by Richard Snow
On the last day of 1942, far north in the arctic storms, a German force of six destroyers, the heavy cruiser Hipper, and the pocket battleship Lutzow* had attacked an eastbound Murmansk convoy defended by a few British destroyers. Two British cruisers steaming with a westbound convoy heard the firing and rushed up, but they had only six-inch guns to oppose the Hipper’s eight-inch, let alone the eleven-inch giants Lutzow mounted. By naval logic this encounter should have meant the end of the convoy, of the destroyers, and of the two cruisers. Instead, for the loss of one aged destroyer and a minesweeper, the British sank a German destroyer, roughed up the Hipper so badly that she never fought again, and scared away the Lutzow.
A U-boat commander who had been on the scene somehow managed to pass along to Berlin that Germany had just gained a decisive naval victory. Hitler was preparing to incorporate the triumph into a New Year’s Eve speech when he heard a London radio broadcast report what had actually happened, right down to the fact that the convoy had lost not a single merchant ship.
It is difficult to imagine news that would be more disagreeable to Hitler (but not impossible: the Stalingrad surrender would come a month later). He “flew into an uncontrollable rage,” wrote Erich Raeder, that correct, aloof champion of a powerful surface fleet at whom the rage was directed. “He announced his intentions of immediately having all the heavy ships laid up, and recorded in the War Diary his view that the heavy ships were utterly useless. … He would not listen to any explanations … but ordered me by telephone to report to him immediately.”
Raeder gave his report on January 6, 1943, at Wolfsschanze, the gloomy concrete headquarters in East Prussia where Hitler was directing his war against the Soviet Union. There, under the pious gaze of Field Marshal Wilhelm Keitel, one of the Führer’s most pliant yes-men, Raeder received a lecture on the history of German sea power. Hitler, he wrote, attacked “the Navy in a vicious and impertinent way. He disparaged its founding, belittled its every role since 1864 and stated that except for the submarines the entire history of the German Navy had been one of futility.”
Hitler went on for an hour, Raeder remembered (one of the two stenographers on hand said it was actually an hour and a half), and “it was glaringly obvious to me that this whole diatribe against the Navy which I commanded was intended but for one thing—to insult me personally.”
Raeder took it all in silence, and when Hitler finally ran down, asked if he could speak with him alone. Keitel and the stenographers left the room, and Raeder, “very quietly” by his account, requested to be relieved of his command.
“Hitler—as he always did when faced with firmness—began to calm down and try to smooth over his remarks.” Raeder was adamant. He had been on active duty for half a century, but now the time had come “for a parting of the ways.”
Compared to the frequent and abrupt firings of the generals on the Eastern Front, it all went decorously. Raeder gave three radio broadcasts summarizing his role in the growth of the Kriegsmarine, saying poor health had forced him to seek a different assignment, praising Hitler, and concluding with a valediction: “I know that the navy will carry on this battle under its new commander in chief with the same obdurate determination, with the same unshakable will to conquer, and with the same loyalty as heretofore.”
That new commander in chief was Karl Doenitz. Though the two men had often quarreled, and there was little warmth between them, Raeder had faith in his fractious subordinate and gave him a warm recommendation. As soon as Raeder was through speaking, his successor came on the radio. “To the U-boat arm,” Doenitz said, “which I have been hitherto privileged to command, I extend my thanks for its courageous readiness to fight to the death and for its loyalty. I shall continue personally to command the U-boat war.
“I intend to command the navy in the same firm martial spirit. … Gathered about our Führer, we will not lay down our arms until victory and peace shall have been won. Hail our Führer!”
Doenitz took up his new duties on January 30, 1943.
Hitler liked Doenitz, liked his utter devotion to his boats and his confidence, which was not a matter of martial propriety, but perfectly genuine. Also, Hitler really had nowhere else to turn. Whole armies had disappeared into the terrible white vastnesses of the Eastern Front. The Americans had taken him completely by surprise with a successful landing in North Africa, and his big surface ships were sunk or, it seemed to him, useless. The Luftwaffe, sucked like the armies into the annihilating void of the Russian front, was no longer the offensive weapon it had been. Formidable though it remained, nobody thought anymore that it could win the war. The U-boats might.
