Believing that he might yet talk Great Britain and France out of going to war, before the invasion of Poland, Hitler imposed severe limitations on the two “pocket” battleships and the U-boats deployed for combat in the Atlantic and North Sea. The “pocket” battleships were not to commence any operations against Allied shipping or naval forces without Hitler’s specific approval. And, as Raeder remembered it, the U-boats “were likewise hedged with severe restrictions.”
One of the first and most important rules Hitler laid down was that the U-boats were not to be concentrated, offensively, against enemy naval formations. The reasons were both political and practical. First, as Raeder put it, Hitler did not want to further antagonize the Allies by sinking a prestigious man-of-war. Second, as Dönitz put it, “U-boat operations against naval forces promised little hope of success.”
On the eve of war, Britain’s Navy was dispersed and holed up in numerous heavily fortified bases, including Scapa Flow, Firth of Forth, Firth of Clyde, Portland, and Portsmouth. Even if the big ships put to sea, it would be very difficult for a U-boat to sink a major man-of-war, such as a battleship. There were not enough U-boats to cover the British bases in depth. The major ships were certain to be heavily escorted by aircraft and sonar-equipped destroyers and cruising at high speed (25 knots)—too fast for a U-boat to overhaul them and get into position to shoot torpedoes. A hit would be a matter of luck: the off chance that a U-boat lay almost directly on the path of an oncoming enemy man-of-war.
For these reasons, Hitler had ruled that in the initial offensive U-boats were to concentrate primarily against merchant shipping. But, again for political reasons, that pressure was to be applied with utmost finesse. All U-boats were to adhere strictly to the 1930 Submarine Protocol, which Germany had signed in 1936. That protocol (Article 22) specified that with certain exceptions, ships were not to be sunk without warning. They were to be stopped and inspected, or “visited and searched.” If found to be an enemy ship or a neutral ship with contraband, inbound to an Allied port, they could be sunk, but only after the safety of the crew had been absolutely assured.
The exceptions—ships that could be sunk without warning, in the German view—were:
• Troopships, i.e., vessels known from intelligence sources or actually observed to be carrying troops and war matériel.
• Vessels in convoy, or any vessel escorted by warships or aircraft.
• Vessels taking part in enemy actions or acting in direct support of enemy operations, including intelligence gathering.
There were not enough U-boats to make any appreciable dent in the enormous Allied merchant fleet in the first offensive. Furthermore, most of the Atlantic boats had sailed on August 19 and were already low on fuel and provisions and would have to be recalled soon. Since there was no reserve to replace them, a “lull” or “gap” of several weeks would occur in U-boat operations. Therefore the initial U-boat offensive was shaped to achieve maximum psychological impact. The goal was to sink as many enemy ships in as many different locations as possible, giving the impression that U-boats were “everywhere,” thereby sowing confusion and panic and reviving memories of the costly World War I U-boat siege of England. So pressured, Hitler believed, the Allies might be less willing to continue combat in behalf of Poland.
The decision to adhere strictly to the Submarine Protocol added great risk to the submarines’ tasks and reduced the odds of inflicting a dramatic first blow. The biggest risk was that during the visit and search procedure, when the U-boat was exposed on the surface, it might be surprised by an enemy warship or aircraft. To minimize the possibility of surprise by aircraft, the Atlantic boats were positioned well offshore—a hundred miles or more. This put them well to sea of the “choke points” in the British Isles, where shipping converged and congregated and thus made the job of locating ships much more difficult, especially in inclement weather.
The restriction also virtually ruled out any chance that the ducks in the North Sea could contribute to the intended psychological impact by torpedo attack. The ducks were too small and underarmed (one dismountable machine gun on deck, which could be manned only in calm water) to stop, visit, and search a merchant ship. Moreover, it was believed, British aircraft patrolled all areas of the North Sea almost continuously in daylight, posing extreme dangers to those pint-sized boats. The best that could be expected of the ducks was a lucky torpedo hit on a British convoy, warship, or submarine and/or kills from the minefields some were to lay.
Even so, there was a great deal riding on this first U-boat offensive. If Hitler’s political intuition was right, a smashing U-boat success might discourage the Allies from continuing the war, and Poland would have been gained at small cost to Germany. For those who did not believe the Allies would back away from war—and those included Raeder and Dönitz—it presented an opportunity to wrest Hitler’s attention away from the land war and focus it on naval warfare and to impress upon him the grave peril posed by the Allied naval powers. A successful U-boat opening blow could persuade Hitler to give the tiny U-boat arm the full backing it desperately needed to wage a credible naval war.
