THE LAST GOOD WAR: A Novel (29 page)

“The weather ships and subs—they communicate with each other?” Lewis Powell wanted to know.

Anna was slow in responding. She had never heard that soft, mellifluous Southern accent before.

Yvonne picked up the slack. “Yes, I think so.”

“Two-way traffic? The submarines also send messages back to the weather ships?”

Yvonne paused. “Again, I think so.” She obviously wasn't sure.

“I wonder....” Powell stopped.

Denniston had been nibbling at his lunch, apparently lost in another world. Now, he came to life.

“Good question. And the right question's half the game. When U-boats talk to weather ships, they
must
use only three wheels. It can't be all four. The weather ships—with only three wheels—wouldn't be able to understand. Maybe we can use the subs' messages to figure out how those first three are set. Once we do, we'll have a leg up on the fourth."

Denniston passed the idea on to Hut 6. They indeed found sub-to-weather ship traffic. The 17 days needed to read submarine messages was reduced. But not enough. A real-time decoding of Shark would have to await another lucky break.

30 October, 1942. Port of Alexandria, Egypt.
Aboard the Destroyer,
HMS Petard
.

C
ommander Mark Thornton looked down over the bow of
HMS Petard
. Workmen had been scurrying all night to complete the installation of a new “hedgehog” antisubmarine system—a set of grenades that could be fired forward. The destroyer would not have to pass over the sub before attacking, the way it would with depth charges.

An urgent message came from the radio room. Three other British destroyers were stalking a U-boat; they had made several depth-charge attacks in the past four hours. They had the sub trapped against the Mediterranean coast, near Haifa, but had not been able to sink it. Could Thornton help?

He certainly could.

He had lived for this chance, keeping his men on constant alert for U-boats. At times, his judgment was overwhelmed by his passion for the hunt. He would climb to the crow's nest, and Ulysses-like, strap himself to the mast, awaiting the siren call of a submarine.

The remaining workmen were hustled off, and the
Petard
was soon under way. Even at full speed, it would take eight hours to join the action.

Aboard U-559, men were grimly silent. They had known the perils when they joined the elite submarine service. But, for many, this was their first taste of the terrors of depth charges—the haunting fear that, at any instant, their vessel might be crushed into a steel coffin. Every time the sub tried to break out toward open water, it was rocked with depth charges. The last were very close indeed; two of the younger men cried out in panic. Several small leaks appeared in the overhead piping; the slow drip, drip mingled with the sweat and stress on the captain's face. The captain ordered oil and debris ejected from the aft tubes. He hoped the attackers were bored, would chalk up a victory when they saw the oil slick, and go away. He directed his sub, dead slow, back toward the coast and let it settle gently toward the bottom. The leaks were under control.

The pings from the destroyers' sonar shattered the silence, but the attackers could not distinguish the sub from the surrounding rocks. The waiting game had begun.

It was a grim contest, favoring the destroyers. They could breath. The sub would have to come up for air within 14 hours. The word was quietly sent around. They would wait until 02:00—the time when the enemy above would be least alert—and make a dash. Every man knew: this time would be the final throw of the dice. They would press on, either to the safety of the open sea or to their destruction.

At 21:10, the hydrophone operator had an urgent report. He detected a fourth ship; another destroyer sent to block their escape? The fourth ship was still far away. But its propellers were thrashing; it was approaching fast.

The captain's reaction was immediate. No time to waste; they couldn't wait until 02:00. He ordered full speed southward, along the coast, and then westward toward deeper waters.

A destroyer's signal lamp flashed, informing
Petard:
the sub is headed south. Block our southern flank.

As they closed, Thornton was grateful for his new gadget; the sub was turning and diving, obviously expecting an attack. Thornton ordered the hedgehog fired, and a pattern of grenades flew forward. He counted the seconds; the sea erupted in front of his ship. That should mean a hit. Unlike a depth charge, the grenades were designed to explode only on contact. But once one went off, the concussion would set off the rest.

