by Erik Larson
Schwieger’s boat was 210 feet long, 20 feet wide, and 27 feet tall. Viewed head-on, it might have seemed to offer its crew a comfortable amount of living space, but in fact the portion occupied by the men was only a cylinder down the center. Much of the boat’s apparent bulk consisted of giant tanks on both sides of the hull, to be filled with seawater when diving and to be emptied when surfacing. The space in between was crammed with berths for three dozen men, a kitchen, a mess room, a cubicle for the wireless operator, a central control room, two 850-horsepower diesel engines, tanks for 76 tons of diesel fuel, two 600-horsepower electric engines and the massive array of batteries that powered them, plus storage for 250 shells for the U-boat’s sole deck gun and space for storing and handling seven torpedoes, known formally as “automobile torpedoes.” The boat had two torpedo tubes in the bow, two in the stern. Linking all this apparatus was an array of pipes and cables as densely packed as the tendons in a human leg. “More dials and gauges than one might ordinarily see in a lifetime,” one crew member said. Schwieger had his own tiny cabin, with an electric light over his bed.
Unlike large surface craft, a U-boat came to reflect the character and personality of its commander, as though the boat were a suit of steel tailored just for him. This arose from the fact that while on distant patrol the captain received no orders from superiors and had more direct control over his own men than would, say, an admiral aboard a flagship, with a fleet of ships and thousands of men under his command. There were cruel boats and chivalrous boats, lazy boats and energetic boats. Some captains made no attempt to save the lives of merchant seamen; others went so far as to tow lifeboats toward land. One U-boat commander sent the captain of a torpedoed ship three bottles of wine to ease the long row ashore.
Under U-20’s previous commander, Otto Droescher, the boat attained a reputation for daring. On one cruise, in September 1914, Droescher and another commander took their submarines into the Firth of Forth, the estuary off Edinburgh, Scotland, and sailed as far inland as the Forth Bridge, hoping to attack British warships anchored at the navy base at Rosyth, just beyond the bridge. The boats were spotted, however, and fled back to the North Sea.
On another patrol, the next month, Droescher became the first U-boat captain to circle all of Britain. He had sailed first into the English Channel, via the Strait of Dover, where he had encountered vigorous antisubmarine patrols. Gauging the strait as too dangerous for his return voyage, he traveled north instead, along the west coasts of England and Ireland and around the northern tip of Scotland, thus further demonstrating the range and endurance of U-boats. Germany kept the feat a secret.
Schwieger became captain of U-20 in December 1914, and within a short time the boat gained further notoriety, now for ruthlessness. On January 30, 1915, while patrolling off the coast of France, Schwieger sank three merchant steamers without warning. During that same cruise, he took his boat into the estuary of the Seine itself, though bad weather and fog forced him to remain submerged for 111 of 137 hours. On February 1, he fired a torpedo at a large ship painted white and marked with large red crosses, the hospital ship Asturias. He missed. But the attempt was considered a new low in German callousness. Even his superiors seemed surprised.
Yet among his peers and crew Schwieger was known for his kindness and good humor and for maintaining a cheerful atmosphere aboard his submarine. “She was a jolly boat, the U-20, and a kindly boat,” said Rudolph Zentner, one of U-20’s junior officers, in an interview with Lowell Thomas, for his 1928 book, Raiders of the Deep. Zentner attributed this wholly to Schwieger. “If you want a good and pleasant boat, you must have a good and pleasant skipper.” Schwieger was the son of a long-established Berlin family, well educated, poised, urbane. “He was the soul of kindness toward the officers and men under him,” Zentner said. “His temperament was joyous and his talk full of gaiety and pointed wit.”
Baron von Spiegel, Schwieger’s friend, said of him, “He was a wonderful man. He couldn’t kill a fly.”