Things were getting tougher for their crews, though. The “air gap”—that stretch of ocean that lay beyond the reach of Allied bombers—was growing narrower and the planes that chewed away at its edges more effective. German sailors had begun calling the passage across the Bay of Biscay, so recently a welcome time-saving convenience, the Valley of Death.
Peter Cremer, on the bridge while U-333 was starting out for Florida the year before, had gotten a premonitory glimpse of what lay ahead. “My eyes were in top form, the lookouts on the bridge were wide-awake, there was good visibility with gathering cumulus clouds, and even so we were surprised, our third day at sea, when from those very clouds an aircraft descended with total suddenness and came directly at us.”
Captain and watch rushed below into the already diving boat. They were one hundred feet down when two bombs exploded. “All the electric lights went out, bulbs and fuses jumped from their sockets. The repeater compass on the control-room bulkhead smashed into fragments, flap valves and hull valves sprung a leak, and a stream of oil three fingers broad poured from a crack.” The rudders were knocked out, all the radio tubes broken, and the conning-tower hatch took such a pounding that for the rest of the voyage “a crash dive brought a stream of water into the boat as from a shower.” Such were the rigors of his service that Captain Cremer ended his account, “All in all the air attack had not caused any considerable damage.”
Still, the incident continued to worry him. “Six pairs of eyes on the bridge—the lookouts, the officer of the watch, and myself—but none had seen the aircraft in time. On the other hand it must have spotted us long before—but with what?” He talked it over with his officers. They’d heard rumors that enemy airplanes were mounting radar, but they’d dismissed them, thinking the equipment far too heavy to take aloft. Now “we did suspect though that, somehow, the epoch of the bare eye, however good, was coming to an end and that the new era of technology … was upon us.”
Cremer and his officers had every reason to be skeptical about the existence of radar-equipped airplanes. Radar was real and radar worked: Cremer’s airborne colleagues had been dealt a war-changing reverse by it. In the last years and finally in the last hours of peace, Britain had built a chain of radar stations along its east coast. These emitted radio waves and, when the waves hit a distant airplane, could pick up the faint signal that echoed back. When the German bombers came in the summer of 1940, the stations were working. They looked across the Channel and the North Sea and saw where the bomber groups were headed in time to alert the British fighter squadrons, whose masters could thus hoard their planes and send up just enough to blunt the successive attacks. In the early fall, without acknowledging defeat in any way—and in later years even saying there had been no such thing as the Battle of Britain—the Germans gave up. That is, they gave up the effort that had been a prelude to an invasion of Britain. They didn’t stop sending their bombers.
The radar that had made possible a victory in one of the decisive battles of the west was not portable. The transmitting masts stood 250 feet tall; the receivers that harvested the fragmented echoes of the ever-widening radio signal were a hundred feet higher. Transmitting equipment weighed several tons. To be carried in an airplane, a radar set could not weigh more than two hundred pounds.
Also, those stations transmitted waves meters long; their broad cur
ves bounced sloppily off everything. They yielded information good enough to save a nation, but nowhere near sufficiently precise to closely track a single plane.
The British badly needed to be able to because the Germans had shifted to night operations. The radar stations could see in the dark, but the pilots sent up to intercept the bombers could not. The scientists had anticipated this. As early as 1937 they had an airborne radar with a wavelength of just over a meter, which gave the promise of homing on an attacker with unprecedented precision. But they needed a device that emitted far greater power from a much smaller source. Four months before Germany knocked France out of the war, they had invented it. The resonant cavity magnetron is something of a miracle, by far the single most important advance in the history of radar. It was smaller, lighter, and allowed more accurate readings than any previous system, firing out much shorter waves. Although these were actually 9.7 centimeters, the development was called “ten-centimeter radar” or, more economically, just “centimetric radar.” In late August 1940, after having produced just twelve magnetrons, Britain sent one to America.
