Hitler’s U-Boat War- The Hunted 1942-45

by Clay Blair

  When the short-signal weather codebook reached Bletchley Park, it offered British codebreakers who could decode weather reports the possibility of cribs to break weather reports reenciphered into four-rotor Enigma. However, it defied them until December 13. That day, the codebreakers discovered to their astonishment that the Germans had made a terrible lapse in code security. In weather reporting, U-boats put the fourth rotor in “neutral,” using their four-rotor Enigma like three-rotor Enigma. Obtaining three of the four Enigma keys of the day from this source, it was not difficult to cycle the bombes through twenty-six more possibilities to obtain the fourth wheel setting.

  This break into four-rotor Enigma enabled Bletchley Park to read immediately eight days of November traffic and all the early days of December with little delay. Still fearful of a leak by the Americans, First Sea Lord Pound notified Admiral Ernest J. King in patronizing language:

  As the result of months of the most strenuous endeavour, a few days’ U-boat traffic will be readable in the immediate future and this may lead to better results in the near future.

  You will, I am sure, appreciate the care necessary in making use of this information to prevent suspicion being aroused as to its source. We have found this especially difficult when action by [ship] routing authorities outside the Admiralty is required. It would be a tragedy if we had to start all over again on what would undoubtedly be a still more difficult problem.

  The captures from U-559 thus equaled in importance those from U-110 in May 1941 as a source for cribs. The short-signal codebook for weather reports was to remain operational until March 1943. By the time it expired, the British had perfected a method of obtaining cribs from the other (tactical) short-signal codebook, which remained in use until the end of the war. Even so, it was to take six months or more for the British codebreakers to completely master Triton. Until then, it was often a nail-biting, hit-or-miss enterprise.

  Bletchley Park immediately telexed the Admiralty’s Operational Intelligence Center its first decoded intercepts. The chief of the Submarine Tracking Room, Rodger Winn, was not present to join in the celebration. Never robust, he had recently suffered a temporary collapse caused by the pressures and strains of his job. His assistant, Patrick Beesly, plotted in the first confirmed U-boat positions, which, amazingly, did not differ markedly from Winn’s guesstimates, Beesly wrote.

  TWO

  TORCH

  The vast Allied armada for Torch closed on Gibraltar and Morocco in the last days of October and the beginning of November. The Axis had only vague intimations as to what was afoot.

  German forces stumbled upon two British units by happenstance. On October 31, Focke-Wulf FW-200 Condors reported a southbound Allied task force, composed of “two carriers and two cruisers,” 280 miles west of Portugal. On November 2, Hans-Jürgen Auffermann in U-514, returning from Trinidad to France, reported “seven large troop transports” in approximately the same area.

  Upon receiving the Condor report, Dönitz directed five boats from the disbanded group Streitaxt, which had been attacking convoy Sierra Leone 125, to attempt to intercept the “carrier group.” The Condors failed to follow up the contact and, as a result, none of the boats could find the “carrier group.” As related, Massmann in U-409, low on fuel, returned to France and the other four boats of Streitaxt were ordered onward to Freetown.

  In response to the November 2 report of seven southbound transports by Auffermann in U-514, Dönitz directed five boats in the area to intercept. All attempted to comply, but Auffermann lost contact. Ritterkreuz holder Ernst Kals in U-130, Hans Geissler in U-440, and Heinz Stein in U-620 reported temporary mechanical difficulties or battle damage, and Heinz Hirsacker in U-572 failed again to react aggressively. Geissler in U-440 came upon an eastbound convoy that may—or may not—have been the one reported by Auffermann. In the event, he was unable to attack or shadow, he reported, owing to diesel-engine difficulties.

  These two sightings, and reports by German and Italian spies of a mounting assemblage of warships and merchantmen of all kinds at Gibraltar, convinced Berlin belatedly that the Allies were staging for a large amphibious operation inside the Mediterranean. Inasmuch as Hitler believed the Allies would not antagonize the Vichy French and drive them into a closer relationship with the Axis, Berlin ruled out Allied landings in French Northwest Africa (Morocco, Algeria, and Tunisia). At first, Berlin believed the likeliest Allied objectives were positions close behind Rommel, perhaps at Tripoli or Benghazi in Libya, together with yet another reinforcement of Malta.

