Operation Storm: Japan's Top Secret Submarines and Its Plan to Change the Course of World War II (42 page)

It was up to the
I-401
to see that it wasn’t needed.

T
HE DAY AFTER THE
I-401
LEFT FOR
U
LITHI
, A
ICHI
’
S
N
AGOYA
facility was bombed again, causing extensive damage. It was the second such attack in July, so when Aichi rolled its twenty-eighth
Seiran
out the hangar door, it was its last.

Aichi wasn’t alone in this problem. The entire Japanese war machine had ground to a halt. The U.S. sub embargo was squeezing Japan for all she was worth. Meanwhile, Admiral Halsey’s armada was closing in.

Ariizumi knew his special attack force was surrounded, but he had two tricks he was counting on to escape undetected. The first was the snorkels he’d installed in May. The longer they helped him hide beneath the surface, the better they could avoid radar. The second trick was the two special anechoic coatings on the outside of each sub designed to improve their stealth factor. The U.S. Navy didn’t need snorkels or stealth coatings, but Ariizumi believed them to be one of the few advantages he possessed besides the courage of his crew.

By the time the
I-401
left Ominato, so much of Japan’s sub force had been destroyed that SubRon 1 was the Sixth Fleet’s only full-strength unit. Operation Storm was a brave undertaking, given its limited chance for success. No sacrifice was too great to protect the homeland.

After nearly being sunk in Tsugaru Strait, the
I-401
spent most of the next two days underwater. The U.S. Navy wasn’t the crew’s only source of fear. Japanese patrol craft could easily mistake a
Sen-toku
sub for American and bomb it, so Nambu kept his sub submerged until he was safely out of range of Japan. It wasn’t until
July 25 that he felt secure enough to surface in daylight. He then headed south at 19 knots, to make up for lost time.
¹

The attack plan was straightforward. The
I-400
and
I-401
would proceed independently of each other, minimizing the chance of both subs being sunk. The
I-401
would navigate south past Saipan, Guam, and Truk.
²
She would then meet up with the
I-400
on August 12 near Ponape Island,
³
where they would review the
I-13
’s and
I-14
’s aerial intel. The two subs would then proceed to the southern waters off Ulithi, to rendezvous one last time before launching their attack.
⁴
It was a convoluted route, made necessary by U.S. dominance of the Pacific. It would take approximately three weeks to reach Ulithi. If all went well, they’d be ready to strike in mid-August.

Meanwhile the
I-400
managed to exit the Tsugaru Strait without being shelled. Kusaka knew the only way to avoid Halsey’s Third Fleet was to head east,
⁵
so he raced to put Japan behind him.

Life aboard the
I-400
was routine at first. Kondo even found time to play a Ouija-like game called Kokkuri-san using three
hashi
(chopsticks) tied together in a tripod. After asking a question, the spirit of a fox assisted in moving the
hashi
until they pointed to various
kanji
spelling out an answer. Senior officers disapproved of the game, believing it superstitious, but the younger officers were fascinated by it.

“Are we going to sink?” Kondo asked.

“No,” the fox responded.

“Will we be attacked?”

“No, you are going home soon.”

The answers were puzzling. Nevertheless, Kondo was relieved to hear they’d survive.
⁶

Once the
I-400
cleared the Japanese mainland, Kusaka had to decide how much to travel underwater. Surface cruising was fastest but risked discovery. Traveling underwater was safer but cost precious time. Nambu faced the same dilemma. But the question took on even more importance after both subs encountered a typhoon.

Nambu did his best to power through the maelstrom, but the
waves rocked his boat so violently, his crew were thrown from their berths.
⁷
At one point, the sub’s exhaust pipe was swamped, creating so much back pressure, the relief valves sounded like a cannon going off. Fearing the
Seiran
would be damaged, Nambu was forced to submerge.
⁸

It’s amazing how calm the ocean is 50 feet beneath the waves, and the
I-400
subs took full advantage of the peace and quiet.
⁹
When both subs finally surfaced, they found their
Seiran
unharmed. Unfortunately, they’d also lost valuable time.

A
WEEK LATER
Nambu moved through the
I-401
careful not to bump his head. It may have been the world’s largest submarine, but he still had to duck when climbing through a hatch. That was the drawback of being six feet tall. Nambu spent most of his time in the control room, and since the
I-401
was Ariizumi’s flagship, the commander spent his time there as well.

Command and control authority was sacrosanct aboard a submarine. The captain issued orders, and his executive officer made sure the crew carried them out. Nambu was captain of the
I-401
, so he gave the commands. But Ariizumi’s presence subtly undermined Nambu’s authority. The
I-401
’s officers knew that many of the orders they received from Nambu originated with their squadron commander—as far as Nambu was concerned, probably too many. It also didn’t help that Nambu was the most junior of Ariizumi’s four sub captains. Additionally, Nambu was the only
Sen-toku
captain who had not served in Penang with Ariizumi. Even if Nambu had served in the Indian Ocean, it’s doubtful Ariizumi would have changed his command style. It wasn’t his nature.

The main problem was chemistry. It wasn’t just that their styles clashed; the two men’s personal philosophies were fundamentally different. Ariizumi was a task-driven martinet, focused solely on the mission. Nambu, however, could see the big picture. Whereas Ariizumi wouldn’t think twice about sacrificing his men in pursuit of a goal, Nambu had his crew’s welfare at heart. It wasn’t easy for a broad-minded man such as Nambu to serve under a narrow-minded
one like Ariizumi. But Ariizumi was Nambu’s commanding officer. He had to ignore the differences.

Nambu grasped the ladder in the control room and climbed into the conning tower. The
I-401
’s sonar operator was reporting numerous contacts, so Nambu raised the sub’s periscope to have a look around. They were approximately two weeks out from Ominato, but as Nambu looked through the eyepiece, he was shocked by what he saw.