• • •
On the day Great Britain and France declared a state of war with Germany, September 3 at 1256 hours Berlin time, the OKM sent an urgent, encoded message to all Kriegsmarine ships, U-boats, and shore stations: “Hostilities with England effective immediately.” A little over an hour later, at 1400, the OKM sent another urgent message: “U-boats to make war on merchant shipping in accordance with operations order,” meaning they were to observe strictly the Submarine Protocol or prize rules. Because theretofore the U-boats had been instructed not to attack any ships except in self-defense, Dönitz felt a clarification was required. From his shore headquarters in Wilhelmshaven, at 1550 German time, he radioed all U-boats: “Open hostilities against England immediately. Do not wait to be attacked first.”
England, yes, but what about France? Believing that France might be even more easily dissuaded from war than Great Britain, Hitler had reached the drastic decision that U-boats should not attack any French ships of any kind. At 1752 that same afternoon, the Berlin naval staff addressed that matter with yet another message: “Boats are to take no hostile action against [French] merchant ships for the present, except in self-defense.”
Another complication—and added danger! U-boats could not assume a ship was French merely because it flew a French flag or insignia. British ships or neutral ships with contraband might hoist French flags. Therefore all ships flying French flags would have to be stopped, visited, and searched to be certain they were French. If positively identified as French, they were to be allowed to sail on unmolested. This procedure could result in a great waste of time, during which the U-boat would be exposed to attack by enemy ships and aircraft.
The limitations virtually ruled out all U-boat attacks at night. In darkness it would be difficult, if not impossible, to positively distinguish a blacked-out French merchant ship from a British merchant ship. Hence no U-boat commander could confidently attack any convoy at night, lest a French ship be sunk by mistake.
At 1630 local time that day, Fritz-Julius Lemp in U-30 was cruising northwest of Ireland on the surface in the extreme northern sector of his patrol area. This put him about sixty miles south of Rockall, a barren sixty-three-foot rock projecting upwards from the sea. Until then, for purposes of concealment, Lemp had been keeping well off the normal sea-lanes. About that time, the bridge watch sighted a ship on the horizon, coming from the direction of the British Isles on a northwesterly course that was taking her unusually close to Rockall. Lemp hauled around on the surface to get on her track and dived for a closer periscope inspection.
The two vessels closed at about 1900 (7 P.M.), by which time the daylight was fading. Through the periscope Lemp could see that she was a very large ship. She was blacked out and zigzagging and appeared to be armed with deck guns. On the basis of this hurried, overeager look, and her unusual track near Rockall, Lemp concluded the vessel must be a British armed merchant or auxiliary cruiser* on patrol and therefore fair game for an attack without warning. He sent his crew to battle stations and ordered two torpedoes made ready.
At 1940 (7:40 P.M.) Lemp initiated the Atlantic U-boat war, firing the two torpedoes. The first ran true and struck the target squarely. The second malfunctioned and ran wild. Believing it might circle back and blow up U-30, Lemp dived deep to evade. When the danger had passed, he surfaced in the evening twilight and examined the listing target from the bridge through binoculars, edging ever closer, taking care to keep U-30 down-moon in the shadows. Since the ship did not appear to be sinking, Lemp fired a third torpedo, but it, too, malfunctioned or missed.
Moving up quietly and close to the target, soon Lemp could clearly see its silhouette. He went below and checked the boat’s copy of Lloyd’s Register of merchant ships. He saw then that he had made an inexcusable and horrendous error. She was not an auxiliary cruiser, but rather S.S. Athenia, a well-known, sixteen-year-old, 13,580-ton British ocean liner of the Donaldson line. She was bound for Canada, jammed with 1,103 men, women, and children, including 311 Americans who were fleeing the war. If there was any doubt in Lemp’s mind about the identity of the ship it was shortly removed. Athenian’s, radio operator repeatedly telegraphed a plain language distress signal, giving her position and the three-letter code, SSS, meaning she had been attacked by a submarine. All this was clearly audible on U-30’s radio receiver.
Lemp then compounded the error. He had been ordered to maintain radio silence to conceal his presence, but the distress signal—and SSS—from Athenia had already given him away. He would not have unduly jeopardized the safety of his boat by breaking radio silence to inform Berlin or Dönitz of this egregious error, thereby giving the German government timely notice of a public storm certain to arise. Possibly fearing that he might be recalled and relieved—or perhaps harshly punished by the Nazi government—Lemp sent no message, thereby leaving Berlin and Dönitz completely in the dark.
