by Attack on Pearl Harbor: Strategy, Combat, Myths, Deceptions
Being generous to the theory, one might estimate that there was an 80% probability that the St. Louis was attacked by one or more torpedoes.
Proponents suggest that one of the other 23 Japanese fleet submarines operating in the area might have fired the torpedoes. However, none of the Japanese fleet submarine Tabular Record of Movement (TROM) chronicles any expenditure of torpedoes that day. All of the submarine patrol areas were well away from of the location of the attack. One submarine was later ordered to close on the channel entrance, but became fouled in a net and did not fire any torpedoes.
Some suggest that submarine I-70, which was sunk days later, might have delivered the attack on St. Louis. Japanese submarines were under strict control by radio by their admiral at Kwajalein Island, both receiving instructions and radioing back contact and attack reports. No orders for I-70 to change station and approach the channel entrance are recorded in the TROMs, and no report of any attack on that day was radioed by I-70. The closest edge of I-70’s assigned patrol area was 30nm from the harbor entrance.
The chances that a Japanese fleet submarine was responsible for the torpedo attack on St. Louis are vanishingly small. It is (generously) assessed at 10%.
If the midget submarine expended its torpedoes against St. Louis and never entered the harbor, it is still a mystery how it got to the bottom in three pieces after undergoing some kind of salvage effort.
There remains the possibility that the midget submarine fired its torpedoes outside the harbor in an attack that was not observed or recorded. Lieutenant William Outerbridge, commanding officer of the destroyer Ward, stated that
There was another thing we saw. That was a lot of explosions along the reefs. I thought that they were explosions of torpedoes fired into the reefs. I didn’t see any other submarines the whole morning. We didn’t actually see any, but we did see a lot of explosions that looked like shallow water explosions of torpedoes.23
Numerous other ships in the area claimed to have been missed by torpedoes, although none observed an associated explosion as in the St. Louis’ case. “Sub Jitters” is a known phenomenon.
The explosions noted by Outerbridge were likely from descending AA shells. The possibility that the midget submarine fired at some other target outside the harbor is small, assessed at 10%.
The two event paths converge with the next step, the submarine penetrating into Pearl Harbor. The net probability up to this point is the combination of the two possible paths, 8% (along the path of a confirmed torpedo attack against St. Louis) and 18% along the other, a combined probability of 26%
Did the Midget Penetrate Into Pearl Harbor?
Of the four other midget submarines, one penetrated the harbor, three did not. The locations of all four hulls are confirmed. Based on this operational experience, the probability that the fifth midget submarine penetrated into the harbor is assessed at 25%.
The “Midget in the Photograph” Firing Torpedoes into Battleship Row
As discussed above, the possibility that the photograph captured a view of a midget submarine in the process of delivering a torpedo attack on Battleship Row is vanishingly small.
However, an alternate possibility exists. The midget submarine might have remained in the harbor unobserved. It might have fired its torpedoes from another location in the harbor and the torpedoes missed, all unobserved.
In the absence of any way to discredit this possibility, the event will be given a probability of 10%.
Firing Torpedoes Against Battleship Row
The proponent’s have searched for confirmation that the midget submarine fired its torpedoes against Battleship Row targets. Its torpedoes carried almost twice as much explosive as the Type 91 aerial torpedoes, so they have looked for evidence of unusually powerful torpedo explosions. There are several possibilities.
Oklahoma
Sailors in Oklahoma’s after steering compartment during the attack described the sounds of the torpedo hits. As related by Seaman First Class Jim Bounds:
I noticed other torpedo hits, but I noticed [the first] three more than anything else, and then there was an extra loud one… it shook the ship, then we got one or two more after that… but they wasn’t as powerful as that one.
The theory proponents believe that the “extra loud one” was evidence of the detonation of a heavier midget submarine torpedo.
