Sunday, April 11, 2010

Did a Japanese Midget Submarine Sink the USS Oklahoma on December 7, 1941? by Vernon Maddux

Painting of attack on USS Oklahoma. On display Oklahoma State Capital, OKC.

In the early pre-dawn hours of December 7, 1941, five Japanese Type-A midget submarines launched from their mother submarines less than 13 miles outside the entrance to Pearl Harbor. They were called the Advance Force, which planned to penetrate inside the harbor and wait to attack American ships docked in Battleship Row. When the first wave of Japanese aircraft attacks were over, the midget submarines were to torpedo capital ships and, if possible, sink one to block the narrow harbor entrance.

Fifty years earlier the United States military created a channel entrance from the Pacific Ocean into Pearl Harbor by blasting through volcanic rock to the depth of 65 the center. During the years after WWI, two anti-torpedo nets were strung across the entrance, one backing the other at the throat. Each stretched across the relatively narrow channel anchored on one shore; the anti-torpedo nets hung down 35 ft. primarily to defend against a torpedo being fired up into the harbor from outside. Workers suspended the nets on floats, which were then moved by small boats attached to the end. When ordered, sailors would power the boats across the channel. Later, a secondary intent was to prevent small submarines from entering the harbor underwater. Outside Pearl Harbor navy destroyers patrolled routinely back and forth for at least a five-mile arc centered on the channel entrance. The torpedo nets were normally open during the day but closed from nightfall to sunrise. In the early hours of Dec. 7, due to naval activities, the nets were opened at 0200 and reported closed at 0846, long after the air attack began. This provided free passage to the two Japanese midget submarines to make their way inside the harbor.

Pearl Harbor Looking southwest toward narrow harbor entrance

For years historians theorized from the little evidence available that two midget subs made it into the Harbor and fired their two 800-pound torpedoes, and that several hit the battleships USS Oklahoma and USS West Virginia, capsizing the Oklahoma. In December 2009, the discovery of a Japanese midget sub at the bottom of Pearl Harbor added fuel to the debate over whether the missile from a Japanese midget submarine was responsible for sending the battleship Oklahoma to a watery grave at the bottom of Pearl Harbor on December 7th, 1941.

For Dan Martinez, the USS Arizona Park Ranger Historian, the new discovery of a midget submarine (both torpedoes missing) on the sea bottom off the channel entrance to Pearl Harbor, provides concrete evidence that a Japanese midget submarine sunk the Oklahoma. Martinez believes the midget submarine found was dredged from the bottom of East Loch inside Pearl Harbor and dumped out at sea from wrecked ships. To Martinez, the missing torpedoes provides positive evidence that this wreck, lying in three pieces tied together by cables, was the midget submarine that appears in a famous photograph of Battleship Row; the midget sub is believed to be seen firing at the battleship Oklahoma.

As convincing as their arguments are, careful scrutiny of pictures and Japanese records provides a more accurate account of the damage the midget-subs inflicted on December 7, 1941. Such evidence suggests that the midget submarines that penetrated Pearl Harbor on that fateful day in December did not sink the USS Oklahoma or any other ship in Battleship Row.

Between 1934 and 1941, the Japanese produced at least 52 Type A midgets at the submarine base at Eta Jima, Honshu. These two-man boats displaced 46 tons, were 78 feet long and carried two 45cm (17.7") diameter, 800 lb warhead, 1000 lb torpedoes mounted in over/under tubes that made up the bow. Powered by a 600 hp electric motor, the design was capable of very high underwater speeds (about 20 knots). Its greatest drawback was its very limited range of only 50-60 miles or 5-6 hours endurance at 9-10 knots. Each boat was given alpha-numeric names in the "Ha" series (Ha-1 through Ha-52). The only known HA number of the five subs that attacked Pearl Harbor is HA-19. The Americans captured the sub intact, along with one of its crewman. The other four midgets that attacked Pearl Harbor are known generally by “M” (midget) and the number of the mother submarine.

Japanese Midget Submarines in dry dock 1946

On 19 October 1941, at headquarters, the Japanese Sixth Fleet (Submarines) staff ordered the immediate conversion of five midget submarines and five Type C-1 mother submarines for the Hawaii Operation. To upgrade the harbor-penetrating capabilities of the midget submarines, mechanics installed a more-precise pneumatically-operated steering system. Shipwrights moved 25 batteries from the forward battery room and replaced them with four air bottles to power the steering system. Test trials indicated the range at low speed was marginally increased, but maximum speed dropped from 20 to 16 knots. Each midget had a scuttling charge installed in the aft battery room, which required lighting a fuse. Each sub acquired net guards/cutters, jumping wires and propeller guards. Workers also painted over peacetime running lights and technicians fitted telephone hook-ups to connect midget and mother for communications between the two at sea. Working frantically, the engineers finished work by 10 November.