  On November 4—four days prior to Torch D day—Berlin asked Dönitz to immediately send seven Type VIIs of the Atlantic force to reinforce the Mediterranean U-boats. In compliance, Dönitz hurriedly formed group Delphin from six boats already at sea plus Jürgen Quaet-Faslem’s U-595, which sailed from France that day. Owing to engine problems, two of the seven boats at sea, U-440 and U-662, could not carry out the mission and were replaced by Klaus Köpke in U-259 and Josef Röther in U-380, both of whom sailed from France on November 5. The first five boats of group Delphin* were to slip through the Strait of Gibraltar on the night of November 8-9, when the moon was new, the U-259 and U-380 to sail later, on the night of November 10-11. These additions were to increase the German Mediterranean force to twenty-five U-boats.

  At the insistence of Dönitz, some torpedoes of the Mediterranean boats were to be equipped at all possible speed with two exotic new features from the torpedo technicians:

  • A new and better magnetic pistol, designated MZ-Pi39H, but generally referred to as the Pi2. The first fifty of these pistols from the production line in Germany went to the U-boat bases at La Spezia and Pola. Until the new pistols were available in quantity, the skippers were directed to fire these torpedoes only at important targets, such as battleships and carriers.

  • A new steering device, which could be set to drive the standard air (G7a) or electric (G7e) torpedo on a looping path (left or right, short or long) through a convoy or naval task force. Designated Federapparat, the device was generally referred to as FAT. Its looping path increased the possibility of a hit in a large ship formation. The twenty-four FAT air (G7a) torpedoes in Kiel ready for service were sent to La Spezia and Pola.

  The use of a FAT torpedo required a minor modification to the torpedo tube from which it was to be fired. Since there were only twenty-four FATs on hand, it was decided to allot these to only four U-boats, all veterans of Mediterranean duty: U-83, U-375, U-453, and U-562. To speed up the departure of the boats, it was further decided to modify at first only two bow tubes in each of these four boats. They were to sail with six FATs in the bow compartment, plus four G7e electrics with Pi2 magnetic pistols in the stern compartment. Since the air FAT left a highly visible bubble wake like an ordinary air torpedo, it was to be used sparingly in day-time, in order to keep the FAT secret from the Allies for as long as possible. On the first patrols, the boats were to load the bow tubes with one FAT and three electrics with Pi2 pistols for daytime operations and two FATs and two electrics with Pi2 pistols for night operations.

  Much was expected of the Axis submarines inside the Mediterranean. But Berlin had evidently forgotten the lessons of Norway two and a half years past: U-boats were virtually useless for stopping massively escorted invasion forces fully alert to possible submarine attacks. Inasmuch as the Torch naval forces included thirteen aircraft carriers (five fleet, eight light—“jeep” or semi-“jeep”), and scores of the warships were fitted with the British Type 271 or the American Type SG centimetric-wavelength radar as well as Huff Duff, the task would be that much more difficult, and perhaps impossible.

  In the period preceding Torch, the Allies made a secret deal with an anti-Axis French hero, General Henri Giraud. He was to enter Algiers on D day, assume command of the French colonial government and armed forces in North Africa, and direct those French to lay aside arms and welcome their liberation by the Allies. However, in arranging this deal, the Allies made three mistakes: They
overestimated Giraud’s prestige and appeal to the colonial French and underestimated the loyalty of many to Vichy; they failed to draw the French Navy into the scheme; and in their determination to keep secret the time and places of the landings, they confided in only a few of the senior French military commanders on the scene. The upshot was to be a decidedly mixed reception for the Allies on Torch D day, November 8.

  The Royal Navy delivered a mixture of American and British amphibious forces to Algiers and Oran. For that job, it organized three task forces: a Main Covering Force of big ships to repel a possible attack by the Italian or Vichy French navies, or both; an Eastern Task Force to occupy Algiers; and a Center Task Force to occupy Oran. The official Admiralty historian wrote that the British utilized 229 ships for these operations. They included the battleships Nelson, Rodney, and Duke of York; the battle cruiser Renown; the modern carriers Formidable and Victorious, and the old carriers Argus and Furious; the new (American-built) “jeep” carriers Avenger, Biter, Dasher, and Archer (the last serving only as an aircraft ferry); and 217 other vessels of all types.

