Hunter-Killers and Victory: U-505, the Schnorkel and the Last Patrols

After Black May the U-boats never again threatened to cut the Atlantic lifeline. For two more years they kept fighting, against escort carriers, aircraft and support groups that hunted them across the ocean, and with new weapons that came too late. On 4 June 1944 an American task group took one of them whole.

Why it mattered

The convoy battles of spring 1943, told in Chapter 7, decided that Germany would not win the Battle of the Atlantic. They did not end it. Grand Admiral Karl Dönitz pulled his wolf packs off the North Atlantic convoy routes on 24 May 1943, after losing 41 U-boats that month (uboat.net, “U-boat losses”), but the U-boats still tied down Allied escorts, aircraft and shipyards, and Germany was building new boats that might restore the balance. The battle went on for almost two more years, and most of the U-boat arm’s dead fell in those years.

What changed was who did the hunting. Until 1943 the escorts had mostly reacted to attacks on their convoys. From mid-1943 the Allies went after the U-boats themselves: in the Bay of Biscay, at their refueling rendezvous, and wherever code-breaking and direction-finding put them. The American instrument was the hunter-killer group, a small escort carrier and four or five destroyers or destroyer escorts, free to chase a contact to its end. By uboat.net’s count the Germans lost 244 U-boats in 1943 and 249 in 1944, against 87 in 1942.

These years also produced the most famous American action of the Atlantic war. On 4 June 1944 Capt. Daniel V. Gallery’s Task Group 22.3 forced U-505 to the surface off French West Africa, boarded her, kept her from sinking and towed her to Bermuda, the U.S. Navy’s first capture of an enemy warship on the high seas since 1815. The boat is in Chicago today.

After Black May: the hunt moves south

When Dönitz withdrew from the North Atlantic, he did not bring his boats home. He sent many of them into the central Atlantic around the Azores, across the American convoy routes to Gibraltar and Casablanca, and on to distant waters off Brazil, West Africa and in the Indian Ocean. Long patrols needed fuel. The Type VIIC boats that made up most of the fleet had reached the American coast in 1942 only because they could refuel at sea from the big Type XIV supply boats, the “milch cows” (uboat.net, “What is a Milch Cow?”). The supply boats became the hinge of the German effort outside the North Atlantic, and the Allies set out to break it.

On 20 May 1943 Admiral Ernest J. King created the Tenth Fleet, a Washington headquarters with no ships of its own, to direct the U.S. Navy’s antisubmarine war (Morison, vol. X). Its submarine tracking room, F-21, sent daily estimates of U-boat positions to commanders at sea (MSI, “Capturing the U-505”). When the Allies could read the U-boat cipher, as they could for most of the rest of the war, it could often say where a refueling rendezvous would take place.

The escort carriers let the Navy act on that knowledge. Built on merchant-ship hulls, they were small, slow and lightly protected, but each carried a composite squadron of Avenger torpedo bombers and Wildcat fighters. Bogue (CVE-9) had sailed with the first American hunter-killer group in March 1943; Core and Santee deployed in June and Card in July (NHHC, H-Gram 064-2). Bogue‘s first kill, U-569 on 22 May 1943, is told in Chapter 7. Her second came three weeks later, when eight of her Avengers caught the large Type XB minelayer U-118 west of the Canary Islands on 12 June and sank her with depth charges; 43 men died and 16 survived (uboat.net, U-118).

Killing the milch cows

Germany commissioned ten Type XIV supply boats, U-459 to U-464 from Deutsche Werke in Kiel and U-487 to U-490 from Germaniawerft. They had no torpedo tubes and no deck gun, only antiaircraft weapons, and they carried about 613 tonnes of fuel oil for the fighting boats, with lubricating oil, food, spare parts and a doctor (uboat.net, Type XIV). By uboat.net’s tally the ten boats supported 437 refuelings and resupplies between them.

