A Taranto–Pearl Harbor Connection

On the night of 11 November 1940, Royal Navy Fleet Air Arm (FAA) aircraft attacked Italian battleships at anchor in the port of Taranto, Italy. On the morning of 7 December 1941, aircraft of the Imperial Japanese Navy’s carrier strike force attacked the battleships and other assets of the U.S. Navy at anchor in Pearl Harbor. Is there a connection between the two attacks? If so, should the Navy have discovered it before 7 December?

It is not obvious that there should be any connection, for the two attacks were very different. Twenty fabric-covered biplanes struck the Italian anchorage in the dark of night, while 355 aircraft attacked many targets on Oahu in daylight. The Taranto task force consisted of one carrier escorted by eight ships. The Japanese employed 6 carriers, escorted by 14 ships and 3 submarines. The Japanese destroyed 174 planes, damaged another 128, and inflicted severe damage to airfields and hangars. The four British planes assigned to bomb targets ashore did little damage, and the bombs dropped on ships by five other planes failed to explode. Three Italian battleships were torpedoed, two of which were repaired and returned to service within six months. Eight U.S. battleships, three cruisers, three destroyers, and four auxiliary craft were either sunk, capsized, or heavily damaged. Still, the fundamental lesson of each operation was the same: The development of naval aviation meant ships no longer were safe in their home ports.

How the Royal Navy Did It

The attack on Taranto came at the end of a week of complex naval activity. Beginning on 4 November, dozens of ships from Alexandria and Gibraltar closed on Malta and delivered 2,000 men and several shiploads of supplies and equipment to that beleaguered island. Supermarina, the Italian naval high command, was aware of these movements but received only sketchy reports because fighters from the carriers Ark Royal and Illustrious consistently chased off Italian reconnaissance planes. These radar-directed FAA fighters also dealt effectively with Italian attack planes.

By the 10th, both groups of Royal Navy warships turned away from Malta, west toward Gibraltar and east toward Alexandria. On the 11th, a task force centered on the Illustrious broke off at 1800 and steamed north at high speed, arriving at the planned point from which aircraft were to be launched at 2000. A screening force of three cruisers and two destroyers sailed parallel to and to the west of the Illustrious force so that any Italian planes would sight them first. In the event, neither group was spotted. So, Supermarina lost contact with the British ships on the 10th and 11th and may have believed that the enemy action was over, but the local command at Taranto remained on alert.

Royal Air Force photo-reconnaissance aircraft from 431 Squadron based on Malta regularly had visited Taranto in the weeks leading up to the attack. The resulting pictures provided valuable information for the attack planners, but the planes’ appearance also tipped off the Italians to the fact that Taranto might be a target. The base and the ships were on alert, guns manned and ready ammunition within reach.

At 2035 on the 11th, from a point 170 miles from Taranto, the first plane lifted off the flight deck of the Illustrious. Eleven more would follow in the next five minutes; all the planes were Fairey Swordfish. With a maximum speed of 140 mph, this biplane was obsolete by the standards of 1940 fighters, but it was a good platform for dropping torpedoes. The Illustrious had left Alexandria with 24 Swordfish, but 3 had experienced engine trouble and dropped into the sea. The problem was traced to bad fuel from one of the tanks on board the carrier, so only 21 were available for the attack.

Of the 12 in the first wave, 6 carried torpedoes, 4 carried 6 250-pound bombs, and 2 carried 16 parachute flares and 4 250-pound bombs. The torpedo planes carried an extra fuel tank in the second seat, immediately behind the pilot, and the bombers carried one suspended below the fuselage. All planes carried a second officer, an observer/navigator. The plan was for flares to be dropped along the eastern shore of the harbor, thus silhouetting the target ships for the torpedo planes coming in from the west. The bomb carriers were to find targets of opportunity ashore or afloat.