On 14 November 1941, at headquarters, Kure Naval District, Vice Admiral Shimizu Mitsumi, C-in-C, Sixth Fleet (Submarines) and his chief of staff, Captain Mito Hisashi conducted the final staff briefing for the submarine portion of the Pearl Harbor attack. They assigned submarines I-16, I-18, I-20, I-24 and I-22 to Captain Sasaki Hankyu's Special Attack Unit. Captain Arima Takayasu, the Combined Fleet's senior torpedo staff officer, briefed Sasaki and the five midget submarine officers of the Special Attack Unit on intimate details of the Hawaii Operation. The battle plan required the midget submarines to be employed only in case a major part of the U.S. Pacific Fleet was actually anchored in Pearl Harbor. They gave orders for midget submarines to penetrate the harbor as quickly as possible, then lay low until there was a lull between the first and second air strikes. After they located their targets and launched their torpedoes, they were to make their way out of Pearl Harbor and arrive at a rendezvous point 7 nautical miles ESE of Lanai Island. At this rendezvous point, Japanese ordered the mother submarines to wait only one day for the Midget sub to reconnect. Orders were to delay their departure no later than one day to midnight 8 December (9 December, Japan time). Given the massive chaos that would ensue from the Kido Butai air attack plus the dangerously shallow water of the channel, the extreme limited endurance of the midget submarines made this impossible and, therefore, a one-way mission.

Mother Subs I-24, I-16, I-20, I-18, and midget from I-24 beached.

Very early in the morning on 18 November 1941, the Special Attack Unit’s five big mother submarines cast off and departed Kure Naval Base for the Kamegakubi Naval Proving Ground. At Kamegakubi each mother submarine loaded aboard one of the top-secret two-man Type A midget submarines. That evening, Cdr Ariizumi held one last conference with the five officers aboard the flagship.

On 19 November 1941 at 0215, the five Special Attack Unit's mother submarines departed for the Hawaiian Islands with the midgets mounted on their backs. Lt Matsuo rode aboard I-22 as XO of the Special Attack Unit. When at sea the midgets’ officers briefed their enlisted men on the Hawaii Operation. The mother submarines followed generally a direct route, except to swing out 600 nautical miles around Wake and Midway islands to avoid detection by patrolling aircraft.

On 2 December 1941, the mother submarines picked up the coded signal. "Niitakayama nobore (Climb Mt. Niitaka) 1208." This broadcast came from the Combined Fleet headquarters on the Nagato. They scheduled hostilities to commence at 0800, 8 December (Japan Time).

By midnight on 7 December 1941(Hawaii Time), Japanese submarines I-68 and I-69 arrived at their patrol points a dozen miles from the entrance to Pearl Harbor. They were to attack American capital ships as they came out and rescue midget submarine crews. Closer in the five mother submarines reached their launch points about the same time.

From 0042 to 0333, the mother submarines launched their midget subs; each midget-sub carried two live Type-97 torpedoes, with an approximately 800-lb. explosive warhead, twice the amount in the Type-91 aerial torpedo. These Japanese torpedoes were fueled by oxygen, and left very little wake. Many considered the Japanese torpedoes more advanced than any of the allied forces’ torpedoes, far better than any in the US Navy.

While the Japanese Mother subs launched the midget sub in the predawn hours of December 7th, one of the duty destroyers USS Monaghan was tied up to the USS Farragut near the north side of the harbor. Patrolling outside were USS Ward and USS Helm. Patrol PBY float planes from VP-14 were also routinely airborne over Oahu.

At 0408, LT William W. Outerbridge's 22 year-old four-stack destroyer USS Ward (DD-139) was on duty off Pearl Harbor. Hard work and tedious, this sort of peace-time work was usually reserved for new captains and naval reservists. The Ward’s crew was a group of St Paul, Minnesota reserves doing their call-up. The ship searched for a suspected submarine reported in the harbor mouth area by minesweeper Condor (AMC-14). Ward roamed through the area for two hours but saw nothing.

USS Ward
At 0630, less than two hours before the attack, Ward headed back out to sea and met Training Squadron 8's flagship USS Antares (AKS-3) as it approached Pearl's outer gate nets. Antares had a gunnery target raft in tow. One of Ward’s lookouts noticed something behind the raft. He made it out to be a small conning tower following in Antares’ wake just behind the target raft. He radioed the captain. The captain, brand new, sounded general-quarters submarine attack. As the general quarters alarm echoed throughout the ship, Captain Outerbridge called for full speed and ordered the helmsman to turn the ship directly toward the submarine’s periscope. Overhead, a patrolling PBY "Catalina" flying-boat 14-P-1, flown by Ensign William P. Tanner of Patrol Squadron VP-14, responded to the radioed contact report and dropped smoke markers to mark the conning tower.

Fifteen minutes after the lookout spotted the conning tower, at 0645, Ward’s scrambling gunners were finally able to unlimber, load, point and open fire at the sub. By then the destroyer was cranking 20 knots and range was down to a point-blank 100 yards. The first 4” round - the first shot fired in anger during WWII by American Forces – was thought for decades to have missed.