An explosion’s sound propagation through a warship’s hull is subject to a great deal of variability. Bounds, inside the armored box of after steering, heard the hits distinctly. Gunners Mate Leon Kolb, on Oklahoma’s main deck, felt the first hit as more of a thud or vibration rather than an explosion. Boatswain Adolph Bothne, on deck preparing to go over the side on a hull cleaning detail, never felt even one of the hits.24 Clearly there were differences in sound and shock propagation to different locations.
How loud or heavy a hit might seem is based on:
• what the torpedo hit (against crushable anti-torpedo bulkheads vs. stiff belt armor anchored to the hull),
• where it hit longitudinally (between 100 to 400 feet away from after steering),
• depth (near the surface, venting most of the explosive force into the air, or deep under the waterline, or even the actual hit that occurred on the second deck above the armored belt as Oklahoma capsized),
• the order of the hits and proximity to damaged portions of the hull (a hit forward of a previously damaged section would be less tightly coupled acoustically to transmit sound waves through the structure of the ship from forward to aft).
Torpedoes with the same warhead weight will propagate different sounds, especially when heard from a location at the extreme stern of the ship. One torpedo sounding louder than others would be expected. Differences in perceived volume of noise cannot be reasonably used as conclusive evidence that a larger submarine torpedo warhead hit Oklahoma.
Photographs of the Oklahoma’s hull taken in drydock after she was raised show much more extensive damage than that inflicted by Type 91 aerial torpedoes on other battleships. One of the Nova program contributors suggests that this was the result of a hit by the heavier Type 97 midget submarine torpedo.
Oklahoma rolled onto her damaged side while capsizing, and was again rolled on that side during the salvage operation. The additional damage resulted from rolling a 27,000-ton hull onto a damaged and weakened structure that was not stressed to handle such loads. If the heavier damage resulted from a single more powerful torpedo hit, the area of heavier damage would have been localized. The heavier damage appears over the entire length of the hull.
There is an area where belt armor plates are missing and one is cracked, but it is unlikely that a torpedo would have been able to create that damage—other aerial torpedoes hitting belt armor deflected belt armor inwards. Increasing the explosive charge would likely just do the more of the same. The missing and cracked plates are more likely the result of the effects of rolling the hull on to them after the plate’s support structure was weakened (or removed) by the aerial torpedoes.
Arizona
The Nova program edited testimony from two sailors from the crew of the Vestal to make a case that Arizona was hit by a dud midget submarine torpedo. There is no corroborating physical evidence.
Witnesses on Vestal claim that a torpedo went under their hull to strike Arizona. If this had been the case, the same kind of damage would have been inflicted on Vestal as that which caused Oglala to sink after a torpedo went under her and detonated against Helena. Vestal’s hull showed no evidence of such damage when she was drydocked, only the damage caused by two AP bomb hits.
A photograph taken by a Kaga high-altitude level bomber shows oil pouring out of Nevada. She was hit by the second-to-last torpedo dropped. There was no oil slick around Arizona.25
Even assuming that they did see a torpedo, there is nothing to indicate that it was launched from a submarine. Just as in the testimony of the sailors on the Dale who testified that they were attacked by AP bombs one hour after th
e last AP bomb was dropped, and the sailors on the Shaw who believed that they were attacked by incendiary bombs when the Japanese had no such weapon, and the soldiers testifying they were strafed at Schofield Barracks, human testimony has to be carefully cross-checked with other testimony and correlated with physical evidence before it is accepted prima fascia.
This is not the only case where eyewitness reports were inaccurate. The captain of Vestal reported that Arizona was hit by a bomb down the battleship’s stack in a letter to the Chief of the Bureau of Ships, making it an “official” rumor, repeated to this day.26 Inspection found the armored grate covering the stack opening was undamaged. There was no evidence of a bomb hit in the vicinity.
This should not in any way be taken as a slur against the veterans. There is a considerable body of literature confirming that eyewitness memories of stressful events are not always accurate—four individuals observing a bank robbery will all give different accounts, to the frustration of law enforcement officers. The brain is a very uncertain recording device when under stress, and memories shift and fade. Veterans’ memories can be influenced by things learned after the attack, like reading battle histories, watching war movies or in reunion discussions.