He wanted to give the sub as little chance as possible. As they passed over the roiling sea, depth charges rolled off the stern. He ordered a hard turn to starboard, returning for a second attack.

Before the
Petard's
turn was completed, moonlight glinted off the snout of the U-559 as it broke the surface. Its hatches opened and the crew began to take to dinghies. The destroyer drew up, preparing to take on survivors as its searchlight illuminated the sub.

A shout came from the bridge: Boarding crew! Boarding crew! A young officer and two ratings stripped. The mission had been drilled into them: they must get code equipment off the sub! Drilled, and practiced. On one training exercise, Thornton had ordered the boarding party to jump into a treacherous, stormy sea and swim around the ship; they were saved from downing only by the presence of a senior officer, who persuaded Thornton to withdraw his order.

The officer leading the boarding party was about to leap into the sea, when he felt a hand restraining his arm.

“Not you, mate. You're married.” Lieut. Anthony Fasson was speaking. He too, was stripped to his skivvies. Fasson and the two other men dove into the Mediterranean.

By now, the U-boat crew were climbing rope ladders to the deck of the destroyer. Swimming vigorously in the opposite direction, the three British figures soon reached the sub. Fasson and Able Seaman Grazier were quickly down the hatch, while the third man, as ordered, stood on the conning tower.

The two men found the wireless room—or more precisely, the wireless cubbyhole. Fasson handed rotors and codebooks to Grazier, ordering him to take them to the conning tower and return as quickly as possible. He began to disconnect what apparently was a coding machine. The water was rising around his ankles, adding urgency to his task.

Meanwhile, four other men set out for the sub, using one of the German dinghies. As they approached, the nose of the sub settled lower the water.

Suddenly, it was gone. As the dinghy arrived, it found only one survivor, treading water and holding a codebook and round discs above his head.

For their heroism, Fasson and Grazier were posthumously awarded the George Cross.

The new material was quickly sent to Bletchley Park. With it, and with the new machines coming on line, Hut 8 finally succeeded in breaking Shark.

When they did, they were in for a shock.
B-Dienst
had been reading the Admiralty's messages to convoys. Not only had the Allies been unaware of the position of U-boats; the U-boats had known where to look.

With the roles reversed, the hunters now became the hunted.

15 May, 1943. 10:00 hrs. Kriegsmarine Headquarters.

A
dmiral Dönitz sat sullenly staring at the large scorekeeping charts on his wall. The first showed U-boat sinkings of Allied ships, revealing a sharp decline in April. This was not surprising. The British had changed their naval code; the Admiral could no longer guide his submarines to their prey.

It was the second chart that alarmed him. During the previous week, no fewer than thirteen submarines had been sent to the bottom. How could that be? Was it possible that the enemy had scored a double success, not only denying him access to their messages but also reading the Kriegsmarine's traffic?

He had asked this question before and received soothing answers. The Enigma simply could not be broken. The wheel settings were changed every 24 hours. Even if the enemy captured one of the new four-wheeled machines, they would need years to figure out a single setting. The submarines would rust away before they could be sunk.

But the question nagged. The fortunes of the undersea raiders had shifted so suddenly. He asked his aide to contact Oberst (Col.) Jurg Lindemann at
B-Dienst
on the secure land line.

“Lindemann? I want another urgent review of Enigma. Our submarine losses have become unbearable, 23 in the past two weeks. Can the enemy be reading our signals?”

“Very unlikely, sir. We're overwhelmed here, trying to crack the new British naval code, but I could spare a few people for another look. Could you tell me something about our losses—perhaps going back over the past few weeks? Anything specific to suggest the enemy is listening?”

“The six lost in the Bay of Biscay certainly do—sunk before they even reached open waters. Before, we've never lost more than one or two per month in that area. Seems the enemy planes know where to look.”

“Hmmm. Sounds as though another review is in order. I'll put several of my best people on it.”

Lindemann looked over at the small sign framed on his wall: 500 billion billion. He wondered.

Dönitz concluded: “I'll send Capt. Hauser to help. He'll have details on our losses.”