  By happenstance, Admiral Jean François Darlan, the heir apparent to Marshal Pétain in the Vichy government, was in Algiers combining business with a visit with his son, who had been hospitalized with poliomyelitis. When the Allied military and political leaders perceived that General Giraud carried little weight with the French in North Africa, they quickly turned to Darlan. After a series of byzantine political maneuvers, Darlan defected to the Allies, who named him High Commissioner of French Northwest Africa. Many in America and Britain roundly criticized Eisenhower for making a “deal” with the “odious Nazi collaborator” Darlan, but the admiral’s exhortations to the French colonials in the days ahead to lay arms aside doubtless saved Allied lives in Algeria and Morocco. Darlan could not, however, deliver Vichy Tunisia or, as Churchill devoutly hoped, those elements of the French fleet neutralized at Toulon and other warships at Dakar.*

  Remarkably, the Allied armada destined for Algiers and Oran suffered only one serious casualty en route. At 6:50 A.M. on November 7, the American troopship Thomas Stone, with 1,450 American shock troops embarked, was hit in the stern by one torpedo, which disabled her rudder and screws. Contemporary accounts credited a German U-boat with the hit, but it has not been confirmed in postwar German records. Nor could Italian naval historians attribute the hit to an Italian submarine. It may have been delivered by a submarine of another nation (France? Spain?), that was lost at sea before reporting, or concealed the attack for various reasons. Or it may have been a loose mine.

  The convoy proceeded, but the British destroyers Wishart and Velox, the corvette Spey, and a tug stood by the damaged vessel. About eight hundred of the soldiers on Thomas Stone bravely set off for Algeria in twenty-four landing craft, escorted by Spey. One by one all the landing craft broke down or foundered during the 150-mile voyage, but Spey took all eight hundred soldiers on board and delivered them to Algiers, a day and a half late. The destroyers and the tug eventually got Thomas Stone to Algiers, where she disembarked the rest of her troops but sailed no more.

  During the Allied landings to the east and west of Algiers early on November 8, two British destroyers, Broke and Malcolm, were detailed to crash through the booms in the main harbor and land commando teams, which were to seize the waterfront and prevent ship scuttlings. That operation was a disaster. Both destroyers encountered heavy damage and casualties from French shore-based naval guns and were forced to withdraw to sea, where Broke later sank, the single serious naval casualty in the Algiers landings. Thereafter the only two French warships left in the Algiers harbor, the submarines Caïman and Marsouin, boldly sailed out to repel the invaders. British aircraft and surface ships spotted and pounded the submarines, forcing them off. Both eventually escaped to Toulon, Caïman severely damaged.

  Inasmuch as a pro-Allied French general was in command of the defenders at Algiers, the main landings east and west of the city were virtually unopposed and the French surrendered by nightfall of the first day. According to the plan, these Allied forces were to race east and capture Tunisia before the Axis could reinforce it, but the Allies botched this important phase of the operation. Reacting with astonishing speed, the Axis rushed heavy armored and infantry units from Italy to Tunisia, wrested control of the nation from the Vichy French, and deployed troops at the western border who solidly blocked the Allies for months, thus creating an escape corridor for the retreating Afrika Korps.†

  The Allied landings at Oran were more difficult than those at Algiers. The local Army commander was pro-Vichy, and the harbor was jammed with Vichy French warships that refused to defect to the Allies. As at Algiers, two Allied vessels were assigned to crack the main harbor boom and land commando teams to seize the waterfront and prevent scuttlings. The vessels designated for this task were the ex-American, 250-foot Coast Guard cutters Pontchartrain and Sebago, rechristened by the Royal Navy as Hartland and Walney. French shore- and ship-based guns blasted the two vessels to pieces, killing hundreds of Allied commandos and ships’ crewmen.