An additional possibility suggested by the proponents is that the torpedo actually went deep and exploded under Arizona. Two testimonies are cited to support this theory. First, Admiral Kimmel spoke of what he saw from the front lawn of his quarters. “I saw Arizona lift out of the water, then sink back down, way down… I knew the ship had been hit hard because even then I could see it begin to list.”
He could have witnessed a torpedo hit, although it is difficult to understand how he saw the ship “lift out of the water” when Vestal was blocking his line of sight. Or, he could have mistaken Oklahoma for Arizona, two ships with very similar silhouettes. The movie footage of Arizona that recorded the magazine explosion does not show a list on the ship, contradicting Admiral Kimmel’s observation.
The water main on Ford Island lost pressure almost immediately after the beginning of the attack. The island’s 12-inch fresh water supply pipe passed under Arizona. It has always been assumed that Arizona’s magazine explosion destroyed the water pipes. The proponents speculate that a midget submarine torpedo slipped under Arizona and destroyed the pipe.
This is not corroborated by physical evidence. An explosion under the keel is considerably worse than one against a ship’s side—the hull would hog from the explosions’ gas bubble, then sag down as the bubble collapsed. This would leave cracks in the hull. Arizona shows no evidence that a torpedo detonated under her keel.
There was a 6-inch temporary fresh water supply pipe at the south end of the island. This pipe was destroyed by one of the first 250kg GP bombs that hit the island. Water gushing out of that damaged pipe would have depressurized the system. A witness reported that water main pressure was low before the Arizona exploded (the torpedo hit supposedly within seconds of the magazine explosion). The reported depressurization of the fresh water system was likely the result of the ruptured 6-inch pipe coupled with high demand for water for firefighting.
A Recovered Dud Midget Submarine Torpedo
The best possible evidence to conclusively prove that a midget submarine fired a torpedo at a battleship would be to recover a dud Type 97 torpedo from the mud next to Battleship Row. Researcher Tom Taylor believes he has found references to such a torpedo. He relates:
The entry “A recovered unexploded torpedo carried a charge of 1,000 pounds of explosive.” was made by Admiral Chester W. Nimitz, Commander-in-Chief, United States Pacific Fleet to The Secretary of the Navy via The Commander-in-Chief, United States Fleet and The Chief of Naval Operations.
It is located in the CINCPAC After Action Report (File No. A16-3/Serial 0479 dtd FEB 15 1942) under Part III, Narrative of Events During Japanese Raid, 7 December, 1941, Phase I - 0755-0825 (Combined Torpedo Plane and Dive Bomber Attacks), (A) Torpedo planes, paragraph 1.
1. Of the four separate torpedo plane attacks made in this Phase, as distinguished by sectors of origin, the major effort was that conducted by 12 torpedo planes which swung in generally from the Southeast, over the tank form, Merry Point, and environs; launching their torpedoes from very low altitudes, and at very short distances, toward the battleships on the South side of Ford Island. All of the outboard battleships were effectively hit by one or more torpedoes. Strafing was simultaneously conducted from the rear cockpits. A recovered unexploded torpedo carried a charge of 1,000 pounds of explosive.27
Taylor asserts that the torpedo with “a charge of 1,000 pounds of explosive” refers to a dud midget submarine torpedo.
Reference to a recovered torpedo with a “1,000 pound warhead” does not necessarily indicate a midget submarine torpedo. The Type 97 torpedo used on the midgets had a warhead explosive weight under 800 pounds. The warhead weights do not match. The figure quoted in the report could have been an underestimate of the total weight of a recovered aerial torpedo, or a typographical error, or a reference to the total weight of an aerial torpedo rather than just the warhead, or some other problem in the documentation.28 Taylor believes otherwise, asserting that the entry must be correct since Nimitz signed the report.29 To accept that he must also believe that Nimitz wrongly associated that torpedo with the aerial attack, so, according to Taylor, Nimitz was both right and wrong. Taylor chooses which facts to accept and which to reject based on which best forward his theory.