The formation held together in the cloudy night, except for one plane, piloted by Flight-Lieutenant H. I. A. Swayne, who, finding himself alone, sped ahead, fearful that he had dropped behind. Swayne’s engine triggered Italian sound detectors, and antiaircraft gunners opened fire. The skies lit up, and the rest of the formation, only minutes behind, clearly saw their approach path. The attack went well—six torpedoes dropped, two hits and one near miss on the Littorio, one of the two new battleships in the harbor, and one hit on Conti de Cavour, an older battleship that had been modernized in the 1930s. The bombers had less success, destroying a seaplane hangar and starting a fire at an oil-tank farm but failing in attacks on ships (several bombs hit cruisers or destroyers but did not detonate). One plane was shot down; its crew swam ashore and was taken prisoner.

The nine planes of the second wave began taking off at 2128, and eight were airborne by 2134. However, planes eight and nine had collided on deck, causing number nine to be struck below. The pilot, Lieutenant E. W. Clifford, pleaded with mechanics to patch up his plane, and—with the encouragement of U.S. Navy Lieutenant Commander John N. Opie III, an observer on board—argued with the commander (flying) that he should be allowed to take off late and join the attack. Approval was given, and Clifford took off at 2158. Meanwhile, the other plane in the collision, piloted by Lieutenant W. D. Morford, suddenly lost its auxiliary fuel tank and had to turn back. Fired on by nervous gunners on board the Illustrious and Berwick, Morford flew around the carrier at a safe distance for 15 minutes before being cleared to land.

Thus, eight planes made up the second wave. Of the five that carried torpedoes, two achieved hits: a third strike on the Littorio and a successful torpedoing of the Caio Duilio, another recently modernized battleship. Two planes missed their target, and the fifth, piloted by Lieutenant G. W. Bayley, with his observer Lieutenant H. J. Slaughter, was blown out of the sky by antiaircraft fire, killing both men. Bombs hitting ships again failed to explode, and further bombing of the oil-tank farm did little damage.

The Illustrious recovered the first-wave planes between 0120 and 0155. The second wave began landing at around 0200. Clifford, of course, was the last to land, coming in at 0250. Senior officers debriefing the pilots were skeptical about the reported success and began to plan a repeat attack for the next night. One pilot drily remarked, “They only asked the Light Brigade to do it once!” As the day wore on, bad weather moved in, and the task force turned away for Alexandria. Late on the 12th, radio messages were received that confirmed the damage: three of the Italian navy’s six battleships were severely damaged, out of action for at least several months. The Illustrious and her escorts rejoined the rest of the fleet, all ships arriving at Alexandria on the 14th.¹

Our Man with the Royal Navy

One man was almost certainly the first down the gangplank once the Illustrious had docked: Lieutenant Commander Opie. Though his official title was assistant naval attaché, London, Opie had come aboard the Illustrious on 22 August, when she departed Britain bound for Alexandria. During the intervening months, he had sailed on board a number of Royal Navy ships on combat operations. He was in the heavy cruiser HMS Kent when she was torpedoed, and he would spend time on board the battleship Warspite, destroyer Jervis, and light cruiser Sydney. He sent back numerous reports to the Office of Naval Intelligence (ONI), reporting on his own observations and also forwarding almost any Royal Navy document he could get his hands on.

On 14 November, he quickly made his way to the American Legation in Cairo and wrote a four-page report on the Taranto attack. He had obtained a copy of the report by the commanding officer of the Illustrious and added his own observations to “supplement the enclosed report.” Under the heading, “Lessons,” Opie wrote:

• AA fire is not effective

• Low flying planes attacking ships limit shipboard gunnery for fear of hitting friendly ships.

• Strain on pilots was intense, doubt that they could have made a second attack

• Some believe that ships should put to sea on moonlit nights, rather than try to defend in harbor.