In 2009, the midget was found on the bottom with two small holes punched through the conning tower.

Ward now steaming at more than 22 knots, closed to 50 yards and the gunners fired a second 4-inch shell almost straight down at the sub’s conning tower. The shell struck the base of the midget submarine's conning tower and punched a 4” hole through its left side. This explosive shell instantly killed both crewmembers. Ward continued over the submarine’s bow, which bounced around and wallowed drunkenly for a few seconds then sank out of sight. Capt. Outerbridge swung his ship hard around and ordered four depth charges to be dropped on the spot where the sub was last seen. Six minutes after opening fire on the sub, at 0651, he signaled 14th Naval District Headquarters.


A few miles away, Japanese Ensign Sakamaki’s midget Ha-19 had all sorts of problems as he groped in darkness toward the harbor entrance. His compass had failed and even though there were plenty of lights on the shore, he could not make out the harbor markers.

By 0700, three and a half hours after leaving the mother sub, Ha-19 reached a point probably a mile from the harbor entrance. Peering through his periscope, Sakamaki tried to maneuver into the channel entrance but was still outside when the air strikes began around 0757. When the first torpedoes and bombs began to fall, all American patrolling aircraft and warships went to full alert. Sakamaki was forced to creep away to avoid detection. By 0800, Sakamaki was raising his periscope often to navigate because Ha-19's gyro compass had failed. He continued to grope his way along the coast toward the harbor entrance using only the periscope to find his way.

At 0817, Ha-19’s periscope was spotted by USS Helm (DD-388) who opened fire on the midget submarine. The shells missed, but Sakamaki increased speed too much and too steeply dived away striking an underlying reef very hard. The sub bounced off the bottom and damaged the lower torpedo tube, net cutter and jammed the lower vertical rudder. The sub stuck to the reef.

Beached HA-19

Over the next several moments, Sakamaki and Inagaki shifted lead ballast bars from the bow back aft of the batteries. Sakamaki ran the engine full power astern and finally the sub slipped backwards off the reef. Sakamaki leveled the boat and slowly and with difficulty, turned out to sea, heading away from the harbor entrance and the relentless destroyers and patrol planes guarding the entrance.

At 6 a.m. Dec. 7, 1941, from 230 miles north of Oahu, 185 of the first wave of a two-wave attack took off from six Japanese fleet aircraft carriers, Akagi, Kaga, Hiryu, Soryu, Shokaku, Zuikaku. It was actually a remarkable testament to the ability of the Japanese mechanics. One aircraft had to turn back, the other crashed into the sea and was rescued by the duty destroyer.

Japanese attach planes

The strike force consisted of 40 Kate torpedo bombers, 51 Val dive bombers, 50 high-altitude bombers and 43 Zero fighters. Inside the lead aircraft, a Nakajima B5N2 Type 97 Model 3 “Kate” torpedo bomber, the drone of the Mitsubishi Sakae 14-cylinder radial engine was music to the ears of the strike commander, Commander Mitsuo Fuchida as the 183 warplanes strung out in tight formations behind him.

At 0740, Fuchida saw Pearl Harbor lying placidly before him. Sliding back his canopy, the strike leader fired a single green flare into the air signaling the start of the attack. Fuchida then ordered Petty Officer 1c Norinobu Mizuki to radio the signal, “Tora, Tora, Tora,” to the fleet commander, meaning the attack had begun.

Directly in front of the first torpedo planes were the USS Oklahoma (BB-37), moored in Battleship Row at mooring #7 outboard (BB-46) USS Maryland. It was bad luck that Oklahoma sat directly across from a small loch that led away to the southeast. This open water gave the “Kate” torpedo planes the most perfect run-in to what might otherwise have been a difficult target. Between 0753 and 0800, the "kates" flying low and slow down the narrow loch launched 22 torpedoes. The Janpanese modified each torpedo with wooden fins so when the metal “fish” fell a hundred feet into the water, it hit at a specific angle that tore off the wooden fins, slowing and shallowing the missile. Each “fish” ran at forty knots across the harbor to strike the broad hull of the Oklahoma and West Virginia just behind. Some were launched at the California across the bay to the left. Each torpedo exploded with 454 lbs of high explosive.

The U.S. Navy commissioned the New York Shipbuilding Corporation of Camden, New Jersey to build the USS Oklahoma on 26 October 1911. The Battleship was launched on 23 March 1914. On hand for the occasion was Miss Lorena J. Cruce, daughter of Governor of Oklahoma, Lee Cruce. The navy moved the battleship to Philadelphia, Pennsylvania, on 2 May 1916 assigning Captain Roger Welles to command.