A refueling took hours on the surface, with hoses strung between two boats lying close together. In the summer of 1943 the escort carriers, guided by the tracking room, began to arrive at those rendezvous. On 13 July five Avengers and Wildcats of VC-13 from Core caught U-487 southwest of the Azores; 31 men died and 33 were picked up by the destroyer Barker (uboat.net, U-487). The next day an Avenger from Santee sank U-160 south of the Azores with a Fido homing torpedo, the American air-dropped acoustic weapon carried under the cover name “mine”; all 57 men were lost (uboat.net, U-160; NHHC, H-Gram 064-2).

Capt. Arnold J. “Buster” Isbell’s Card group did the most damage. In five days in August it sank U-117, a Type XB minelayer serving as a supply boat, U-664 and U-525. On 27 August its aircraft sank U-847, another boat pressed into service as a tanker, and on 4 October they caught the milch cow U-460 refueling boats north of the Azores; two of her 64 men survived, and U-422 went down with her (NHHC, H-Gram 064-2). After losing two aircraft to U-boat flak, the squadron flew in teams of three: a Wildcat to strafe the gunners, an Avenger with bombs, and an Avenger with depth bombs and a Fido.

One of Card‘s escorts fought the strangest action of the campaign. On the night of 1 November 1943 the old four-stack destroyer Borie (DD-215), Lt. Charles H. Hutchins, USNR, rammed U-405 north of the Azores and fought her at point-blank range with the two ships locked together. U-405 sank with all hands. Borie had to be scuttled the next day; 27 of her men were lost, and her engineer officer, Lt. Morrison R. Brown, received the Navy Cross posthumously (NHHC, H-Gram 064-2). By the end of the war Card and Bogue had each been credited with 11 U-boats; Bogue‘s group also sank two Japanese submarines.

The other supply boats went the same way. U-463 was sunk in May 1943, U-459 was scuttled on 24 July after a Wellington caught her two days out of Bordeaux, U-489 was sunk south of Iceland on 4 August, and U-461 and U-462 were lost together in the Bay of Biscay on 30 July. Four destroyer escorts of the Croatan group sank U-488 with all 64 men on 26 April 1944, and the last of the class, U-490, was depth-charged northwest of the Azores on 12 June 1944; all 60 of her crew survived (uboat.net; NHHC, H-Gram 064-2). Uboat.net counts 289 dead among the 530 to 576 men who served in the milch cows. Without them, the Type VIIC boats could no longer reach distant waters.

The Bay of Biscay, summer 1943

Every U-boat based in France had to cross the Bay of Biscay twice on each patrol, outbound from Brest, Lorient, St. Nazaire, La Pallice or Bordeaux and home again. By 1943 the aircraft of RAF Coastal Command’s No. 19 Group carried centimetric radar that the U-boats’ Metox receivers could not detect, Leigh Lights for night attacks and better depth charges, and U.S. Navy Liberators joined them from southwest England. In the spring Dönitz tried to beat them by having the boats cross in small groups on the surface by day, with extra antiaircraft guns, and fight back (Blair, Hitler’s U-Boat War, vol. 2).

The policy reached its crisis on 30 July 1943. A Liberator of No. 53 Squadron RAF sighted three outbound boats together northwest of Cape Ortegal: the milch cows U-461 and U-462 and the Type IXC U-504. Its report brought six more aircraft and Capt. F. J. Walker’s 2nd Support Group (uboat.net, U-461). A Sunderland of No. 461 Squadron RAAF, flown by Flt. Lt. Dudley Marrows, sank U-461; 53 men died and 15 survived. A Halifax of No. 502 Squadron and the gunfire of Walker’s sloops Wren, Kite, Woodpecker, Wild Goose and Woodcock finished U-462, whose crew scuttled her; 64 of 65 men survived. The sloops then hunted down U-504 and sank her at 1543 with all 53 hands (uboat.net, U-462 and U-504).