• RN has given up on high level bombing, and prefers torpedo attack to dive bombing.²

The U.S. Navy’s Response

Opie’s documents went to Washington via the diplomatic pouch and would arrive in January. But the leaders of the U.S. Navy did not need to wait for the lieutenant commander’s report to arrive because the Taranto attack was front-page news. The New York Times ran a six-column headline on page one. The Washington Post gave the story similar play, and Time magazine published three pages of coverage.³ Chief of Naval Operations Admiral Harold R. Stark must have been reading these stories, because on 22 November, just ten days after the raid, he wrote to his commander in Hawaii, Admiral James O. Richardson, mentioning the Taranto attack and asking Richardson about installing torpedo netting to protect the ships anchored at Pearl Harbor. Richardson replied negatively, citing the restricted space in the anchorage and the distance of the mooring spots from the entrance to the harbor.⁴ This last remark indicates that Richardson may have been thinking of submarine-launched torpedoes rather than aerial ones.

Stark continued to express concern about Taranto-style attacks, and around the first of December, the newest officer in the Navy’s War Plans Division, Commander Walter C. Ansel, was given the task of preparing a comprehensive report on the security of Pearl Harbor. Ansel worked with the Army on this project, and the result was a letter signed by Secretary of the Navy Frank Knox and addressed to Secretary of War Henry L. Stimson.⁵ Dated 24 January 1941, Knox’s letter detailed the woeful state of Hawaiian defense forces, made numerous suggestions for improvement, and promised the full cooperation of the Navy if the Army would commit to implementing the Navy’s suggestions. Stimson replied on 7 February that while Hawaiian forces might be weak, they were stronger than at any other U.S. base.⁶ He promised improvements, including radar, more fighter planes, and more and better AA guns.

Meanwhile, another officer was worried about the defenses—or more pointedly, the absence of defenses—at the Hawaiian naval base: Admiral Claude C. Bloch, commandant of the 14th Naval District at Pearl Harbor. Bloch, who was responsible for the Navy’s effort to defend the base and its facilities, submitted a long report to Stark, through Richardson, listing area after area where men and materiél were pitifully short of what was needed. This tale of woe might have stimulated some action out of Washington had not Richardson totally downplayed it in his endorsement. He mentioned “the improbability of an attack” several times and went on to say that the fleet could defend itself using shipboard guns and carrier planes in the highly unlikely event of an attack.⁷ This report was received in Washington on 7 January, two days before Opie’s Taranto report arrived there.

The latter must have sat at the bottom of somebody’s in-box because it was more than a month before a one-page summary was sent from the ONI to recently appointed fleet commanders Admiral Husband E. Kimmel (Pacific), who had replaced Richardson on 1 February, and Admiral Ernest J. King (Atlantic); War Plans; the Ordnance and Aeronautics bureaus; and others. The summarizing was done by Lieutenant Commander Herbert F. Eckberg, who briefly stated the facts of the attack—number of planes, pilot training, torpedo settings, results. He then restated Opie’s five lessons almost verbatim. This report went out on 14 February.⁸

Remarkably, another document dated 14 February was headed for Kimmel: a letter from Stark, repeating the qualms he had expressed to Richardson about the dangers of aerial torpedo attacks on the fleet in Pearl Harbor. Over the course of three pages, Stark listed all the arguments against installing torpedo nets—the tight space in the anchorage, the hills surrounding the harbor that make it difficult for the planes to get down to water level, the shallow water of the harbor (40 to 50 feet), the shore-based AA and aircraft, and the fact that such nets are heavy, expensive, and take up a lot of space. This memo makes the categorical statement “a minimum depth of water of 75 feet may be assumed necessary to successfully drop torpedoes from planes.”⁹

Stark ended curtly: “Recommendations and comments of the Commander-in-Chief are especially desired.” Kimmel took the hint. He never pursued the idea of torpedo nets, and he never believed—until 7 December—that aerial torpedoes would run in the shallow water of Pearl Harbor.¹⁰

While the “thinking Navy”—the staff officers in their Washington offices—was downplaying aerial torpedo attacks, the “fighting Navy” out on duty with the fleets had a different response. In February Rear Admiral John S. McCain and in March Vice Admiral William F. Halsey Jr. wrote letters to the chief of the Bureau of Ordnance concerning aerial torpedoes. Both letters began by citing “recent developments” in the European war, and both requested that the bureau develop new and improved aerial torpedoes for the fleet. Rear Admiral Aubrey W. Fitch made 55 copies of Opie’s report and on 3 March sent them to almost every senior officer in naval aviation.¹¹ All three officers showed an awareness of the success of torpedo attacks in the European fighting that was lacking among the staff officers back in Washington.

