by Clay Blair
Prisoners’ reactions to the Schnorchel were all of a pattern: Every one objected to its use and hoped that it would be discarded. Some feared the sudden creation of a vacuum in the U-boat if a wave should wash over the top of the intake mast; some complained of fumes in the diesel compartment, caused by insufficient exhaust; all feared that in a phosphorescent sea they could easily be detected by enemy aircraft and would rather proceed submergedA radio rating objected to the Schnorchel because, he said, it interfered with listening on the multi-unit hydrophones, especially aft. It was impossible to pick up sounds of any but greatest intensity at a safe distance.
Like the other lost VII snort boat U-264, the U-575 had been at sea on her maiden snort patrol for merely two weeks. When the news of these two losses (of three snort VIIs) spread throughout the Atlantic U-boat force, it did nothing to build confidence in this clumsy and much-detested device.
• The next two VIIs sent to join group Preussen departed Brest on February 29.* These were the U-625, commanded by a new skipper, Siegfried Straub, age twenty-five, and the U-741, commanded by Gerhard Palmgren. While crossing the Bay of Biscay, the U-741 was twice attacked by Allied aircraft at night, but neither attack was crippling.
On the eighth day out of Brest, Straub in U-625 reported that a diesel engine had failed as well as his Wanze and Naxos. Control radioed instructions on how to make repairs and directed the Preussen boat U-963, commanded by Karl Bodden-berg, to render assistance. Thereafter U-625 proceeded to group Preussen, which had moved farther west.
A Sunderland of Canadian Squadron 422, manned by a new crew, spotted U-625 on the surface on the afternoon of March 10. At that time, the controls were in the hands of an RAF check pilot, Sidney W. Butler. He attacked into very heavy flak and accurately dropped six depth charges. The U-625 submerged, then resurfaced almost immediately. Moving beyond flak range, Butler circled the scene for ninety minutes, giving the alarm.
Skipper Straub in the U-625 assessed the damage and decided to abandon ship. While preparing to do so, he got off an SOS to Control, which, in turn, directed two nearby Preussen boats, the ex-flak boat U-256, commanded by Wilhelm Brauel, and Palmgren in U-741, to rescue Straub and his crew. After the crew of U-625 had abandoned ship in rafts and dinghies, Straub scuttled the boat.
While racing to locate and rescue the shipwrecked Germans, the U-256 and U-741 ran into difficulties. On March 11, a Leigh Light-equipped Wellington of Canadian Squadron 407, piloted by E. M. O’Donnel, found and attacked the boats. The inbound U-256 incurred “severe” damage. British and Canadian sources state that U-256 shot down the Wellington, but Brauel told Control that the plane “crashed 1500 meters off*before own fire opened up.” Palmgren in the outbound U-741 also reported an air attack. When he later surfaced, he said, he was attacked again, this time by “four carrier aircraft and three destroyers,” which pursued him for hours, but inflicted only “slight” damage.* Control ordered both boats to continue the search, but no trace of the U-625 crew was ever found by friend or foe. The U-256 reached Brest on March 22; the U-741 continued her patrol.
• The U-629, commanded by Hans-Helmut Bugs, which sailed from Brest on March 4. The next day an aircraft of British Squadron 304 hit and damaged the boat, forcing Bugs to return to Brest on March 7. He resailed on March 9, but in the early hours of March 12, a Leigh Light-equipped Wellington of British Squadron 612, piloted by D. Bretherton, attacked into heavy flak and dropped four depth charges. These inflicted so much damage that Bugs was compelled to abort to Brest a second time, arriving on March 15. The boat did not resail until June.
• The U-653, commanded by Hans-Albrecht Kandler, which sailed from Brest on March 2. On March 15, as U-653 was joining Preussen, a Swordfish from the new British “jeep” carrier Vindex, on her maiden combat mission, got U-653 on radar and the pilot, P. Cumberland, marked the spot with flares as Kandler crash- dived. In response to this alarm, the sloops of Johnny Walker’s Support Group 2, which, with the Canadian Escort Group 6, was providing escort for Vindex, raced to the scene. “Dickie” Wemyss in Wild Goose made sonar contact but deferred to Walker in Starling. Much to his chagrin, Walker sank U-653 with a preliminary depth-charge run designed not to sink the boat, but to drive her deep for a main at tack by Wild Goose.