Losses like these forced Dönitz to give up the group crossings and the order to fight it out on the surface in early August. Boats went back to crossing submerged by day and surfacing only at night, hugging the Spanish coast (Blair, vol. 2; Roskill, The War at Sea, vol. III). Sinkings in the bay fell, but the slow crossings cut days off every patrol.

The wren’s sting: Zaunkönig and Foxer

Dönitz’s answer to the escorts was a new torpedo. The T5, named Zaunkönig (wren) and known to the Allies as the GNAT, for German Naval Acoustic Torpedo, was an electric torpedo with a passive acoustic homing head. It ran at 24 knots for up to 5,700 meters and, after a run of 400 meters, steered toward the loudest noise in the water: in practice, the propellers of an escort coming in to attack (uboat.net, “Torpedoes”). The idea was to shoot the escorts first and then fall on the merchant ships. In September 1943 Dönitz sent his boats back to the North Atlantic with it.

The first test came between 19 and 23 September against two westbound convoys, ONS 18 and ON 202, attacked by the 21 boats of group Leuthen. On 19 September U-270 hit the frigate HMS Lagan with a T5, the first Allied warship damaged by the weapon. The next day U-305 sank the Canadian destroyer HMCS St. Croix, and U-952 sank the corvette HMS Polyanthus, which had one survivor. The frigate HMS Itchen picked up 81 of St. Croix‘s men and the survivor from Polyanthus; on the night of 22–23 September U-666 torpedoed Itchen herself, and only three men were rescued, two of her own crew and one from St. Croix. The U-boats claimed 12 escorts and nine merchant ships. The real figures were three escorts and six merchant ships sunk, for three U-boats destroyed (Roskill, vol. III; Blair, vol. 2; uboat.net).

The Allies had expected an acoustic torpedo and had a countermeasure ready within weeks. The British Foxer, and its Canadian and American cousins, the CAAT and the FXR, were noisemakers towed astern of an escort, rattling metal bars that made more noise than the ship’s propellers and drew the torpedo to the decoy. They interfered with the escort’s own sonar and limited its speed, but they worked. The T5 was never the war-winner the Germans had hoped for, though it kept sinking escorts until the last weeks of the war, and it was dangerous to its users. U-boats were ordered to dive to 60 meters at once after a bow shot, and uboat.net judges that U-972 in December 1943 and U-377 in January 1944 were almost certainly sunk by their own torpedoes.

The hunters in 1944

By 1944 the hunting was methodical. In January and February Walker’s 2nd Support Group sank six U-boats in a single patrol west of the British Isles: U-592 on 31 January, U-762, U-238 and U-734 on 9 February, U-424 on 11 February and U-264 on 19 February (uboat.net). U-264 had been fitted with a schnorkel only two months earlier; Woodpecker and Walker’s own Starling sank her southwest of Ireland, and all 52 of her crew were rescued (uboat.net, U-264). Walker died of a cerebral thrombosis on 9 July 1944, worn out, and was buried at sea from the destroyer Hesperus off Liverpool.

The American groups were working farther south. Block Island (CVE-21) caught U-1059, carrying torpedoes to the Indian Ocean, southwest of the Cape Verde Islands on 19 March 1944; only eight of her crew survived (uboat.net, U-1059). On 6 May her destroyer escort Buckley (DE-51), Lt. Cmdr. Brent M. Abel, was vectored by an unarmed night-patrol Avenger onto U-66 on the surface. Buckley hit her with 3-inch and 40-mm fire and rammed her, and U-66 sank within minutes; Buckley lost no one, and Abel received the Navy Cross (NHHC, H-Gram 064-2).

Three weeks later the hunters lost a carrier. On the evening of 29 May 1944, west of the Canary Islands, U-549 (Kptlt. Detlev Krankenhagen) slipped inside Block Island‘s screen and hit her with three torpedoes, at 2015 and 2023; she sank at 2155. Seven of her crew died, four of her airborne pilots were never recovered, and the destroyer escorts Ahrens and Robert I. Paine rescued 951 men. U-549 also damaged the destroyer escort Barr before Eugene E. Elmore sank her with a Hedgehog salvo, killing her whole crew (NHHC, H-Gram 064-2; uboat.net, U-549). Block Island was the only American aircraft carrier lost in the Atlantic.