Our Man Returns

Meanwhile, Lieutenant Commander Opie still was busy in the Mediterranean. In December he had sailed on board HMS Jervis, and in January 1941 he was on board the Warspite when the nearby Illustrious was attacked by swarms of Stuka dive bombers. Opie wrote a report on the battle as well as a personal letter to his boss, Captain Alan G. Kirk, the U.S. naval attaché in London. He told Kirk, “I am not trying to drum up my own trade but I honestly feel that I should fly to Hawaii and talk to the boys there on war experiences and how to train to meet the lessons learned.”¹² He received no answer.

Opie turned up in London on 10 March, but how or when he arrived there is unclear. He finished up a few reports and on 5 April boarded the battleship HMS Resolution, heading home. After stops at Hvalfjord, Iceland, and Halifax, Nova Scotia, he arrived in Philadelphia on 20 April and three days later reported to the CNO’s office.¹³ On the 29th, Opie “talked to members of the General Board and representatives of interested Bureaus and Offices on his observations and experiences abroad.” The minutes for this meeting state only that Opie made remarks about his experience and do not include an attendance list, but his lecture was written up as an intelligence report and sent to Kimmel, King, and seven offices within the Navy Department on 2 May.¹⁴

Opie began his talk with “three outstanding lessons”: materiél differences are small, spirit is what counts, and training must go on in war. He described radar as the “greatest development in materiél.” He talked about the Royal Navy’s armored-deck carriers, which gained protection at the expense of reducing the complement of aircraft. He finished by emphatically criticizing antiaircraft gunfire. He called it the “bug-a-boo” of the war and stated flatly that “[t]he only answer against planes is planes.”

Thus ended Jack Opie’s career in naval intelligence. He worked at a desk job in the Navy Department for four months and then took command of an Atlantic Fleet destroyer, the Roe (DD-418). On 7 December, his ship was docked at Reykjavik, Iceland.

A Final Failure

On 13 June, the Navy Department had produced a remarkable report sent to all naval districts, with a copy also going to the three fleet commanders—Kimmel, King, and Admiral Thomas C. Hart (Asiatic). This memo was significant because it revoked the advice given in February that a minimum water depth of 75 feet was necessary for a successful torpedo attack. Now, the word was that “recent developments” had shown that drops could be made from 300 feet and make “initial dives of considerably less than 75 feet.”¹⁵ This clear warning was somewhat muddied by remarks that “sufficient distance” would be needed for the aircraft to get into attack position, depth of water was only one factor of many for an attacker to consider, and attacks in deeper harbors would be “much more likely.”

The War Plans staff at the 11th Naval District in San Diego must have read the new memo because it began talking to torpedo-squadron pilots at the naval air station about depth of water for a successful attack. The pilots told staffers that 10 to 12 fathoms (60 to 72 feet) was necessary. Somehow, this matter was referred to U.S. Navy Lieutenant Albert K. Morehouse, who was then on board the British carrier Ark Royal, as Opie had been on board the Illustrious. Morehouse laid it on the line: “Records of the RN Mk. XII indicate that this torpedo can be dropped in water as shallow as 4 fathoms.”¹⁶

The ONI receive Morehouse’s report on 22 July, and Kimmel was sent a copy. But nothing seems to have happened, and no one may have read Morehouse’s remarks until this author found them at the National Archives. The reason is typographical. Page one of the three-page report lists a “table of contents” that includes four topics. But on page three, Morehouse’s two paragraphs appear as item five. If the original report already had been typed, with four subjects listed, and Morehouse’s brief report arrived at the last minute, the typist may have rolled the original page three into his typewriter and tacked it on. Had this been done, item five would appear only on the original, not the carbon-paper copies.