In his account of Walker’s wartime operations,† the British writer Terence Robertson stated that since it was customary in this group to allow the first ship to detect a U-boat to sink it, Walker signaled Wemyss: “I am guilty of flagrant poaching. Very much regret my unwarrantable intrusion into your game.”
The Admiralty divided credit for the kill of U-653 between Wild Goose and Starling of Walker’s group and Vindex. There were no German survivors.
One of the newly arrived Preussen reinforcements, the VII U-311, commanded by Joachim Zander, found a convoy on March 16. This was another big, heavily guarded tanker formation, CU 17, en route from the Caribbean to the British Isles via New York. Zander gave the alarm and shot a T-5 at a “destroyer,” but it missed. Four escorts hunted and depth-charged U-311 for four hours, Zander reported, but he hung on tenaciously. In the early hours of the next day, the American destroyer escort Daniel T. Griffin got U-311 on sonar, but Zander eluded her and shot two FAT (looping) torpedoes into the formation. These hit and wrecked the 10,300-ton American tanker Seakay, which was put under by the convoy escorts. She was only the fourth Allied merchant ship sunk by U-boats in the North Atlantic area in five months.*
During this convoy chase, the escorts found and heavily damaged another newly arrived Preussen boat. She was the U-415, commanded by Kurt Neide. For the second time in as many patrols, she was forced to abort because of aircraft damage. Neide limped into Brest on March 31. The next day, Neide, who had sunk the British destroyer Hurricane and two freighters for a total of 8,000 tons, left the boat for other duty. Her new skipper was Herbert Werner from the U-230, author of the 1969 best-seller Iron Coffins.
Control in mid-March logged that owing to the decision to concentrate U-boats in ports to defend southern Norway (group Mine) and France (group Landwirt), the flow of new boats to the Atlantic force had virtually stopped. For that reason, and also because of the failure of Luftwaffe support, the ruinous battle losses in the North Atlantic, and the urgent need to upgrade the Atlantic boats with reliable 37mm flak guns and snorts and search radars, it was no longer possible to even pretend to mount anticonvoy warfare in the North Atlantic. Thus on March 22, Control dissolved Preussen, the last anticonvoy U-boat group of the war, and recalled to France eleven VIIs that were scheduled to reinforce that group: seven new VIIs from Norway and four VIIs from France.
Of the four boats that put out from France for Preussen and were recalled, one was lost. She was the U-976, commanded by Raimund Tiesler, who sailed from St. Nazaire on March 20. On the sixth day, when she was on the surface outside the port meeting her three German escort vessels, a flight of six Mosquitos attached to British Squadron 248 attacked the group. Two of these Mosquitos, piloted by Douglas J. Turner and Aubrey H. Hillard, were fitted with experimental 57mm cannons (code-named “Tsetse”).† Turner attacked U-976 four times with Tsetse, Hillard one time. These attacks destroyed the U-boat, killed four men, and badly wounded three others. The German surface escorts rescued Tiesler and forty-eight survivors and took them into St. Nazaire. Tiesler returned to Germany to command a big electro boat.
Another of these four recalled boats had a close call. She was the U-960, commanded by Günther Heinrich, which sailed from La Pallice on March 19. While inbound to La Pallice on March 27 with another U-boat and eight surface escorts, another flight of six Mosquitos, including Turner and Hillard with their 57mm Tsetse cannons, attacked U-960, wounding Heinrich and fourteen of his men, four seriously. Other Mosquitos attacked the surface escorts. The U-960 survived this attack and limped into La Pallice that same day.
At the time Control issued the orders to dissolve group Preussen, it consisted of about a dozen boats. Eight continued independent patr
ols and returned to France in the period from March 27 to May 20.
One of these ex-Preussen boats, the U-302, commanded by Herbert Sickel, found a convoy on April 6. It was eastbound Slow Convoy 156. In a rare and notable success of this period of the Atlantic naval war, Sickel got around the escort and sank two Norwegian ships, the 6,200-ton tanker South America and the 3,500-ton freighter Ruth L In the counterattack, the British frigate Swale of Escort Group B-5, commanded by Richard C. Boyle, sank U-302 with depth charges and Hedgehogs, with the loss of all hands. Control knew nothing of this only successful attack by a U-boat in the North Atlantic in April, nor of the loss of the boat.
Three other ex-Preussen boats were lost, all to Allied surface ships using depth charges or Hedgehogs.
• On April 8, the sloops Crane and Cygnet of British Support Group 7, a hunter-killer unit, found and sank the U-962, commanded by Ernst Liesberg. There were no survivors.