Schwieger set the tone for life aboard U-20 early in his tenure. The boat was ordered to leave on patrol on Christmas Eve, 1914, a depressing time to be going to sea and to war. It was Zentner’s first cruise. The boat was assigned to patrol the Heligoland Bight. The next day, Christmas—the first Christmas of the war—the crew awoke to a brilliant December morning, with bright sun, “frosty air,” and a calm sea in its winter hue of blue-black. U-20 remained on the surface throughout the day, the better to watch for targets. In clear weather like this, the smoke from a steamer’s funnels could be spotted twenty miles off. The lookouts saw nothing all day. “Apparently the enemy was at home spending Christmas as a Christian should,” said Zentner.
That night, Schwieger ordered a dive to the sea bottom, 60 feet below the surface. He chose a spot where his charts indicated sand, not rock. For a time everyone was silent, listening as always for sounds of dripping or flowing water. The crew monitored gauges that measured interior pressure, keeping watch for the kind of sudden increase that might indicate a high volume of water penetrating the crew compartment. The refrain “All is tight” was relayed from bow to stern.
Spending the night on the ocean floor was common practice for U-boats in the North Sea, where depths rarely exceeded the maximum allowable for submarines. On the bottom, Schwieger and his crew could sleep without fear of being run over in the dark by a steamer or stumbling across a British destroyer. It was the one time a U-boat captain dared undress for bed. But on this particular night, Schwieger had something in mind other than sleep. “And now,” Schwieger said, “we can celebrate Christmas.”
A wreath was hung at one end of the mess room. The men piled food on the table. “It all came out of cans, but we didn’t mind that,” Zentner said. Schwieger and U-20’s three other officers usually dined by themselves in a small officer’s dining area, but now they joined the crew, thirty-six men in all. They spiked their tea with rum. “I lost count of the number of toasts that were drunk,” Zentner said.
Schwieger stood and gave a little speech, “and a jolly ovation it was,” said Zentner. Then came music. “Yes,” Zentner said, “we had an orchestra.” One man played a violin, another a mandolin. A third—a squat fisherman with a giant flaring red beard—brought out his accordion. He looked like a gnome and could neither read nor write but apparently had a certain appeal to the opposite sex, for twice Schwieger received letters from women demanding that he allow the sailor to go on leave to marry them. No effective means yet existed that allowed surface ships to track a submarine underwater, so no one aboard took much care about noise. The trio “played with soul,” Zentner said, especially the accordionist. “His little eyes were half closed with ecstasy, and his bearded mouth was curved with a grin that was like the crescent of the moon.”
The music and drinking went on into the night; the sea outside was cold, black, and impenetrable.
UNDER SCHWIEGER, U-20 had at least one dog aboard. At one time, it had six, four of them puppies, all dachshunds, the unexpected product of an attack off the coast of Ireland.
On that occasion, following cruiser rules, Schwieger chased and stopped a Portuguese ship, the Maria de Molenos. After waiting until its crew got away, he ordered his gun crew to sink the vessel. This was his favored mode of attack. He saved his few torpedoes for the best and biggest targets.
His gun crew was fast and accurate, and fired a series of shells into the freighter’s waterline. Soon the ship disappeared from view, or, as Zentner put it, “settled down for her bit of vertical navigation.”
Amid the usual debris left adrift on the surface, the men spotted a cow, swimming, and something else. The bearded accordion player saw it first and shouted, “Ach Himmel, der kleine Hund!”
He pointed to a box. A tiny head and two paws protruded over its edge. A black dachshund.
U-20 approached; the crew lifted the dog aboard. They named it Maria, after the sunken freighter. They could do nothing for the cow, however.
U-20 already
had a dog aboard, a male, and in short order Maria became pregnant. She bore four puppies. The accordion player became the dogs’ caretaker. Deeming six dogs too many for a U-boat, the crew gave three puppies away to other boats but kept one. Zentner slept with one in his bunk, next to a torpedo. “So every night,” he said, “I slept with a torpedo and a puppy.”
