet deeper than designed.
29:33A rudder hinge with .003 inches extra play would create a 2-degree angle that sent the weapon diving.
29:41Serial number 11847 had both problems.
29:44Post-war analysis of similar torpedoes from manufacturing lot 237 revealed consistent depth control issues.
29:52The lot had been produced during a period when Newport Naval Torpedo Station was running three shifts to meet wartime
29:59demand.
30:00Quality control inspections were abbreviated.
30:03Acceptance testing was reduced from 12 test firings per lot to 6.
30:07The torpedo that struck Abukuma ran at approximately 15 feet below the surface, 5 feet deeper than designed, deep enough
30:15to pass completely under the Japanese destroyer's hull.
30:18Japanese destroyers of the Fubuki and Akatsuki classes drew 5 feet of water.
30:24Even adding 2 feet for below-waterline hull contours, the destroyers presented 7-foot targets from keel to waterline.
30:31A torpedo running at 15 feet would pass underneath with 8 feet of clearance, but Nagara-class light cruisers drew
30:3816 feet.
30:39Abukuma's keel sat 16 feet below the waterline when fully loaded.
30:43Her hull extended another 28 feet above waterline to her main deck, a 44-foot vertical target.
30:50The 15-foot-deep torpedo struck Abukuma's hull 11 feet below the waterline, in the most vulnerable location possible, directly
30:59beside the No. 1 boiler room.
31:01If serial number 11847 had run at its design depth of 10 feet, it would have struck the destroyer.
31:08The explosion would have damaged or sunk a 1,500-ton destroyer.
31:12A valuable kill, but not a strategic impact.
31:16One destroyer, more or less, wouldn't have affected Admiral Shima's decision to retreat.
31:21Instead, the deep-running torpedo missed the destroyer and hit a 5,000-ton cruiser.
31:27The hit crippled Admiral Shima's flagship capability.
31:31Abukuma served as command ship for Destroyer Squadron 1, coordinating movements of four destroyers in the formation.
31:38When the cruiser fell out of formation, Admiral Shima lost his destroyer coordination platform.
31:43The subsequent collision between cruiser Nachi and cruiser Mogami occurred partly because Abukuma wasn't in position to relay course change
31:52orders to the formation.
31:53The torpedo's defect had strategic consequences.
31:57A weapon that failed to perform as designed achieved better results than a weapon working correctly would have accomplished.
32:03The United States Navy had spent six years developing depth control systems for Mark 8 torpedoes.
32:10Engineers had tested hundreds of prototypes.
32:13The Bureau of Ordnance had invested millions of dollars in hydrostatic valves, pressure sensors, and control mechanisms.
32:19All of that engineering effort was defeated by manufacturing variations measuring thousandths of an inch.
32:26But those manufacturing variations saved PT-137.
32:31If Kovar's torpedo had run at 10 feet and struck the destroyer, the explosion would have alerted every Japanese ship
32:38in the formation.
32:39Searchlights would have found PT-137 within seconds.
32:435-inch guns from four destroyers would have concentrated fire on one wooden boat.
32:48PT-137 displaced 56 tons.
32:52A single 5-inch shell carried 70 pounds of high explosive.
32:56Two or three hits would have sunk the PT boat.
32:59The deep-running torpedo gave Kovar different results.
33:03The destroyer never knew it had been targeted.
33:05The explosion 900 yards behind the destroyer looked like a different PT boat's attack.
33:11Japanese searchlights swept in the wrong direction.
33:15PT-137 escaped because its torpedo missed the intended target.
33:20Kovar survived because his weapon malfunctioned.
33:23His crew lived because a hydrostatic valve spring was compressed .005 inches too much at Newport Naval Torpedo Station in
33:33August 1944.
33:3412 men owed their lives to a manufacturing defect.
33:39The United States Navy never corrected the Mark 8 torpedo's depth control problems.
33:44By late 1944, the Bureau of Ordnance had shifted focus to the Mark 13 aircraft torpedo and the Mark 14
33:53submarine torpedo.
33:54PT boat torpedoes received lower priority.
33:58Manufacturing lot 237 continued in service through the end of the war.
34:03Hundreds more Mark 8 torpedoes ran deep, missed their targets, or achieved unexpected hits.
34:10No one ever thanked the factory worker at Newport who compressed that spring .005 inches too much.
34:18No one knew which worker it was.
34:20But that unknown error saved 12 American lives and sank a 5,000-ton cruiser.
34:26Sometimes, the difference between success and failure measures thousands of an inch.
34:32Lieutenant Junior Grade Isidore Michael Kovar left active duty in August 1945, two weeks after Japan surrendered.
34:40He returned to civilian life in the United States.
34:43No interviews, no memoirs, no publicity tours.
34:46The Navy Cross recipient who sank the largest warship ever credited to a PT boat disappeared from public record.
34:54While other PT boat commanders became famous, John F. Kennedy, John D. Bolkley, Kovar remained unknown.