USS Oklahoma

The ship was 583 feet long, 95 feet wide and needed 29 feet of draft. Its top speed was a relative slow 20.5 knots but it was extremely long-ranged, carrying 2,000 tons of fuel oil for a range of over 8,000 miles. It was the last US Navy capital ship not to have steam turbines for its main propulsion. Initially the ship’s complement was 864 officers and men, but after 1929 it had quarters for 1,398 officers and men. On the morning of December 7th, 1941, the navy docked the USS Oklahoma in battleship row at mooring #7, which sat directly across from a small loch that led away to the southeast.

USS Oklahoma on Fire

The open water left the Oklahoma vulnerable. In a horrible irony of bad luck, the Oklahoma had no watertight integrity, as all portholes and watertight doors had been ordered opened for inspection scheduled for Monday morning.

Japanese bombs exploded on Ford Island at 0757,waking sailors on the Oklahoma.

One minute later, at 0758, a blast struck the side of the Oklahoma. The blisters attached to the hull of the ship held for a few seconds but were blown away by a second and third torpedo that hit in the same place eliminating the protective blister. Inside “C” deck, a wall of dirty water burst though the open deck and began flooding down the double ladders of the still sleepy ship. More torpedoes struck, one after another, many slamming into the same area, blasting a 70 foot hole through the five inch steel armor. The ship lurched to port but paused. It was now 0800. A moment later, the roaring engines of another wave of Kates flashed over the ship and one of the first to pull up to the right took a photo back at Battleship Row. Shown below there are several wakes of torpedoes heading for Oklahoma, West Virginia and California as plane after plane dropped their “fish” and pulled up to the side to miss the battleships’ high superstructure. Stunned by heavy explosions blasting holes though the heavy side armor, men responded to the alarm bells which belatedly clanged and gonged throughout the ship. One boson seeing the meatballs on the planes, keyed the PA mike and yelled “This is an air attack, NO SHIT!” Men below hurried from their bunks and ran to their battle stations. Those who did not have a fighting station during an air attack ran below to “C” deck where they had heavy armor over their heads, as they had been trained. Sailors and Marines tried to smash open ammunition lockers but all the guns had been dismantled for the upcoming inspection. The ship lurched again and men found themselves fighting for footing on the smooth decks as the list increased markedly. As the Oklahoma began to list, more torpedoes, at least two more, struck home. By 0802, the big ship had rolled left to a dangerous 20 degrees.

In the US Navy photo above, the hull of the capsized USS Oklahoma lies directly in front of USS Maryland. The burning ship just to the right is the USS West Virginia. West Virginia took five 18-inch aircraft torpedoes in her port side and two 15-inch armor-piercing shells fitted with fins. The first bomb penetrated the main deck, wrecking the port casemates and causing that deck to collapse to the level of the galley deck below. Four casemates and the galley caught fire immediately, with the subsequent detonation of the ready-service projectiles stowed in the casemates. The second bomb hit further aft, wrecking one Vought OS2U Kingfisher floatplane

For a few minutes, ropes held the Oklahoma the ship to the USS Maryland, the captain of the latter ordered the ropes cut and at 0809, the Oklahoma fell suddenly on its side, and continued turning, crushing the high top tripod mast into the muddy bottom. Observers around the harbor hardly noticed. Most were overwhelmed by the explosions raining down on and around the seven battleships. After only 12 minutes from the first bomb explosion, where the Oklahoma had been moored, only a part of the hull protruded, the starboard third of the hull above water with its starboard brass propeller raised in the air. The 25 year-old ship’s career ended that instant, having served in two world wars but, amazingly, never firing a single round from any of its hundreds of guns in anger. Oklahoma’s topside and ready crew were able to leap overboard as the ship rolled to port. Many dove in the water and clambered aboard Maryland where they joined that ship’s crew in manning the anti-aircraft batteries. The battleship Oklahoma was the only ship of the United States Navy to ever be named for the 46th state, and was the second of two ships in her class; she was the sister ship of USS Nevada.

The crew compliment on the Oklahoma the morning of December 7, consisted of 83 officers, 1215 enlisted navy, 3 U.S. Marine officers, and 64 enlisted Marines, for a total of 1,365 men. During its 12 minutes of combat, 20 officers and 395 enlisted men were killed or were never recovered. Only 32 men were wounded. Two men were given Medals of Honor for sacrificing their lives to save their fellows. Several sailors and marines died doing the same thing but were given lesser honors. The navy moved ahead, it had a difficult war to fight.

One of the dead was the fleet’s Catholic priest, Lieutenant Junior Grade Father Aloysius Schmitt, the first American chaplain of any faith to die in World War II. He and several men were trapped in an overturned compartment with only a small porthole as the means of escape. Schmitt declined to leave but helped a number of men through this porthole. Twelve men escaped before the air ran out. Father Schmitt was posthumously awarded the Navy-Marine Medal and in 1943 a destroyer escort (DE-676) USS Schmitt was named for him.

