Conceived by Fleet Admiral Isoroku Yamamoto, the brilliant, fifty-seven-year-old commander of Japan’s Imperial Combined Fleet, the surprise attack was code-named Operation Z—after Admiral Togo’s famous “Z” signal before the Japanese victory against the Russian navy at the Battle of Tsushima in 1905.
Yamamoto, Harvard-educated and highly regarded in the United States, where he had served as a naval attaché, had initially urged his colleagues to avoid war with the Americans. Overruled by the Imperial General Staff, he set to work on a plan to do even greater damage to the Americans.
Admiral Yamamoto was the strategist of the Pearl Harbor attack and CINC of the Imperial Combined Fleet until American pilots shot down his plane in 1943.
Yamamoto was a lifelong gambler, and he drafted a war plan that was bold and brilliant, but risky. He told the Japanese military planners, “If we are to have a war with America, we will have no hope of winning unless the U.S. fleet in Hawaiian waters can be destroyed.” It meant annihilating America’s Pacific Fleet before it could sortie toward Japan, and it required that the Imperial Army seize key bases in the Philippines and Guam, with near simultaneous strikes against the British in Hong Kong and against Dutch possessions in Indonesia.
He told the Imperial General Staff that “if successful,” the raid would enable them to hope for a short, limited war, after which Japan would quickly sue for peace on its own terms. The overall concept was approved by the General Staff by June 1941. Yamamoto then set his best naval planners to the most difficult part of the task: a surprise air assault of unprecedented size against Pearl Harbor, 4,000 miles from Japan. By August, working around the clock in absolute secrecy, Rear Admiral Takajiro Onishi and his fellow naval aviators Minoru Genda and Mitsuo Fuchida were able to deliver a final attack plan requiring six aircraft carriers and more than 350 aircraft.
In early September 1941, the Japanese Imperial General Staff approved Yamamoto’s daring war plan, and fleet units commenced a rigorous period of pre-attack training, though they were not told their target. By early November, the six carriers, two battleships, three cruisers, nine destroyers, thirty submarines, and eight tankers—constituting Nagumo’s First Carrier Strike Force—began to assemble at Tankan Bay in the Kurile Islands, Japan’s northernmost and remotest naval base. On the night of 26 November, this armada, the mightiest battle fleet ever assembled in the Pacific, was ordered to sortie into the frigid waters of the north Pacific and head east. Once out of port and sailing without lights under strict radio silence, the captains of the fifty-eight ships opened envelopes containing their secret orders and learned their target: Pearl Harbor.
Meanwhile, as Nagumo’s force steamed undetected toward its objective, the Americans at Pearl Harbor were woefully unprepared for the coming onslaught. Some, including Admiral Husband E. Kimmel, commander in chief of the Pacific Fleet, and Lieutenant General Walter C. Short, commanding general of the U.S. Army’s Hawaiian Department, believed that they would have sufficient advance knowledge of any Japanese attack.
Both Kimmel and Short knew that American cryptographers had broken the Japanese Purple code, giving senior U.S. officials access to Tokyo’s diplomatic messages. Using intercepts of cables sent from Tokyo to the Japanese ambassadors in Washington, the Department of the Navy issued a “war warning” to the Pacific Fleet headquarters on 27 November—the day after Nagumo’s battle group departed Japanese waters.
On 2 December, the U.S. code-breakers intercepted a message to all Japanese diplomatic and consular posts to destroy their code and cipher material and burn all classified documents. Based on this intercept and one directing the Japanese consulate in Honolulu to continue reporting on U.S. fleet activities at Pearl Harbor, another “war warning” message to all units in Hawaii was issued by the War and Navy Departments. Still, both commanders and their staffs believed that they had several weeks—if not a month or more—to prepare.
They had not ignored the situation. Ever since President Roosevelt had “indefinitely” stationed the entire Pacific Fleet in Hawaii in May 1940, naval officials had been complaining about the risk from Japan. In October 1940, the fleet commander, Admiral James O. Richardson, visited Washington to personally point out their deficiencies to Navy Secretary Frank Knox. Shortly after Richardson turned command over to Admiral Kimmel on 1 February 1941, almost one-quarter of the Pacific Fleet was transferred to the Atlantic to help contend with the German submarines wreaking havoc on Lend-Lease shipments to England. Though his organizational tables called for six twelve-plane squadrons of patrol aircraft, Kimmel had only forty-nine operational patrol planes available.