• On April 17, two American warships, the minesweeper Swift and the PC 619, which were escorting a small coastal convoy in the approaches to the English Channel, sank the U-986, commanded by Karl-Ernst Kaiser, still on her maiden patrol and fitted with the antiaircraft rocket array. As a consequence of this loss, Control did not receive a comprehensive combat evaluation of the rockets, which in any case were not pursued.
• On April 22, the Canadian Support Group 9 (three frigates, one upgraded corvette) destroyed the U-311, commanded by Joachim Zander, who had sunk the tanker Seakay from convoy CU 17. At the time the British credited the kill of U-311 to an aircraft of Canadian Squadron 423. However, in a postwar reassessment in 1986, it reassigned the credit to the Canadian frigates Swansea and Matane.*
Two other ex-Preussen boats had close calls. Off Brest on March 26, unidentified Allied aircraft hit the inbound U-963, commanded by Karl Boddenberg, who had just met his escort. Boddenberg reported that nine men were wounded, two badly. The boat entered Brest the next day, March 27. Off Gibraltar that same day, unidentified Allied aircraft hit the U-255, commanded by Erich Harms, who had been ordered into the Mediterranean. Forced to abort, he reached the approaches to St. Nazaire on April 11, whereupon fifteen Mosquitos attacked the U-boat and her escort. Ten JU-88s in turn attacked the Mosquitos and claimed five destroyed for the loss of three German planes. U-255 reached St. Nazaire with only slight damage.
THE ATLANTIC CONVOY WAR CONCLUDED
By early April 1944, the primary task of U-boat Control was to prepare three U-boat commands to repel Allied invaders. These were the Arctic force, the southern Norway force (group Mine, or Central), and the Atlantic force (group Landwirt). The aim was to build to thirty ready boats in the Arctic, another thirty in group Mitte, and about fifty in group Landwirt.
In effect, these U-boats were to play strictly defensive roles. Although the experience of war had demonstrated time and again that U-boats were virtually useless against alert, strongly escorted amphibious forces,* the U-boat force had no option but to do the best job it could. It was still Hitler’s “first line of defense” against invasion in the west. Equipped with snorts and the supposedly infallible T-5 torpedoes, the U-boats might delay and cause decisive damage to the invaders.
Only eleven U-boats sailed into the Atlantic in the month of April. Two were sent to the Mediterranean. Of the remaining nine, six were new boats from Norway that were to report weather, then put into France, five of these Type VIIs to reinforce group Landwirt. Three other boats sailed from France to serve as weather reporters, radio decoys to disguise the U-boat withdrawal from the North Atlantic, or for other purposes. These were to join about ten ex-Preussen boats still on patrols, including the two VII snort boats U-267 and U-667.
All the boats on patrol in the North Atlantic in April confronted saturation air patrols mounted by land-based and “jeep” carrier aircraft. Control logged about twenty different reported aircraft attacks on U-boats in April. Two resulted in U-boat sinkings, as will be described. However, the few boats with the Fliege radar detector, which could operate in the centimetric-wavelength band, reported good results, doubtless averting several other aircraft attacks.
On the other hand, reports from the boats at sea about the automatic, rapid-fire 37mm flak gun continued to be negative. By April, the OKM had established that some elements of the gun’s automatic-feed mechanism had been manufactured of nonrustproof metal, a striking stupidity. Until rustproof replacement parts could be made, tested, and distributed, the gun was not in the least reliable and, in almost all cases, had to be loaded by hand, an intolerable handicap while under enemy air attack. Besides that, more boats reported “rapid decay” of some of the gun’s supposedly exotic ammunition.
Owing to the steady flow of Enigma decrypts, Allied intelligence on U-boat movements in April was exceptionally thorough. Ironically, the Germans unintentionally helped Allied codebreakers by adding a new Stichwort procedure to take effect on April 13. In order that recently sailed boats could supply the boats already at sea with material for the change, a dozen or more rendezvous had to take place, arranged in the current Enigma. In one instance, the rendezvous failed owing to foul weather, and Control had to radio the new material to that boat in current Enigma, doubtless a windfall for Allied codebreakers.