Nor did Lemp make any effort to render assistance to Athenia’s passengers and crew. Fortunately the seas were calm and the weather was good, and Athenia remained afloat until the following morning, enabling passengers and crew to abandon ship in an orderly manner. Three merchant ships and three British destroyers raced to the rescue and, as a result, the loss of life on Athenia was not calamitous: 118, including twenty-eight Americans, some deaths being caused when one of the rescue ships, the Norwegian freighter Knut Nelson, clumsily churned up a lifeboat with her propellers.*
The hue and cry arising from this first U-boat sinking of the war was thunderous. Although the casualties had not been heavy, the incident evoked the horror of the 1915 Lusitania sinking in which 1,198 people, including 128 Americans, had perished. The Admiralty hurried to inform the media that Athenia had been sunk by a torpedo from a U-boat, which had been seen by some passengers. The obvious implication was that Germany had abrogated the Submarine Protocol and had launched World War II with a barbarous and inhumane campaign of unrestricted submarine warfare.
Berlin and Dönitz first learned of the Athenia sinking from radio news broadcasts. It came as a rude shock. Such was the care that had been exercised, both in oral and written orders, to avoid a violation of the Submarine Protocol, that it seemed inconceivable that the very first British ship—a passenger liner at that—had been sunk illegally. It was a terrible blot on the honor of the Kriegsmarine. It was certain to undermine—and perhaps even collapse—Hitler’s attempts to negotiate Great Britain out of the war, and it would also seriously antagonize the United States.
Such was the gravity of this matter that early on September 4, Raeder flew to Wilhelmshaven to confer with Dönitz. Together they reviewed the operational orders and patrol areas of the U-boats. Although both later stated otherwise, there is little doubt that they knew that morning that Lemp in U-30 had sunk Athenia. Owing to radio silence and his freedom to move about his assigned area, Lemp’s position was not precisely known. But Athenia definitely had been sunk within the boundaries of Lemp’s patrol zone, Area U.
Hitler’s greatest concern was that the British would balloon the Athenia sinking into another Lusitania and generate sufficient outrage to pull the United States into the war. Before Raeder returned to Berlin, Hitler issued orders that Germany should categorically deny that a U-boat sank Athenia and characterize any charge that one did so as a false “British atrocity report.” The German Foreign Ministry issued the official denial at noon on September 4. The spokesman asserted that no U-boat could have sunk Atheniainasmuch as the northern boundary of the patrol zone of the nearest U-boat lay “seventy miles to the south.” The Germans claimed Athenia must have been sunk by a British mine or submarine.
Hitler’s decision to lie about Athenia set in motion a complicated cover-up in which Raeder and Dönitz participated. Four days later, Raeder sent a telegram to a newspaper reporter (which was leaked to foreign naval attaches in Berlin) in which he stated that the British claim that Athenia had been torpedoed by a U-boat was an “abominable lie” because the nearest U-boat was “170 sea miles away” and, furthermore, the Kriegsmarine strictly adhered to international law, the prize rules in particular. Still later, with the full knowledge that U-30 had sunk Athenia, Hitler’s Propaganda Minister, Joseph Goebbels, published a preposterous article in Germany charging that the Admiralty had deliberately ordered the destruction of Athenia to curry favor with neutral nations and bring America into the war.
The Athenia sinking led directly to further complications—and risks—for U-boat skippers. Insisting that there be no repetition of this politically disastrous sinking, Hitler imposed yet another restriction. On September 4, the OKM radioed Atlantic forces, including the “pocket” battleships and all U-boats: “By order of the Führer: No hostile action is to be taken for the present against passenger ships, even in convoy.”
Although the order was no doubt meant to apply mainly to large ocean liners, it did not define “passenger ships.” Many ships, including tramp steamers, carried passengers. Were U-boat skippers to allow a tramp steamer with ten or twenty passengers to pass unmolested? If not, what was to be the cutoff point? Were “passenger ships” obviously transporting troops (and therefore “troopships” by the Submarine Protocol) likewise to be spared? Were convoys that included “passenger ships” to be unmolested out of fear that a stray torpedo might hit one? Unable to answer these questions or to clarify the order in any way, Dönitz was powerless to help his skippers.