On a September night, a group of British and American scientists and military men gathered at a Washington hotel discovered that both countries had walked similar paths developing radar. The Americans were appreciably ahead in receiver technology; and they had a ten-centimeter system, but it was woefully underpowered.
The British said they’d been working on that as well. They produced a wooden box, twisted loose the thumbscrews that held it shut, and took out the magnetron. Like so many of the century’s momentous inventions, it did not appear impressive in its natal form. The historian Robert Buderi, who half a century later spoke with many of the people who’d brought it into the world, wrote, “Small enough to fit in the palm of a hand, the magnetron looked like a clay pigeon used in skeet shooting, with a few couplings thrown in.” But once those couplings were hooked up, it could put out ten kilowatts of power at ten centimeters. This was well over a thousand times more than its American counterparts could generate.
The British scientific mission was working with American military and civilian organizations alike, and since the military already had meter-length radar, the magnetron went to a civilian agency, the National Defense Research Committee. The NDRC had been coaxed into being just a few months earlier by the head of the Carnegie Institution, Vannevar Bush. As a young engineer working on submarine detection during World War I, Bush had seen enmity between civilian scientists and the military blight one promising initiative after another. Hoping to prevent that from happening again, he devised an agency that could serve as a bridge between civil and military spheres, distilled his plan into four paragraphs on one sheet of typewriter paper, and handed that piece of paper to Franklin Roosevelt. The president liked the idea, and no man had more relish for working outside established channels. Within ten minutes Bush’s synopsis had “OK, FDR” written on it.
This seminal document swiftly led to the establishment of a research and development organization with five sections, the one devoted to radar colonizing ten thousand square feet of laboratory space at the Massachusetts Institute of Technology. Initially called the Microwave Laboratory, the name was soon changed to the Radiation Laboratory, on the premise that this would persuade any spies that its job was doing nuclear research, of purely theoretical military utility and thus innocuous.
The Rad Lab—as it was immediately known—recruited young physicists and engineers from across the country, as well as Isidor Isaac Rabi, forty-two years old and dedicated to doing all a scientist could to stop Hitler. Confronted with a new piece of equipment or a new idea, his first question was almost always “How many Germans will it kill?”
All the recruits were amazed by the cavity magnetron. One of them, Luis Alvarez, said of it forty years afterward, “A sudden improvement by a factor of three thousand may not surprise physicists, but it is almost unheard of in engineering. If automobiles had been similarly improved, modern cars would cost about a dollar and go a thousand miles on a gallon of gas.”
The Rad Lab men spent a lot of time speculating about how it actually worked. Clouds of electrons rotated inside it, accelerating through six or eight holes set like the chambers in a revolver—the cavities—until they generated the energy to shoot out a tremendously strong signal. Early in the program, a group of physicists stood around a disassembled magnetron, speculating on its occult power. “It’s simple,” Rabi said breezily. “It’s just a kind of whistle.” “Okay, Rabi,” a colleague shot back, “how does a whistle work?”
What was clear was that it did work, but as Elting Morison pointed out, “Any strange device that alters the familiar procedures tends to disturb the military society.” Radar most dramatically altered familiar procedures. George Marshall didn’t particularly want to hear about it, and neither did Hap Arnold, head of the Army Air Forces. But Henry Stimson got word of what was going on in the Rad Lab, and he listened. In the spring of 1942, with the East Coast under attack, he went on an inspection tour of Panama and was impressed by the radar he saw in airplanes stationed there: it was crude, but it could spot approaching ships. Back home, he had a plane with better radar take him out to sea. The set picked up three ships fifty miles away. Stimson watched “until we were right over them and I could look out at the little window … and actually see the ships right under us.” It was, said the secretary, “interesting and wonderful.”