Admiral Husband E. Kimmel planned for traditional naval war and didn’t foresee the importance of aircraft. He became a scapegoat for the attack on Pearl Harbor.
Because the Army was responsible for defending Hawaii, General Short’s requests for men and matériel were equally severe. He had requested 180 B-17 bombers, but had only six that were flyable, and all his fighters were obsolete. Though the Army had only 102 out of the 233 anti-aircraft guns that were deemed necessary, thousands of them were being shipped to our struggling British and Soviet allies. And while five of the new, highly secret mobile radar units had been delivered to Hawaii in November, few operators had been trained. Worse still, because the Army and Navy in Hawaii operated independently, with no unified command structure, even if a radar operator detected an incoming attack, the Army had no other means of alerting the Navy besides a phone call to the Fleet headquarters.
Uppermost in the mind of Admiral Husband Kimmel was the security of his ships, oil storage tanks, and naval aircraft. His long-range reconnaissance aircraft could fly 750 miles on patrol and sink any submarines in sensitive areas, especially at the entrance to Pearl Harbor. Kimmel regarded enemy submarines as the most serious threat to his fleet. Across the mouth of the harbor, the Americans had installed an anti-sub, anti-mine, and anti-torpedo net that extended almost to the bottom of the harbor floor, only forty-five feet deep. Though the anti-submarine net was highly classified, and the area around it designated as a restricted zone that was off-limits to civilian or foreign vessels, the Japanese were fully aware of it. German agents and Japanese spies routinely gathered remarkably detailed intelligence on our installations, ships, and aircraft. More than half a dozen reports provided data on the net at the harbor entrance.
Unaware of the magnitude and accuracy of the Japanese espionage but concerned about the inadequacies they had reported back to Washington, both Admiral Kimmel and General Short believed that they had done all they could to prepare for war. Warned of possible sabotage to his aircraft, General Short ordered them to be grouped close together so that they could be more easily guarded at Hickam and Wheeler Fields.
All combatant ships in port were ordered to maintain Readiness Condition Three, allowing for a 25 percent watch set on the guns and an ability to get under way in twelve hours. In the early morning of 7 December, Admiral Kimmel, trying to save on spare parts and aircrews, dispatched only three of his scarce long-range PBYs out on patrol—but none of them were sent north of Oahu, where Nagumo launched his air strikes. Both Kimmel and Short went to bed on Saturday 6 December believing that they had plenty of time before Japan launched an attack. They were, of course, dead wrong.
It might appear from the results that all went exactly according to Yamamoto’s plan, but that wasn’t so. In Tokyo, at the last minute, Prince Hiroyasu Fushimi insisted that the attack include some special weapons that were hidden away at the top-secret Kure Naval Base. These weapons—so secret that only a handful of Japanese military officers knew about them—were midget submarines. The Japanese had been quietly working on these specialized subs for years. Fushimi was convinced that they could penetrate the highly secure Pearl Harbor. He wanted five of them to be included on the mission so that by attacking U.S. ships right at their docks, the submarine service would be part of the great victory over the American fleet.
The undersized subs, seventy-eight
feet long and six feet high, were significantly smaller than conventional submarines. Displacing only forty-six tons, they had room for just two crewmen, specially trained for this mission.
Yamamoto was at first reluctant to include the unproven submarines in the attack, fearing that they could cost him the advantage of surprise if they were detected before his aircraft were over the target. Fushimi’s tiny subs would have to be moved into position hours ahead of the planned attack, risking the possibility of detection and thereby alerting the American military to the impending air strike.
The midget subs, officially called Special Purpose Submarines (SPS), had been under development since the late 1930s and had been subjected to intensive testing by the Imperial Navy at the secret base in Kure. But they were a new weapon, dependent on unproven tactics. Yamamoto, not only skilled in the art of war but also wise to political realities, understood that Prince Fushimi had powerful allies in the emperor’s household, so he reluctantly modified his plan of attack to include the midget subs.