15 May, 1943. 15:00 hrs.
B-Dienst
Headquarters.

W
hen Hauser arrived, the meeting on Enigma security was already in progress; he was ushered in immediately. Lindemann invited him to report on recent U-boat losses.

“Unfortunately, since you spoke to Admiral Dönitz this morning, we've lost another sub—the 24th in the past two weeks.

“Nine were sunk when they located a convoy and began to radio other subs, calling them to form a wolf pack. Their transmissions ended abruptly, indicating they were under attack.

“Seven were sunk in the Bay of Biscay, before they reached the Atlantic.

“We have no information on the other eight; they simply vanished. Five failed to report after they had been on the surface at night, charging their batteries.”

Hauser paused to let the numbers sink in.

Wilhelm Stumpff had been working on the Enigma for six years; he was responsible for the introduction of the fourth wheel. He exuded supreme confidence in his creation.

“I don't think Enigma can be broken. But, for the sake of argument, let's suppose it could. We still wouldn't have any explanation for the nine subs lost while sending messages. U-boats are given areas to patrol, not precise locations. Even if the enemy could read Enigma traffic, they wouldn't know exactly where to look. And, even if they did know exactly where to look,
why
would so many U-boats be attacked right in the middle of their radio messages? There's only
one
possible explanation.
The enemy must have some new technology.
They've found some way to locate U-boats by their radio transmissions.”

“We've considered that,” responded Hauser. “But even if they've developed much more powerful receivers in Iceland and Britain, it would be impossible to triangulate precisely and quickly enough for an attack.”

“Impossible? Perhaps, sir,” responded Stumpff. “But that's the thing about new technology. We
don't know
what it will do.”

“Exactly,” Hauser countered. “And that argument cuts both ways. You say it's impossible for the enemy to break Enigma. Perhaps they've developed new technology to do just that.”

Stumpff ignored the jab and continued his argument. “Consider next the five lost on the surface at night. We
already
know what might be responsible. Recall our intercept two months ago—long-range bombers being equipped with radar and powerful searchlights. Unfortunately, it seems that this weapon is effective. The poor devils on the U-boats,” he added, showing empathy for the naval officers in the room. “I don't know which would be worse—to be depth charged, or to be on deck at midnight when a blinding searchlight suddenly flashes on.”

Hauser was scarcely mollified. “Granted, they may have much better radar. But the American planes apparently knew where to look. Furthermore, think of what happened early last year. We introduced the fourth wheel; then we sank many more ships. What does that suggest? The enemy had been listening in, but were stopped by the new four-wheel Enigma. If they could read the old three-wheeled machine, isn't it possible that they've now broken the new four-wheeled version?”

“Not necessarily,” Stumpff countered. “There's a simpler explanation for our successes early last year. That's when
we
broke the British naval code.

“But I also grant a point,” he continued. “The Bay of Biscay losses are hard to explain. But which is more likely: a breaking of Enigma, or some new enemy gadget? Bombers with the new radar might be the culprit, or some other new technology. For example, they may be locating U-boats with airborne infrared detectors. For reasons we've been over repeatedly, such technology is much more plausible than a breaking of Enigma.”

Within a week, the group presented a preliminary report, preliminary only because Hauser insisted on further study. Once more, the report reassured Dönitz. Enigma could not be broken. The sudden change in fortunes was most likely the result of new enemy technology. But
B-Dienst
would keep an open mind; they would continue to look for weaknesses in Enigma.

Admiral Dönitz could not wait. At the end of May, with U-boat losses averaging two per day, he ordered his wolf packs withdrawn from the Atlantic. The Allies had won the second battle of the Atlantic.

There would be no third round. By early June, a prototype American bombe was running. An early problem—rotors overheating and warping because they were spinning at 2,000 rpm—had been solved. But the machine ran so fast that the rotors could not be stopped immediately when a decryption was registered. To deal with this problem, the machine had a novel and ingenious feature: it automatically rolled the rotors back to the decryption setting.