On the morning of December 7, 1941, just four days before his 21st birthday John Charles England volunteered to work in the ship's radio room for a friend so that he might have more time with his family when they arrived. Ensign England survived the initial attack and escaped topside as the ship was capsizing. He remembered the men still in the radio room. He returned three times to the radio room, each time guiding a man to safety. He left to go back below decks for the fourth time and was never seen again. He was one of twenty officers and 395 enlisted men died on board USS Oklahoma that morning. Ensign England's gallant effort saved three men, but his fourth trip back inside cost him his life. The navy did not award England a medal, but it did name two ships for him. In 1943, USS England (DE-635) was commissioned and in 1963, USS England (DLG-22) was named in his honor. In a twist of fate, the first USS England on May 9, 1944, destroyed the I-16, the mother submarine of the first mini-sub launched on the morning of December 7, thus revenging its namesake.

After the battle ended, the Navy sent divers and rescue teams to scour the hull of the ship and found many trapped within the capsized hull. Julio DeCastro, a civilian yard worker, organized a team that cut holes in the hull and eventually saved 32 Oklahoma sailors over the next three days.

The next morning, the navy base command immediately began efforts to remove the Oklahoma from the harbor mud, primarily because it blocked the sea channel. Divers penetrated inside and at least 35 bodies were found and removed over the next three weeks and each individually identified. These men were buried in the Nuuanu (Oahu) Cemetery. In 1943 the remains of all crewmen found were buried in Halawa Cemetery because Nuuanu Cemetery had no more room. All 35 men were dug up 1949 and re-interned in the "Punchbowl” National Cemetery. For some reason, presumably the incompetence of low paid laborers, the names of these men were lost in the move and their bones were collectively dumped in a common grave in the National Punch Bowl Cemetery.

The Question
Did a missile from a Japanese Midget Submarine capsize the USS Oklahoma?

In 2009, Marine historians and history buffs claimed that at least one of the torpedoes that hit the USS Oklahoma was from a Japanese midget-submarine. IT is clear from the evidence that two of the midget-subs did managed to penetrate inside the harbor before the attack began
The single most pertinent evidence offered by Marine historians that supports their view that it was a Japanese midget Submarine that capsized the USS Oklahoma is the picture below taken by a Japanese crewman in the second wave of Kate bombers that attacked the ship in Battleship row.

In the photo above, a small puff of smoke can be seen rising from the Light Cruiser USS Helena and the USS Ogalala (center). The big smoke rising in the background are burning aircraft at Hickam Field. This photo indicates several torpedoes are in the water by 0800. USS California, upper right, has been hit by a torpedo and is gushing oil, the USS Oklahoma had been torpedoed (at least twice). USS West Virginia just behind Oklahoma had been struck by at least one torpedo and is listing to port.

Location of U.S. ships in Pearl Harbor Dec. 7th, 1941

USS Arizona Historian Dan Martinez comments on the photo:

Six torpedo tracks are seen in the water headed for Oklahoma and West Virginia. Four appear partially erased by the traveling surface concussion waves. Two tracks appear to be thinner and show less alteration by the wave concussion. Four of the torpedo tracks can be seen in alignment with respective water splashes associated with aerial torpedo drops. The two thinner tracks that were less affected by the wave concussions converged at a point coinciding with the linear object but without water splashes. One of the thinner tracks terminated with a small water plume characterized by the beginning of an underwater explosive detonation against the side of the West Virginia’s hull. The surface concussion rings propagated radially from the West Virginia’s and Oklahoma were the result of the torpedo detonation, its gas bubble in expansion and contraction, a phenomenon of underwater explosion. The magnitude and propagation velocity of the concussion waves can be measured. Thus total elapsed time intervals were computed to be 174 seconds (approximately three minutes) after the Helena was hit. This substantiated that the combat photo was taken at approximately 0801. (Rudimentary shadow analysis agrees that the time was 0801-0803).

The USS Monaghan (DD 354) was one of the “ready duty” destroyers in Pearl Harbor that morning. At 07:51 the ship was ordered to leave the harbor and join Ward, who had just reported sinking an unidentified submarine off the entrance to Pearl Harbor. A few minutes later, before Monaghan could cast off and get underway, the Japanese air attack began. Monaghan went to battle stations and soon opened fire. It still took until 08:27 before steam came up on all boilers and the ship cast off and headed out to join Ward. It was at this point when the captain became aware of an unknown type midget submarine inside the harbor. The following are excerpts from the Monaghan’s log.

1. 0835. Signalmen reported to Monaghan’s captain that USS Curtiss was flying a flag hoist indicating the presence of an enemy submarine. Shortly thereafter the Captain and other personnel on the bridge observed the conning tower of a submarine located approximately 200-300 yards on the starboard quarter of the Curtiss (moored at berth X-22) and that the sub was under vigorous fire by machine guns from Tangier (moored at Northwest end of Ford Island) and from machine guns and the 5" turret from the Curtiss.

2.0837. Captain (of Monaghan) ordered "all engines ahead flank speed" and word was passed that it was intended to ram the submarine – then distant about one thousand yards. At about the same time Williamson, D.C., (CQM) who had the helm, was directed to head for the submarine when he gave assurance that he saw it.