Five I-Class submarines, Japan’s largest, were fitted with special cradles enabling each “mother sub” to carry an SPS behind the conning tower. Yamamoto designated the group as the Special Attack Unit.
The 600-horsepower, battery-powered mini-subs were capable of twenty-three knots surfaced and nineteen knots submerged, but only for two hours. At two knots they could run for nearly ten hours submerged, if the two-man crew didn’t run out of air first. Because of these limitations, Yamamoto ordered the Special Attack Unit I-boats to approach within ten miles of Pearl Harbor early on the morning of 7 December, fan out around the entrance, and launch their midget submarines. The mother subs would then retreat to a rendezvous point off Oahu and await the return of the SPSs after the attack.
Each SPS was outfitted with two Type 97, eighteen-inch-diameter torpedoes. There was nothing “midget” about these weapons—each had a 772-pound warhead. When fired from the vertical tubes at the bow of the subs, they could run up to three miles at fifty miles per hour. The midget subs were also packed with high-explosive charges that could be detonated by the crew, effectively making the subs suicide bombs.
Once released by their mother subs, each SPS was to make its way through the anti-submarine nets and into the harbor to launch its torpedoes at the U.S. ships moored around Ford Island.
Ten men had been chosen and trained for the two-man crew of each midget sub. They had to be able to tolerate confinement in a tiny space for long periods of time; be able to withstand extreme cold and heat; and be able to endure the foul air and the buildup of sulfuric acid gases given off by the sub’s lead-acid batteries. Those serving on Japanese midget subs had to have not only no fear of death, they had to expect to die.
Early on the morning of 7 December, while Nagumo’s six carriers were preparing to launch aircraft 230 miles north of Oahu, the five mother subs of the Special Attack Unit arrived on station off the mouth of Pearl Harbor. Navy Lieutenant Kichiji Dewa was aboard the mother ship for SPS I-16 TOU, one of the midget subs. (The midget subs didn’t have individual names like all of the large ships. Instead, they were referred to by the designation of their mother ships, followed by the suffix TOU.) He spoke by telephone to the officer inside the SPS as the tiny vessel prepared to disconnect from its mother ship, wishing that he were one of the ten brave men in the five midget subs headed for Pearl Harbor.
SIGNALMAN KICHIJI DEWA
Aboard Submarine Chiyoda
6 December 1941
2210 Hours Local
We were the chosen ones among the chosen. We had realized the importance of our mission, so despite the kind of work we were doing, there was not much dreading. We were gradually making progress in training for the port and harbor assault.
When I went on the Chiyoda, I did a lot of training and learned many spiritual lessons [as] the “chosen ones among the chosen.” It was maybe two months after I went on the Chiyoda that I really started to become aware of my status as a crew member of the SPS. I felt that we were working on something really important.
During training they created what is called “port and harbor assault.” The strategy was that when SPSs encountered enemy warships, the first thing they tried to do was lessen the numbers of warships, battleships, and troops—to decrease the enemy military units. The SPS was to be used for this “reduction of enemy forces” plan.
While we were submerged, we devoted ourselves to sleep. When we surfaced at night, we maintained the ship. Our major duties were charging the batteries and ventilation. Since we carry large batteries, if we leave the hatch closed all day long, a lot of gas gets generated. And if the motor is turned on with that generated gas, it can spark and blow up. Someone actually died from an explosion, so we were constantly careful about that. Otherwise, it was cleaning the ship. Bilge, filthy water, would accumulate. We can’t just leave it, especially in places like the motor room.
After we loaded the SPS on the mother submarine and sailed, it was officially announced by the captain that our target was Pearl Harbor.
I heard that the upper staff officers weren’t going to grant permission [for the mission] unless there were arrangements for the crew members to return alive, but I don’t think the commanding officer, Lieutenant Commander Masaji Yokoyama, expected to return alive. He used to say, “There is a saying, ‘Kill the small insect to get the big insect.’”
Basically, even if they were to succeed with the assault and return, the U.S. was no doubt going to track us down, and once they did, the existence of the mother ship would be discovered, and if it were attacked, we would lose everything. So it would be for the best if just the two in the SPS died. That was our way of thinking. I don’t think anyone expected to come back.
