Operation Storm: Japan's Top Secret Submarines and Its Plan to Change the Course of World War II (16 page)

Fujimori’s breakthrough came when he realized two important things: first, they wouldn’t have to destroy all the gates to put the canal out of commission, just the gates of the topmost lock. And second, the best way to destroy the lock gates wasn’t by using just bombs or torpedoes, it was by unleashing the power of Gatun Lake.

Normally, it took 26 million gallons to float a ship 85 feet above the Atlantic.
¹²
All of this water flowed down from Gatun Lake, which sat behind the last set of gates of the topmost lock. If the Japanese could concentrate their forces against destroying the top gate, the gate opening onto Gatun Lake, then a torrential outpouring of water would drain into the Caribbean, destroying the other gates in its path. It was an elegant plan. At this time Gatun was the world’s largest man-made lake;
¹³
it held millions of pounds of water pressure. The
Seiran
attack planes had only to release it.

Launching an aerial torpedo against a lock gate was a risky undertaking. Fortunately, static objects are easier to hit than moving ones, and nothing was more static than a 745-ton lock gate that was closed. With practice, they could learn to hit it accurately, but they’d have to get past the canal defenses first.

The Panama Canal was situated at one of the most strategic locations in the world, and the United States guarded it accordingly. Nearly 40,000 troops were based throughout the canal zone,
¹⁴
and the Atlantic approach was mined. Antitorpedo netting and mine-detecting equipment in each lock made it almost impossible for sabotage to succeed. Major fortifications were located at Colón, Margarita Island, and Toro Point. Fort Sherman, the primary military installation, boasted the largest artillery in the U.S. arsenal,
¹⁵
16-inch cannons comparable to the fabled guns of Navarone. With a range of 25 miles, it was a good bet the 11-gun batteries would prevent any battleship from shelling the canal.

But the greatest risk in 1944 was aerial bombardment. Low-altitude barrage balloons hung over the locks, supplemented by 60 square miles of chemical smoke pots to obscure the canal from the air. Antiaircraft batteries were planted throughout the canal zone, and two long-range radar stations were set up on each coast. Finally, the United States had 634 searchlights to protect the canal from night attack and had built nine airbases and 30 aircraft warning stations, not counting newly constructed bases in Peru, Ecuador, Guatemala, Nicaragua, and Costa Rica.
¹⁶

If that wasn’t enough, a 1,000-mile defense perimeter extended from the canal into the Caribbean and was continually patrolled by U.S. planes and warships. Even if the
I-400
subs got close enough to launch an attack, it was unlikely the
Seiran
could reach the canal without being spotted.

As the weeks passed, Fujimori’s team developed a plan for attacking the Gatun locks. Since ships transited only during the daytime, a dawn attack would be best, when the gates were closed and defenses lax. It also made sense to bomb the canal during the dry season (January through April), when it would take longer to refill Gatun Lake.
¹⁷
Finally, a combination of bombs and aerial torpedoes was proposed to destroy the lock gates.

Interestingly, the
Seiran
were to be abandoned after the mission, and their pilots rescued. This was not a suicide attack, however; the Imperial Japanese Navy wasn’t that desperate.
¹⁸
Everyone would be coming home.

Fujimori reviewed his findings with various NGS officers to receive their endorsement. If anything, they wanted the mission hurried up. Though the final plan would be left to the
Sen-toku
commander, the
attack was set for early 1945.
¹⁹
That meant they had a year to get ready. It wasn’t much time, considering that none of the submarines were complete and that the
Seiran
weren’t even in production, but time was of the essence. And there were other problems.

U.S. submarines had so clamped down on ocean routes that few essential materials were making it to Japan. Steel was particularly in short supply, and naval construction was affected. The
I-400
program was no exception. By October 1943 plans for 13 of the 18
I-400
subs were canceled due to shortages.
²⁰
This left only 5 subs: the
I-400, I-401, I-402, I-403
, and
I-404
, plus the
I-13
and
I-14
.
^‖
The fact that 5 out of 18
I-400
subs survived the cutback signaled the importance of the mission. But it was still a blow to the program.

The rest of 1943 and early 1944 would be spent modifying and test-flying the
Seiran
. The planes had to be ready when the
I-400
subs were deployed in January 1945. The big question though was whether the subs would be finished by then. It was difficult to answer given that they were still on the building ways. Fujimori’s job was to make sure they were finished on time no matter what.

Meanwhile, the
Sen-toku
squad’s future commander was about to undertake the most important assignment of his career.

W
HEN
C
DR
. T
ATSUNOSUKE
A
RIIZUMI FIRST SPOTTED THE
SS
Tjisalak
, the Dutch freighter was 600 miles south of Colombo, Ceylon (Sri Lanka). The 5,787-ton break bulk carrier was traveling unescorted, an invitation to trouble given Ariizumi’s orders to disrupt Indian Ocean supply lines. It was early the morning of March 26, 1944, and the
Tjisalak
was 19 days out of Melbourne. As dawn broke, the day promised to be fair, with light winds and a gentle swell. Fortunately for Ariizumi, the Dutch cargo ship showed no interest in zigzagging to avoid enemy subs.
¹

It must have been a relief to be out from behind a desk. After serving two and a half years on the Naval General Staff and nearly two years as senior staff officer for SubRons 8 and 11,
^*
the
Sen-toku
squadron’s future commander finally had a sub of his own. It wasn’t Ariizumi’s first sub command; that had been the
RO-33
before the war had begun.
^†
But after three staff jobs, he was happy to have a line officer assignment again. Unfortunately, necessity had as much to do with it as choice. The Sixth Fleet was running out of sub captains.