That Schwieger was able to conjure so humane an environment was a testament to his skill at managing men, because conditions in a U-boat were harsh. The boats were cramped, especially when first setting out on patrol, with food stored in every possible location, including the latrine. Vegetables and meats were kept in the coolest places, among the boat’s munitions. Water was rationed. If you wanted to shave, you did so using the remains of the morning’s tea. No one bathed. Fresh food quickly spoiled. Whenever possible crews scavenged. One U-boat dispatched a hunting party to a Scottish island and killed a goat. Crews routinely pillaged ships for jam, eggs, bacon, and fruit. An attack by a British aircraft gave one U-boat’s crew an unexpected treat when the bomb it dropped missed and exploded in the sea. The concussion brought to the surface a school of stunned fish.
The crew of U-20 once scavenged an entire barrel of butter, but by that point in the patrol the boat’s cook had nothing suitable on hand to fry. Schwieger went shopping. Through his periscope he spotted a fleet of fishing boats and surfaced U-20 right in their midst. The fishermen, surprised and terrified, were certain their boats would now be sunk. But all Schwieger wanted was fish. The fishermen, relieved, gave his crew all the fish they could carry.
Schwieger ordered the submarine to the bottom so his crew could dine in peace. “And now,” said Zentner, “there was fresh fish, fried in butter, grilled in butter, sautéed in butter, all that we could eat.”
These fish and their residual odors, however, could only have worsened the single most unpleasant aspect of U-boat life: the air within the boat. First there was the basal reek of three dozen men who never bathed, wore leather clothes that did not breathe, and shared one small lavatory. The toilet from time to time imparted to the boat the scent of a cholera hospital and could be flushed only when the U-boat was on the surface or at shallow depths, lest the undersea pressure blow material back into the vessel. This tended to happen to novice officers and crew, and was called a “U-boat baptism.” The odor of diesel fuel infiltrated all corners of the boat, ensuring that every cup of cocoa and piece of bread tasted of oil. Then came the fragrances that emanated from the kitchen long after meals were cooked, most notably that close cousin to male body odor, day-old fried onions.
All this was made worse by a phenomenon unique to submarines that occurred while they were submerged. U-boats carried only limited amounts of oxygen, in cylinders, which injected air into the boat in a ratio that varied depending on the number of men aboard. Expended air was circulated over a potassium compound to cleanse it of carbonic acid, then reinjected into the boat’s atmosphere. Off-duty crew were encouraged to sleep because sleeping men consumed less oxygen. When deep underwater, the boat developed an interior atmosphere akin to that of a tropical swamp. The air became humid and dense to an unpleasant degree, this caused by the fact that heat generated by the men and by the still-hot diesel engines and the boat’s electrical apparatus warmed the hull. As the boat descended through ever colder waters, the contrast between the warm interior and cold exterior caused condensation, which soaked clothing and bred colonies of mold. Submarine crews called it “U-boat sweat.” It drew oil from the atmosphere and deposited it in coffee and soup, leaving a miniature oil slick. The longer the boat stayed submerged, the worse conditions became. Temperatures within could rise to over 100 degrees Fahrenheit. “You can have no conception of the atmosphere that is evolved by degrees under these circumstances,” wrote one commander, Paul Koenig, “nor of the hellish temperature which brews within the shell of steel.”
The men lived for the moment the boat ascended to the surface and the hatch in the conning tower was opened. “The first breath of fresh air, the open conning-tower hatch and the springing into life of the Diesels, after fifteen hours on the bottom, is an experience to be lived through,” said another commander, Martin Niemöller. “Everything comes to life and not a soul thinks of sleep. All hands seek a breath of air and a cigarette under shelter of the bridge screen.”
All these discomforts were borne, moreover, against a backdrop of always present danger, with everyone aware they faced the worst kind of death imaginable: slow suffocation in a darkened steel tube at the bottom of the sea.
On one of U-20’s patrols, this prospect came to seem all too real.