3. The first shot from Monaghan struck over and ricocheted into a derrick moored near the west bank. When it was evident that we were attempting to ram the sub the guns were ordered to cease firing. Within 75 yards the submarine turned sharply toward our bow and released a torpedo. The torpedo porpoised twice and then passed parallel to the ship's starboard side a distance of about 20-30 yards. The torpedo was seen to go up against the north bank throwing up a geyser of water about 200 feet high. The midget submarine was struck a glancing blow causing it to slide aft along the starboard side. The bow lifted out of the water as if the boat was blowing ballast (this was the natural result of firing one of the torpedoes). As the sub passed astern the first depth charge was released. The explosion brought the bow and superstructure of the sub into full view.

4. At about 0843 word was passed to stand by for a shock forward as the submarine had disappeared from the view of those on the bridge and ramming was considered imminent. Shortly thereafter a slight shock was felt and about 0844 the two depth charges released exploded violently about 50-100 yards astern of the Monaghan.

5. At about the same time of the depth charge explosions the order was given "all engines back emergency full speed", which, although carried out promptly, was insufficient to check the headway of the ship which consequently struck a derrick moored near Beckoning Point a slight blow.

6.Upon attempting to back clear of the derrick it was discovered that we were entangled with one of her mooring lines but by going ahead slowly we were able to free the Monaghan and at about 0847 we swung into the channel astern of the Dale and proceeded out of the harbor passing the Entrance buoys at 0908 from where we proceeded to our assigned station on the Offshore Patrol.

About two hours after Monaghan left Pearl Harbor, the damaged and barely functional Ha-19 passed Honolulu beach and rounded Diamond Head. The shock of the earlier collision with the reef had cracked the batteries, which emitted chlorine gas. The gas became so thick inside the hull that it rendered the crew unconscious. When Sakamaki finally regained consciousness, he found that the sub had surfaced and was rolling in the surf on the surface near the shore. He opened the hatch to breathe fresh air. Looking west over the crest of Diamond Head, he could see dense smoke rising from ships burning in the harbor. Sick and confused, Sakamaki tried to drive the craft up on the beach but struck hard on a reef several yards offshore. Sakamaki and Inagaki shifted ballast and freed the midget submarine, but now the rudder was so damaged that the boat would not answer the helm. Drifting helplessly, Ha-19 was spotted and depth charged by a patrolling PBY. Sakamaki again tried to beach the boat, but stuck on an outer reef again. Finally, the officer gave up and lit the fuse of the midget submarine's self-destruct charge. He and Inagaki then crawled out of the hatch and leapt into the surf. Sakamaki was knocked unconscious by big waves crashing over the reef. Battered, his unconscious body washed ashore on Waimanalo Beach near Bellow's Field. PO2C Inagaki Kiyoshi’s body was never found.

Ha-19’sscuttling charge failed to explode. When the authorities found the derelict Ha-19 the next day after the attack, they found both torpedoes intact and inside there was a map indicating that none of the midget submarines were supposed to attack the capital ships until at least 10 AM, a full two hours after the attack was supposed to begin. This was to avoid interference with the aerial torpedo and bombing attack.

Injured and confused, Sakamaki was captured the next morning, December 8 (Hawaii time). He was Japanese POW number one. Under interrogation, he refused to answer any questions and repeatedly demanded he be allowed to die by his own hand or preferably, to be shot by a firing squad.

At 10:40 pm December 7 (Hawaii time) submarine I-16 picked up a garbled radio transmission the captain interpreted to be the midget-submarine’s code words for "Success, success, success". It is not certain if the message came from M-16 but it was from one of the midgets. Another transmission "unable to navigate" was received at 12:51 am the following morning 8 December (Hawaii Time). This was believed to have been sent by M-16’s officer.

Three of the subs have been found outside the harbor and two midget-subs are known to have penetrated the harbor. One was certainly destroyed by Monaghan in the main channel inside the harbor around 0844. It fired both of its torpedoes. The other midget that penetrated inside the harbor may have hidden to be scuttled the next day. What happened to its two-man crew is uncertain, but they did not escape or survive the war.

Sakamaki’s capture was quickly discovered by the IJN. During the war, the Japanese Navy proclaimed the lost mini-submariners to be great heroes and erected a shrine to them at Etajima. The high command officially ignored Sakamaki. PO2C Inagaki is inscribed as the only crewman in HA-19. None returned to the mother submarines.


1. M-16. About five miles from the harbor entrance, USS Ward’s Lookouts spotted a periscope heading toward the entrance to the naval harbor. At 6:53, about an hour before the aerial attack on Pearl Harbor began, the Ward sent a radio message that it fired on and dropped depth charges on a submarine. The vessel did not come up after being depth-charged. This was no doubt M-16...... At 12.20 p.m. on August 28, 2002, the Pisces IV and Pisces V, two deep diving submersibles operated by the Hawai‘i Undersea Research Laboratory (HURL), which are carried aboard the research vessel Ka'imikai-o-Kanaloa came upon the 78-foot, two-man submarine three to four miles off Pearl Harbor in about 1,200 feet of water. It had a 4 inch hole at the base of the conning tower exactly as Ward had claimed.