There were so many American warships heading west toward Japan, the sight was overwhelming. And the armada was so confident, it didn’t even bother to dim its lights at night.
¹⁰
The size of the enemy’s fleet gave Nambu pause. Could Japan really expect to defeat such superior numbers?
¹¹
Given the countless U.S. warships he saw, Operation Storm threatened to become meaningless.

Normally, Nambu didn’t think in defeatist terms, but what was the point of dying if it would have a negligible impact against the American Goliath? Every one of his men was prepared to lay down his life, himself included.
¹²
But from what Nambu saw, the U.S. fleet could easily absorb their blow and still invade Japan. Nambu was a patriot, and he had no intention of standing down. Still, a seed of doubt had been sown. He shuddered to think what awaited his countrymen.

The enemy armada forced the
I-401
to remain underwater. With a submerged speed of only two to three knots, the sub fell farther behind schedule. Nambu worried they’d miss their rendezvous if they didn’t travel on the surface,
¹³
but the farther south they moved, the more enemy ships they encountered.

Ariizumi was concerned for a different reason. He feared the
I-401
would be discovered. Discovery would mean death, so to avoid putting the mission at risk, Ariizumi decided to make a detour. The detour he proposed involved sailing east of the Marshall Islands before rendezvousing with the
I-400
and heading to Ulithi.
¹⁴
Naturally, Nambu protested the change. The detour would significantly lengthen their journey, costing them valuable time. Importantly, the warships they saw were probably coming from Ulithi. The sooner they attacked the island’s anchorage, the more ships
they could sink. Finally, a detour didn’t necessarily mean they’d avoid enemy contact, particularly since the Americans were everywhere. Nambu argued to maintain course.

But Ariizumi was as conservative as he was overbearing. Nambu found it maddening, though he hid his irritation. Arguing with Ariizumi never did any good. The pint-size commander just dug in his heels. After failing to change Ariizumi’s mind, Nambu ordered a new course. The detour meant a new rendezvous location, which would have to be radioed to the
I-400
. It’s doubtful Nambu felt comfortable with the plan. Then again, he had no choice. Those were the rules of command.

N
AMBU WASN
’
T ALONE
in his suffering. Cdr. Tsuruzo Shimizu, captain of the
I-14
, had nearly lost his sub from a grueling depth charge attack that lasted a day and a half. Shimizu’s survival would add to his reputation as a lucky skipper. The
I-13
, however, had not been so fortunate. The sub had still not arrived at Truk, even though she’d left Ominato six days ahead of the
I-14
.
¹⁵
Of more concern, nothing had been heard from her since July 16, five days after she’d departed. Operation Storm depended on the
I-13
and
I-14
’s reaching Truk, getting their
Saiun
into the air, and reporting on conditions at Ulithi. It would be senseless to attack the anchorage if American carriers weren’t there. Nobody wanted to repeat the mistakes of Pearl Harbor.

Nambu feared for the
I-13
’s safety, and with good reason. ULTRA intelligence had not only been tracking the
I-13
and the
I-14
since their refueling stop at Chinkai, it had more than 28 mentions of Ohashi’s sub in its contact logs.
¹⁶
In other words, once Nambu radioed the new rendezvous coordinates to the
I-400
, the U.S. Navy would be there to greet them. They were sailing straight into an ambush.

T
HE
I-14
ARRIVED AT
T
RUK ON
A
UGUST
4,
¹
AND FOR THE FIRST
time in three weeks, her crew set foot on dry land. Shimizu was happy to have escaped the Allied dragnet and immediately sent a message to Sixth Fleet headquarters relaying his arrival.
²
Unfortunately, Truk was not what he’d expected.

What had once been the empire’s premier forward naval base was now a shambles. The harbor was filled with sunken ships, and the skeletons of burned out planes littered the airfield. Those who had known Truk in its glory days could only weep at its destruction.
³
If this was what an island looked like when the enemy bypassed it, what was in store for Japan?

Under the circumstances, Shimizu’s arrival was nothing short of miraculous. The
I-14
should have been lying at the bottom of the ocean, a gaping hole blown in her side, but Shimizu had run the Allied gauntlet. Ariizumi’s snorkel may have had something to do with it; still, Shimizu wasn’t just lucky—he was competent as well.

As soon as the
I-14
docked at Truk, her crew sprang into action. First they unloaded the two
Saiun
aircraft. Next, the planes were assembled and flown over Ulithi.
⁴
That same day Ariizumi received orders for another mission.
⁵
It seemed premature to plan a second attack before the first one had launched, but the Imperial Japanese Navy was running out of combat units. After the
I-400
and
I-401
sent their
Seiran
against U.S. carriers, the
Sen-toku
force was to travel to Hong Kong and pick up a new ten-plane squadron.
⁶
After refueling in Singapore, they would then return to Ulithi for
a second attack.
^*
7
A contingent from the 631st had already been dispatched by submarine to help with preparations.
⁸

Given Ulithi’s heavy security, the odds the
I-401
would survive the first mission were slim at best; a second attack had only a one-in-a-million chance. It wasn’t being outnumbered that put them at risk as much as a top secret U.S. intelligence operation called ULTRA, which had broken the IJN’s naval codes. The IJN’s high command refused to believe their codes had been compromised, but U.S. naval intelligence knew the whereabouts of virtually every remaining Japanese submarine. Fortunately, Ariizumi’s sub captains had maintained radio silence since leaving Ominato.
⁹
There were a few exceptions, such as Shimizu’s message confirming his arrival at Truk. But by and large, the
Sen-toku
subs were absent from the airwaves, which made it harder to find them.