Morehouse’s information should have made it out to the fleet. Opie should have made that trip to Hawaii. The Morehouse report would have destroyed the idea that shallow water was protection against aerial torpedo attack. Admiral Kimmel testified under oath that he did not believe torpedoes would run at Pearl Harbor. Had Opie gone to Hawaii, he would have found a U.S. Naval Academy classmate there, Fleet Intelligence Officer Captain Edwin T. Layton, who talked to Kimmel every morning. There is no evidence that Opie and Layton were close, but classmates would certainly talk to one another. Opie’s high opinion of radar, his very low opinion of antiaircraft fire, and his sense that ships were safer out at sea than anchored in a harbor might have provoked changes in Kimmel’s handling of his fleet.

So the U.S. Navy never made a Taranto–Pearl Harbor connection. Officers out with the fleet were aware that successful aerial torpedo attacks were being made in Europe. Officers serving as neutral observers with the Royal Navy were getting and forwarding the facts about these successes. But officers serving in staff jobs at the Navy Department failed to connect the two groups. This was not a case of deliberately withholding intelligence needed by the fleet commanders but rather an ordinary bureaucratic failure to overcome preconceived notions, to send clear messages without adding “on the other hand” comments, and to keep up with changing technology. A failure nevertheless, and, indeed, a catastrophic one.

A Japanese Connection?

By Christopher P. O’Connor

Historians have claimed that the Japanese Navy “studied the Taranto attack” as it prepared for its own attack on Pearl Harbor. The evidence usually features the travel of Lieutenant Commander Takeshi Naito, assistant naval attaché in Berlin, to Taranto in December 1940 to view damage and discuss the attack with Italian naval officers. If Naito wrote a report about this trip, it has not been published.

Many writers note that Naito and Commander Mitsuo Fuchida, who led the first wave of Pearl Harbor attackers, discussed Naito’s trip when the lieutenant commander returned to Japan. Not all of them state that this meeting took place in October 1941, by which time the planning and training for the Pearl Harbor attack was well along. The evidence for this meeting is an interview of Fuchida conducted in 1964. Fuchida recounts no tactical or engineering information that he received from Naito, only the encouragement that if the British could successfully launch torpedoes in a harbor, then so could the Japanese.¹

A more substantial exchange of information probably took place when a Japanese military mission visited Italy and Germany. While in Italy from 18 May to 8 June 1941, the naval members of the mission, headed by Rear Admiral Koki Abe, spent many days in Rome talking with Supermarina officers, then traveled to Taranto to see the fleet. Each side had particular questions for the other. The Italians wanted to learn about carrier operations because dictator Benito Mussolini had recently approved the conversion of two liners to aircraft carriers. The Japanese wanted to know about the operation of the Italian navy, providing a list of 83 topics for discussion. “Finally the Japanese showed great interest in the aerial torpedo attack against the ships anchored at Taranto the night of November 11, 1940.”²

The Italians mounted a wooden fin to their torpedoes to control the weapon’s attitude as it fell through the air. The Japanese solution to the problem of getting torpedoes to run in the shallow water of Pearl Harbor was mounting a wooden fin on the projectile. They already had begun to experiment with fins before the mission set out. In the end, they produced successful shallow-water torpedoes by dint of their own hard work and rigorous practice. There was tremendous compartmentalization and security around all the Pearl Harbor preparations; none of the mission’s officers would have known of the plan to attack the U.S. Navy.

Still, it is possible that some part of what the Italian navy showed off to its visitors contributed to Japanese success. If there was a connection between Taranto and Pearl Harbor, it ran through Rome.