  Eight French warships in the harbor at Oran sailed out to repel the invaders: the super-destroyer Epervier; the destroyers Tramontane, Tornade, and Typhon; the sloop Surprise; and the submarines Argonaute, Actéon, and Fresnel. British warships and aircraft met these ships head-on with murderous fire. Four of the five surface ships were driven back or forced to beach. The British destroyer Brilliant sank the Surprise. The veteran British destroyers Wescott and Achates sank the submarines Argonaute and Actéon, respectively. The defiant crewmen of the destroyer Typhon blew up their ship in the harbor. The French also scuttled five other dry-docked or decommissioned submarines. Only the submarine Fresnel escaped to Toulon.

  The third leg of Torch was the American invasion of Morocco. For that purpose, the U.S. Navy’s commander in chief, Admiral King, created the Western Task Force, commanded by Henry Kent Hewitt, which sailed directly from the United States. The armada consisted of three battleships (the new Massachusetts, the aged New York, and Texas), the carrier Ranger, four new, thinly trained light carriers (Suwanee, Sangamon, Santee, and Chenango, the latter serving only as an aircraft ferry),* and ninety-six other vessels of all kinds, including thirty-eight American destroyers. Hewitt’s task was to put ashore about 35,000 Army troops, commanded by General George S. Patton, at three sites: Fedala and Mehdia-Port Lyautey, fourteen and sixty-five miles north of Casablanca, respectively, and Safi, 125 miles south of Casablanca.

  The largest and most powerful of the American amphibious forces struck at Fedala to encircle and capture Casablanca. The new battleship Massachusetts (on her shakedown cruise), the veteran fleet carrier Ranger, the new light carrier Suwanee, and numerous cruisers and destroyers provided offensive and defensive support for the twelve big troop transports and three cargo vessels. The very unfriendly French forces in Casablanca harbor included the battleship Jean Bart, unfinished but with one operable turret of four 15” guns, the light cruiser Primauguet, two super-destroyers, fifteen conventional destroyers and sloops, and eleven submarines.

  A tough naval battle ensued off Casablanca on D day. The Jean Bart and coastal batteries opened fire on the Massachusetts and other covering ships. Remarkably, in return fire, Massachusetts hit Jean Bart five times in sixteen minutes, knocking out her single operating big-gun turret. Thereafter, eight French surface ships valorously sailed out to repel the invaders: the cruiser Primauguet, the super-destroyers Milan and Albatros, and five conventional destroyers. American ships and aircraft sank at sea the destroyers Boulonnais, Brestois, and Fougueux, and forced the Primauguet, Milan, Albatros, and Frondeur to withdraw to anchorages close inshore or to beach outside Casablanca. Subsequently, American aircraft destroyed these four ships as well. Only one of the eight ships, the destroyer Alcyon, returned to Casablanca harbor undamaged.

  The eleven submarines at Casablanca were likewise roughly handled. American gunfire in the early actions sank three (Amphitrite, Psyché, O
réade) in the harbor. The other eight sailed out to repel the invaders. The Amazone shot five or more torpedoes at the cruiser Brooklyn, but all were evaded. Tonnant shot at the carrier Ranger, but missed. Méduse and Antiope attacked the transports at Fedala, but they also missed. Four of the eight submarines were lost. Three aircraft from the light carrier Suwanee sank Sidi-Ferruch, thus becoming the first Allied carrier-based planes to destroy a submarine unassisted by surface craft. Two U.S. Navy Catalinas arriving at Casablanca found Conquérant on the surface and sank her with three shallow-set, 325-pound Mark XVII depth charges. Under fire from a British aircraft, Tonnant scuttled. Sibylle disappeared without a trace. Amazone, Antiope, and Méduse set off to join French naval forces at Dakar; Orphée returned to Casablanca without serious damage and eventually joined Allied forces.

  To the north, at Mehdia-Port Lyautey, American forces also met a hot reception. The battleship Texas, the new light carriers Sangamon and Chenango (the aircraft ferry), and other vessels provided offensive and defensive support for the six troop transports and two cargo vessels. In a remarkable, bold, and innovative operation, the four-stack destroyer Dallas won high honors for pushing deep up a river to land troops at the airport. There were no French naval forces present to challenge the Americans, but French shore batteries and ground forces put up a stiff fight before Admiral Darlan’s exhortations to cease firing reached them and could be verified. The capture of Mehdia-Port Lyautey provided the Allies with the only airfield with paved runways in Morocco.