2. M-20. At c 0730 a patrolling PBY "Catalina" flying-boat 14-P-1, piloted by Ensign William P. Tanner of Patrol Squadron VP-14, spotted another periscope (he had helped USS Ward find and attack M-16) in the waters off the entrance to Pearl Harbor. This was possibly M-20. Tanner attacked this mini-sub with depth charges. The fate of this sub is not known and may have made it inside the main harbor where it fired its torpedoes and then was abandoned.

3. M-18. This sub was spotted inside the Keehi Lagoon next to Pearl Harbor by a destroyer and depth charged and sunk. On 13 June 1960, the submarine discovered lying on the bottom of the lagoon in 75 feet of water. On 6 July 1960, this boat was raised by the submarine rescue ship USS Current (ARS-22).

4. M-22. One midget, probably Lt Iwasa's M-22, penetrated inside Pearl Harbor and is known to have fired both torpedoes. It is confirmed that a mini-sub attacked the seaplane tender AV-4 Curtiss and DD Monaghan (DD 354). At 0836, Curtiss, underway and moving in the harbor, sighted a periscope and opened fire. A torpedo from the submarine missed Curtiss, but blew up a dock at Pearl City. Four minutes later this Japanese midget submarine surfaced and was further damaged by gunfire before diving again, after which USS Monaghan attacked it directly and dropped depth charges. Recently, the Los Angeles Times reported that Iwasa may have attacked and hit the battleship Oklahoma. According to Admiral Nimitz’s official testimony to Congress, one intact Japanese 800 lb (warhead-1000 lb total weight) submarine-type torpedo was later reportedly recovered from the bottom of the harbor which may or may not have been from M-22.
5. M-24 (Ha-19). Sakamaki’s boat was discovered damaged but intact, washed up on Waimanalo Beach below Bellows Field on the day following the attack. The sub was perfectly operational except for some external damage. It was repaired and shipped to the United States.

The Fifth and Last Midget Submarine

Three pieces of the sub (with cables intermingled, showing how the pieces were salvaged) were found during routine test dives between 1994 and 2001 by Terry Kerby, chief pilot of the Hawaii Undersea Research Laboratory's submersibles Pisces IV and Pisces V. But Kerby and others assumed they were a part of a war trophy that had been captured by allied forces at Guadalcanal or elsewhere, towed back to Hawaii and scuttled. Stephenson got involved in 2007 because he was looking for the fifth Japanese mini-sub. In 1941, a crewman on the I-16 had received a radio call from the I-16-tou at 10:41 p.m. on Dec. 8 reporting the success of its mission. That indicated to Stephenson that the mini-sub had found a calm place in the harbor and hidden until the next night before surfacing and sending the call. The crew members would have then scuttled the craft because they could not get it out of the harbor. The West Loch would have been a good location to hide, but researchers could find no trace of the boat there. A diver who had been looking for the mini-sub suggested that Stephenson talk to Kerby, who sent him pictures of his find.

"As soon as I saw the bow section with the distinctive net cutter, I knew that we had found the fifth midget sub," Stephenson said. No torpedoes were found on the wreck, and evidence suggests that they were not present when the boat was sunk. In looking at the photo of torpedoes in the water striking battleship row, Stephenson believed was from a mini-sub firing a torpedo into Battleship Row. A report to Congress in 1942 by Adm. Chester W. Nimitz describes an unexploded 800-pound torpedo recovered after the battle. That's twice the size carried by the torpedo bombers. That torpedo was apparently a dud that missed the West Virginia. But an examination of the remains of the Oklahoma shows that it apparently had underwater damage much larger than that associated with aerial torpedoes. An underwater blast would have caused it to capsize, Stephenson said. "Otherwise it would have settled to the bottom upright," like the other sunken ships. (Author’s note: Stephenson either ignores the fact that Oklahoma was wide open, or was not aware that the ship was being prepared for an intensive Captain’s inspection. It was also struck repeatedly, perhaps as many as a dozen aerial torpedoes).

Recovered sub sunk by the USS Ward

Sub sunk by USS Monaghan

Out of the five midgets, Ward sunk the one above outside the harbor entrance (see photo-1); the second, HA-19 beached off Bellows Field (see photo-2); a third was sunk and later recovered from inside the Keehi Lagoon (see photo-3); a fourth midget made it inside the channel to Pearl Harbor and launched both torpedoes at the cruiser USS St Louis near the harbor entrance and was sunk by Monaghan (see photo-4). The fifth midget has been found among the debris off the entrance to the harbor but its activities remain a mystery (photo-5). This last midget submarine may have laid low inside the harbor during the confusion of the air raid after firing its torpedoes then scuttled itself when it could not exit the harbor. In the evening hours of December 8, the mother sub I-16 received a message that one of the midgets was experiencing "navigational problems."