When they were leaving, they were dressed in the uniforms that airplane pilots wore. They took their Japanese sword and food we prepared for them.
On the night of 6 December, I was in charge of the phone connecting the [mother] ship and the SPS. I was talking about maintenance and ordinary things. On the other end, Lieutenant Commander Masaji Yokoyama, the commanding officer of the SPS, spoke, thanked us for the job well done, and things like that. Both of us were matter-of-fact. It was just an ordinary conversation. We weren’t really thinking about death. We were only thinking about carrying out our duties properly.
PACIFIC OCEAN
ONE MILE SOUTH OF OAHU
SUNDAY, 7 DECEMBER 1941
0245 HOURS LOCAL
Once released from their “mother subs,” the skippers of the midget subs tried to find a way into the harbor so they’d be in place around Ford Island when the aerial attack started.
The crews of the midget subs could see the lights of Honolulu through their periscopes and hear big-band jazz music coming from the local radio stations—the same ones whose signals had guided the mother subs to the release point ten miles from the harbor mouth. Getting this far had been relatively easy. Slipping undetected through the anti-submarine net into the anchorage behind or beneath one of the American ships as it entered the harbor presented a much more formidable challenge.
The commander of the five-sub Special Attack Unit, twenty-nine-year-old Lieutenant Commander Naoji Iwasa, had been a Japanese test pilot. He had trained the other nine men and emphasized the importance and seriousness of their task. He hadn’t exactly said that theirs was a suicide mission, but none doubted that it was. “No one intends for us to come back,” Iwasa had told his men. Iwasa, the skipper of the mother ship I-22, was also skipper of the SPS I-22TOU. Iwasa was the oldest of all the crew members, and his crewman was Naokichi Sasaki, an expert kendo swordsman.
Lieutenant Commander Masaji Yokoyama, the skipper of SPS I-16TOU, was assisted by Petty Officer Sadamu Uyeda, a quiet mountain boy.
Skipper Shigemi Furuno of SPS I-18TOU had told his parents that he couldn’t get married because he had to be ready to die at any moment. His crewman was Petty Officer Shigenori Yokoyama.
Ensign Akira Hiro-o, the skipper of S
PS I-20TOU, at twenty-two years old, was the youngest of the midget submariners. Petty Officer Yoshio Katayama, a farm boy, was his crewman and engineer.
Ensign Kazuo Sakamaki was the skipper of SPS I-24TOU, along with crewman Chief Warrant Officer Kiyoshi Inagaki.
At 0342 hours, the minesweeper USS Condor, on patrol just outside the harbor entrance, sighted what appeared to be a submarine periscope following in the wake of the USS Antares as she steamed slowly toward the harbor, waiting for the submarine net to drop at dawn so she could enter. The crew of the Condor immediately broadcast a warning over the radio: “SIGHTED SUBMARINE ON WESTERLY COURSE SPEED FIVE KNOTS.” Alerted by the Condor, the crew of the Antares also spotted the sub and repeated the message. The calls were heard by a PBY reconnaissance aircraft overhead and by the USS Ward, an ancient four-stack destroyer manned by Navy Reservists from the upper Midwest under a brand new captain, Commander William Outerbridge.
Aboard the Ward, Fireman First Class Ken Swedberg, a fresh-faced Navy Reservist from St. Paul, Minnesota, was at his “general quarters” battle station within seconds of the alert. As he peered into the darkness, his first thought was that it had to be one of Hitler’s submarines.
FIREMAN FIRST CLASS KEN SWEDBERG, USN
Aboard USS Ward, Pearl Harbor
7 December 1941
0630 Hours Local
I was a Fireman First Class, which meant I was normally in the boiler rooms. This is what I was trained for. But my job for “general quarters” was topside, up on deck, assigned to a World War I balloon gun designed to shoot down dirigibles.
About one o’clock Saturday afternoon, 6 December, the captain called a “general quarters” drill to test his reserve crew. This was his first drill, and I think he was very wise to do that, as it later proved. We went to battle stations and I manned my three-inch gun up on the bow, right below our main battery, the number-one four-inch gun. We went through our drills and the captain was pleased, so we went back to our regular watches.
War Stories II Page 2