35:01The contrast was stark.
35:03Lieutenant Commander John Bolkley received the Medal of Honor for evacuating General Douglas MacArthur from the Philippines in March 1942.
35:10He became a national hero.
35:13Hollywood made a movie about his exploits.
35:16Bolkley gave speeches, attended ceremonies, and remained a public figure for decades.
35:22Lieutenant Junior Grade John F. Kennedy commanded PT-109 when it was rammed by Japanese destroyer Amagiri in August 1943.
35:31Kennedy saved his crew by swimming for hours while towing a wounded sailor.
35:35He became President of the United States 19 years later.
35:39PT-109 became the most famous patrol torpedo boat in history.
35:44But Kovar sank a cruiser, a 5,000-ton warship with a crew of 500,
35:50the most significant combat achievement by any PT boat commander in terms of tonnage destroyed,
35:56and history forgot him.
35:58Part of the reason was timing.
36:00Kovar's action occurred during the Battle of Leyte Gulf, the largest naval battle in history.
36:05Four separate engagements occurred simultaneously across 500 miles of ocean.
36:10The Battle of Samar, where escort carriers and destroyers fought Japanese battleships, dominated headlines.
36:17The sinking of one Japanese cruiser by a PT boat torpedo barely registered in the flood of battle reports.
36:24Part of the reason was the accidental nature of the hit.
36:27The Navy Cross citation credited Kovar with extraordinary heroism under fire.
36:32It didn't mention that his torpedo had missed the intended target.
36:36It didn't explain that a manufacturing defect had caused the unexpected hit.
36:41Military citations avoid mentioning luck or accidents, focusing instead on courage and tactical skill.
36:47And part of the reason was Kovar himself.
36:50After the war, he chose obscurity.
36:52No book deals, no documentary interviews.
36:55He let Kennedy and Bulkley have the spotlight,
36:58while he returned to whatever civilian life he'd built before December 1941.
37:02The United States Navy decommissioned its last operational PT boat in 1946.
37:08The wooden vessels had served their purpose.
37:10Radar-equipped destroyers and destroyer escorts could perform PT boat missions more effectively.
37:15Jet aircraft could attack enemy shipping faster than PT boats could reach targets.
37:21The era of wooden motor torpedo boats ended with World War II.
37:25Most PT boats were destroyed immediately after the Japanese surrender.
37:29The Navy burned them, sank them, or sold them as scrap lumber.
37:33Out of 326 Elko 80-foot boats built, fewer than 12 survived into the 21st century.
37:40Most survivors sit in museums, preserved as examples of wartime innovation
37:44and the courage of their crews.
37:47PT-137 was not among the survivors.
37:50The boat was scrapped in 1946 at Samar, Philippines.
37:54The wooden hull was disassembled.
37:56The three Packard engines were removed and sent to depot maintenance facilities.
38:00The Mark 18 torpedo tubes were salvaged for parts.
38:03Nothing remained of the boat that fired the most significant torpedo shot in PT boat history.
38:09No memorial exists for PT-137.
38:13No museum display commemorates the accidental hit that crippled Abu Kuma.
38:17The National Museum of the Pacific War in Fredericksburg, Texas has PT boat exhibits,
38:22but PT-137 isn't mentioned.
38:26The PT boat museum in Fall River, Massachusetts preserves PT-796 and PT-617,
38:33but has no artifacts from PT-137.
38:37The only physical evidence of PT-137's achievement is underwater.
38:42Abu Kuma's wreck lies in 40 feet of water off Negros Island in the Philippines.
38:46Sport divers occasionally visit the site.
38:48The cruiser's bow section, blown off by the torpedo magazine explosion,
38:53sits 200 yards from the stern section.
38:55The hull is heavily corroded.
38:58Tropical marine life has colonized the wreck.
39:01In another 50 years, the ship will be unrecognizable.
39:04But the story remains.
39:06A 24-year-old officer commanded a blind PT boat through enemy-controlled waters.
39:12He fired a defective torpedo at a destroyer.
39:14The torpedo missed.
39:16It ran deep.
39:17It struck a cruiser he didn't know was there.
39:20The cruiser sank.
39:22250 Japanese sailors died.
39:24The officer received the Navy Cross and disappeared into history.
39:29The mock torpedo, the failed shot, destroyed 5,570 tons of Japanese steel.
39:36Not through superior engineering.
39:38Not through tactical brilliance.
39:40Through a manufacturing defect measuring 0.005 inches.
39:44And that might be the most honest war story ever told.
39:49The Battle of Surigao Strait changed naval warfare forever.
39:52It was the last time battleships would engage battleships in combat.
39:56Radar fire control, coordinated destroyer torpedo attacks, and aircraft carriers had made the battleship obsolete.
40:04The six American battleships that crossed the T at Surigao Strait, West Virginia, Maryland, Mississippi, Tennessee, California, and Pennsylvania, never
40:15fired their main batteries in combat again.