Several aerial torpedoes were recovered, one from the Naval Shipyard’s woodpile after it was jettisoned, most likely that of Petty Officer First Class Kitahara Syuzo. There are eyewitness accounts of another torpedo that slid up a muddy beach and spun its prop to exhaustion, “buzzing its life out in a parking lot.”30 So, the Americans had samples of Japanese aerial torpedoes. They also had samples of the Type 97 torpedo as two were recovered on the midget submarine that beached off Bellows Field.
Since a warhead weighing 1,000 pounds does not match the two torpedo types employed at Pearl Harbor or, for that matter, none of the torpedoes that ever existed in the Japanese inventory, the entry is simply an error. Erroneous information cannot be used to either prove or disprove a hypothesis. It is like finding a document where a man says he found a 20 cent coin. Taylor would have us accept that since 20 cents is closer to a quarter than a dime, the man therefore found a quarter. But it could have been a typographical error, either substituting a “2” for a “1,” meaning the man found a dime, or a “0” for a “5,” meaning the man found a quarter. Erroneous information cannot be used to support an argument either way.
Others feel that further documentation would be helpful, hopefully in the form of an ordnance intelligence exploitation report documenting a Type 97 torpedo recovered from Battleship Row. Such a document has yet to be found. If such a report is found, it hopefully will specify the locations from which the torpedo was recovered.
It is impossible to either prove or disprove the possibility that the missing Japanese midget submarine fired its torpedoes inside Pearl Harbor. There is always the possibility that the weapons were expended without anyone noticing—unlikely, considering the thousands of witnesses surrounding the harbor that day—but impossible to disprove without indisputable evidence of how the torpedoes were used. So as to not bias the calculation, a probability of 100% will be assigned to this event.
The Midget Navigates to West Loch
After expending its torpedoes the midget submarine must navigate to the West Loch and scuttle. Proponents point to several sightings of periscopes in the areas between Battleship Row and the entrance to the West Loch between 0837 and 0900, heading outbound.
Alternate explanations are again possible. The “periscope sightings” occurred 40 minutes to an hour after Arizona exploded and Oklahoma capsized. Both of these catastrophes threw massive amounts of debris into the water, all of which would be floating with the current out of the harbor, down the channel and past the entrance to West Loch. Photographs
show evidence of this debris.
The periscope sightings were about a mile downstream from Battleship Row. There was a brisk current. The locations and times of the sightings are such that they could be from debris floating in the current.
Debris has often been misidentified as submarine periscopes. In the Atlantic, German submarines used to throw swabs into the water ahead of convoys. The mop head would become saturated and sink, leaving the wooden handle floating straight up and down and looking remarkably like a periscope. Many swabs suffered crippling damage from depth charge attacks by Allied escorts.
Ships store their swabs in racks on the weather decks to allow them to dry in the sun without introducing a bad odor into the ship. Many were dumped in the water when Oklahoma capsized.
There is the very human propensity to see things that are not quite so. “Submarine Jitters” has already been mentioned. For example, during the Falklands War in 1982 the British were concerned about the Argentine submarine threat. They maintained close attention to their ASW searches. A number of contacts were prosecuted but all eventually proved to be false alarms. However, when British intelligence reported that an Argentine submarine had left her berth in a port hundreds of miles away, the number of submarine contacts went up by a factor of ten. The British began to run short of ASW torpedoes as they attacked whales, schools of fish, and thermoclines. The contact rate returned to normal when the Argentine submarine was found to have moved to a different berth.
A similar thing happened to the Japanese battleline, which was at sea the day of the Pearl Harbor raid. On 10 December reconnaissance flights and patrol boats reported five enemy submarines in the vicinity of the Japanese Main Body. They decided to return to port. Combined Fleet Chief of Staff Ugaki recorded in his diary, “How dangerous our invisible enemy is!”31 There were no American submarines within 1,500nm.
After Ward’s engagement with a midget submarine outside the harbor, and Monaghan’s engagement inside the harbor, it would be natural for people to mistake swabs for periscopes.