IT WAS EARLY in the war, when U-boat commanders and British defenders alike were developing new tactics to deploy against each other. Schwieger was scanning the sea through his periscope when he spotted two buoys ahead, spaced far apart. They had no obvious purpose, and their presence in that area of sea was unexpected.
Schwieger saw no danger. He called out, “Two buoys sighted. Keep exact depth.” The boat continued forward at “periscope depth,” 11 meters below the surface, about 36 feet, deep enough that only the top of the periscope showed above the water.
Something banged against the exterior, and then came a grating sound, like steel moving along the hull. “It sounded as if huge chains were banging against the boat and were being dragged over it,” said Rudolph Zentner, then on duty in the boat’s control room.
The men operating the ship’s horizontal rudders, the dive planes, called out in alarm. The rudders weren’t responding. Zentner checked the gauges that monitored depth and speed. The boat was slowing and sinking. It heaved and lurched from side to side.
Zentner watched the depth gauge and called each change to Schwieger. The boat sank deeper and deeper. At a depth of 100 feet, U-20 struck bottom. At this depth the pressure posed no threat, but the boat now seemed fused to the ocean floor.
Zentner climbed the ladder into the conning tower, and there looked out through one of the small windows of thick glass, the only means of observing the surrounding ocean while submerged. What he saw stunned him: a crosshatch of chain and cable. “Now we knew the meaning of those buoys,” he said. A giant steel net had been suspended between them, a submarine trap, and U-20 had run right into it. The boat lay on the bottom, not just ensnared but pinned down by the weight of the net.
And now, something else: through the walls of the hull the crew heard the thrum of propellers overhead. They knew from experience that this particular pattern of sound was generated by destroyers—“a shrill, angry buzz.” Depth charges did not yet exist, but the presence of destroyers waiting above was anything but reassuring. These were the ships that U-boat commanders most feared. A destroyer—a Donnerwetter—could move at 35 knots, or 40 miles an hour, and fire a lethal shot from a mile away. It could also kill a submarine by ramming. With a bow edged like a carving knife, a fast-moving destroyer could slice a U-boat in half.
The interior grew warm and close. Fear settled over the men like silt in a tide. “You can bet there was no laughing and singing on board now,” Zentner said. “Each man thought of his home in Germany and how he would never see it again.”
These were the hard moments of command. Schwieger was not permitted to show fear, though he undoubtedly felt it. In such close quarters, to act with anything other than confidence and reassurance would have amplified the fear already at play.
Schwieger ordered, “Reverse engines.”
The engines responded. The boat strained. Steel rasped against the hull. Meanwhile, the propeller sounds above grew more distinct.
Zentner watched the dials and indicators in the control room. “The gauges were the whole world to us now,” he said. “I had never gazed at anything so eagerly before.”
The boat began slowly backing, amid the shriek of steel outside. And then, it was free.
Schwieger ordered ascent to cruising depth, 22 meters, or 72 feet, and full speed ahead. There was relief, until the men realized the propeller sounds
above were not fading. The destroyers seemed to know the boat’s exact location. Schwieger ordered a zigzag course, wide to right and left, but the destroyers always followed.
Schwieger traveled blind. He could not attempt to use his periscope because the destroyers would spot it immediately and begin shooting or attempt to ram the boat, or both. Schwieger ordered the helmsmen at the dive planes to maintain as deep a depth as the charts for these seas allowed. The pursuit continued “hour after hour,” Zentner said, with U-20 following “a wild, weird course, going as fast as we could.”
The best hope now was night. As darkness fell on the seas above, the propeller sounds began to fall away until they faded to nothing. Schwieger brought the boat back to periscope depth and took a fast look around, 360 degrees, to make sure no threat was near. This was a strenuous maneuver. The fittings on the periscope, where it jutted through the exterior of the conning tower above, had to be tight to keep water out and to withstand the pressures of a deep dive. Turning the apparatus required strength. The snugness of the fit was never perfect, however: a certain amount of oil-laced water inevitably dripped onto Schwieger’s cap and face.