Ariizumi’s new command was the I
-8
, a frontline fleet boat tricked out with everything she needed to wage war against the Allies. A 2,231-ton
Junsen-class
Type 3 submarine,
²
she boasted a floatplane and a dual 5.5-inch gun mount.
³
One five-incher was standard on Japanese submarines, two was unusual. There was no more powerful configuration in the Sixth Fleet.

Ariizumi was familiar with the I-8. He’d served as senior staff officer for her squadron in Penang. It also didn’t hurt that the Imperial Japanese Navy ran in his blood. The firstborn son of a lieutenant commander and a naval accountant,
⁴
Ariizumi had attended Etajima, Japan’s elite naval academy.
^‡
Etajima had a profound effect on him. Both mentally and physically rigorous, it emphasized absolute obedience and left little room for individual initiative. It also made clear that there was no middle ground between victory and defeat, a lesson Ariizumi had absorbed.
⁵

After graduating with Etajima’s fifty-first class, he served his naval apprenticeship aboard a variety of ships, including the aircraft carrier
Akagi
.
⁶
Eventually, he enrolled in submarine school and worked his way up the ladder, including a stint aboard the
I-3
. When he showed promise, Ariizumi was admitted to Japan’s Naval War College,
⁷
where only the top-performing officers were accepted. Attendance virtually guaranteed a senior position at the NGS and eventual command of an IJN warship.

After graduation, Ariizumi was assigned to the First Section, First Bureau of the Naval General Staff. First Section was considered the “brain” of the IJN.
⁸
Responsible for policy and strategic planning, it was a chance for Ariizumi to operate at a senior level where political acumen counted as much as smarts. Though serious in manner and autocratic in style, he had two years to familiarize himself with the labyrinthine workings of the Naval Ministry. Since Japan was already planning for war with the United States, it was an important position.

Ariizumi’s most significant contribution as senior submarine
staff officer was championing the inclusion of five midget subs as part of the attack on Pearl Harbor. They’d been a last-minute addition to the plan.
⁹
Recently perfected, the two-man subs were to secretly navigate the entrance to Pearl Harbor, slip up its channel, and attack the U.S. fleet where it lay at anchor.

Yamamoto was not enthusiastic about the plan.
¹⁰
First, he insisted that all midget crews be rescued when the mission was over. Then he worried the midget subs would accidentally betray his surprise and demanded they not attack until after the aerial bombardment had begun.

Ariizumi waited all day December 8 for news of the midget sub attack, but Yamamoto’s worst fears had been realized. At least one midget sub was detected before the aerial attack commenced. Though the Japanese maintained the element of surprise, Ariizumi’s “special attack group” had made a poor showing. Only one midget sub penetrated the inner harbor and fired a torpedo. The rest either got lost or were discovered and sunk. Nine of the subs’ ten crewmen were killed in the attack. The tenth was captured along with his sub, making him America’s first Japanese prisoner of war.

Despite the debacle, Ariizumi lobbied to credit one of the midget subs with sinking the USS
Arizona
(BB-39).

“The world will scoff!” Mitsuo Fuchida, the leader of the aerial attack against Pearl Harbor, responded.
¹¹

It was obvious that a midget sub couldn’t have sunk the
Arizona
, since she was shielded from torpedoes by another ship. This didn’t stop Ariizumi, and a midget sub was credited with sinking the U.S. battleship. Ariizumi succeeded in having nine of his dead crewmen promoted twice in rank and enshrined as war gods at Yasukuni temple. It was an amazing accomplishment considering no one really knew how the midget subs had performed.

After the Pearl Harbor attack, Ariizumi became involved with Yamamoto’s
I-400
subs. As senior submarine staff officer, he was responsible for shepherding them through the naval bureaucracy. Some people considered him the father of the
Sen-toku
squadron, an appellation he was proud of if not fully deserving of. Now, two
years later, he was out from behind a desk and ready to do some torpedoing of his own.

Ariizumi launched his first “fish” when the
I-8
was a mile away. The torpedo struck the
Tjisalak
’s port side, just aft of her bridge. The freighter was rocked by a huge explosion, followed by a geyser of spray. Moments later the ship took on a sickening list. As the
Tjisalak
heeled over 20 degrees, Ariizumi launched a second torpedo. The situation deteriorated rapidly after that. The
Tjisalak
settled so quickly,
^§
12
her main deck was awash in no time.
¹³
Unable to send out a distress signal, the captain gave the order to abandon ship.

The last to leave the sinking freighter were her gun crew, who jumped into the ocean only when the water reached their ankles. Ariizumi had mistaken their cannon fire for depth charges and had kept the
I-8
submerged.
¹⁴
But once the
Tjisalak
went down, there was nothing left to fear.

Most times an I-boat slipped away after sinking an enemy ship. It was a bad sign if one lingered. When Ariizumi surfaced his sub, he spotted lifeboats in the water and decided to investigate.
¹⁵
Once the sail cleared the waves, he scrambled onto the bridge and ordered the machine guns manned. The
I-8
’s 25mm antiaircraft guns had been swapped out for 7mm guns while the sub was in Kure.
¹⁶
The change had surprised the crew, which wondered why anyone would want to downgrade their armament.
¹⁷

Ariizumi turned to Lieutenant Honda, his executive officer, and told him to muster all off-duty personnel on deck.
¹⁸
Then speaking to his translator, Jiro Nakahara, Ariizumi directed him to address the lifeboats.

“Where’s the captain?” Nakahara called using a megaphone.

The
Tjisalak
’s crew stared in silence.

“Where is your captain?”

When there was no response, Nakahara tried again:

“Where-is-the-captain!”

Finally, the
Tjisalak
’s master, Capt. C. Hen, stood in his lifeboat and shouted: “I am the captain! What do you want?”

“You must come alongside and report!”
¹⁹