The two boats that sailed to the Mediterranean in April were the U-731 and U-960, commanded by Alexander von Keller and Günther Heinrich, respectively. Heinrich got through (see below) but von Keller, a new skipper, did not. On the afternoon of May 15, two Catalinas of U.S. Navy Squadron VP 63, fitted with MAD gear, detected von Keller in U-73L The pilots, Matthias J. Vopatek and H. L. Worrell, attacked with retrorockets and, per doctrine, summoned British surface craft. The sloop Kilmarnock, corvette Aubrietia, and ASW trawler Black Fly responded, and Kilmarnock, commanded by K. B. Brown, blasted U-731 with depth charges and Hedgehogs that destroyed the boat. There were no survivors.
Apart from the attack of U-302 on Slow Convoy 156 and by U-621 on a destroyer, as related, three U-boats patrolling in the eastern North Atlantic had noteworthy encounters with enemy convoys or ships.
• The new VII U-385, commanded by Hans-Guido Valentiner, age twenty-three, which sailed from Norway on April 5 fitted with Fliege search radar. Southbound near Iceland on April 13, Valentiner attacked a “destroyer” of a small convoy with a T-5; it missed. Two days later he fired a three-torpedo salvo at what he described as an “Empress “-class ocean liner, but in fact it was the monster liner Queen Mary. He claimed “two hits” and “two boiler explosions,” but Queen Mary was not hit. On that day and at that place she reported a heavy “underwater explosion,” perhaps a premature or some other torpedo malfunction. On April 29, Valentiner shot a T-5 and reported a hit on a “destroyer” near the western mouth of North Channel, but it was not confirmed either.
• The VII snort boat U-667, formerly of group Preussen, commanded by Heinrich Schroeteler. On April 16, Schroeteler came upon a hunter-killer group and shot a T-5 at a “destroyer escort.” It missed and the group chased U-667 for twelve hours. The snort allowed Schroeteler to refresh the air in the boat during the chase and, finally, to escape. When he returned to France on May 19, he had high praise for the snort but cautioned that extensive drills were required to master snorting.
• The VII U-473, commanded by Heinz Sternberg, which sailed from Lorient on April 24, carrying a number of electronic specialists who were to test radars and radar detectors. On the night of April 28, a Halifax of British Squadron 58, fitted with a Leigh Light, found U-473 on radar. The Halifax dropped seven depth charges but Sternberg repelled the plane and continued onward. The next day, April 29, a Wellington of British Squadron 304 attacked the boat with six depth charges, but still Sternberg did not turn back. On May 3, when he happened upon the eastbound tanker convoy CU 22, he attacked boldly and hit the 1,400-ton American destroyer escort Donnell with a T-5. The explosion blew off the stern of this ship, killing twenty-nine men and wounding another twenty-five. Two other destroyer escorts, Reeves and Hopping, towed Don
nell to Londonderry, where she was converted to an accommodations (barracks) vessel. Sternberg erroneously reported a T-5 “miss.”
Of the nine boats that sailed for patrols in the North Atlantic in April, five were lost in April and early May. In brief:
• The new VII U-342, commanded by Albert Hossenfelder, age thirty-six, which sailed from Bergen on April 3 for weather-reporting duties en route to France. On the morning of April 17, a Canso (Catalina) of the Iceland-based Canadian Squadron 162, piloted by Thomas Charles Cooke, spotted U-342 on the surface and attacked out of the sun. Hossenfelder saw the Canso coming and put up heavy flak, but Cooke pressed on and dropped three close depth charges and riddled the superstructure with machine-gun fire. A few moments later, Cooke saw a “violent” explosion on the bow superstructure that destroyed the boat with the loss of all hands. The airmen reported that oil and all kinds of wreckage came to the surface (pieces of wood, cylindrical objects) but no bodies.
• The IXC40 U-193, which sailed from Lorient on April 23 to report weather and to serve as a provisional refueler if needed. This was the boat that had been driven into El Ferrol for repairs on February 10 at the end of her prior patrol, and finally reached Lorient on February 25. She had a new skipper, the lawyer Ulrich Abel, the former first watch officer of U-154, who had denounced his skipper, Oskar Kusch, for sedition and defeatism, resulting in a court-martial and death sentence.
In Biscay in the early hours of April 28, the sixth day out, the Admiralty believed, U-193 came under air attack. A Leigh Light-equipped Wellington of British Squadron 612, piloted by the Australian C. G. (Max) Punter, a veteran of the U-boat wars, supposedly got U-193 on radar and from wave-top level, dropped a salvo of depth charges that destroyed the boat. Punter reported “about ten small bluish lights in the water,” evidently illuminants on the life jackets of the German survivors. However, Niestlé doubts this kill and lists the cause of the loss of U-193 as unknown.