IT is clear that from the evidence that two Japanese midget submarines entered Pearl Harbor. One fired both torpedoes, which were spotted by USS Curtis and then destroyed by the USS Monaghan. Ultimately salvage crews dredged this midget sub from the harbor with its stern crushed by depth charges. The other midget, which entered Pearl Harbor apparently also fired both its torpedoes, at something--perhaps the ships on the west side of Ford Island. It was then probably scuttled by its commander, killing both crewmembers. Salvage crews scooped-up debris from the Forager disaster from southwest loch, including the second midget sub, and hauled the debris out to sea; it was re-discovered with its dredging cables still attached to the three pieces of the hull in 2009. Neither of these two midget subs could have fired at the USS Oklahoma. There is no doubt that the Oklahoma’s sinking was the result of multiple aerial torpedo hits (at least seven and perhaps ten or more) and the fact that the ship was in a fragile, non-water tight configuration. No bombs hit Oklahoma because by the time the level and attack bombers got around to hitting Battleship Row, the ship had already capsized.

The air attack was a stunning success, although one can argue that it helped the US Navy by knocking out the battleships ending forever the argument over which were more important: aircraft carriers or battleships. The third wave, which Nagumo cancelled, was planned to hit the repair facilities and fuel farms. These were far more important to the US Navy than the battleships--but not nearly as attractive to the Japanese mind-set. The midget submarine attack in any case was a dismal and completely unnecessary failure for the Japanese Navy. The old men in command consistently believed that young, dead heroes and their “honorable” deaths were far more desirable than live, successful, pilots. This attitude was repeated throughout the war. Competent, tough and well equipped at first, when given the opportunity, the Japanese pilot and marine would always take their own lives, rather than to risk being captured. This made it easier to win the war.


  1. Great research/article. I'll have to save this for my grand kids.
    Thanks, Craig Monaghan

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  4. There appears to be some confusion regarding the account of the Japanese Midget Sub M-16 and it's actions during the Pearl Harbor attack.

    If, as this article claims that the M-16 midget sub was sunk by naval gun fire by the U.S.S. Ward prior to the start of the Japanese "sneak-attack" on Pearl Harbor at 6:53 AM, 12/7/41 (HST), a full hour ahead of the main Japanese aerial attack at 8:00 AM (HST), then how can the M-16 sub be sending a confirming radio signal (ref: I-16-tou = M-16?) of a successful attack on Pearl Harbor to the I-16 mothership at 10:41 PM on Monday, 12/8/41 ?!?

    Also, if it was the M-16 that was sunk by the U.S.S. Ward that sad morning, the Midget sub (M-16?)found 3-4 miles south of Pearl Harbor, with a 4" penetration at the base of its conning tower AND BOTH TORPEDOES INTACT, conflicts with the claim of the previous radio transmission being referenced as coming from midget sub M-16 ?!?

    Please clarify and/or correct the record accordingly.

  5. From the author of the article "Did a Japanese Submarine ...."

    Here is what I found from an article December, 2009, and from several other sources, including the National Park Service briefings.
    Late the night of December 7, I-16 received a radio transmission of a mini-submarine‘s code for "Success, success, success" at 10:40 PM December 7 (Hawaii time). It is not certain if the message came from M-16 but it must have come from one of the mini-subs. Another transmission "unable to navigate" was received at 12:51 AM the following morning 8 December (Hawaii Time). This was believed to have been sent by M-16s submarine's commander ( article Dec. 2009).
    Three of the mini subs are definitely accounted for outside the harbor that were sunk or disabled before they could cause any harm. One mini-sub certainly penetrated the harbor and was destroyed by the USS Monaghan in the outbound channel inside the harbor around 0844. It is possible that another mini-sub penetrated inside the harbor and that it fired its torpedoes but unless they were fired at the battleships, no one reported them. The second mini sub could have hidden to be scuttled the next day. The head of the Pearl Harbor National Park service thinks this may have happened. What happened to the missing two-man crew is uncertain, but they seem not to have survived the war. The names of the mini-subs are unknown except for the one that was captured washed up on the beach at Waimanalo. It was HA-19. The others were named after their mother ships. M for mini-sub plus the mother identifier; I-16, I 18, I 20, I 22, and I 24. The transmission, if any, that was received by one (unknown) fleet Japanese submarine was never identified to a certain mini-sub.
    It is thought that wreckage of the second mini-sub was mingled with several wrecked LST ships which blew up later in the war in a loading accident, then picked up and carried out to sea and dumped. A wrecked mini-sub minus its torpedoes was found in the dump. It is puzzling that no one noticed the second mini-sub fire its torpedoes during the battle or later, when thousands of eyes were trained on the harbor and especially on battleship row.