Stimson had no yearnings for modernity. Once he received a letter from a horse soldier decrying the “destruction of our fine old cavalry” and urging the secretary to restore the arm. Stimson wrote the man that some of his “oldest and choicest recollections are pervaded with the smell of horse sweat and saddlery … that goes with a good cavalry unit,” but that “nearly all of us have to see some of the things we love remorselessly replaced in the modern mechanized world—a world that is just as repellent to me as I think it is to you.” Repelled or not, Stimson had the breadth of mind to see that this war was germinating new weapons and systems of communication that held within them the means of winning it. He had been impressed enough by his flight to issue what a colleague called “the closest approach to an order” he ever gave Marshall and Arnold. Both generals found this note on their desks: “I’ve seen the new radar equipment. Why haven’t you?” By the summer some hundred B-18s were being outfitted with centimeter sets and their crews taught how to use them.
Those were army planes. Admiral King proved a more resistant customer for radar. Shown a new set installed on one of his destroyers, he said, “We want something for this war, not the next one.” Convoy was the way to fight submarines, King now firmly believed. It had proved its effectiveness, and developing radar-equipped airplanes as a primary weapon of attack in the middle of a war would be an enervating distraction. “Admiral King has a terrible blind spot for new things,” Vannevar Bush wrote, “about as rugged a case of stubbornness as has been cultivated by a human being.” Still, Bush was as determined a man as King, and he approached the admiral directly, with a tactful but forthright letter sent on April 12, 1943:
“Antisubmarine warfare is notably a struggle between rapidly advancing techniques. It involves, to a greater extent than any other problem I could name, a combination of military aspects on one hand, and scientific and technical aspects on the other.” Bush followed with some emollient thoughts on how no scientist can hope to understand naval tradition, but then he added that scientific training, too, takes a lifetime to master and must be respected. “Recent advances in airborne weapons greatly increase the potential probability of a kill of a submarine after aircraft sighting. These are of such striking nature as to warrant a review of our plans in regard to the balance between seaborne and airborne attack, and a re-orientation of our strategy.”
King called Bush in for a meeting, and the men talked for two hours. Finally, King said something that sounded close to acquiescence: “Wouldn’t our problem be met if one of your scientists sat with Admiral
[Francis] Low and participated in planning with him …?” Bush pressed his advantage: three scientists, who would have complete access to every aspect of the U-boat campaign, and the guarantee that their recommendations would go straight to King and Low. Agreed, said King.
OUT IN THE ATLANTIC, the new radar was already making its presence felt. The U-boats had been carrying what the sailors called the Biscay Cross, an assemblage of wood and wire that hung from the conning tower like some inscrutable piece of folk art. Primitive though it looked, it could pick up metric radar beams from an approaching airplane in time for the ship to save itself (the cross had to be pulled apart and bundled below once it had given its warning). The Biscay Cross was blind and deaf to centimetric radar.
The May 20, 1943, entry in the war diary kept by German naval command chronicled a futile pursuit of an eastbound convoy: “It was not possible to maintain contact and proceed in the vicinity of the convoy owing to continuous surprise attacks from low-lying cloud. These attacks are explicable only in terms of very good location gear that enables a plane to detect the boat even from above the clouds.” The report concluded, “The loss of U-954 in the vicinity of the convoy is taken as certain as this boat reported making contact when up to the convoy, possibly lost in underwater attacks.”
The tone is straightforward; nothing suggests that Doenitz’s son Peter, just turned twenty-one, was the second watch officer aboard U-954.
Doenitz’s response, if response it was, came in his message redirecting the submarines that had survived the costly attack—five boats lost, out of forty-one that would be destroyed that month—to engage another convoy. “If there is anyone who thinks fighting convoys is no longer possible, he is a weakling and no real U-boat commander. The Battle of the Atlantic gets harder, but it is the decisive campaign of the war. Be aware of your high responsibility, and be clear you will answer for your actions.”