40:17Vice Admiral Shoji Nishimura went down with battleship Yamashiro.
40:22He was 54 years old.
40:24His decision to charge into Surigao Strait without waiting for Admiral Shima's support force cost Japan two battleships, four destroyers,
40:32and over 4,000 lives.
40:34But Nishimura followed orders.
40:37The Imperial Japanese Navy's plan for defending the Philippines required his sacrifice.
40:42Admiral Kiyohide Shima survived.
40:45His force retreated to Brunei, then to Japan.
40:47He commanded increasingly desperate operations as American forces closed on the home islands.
40:54After the war, Shima testified at war crimes tribunals, providing evidence about Japanese naval operations.
41:00He died in 1973 at age 76.
41:04Destroyer Ushio survived the entire war.
41:07The ship that rescued 283 survivors from Abukuma continued operations through August 1945.
41:14Ushio was the only Japanese destroyer from the Pearl Harbor attack force still afloat when Japan surrendered.
41:21The ship was scrapped in 1947.
41:24Abukuma had participated in the attack on Pearl Harbor on December 7, 1941.
41:29The cruiser served as flagship for Destroyer Squadron 1 in Vice Admiral Chuichi Nagumo's carrier strike force.
41:36Abukuma screened the six carriers that launched 353 aircraft against the American Pacific Fleet.
41:44Three years and ten months later, an American torpedo sent her to the bottom.
41:49Lieutenant Junior Grade Isidore Michael Kovar earned the Navy Cross for extraordinary heroism at the Battle of Surigao Strait.
41:57He commanded PT-137 through enemy-controlled waters without radar or radio.
42:02He closed to 900 yards of Japanese warships under star shell illumination.
42:08He launched a torpedo that the Navy had designed to run at 10 feet below the surface.
42:13Manufacturing variations at Newport Naval Torpedo Station caused serial number 11847 to run at 15 feet instead.
42:22The defect measured .005 inches in a compressed spring.
42:27That tiny error made the torpedo run 5 feet deeper than designed,
42:30deep enough to pass completely under the Japanese destroyer Kovar was aiming at,
42:35deep enough to continue traveling until it struck light cruiser Abukuma 900 yards beyond.
42:41They mocked the Mark 8 torpedo.
42:4330% failure rate.
42:45Unpredictable depth control.
42:47Weapons that porpoised across the surface or dove to the ocean floor.
42:52PT boat crews called them swimming slot machines because hitting anything was pure chance.
42:57But serial number 11847 didn't fail.
43:01It ran exactly deep enough to miss a 1,500-ton destroyer and hit a 5,570-ton cruiser.
43:10The explosion at 0335 destroyed Abukuma's forward boiler room in seconds,
43:17killed 37 crew instantly, flooded two compartments,
43:21reduced speed from 36 knots to 10 knots,
43:25turned a combat-ready flagship into a crippled wreck
43:29that would sink under B-24 bombs 27 hours later.
43:34The failed torpedo destroyed the largest warship ever credited to an American PT boat,
43:40not through superior engineering, not through tactical brilliance,
43:44through a manufacturing defect measuring thousands of an inch and 900 yards of blind luck.
43:51Kovar returned to civilian life after the war and disappeared from history.
43:56No book deals, no interviews, no memorial.
44:00While John F. Kennedy became president and John Bulkley became famous,
44:05Isidore Kovar remained unknown.
44:07The officer who sank a 5,000-ton cruiser was forgotten,
44:11while officers who sank nothing became celebrities.
44:15PT-137 was scrapped in 1946.
44:18No museum preserved the boat.
44:21No artifacts survived.
44:23The only evidence of its greatest moment lies underwater off Negros Island,
44:28where Abukuma's broken hull rests in 40 feet of water.
44:32Sometimes, the mocked weapon becomes the most effective weapon.
44:36Sometimes, the failed shot becomes the killing blow.
44:39Sometimes, the forgotten heroes change history while everyone watches someone else.
44:46If this story moved you the way it moved us, do me a favor.
44:50Hit that like button.
44:51Every single like tells YouTube to show this story to more people.
44:55Hit subscribe and turn on notifications.
44:58We're rescuing forgotten stories from dusty archives every single day.
45:02Stories about PT boat commanders who sank cruisers with defective weapons.
45:08Real people.
45:09Real heroism.
45:10Drop a comment right now and tell us where you're watching from.
45:14Are you watching from the United States?
45:16United Kingdom?
45:17Canada?
45:18Australia?
45:19Our community stretches across the entire world.
45:22You're not just a viewer.
45:24You're part of keeping these memories alive.
45:26Tell us your location.
45:27Tell us if someone in your family served.
45:29Just let us know you're here.
45:32And thank you for making sure Isidore Kovar doesn't disappear into silence.
45:37These men deserve to be remembered.
45:39And you're helping make that happen.