Gallery’s Guadalcanal group had made its own reputation in April. On 9 April 1944 its Avengers and Wildcats, firing rockets, and the destroyer escorts Pope, Pillsbury, Chatelain and Flaherty sank U-515 northwest of Madeira. Her commander, Kptlt. Werner Henke, was among the 44 survivors; he was shot dead on 15 June 1944 while feigning an escape at an American interrogation camp, which uboat.net describes as suicide. The next day the group’s aircraft sank U-68 nearby, with one survivor (uboat.net, U-515 and U-68). Gallery was already thinking about something more ambitious than sinking U-boats.

U-505: the hunt

U-505 was a Type IXC, built by Deutsche Werft in Hamburg and commissioned on 26 August 1941. She sank eight ships of 45,005 tons, most of them in 1942 under Kptlt. Axel-Olaf Loewe. Then her luck turned. Under Kptlt. Peter Zschech she was damaged and forced back to port again and again, and on 24 October 1943, during a heavy depth-charge attack, Zschech shot himself, the only such case among U-boat commanders in the war, according to uboat.net. Paul-Franz Meyer brought her home. Her last commander, Oblt. z. S. Harald Lange, a reserve officer, took over in November 1943 (uboat.net, U-505).

Task Group 22.3 sailed from Norfolk on 15 May 1944 for an antisubmarine patrol near the Cape Verde Islands: the escort carrier Guadalcanal (CVE-60), with composite squadron VC-8, and the five destroyer escorts of Escort Division 4, Pillsbury (DE-133), Pope (DE-134), Flaherty (DE-135), Chatelain (DE-149) and Jenks (DE-665) (NHHC, “Defeating the Sharks”; MSI). Gallery had ordered every ship to organize a boarding party; he meant to capture the next U-boat his group brought to the surface (Gallery, “Wrangling a Runaway U-Boat,” Naval History).

For days the Wildcats and Avengers searched for a U-boat the tracking room had placed in the area, without result, and on the morning of Sunday, 4 June, low on fuel, Gallery called off the search and turned for Casablanca (MSI). The group was about 150 miles off Rio de Oro, on the coast of French West Africa (NHHC). Chatelain, Lt. Cmdr. Dudley S. Knox, was on her station in the screen, zigzagging with the carrier at 13 knots.

At about 1109 by the Greenwich time that Chatelain‘s report used (the museum gives 1110), her sonar operator reported a contact at about 800 yards. At 1116 she fired a Hedgehog pattern, which missed. Two Wildcats were overhead, and at 1117 one fired into the water to mark where the pilot could see the U-boat. At 1121 Chatelain dropped a full pattern of 14 depth charges set shallow (USS Chatelain action report, uboatarchive.net). The pilot’s messages to the ship survive in her report.

In their words

You struck oil. … Sub is surfacing.

The depth charges jammed U-505’s rudder, put her auxiliary steering out of action and started flooding aft (NHHC). Lange, believing his boat was going down, blew his tanks. At about 1122 she broke surface bow first some 700 yards from Chatelain, which opened fire with every gun that would bear. The escorts and Wildcats raked her deck, and her crew went over the side as she ran in a circle, rudder jammed. In the firing three of the crew were wounded and one sailor, Gottfried Fischer, was killed, the only German death of the action (National WWII Museum; MSI). The scuttling procedure was only partly carried out (NHHC).

U-505: “Away the boarding party”

Gallery wanted the boat, not a kill. Escort Division 4’s commander, embarked in Pillsbury, ordered her whaleboat away. Lt. (j.g.) Albert L. David, a former enlisted man, led a party of eight enlisted men across to the circling submarine, which Gallery put at about 10 knots with her rudder hard over (the citation says 5 or 6). The whaleboat came alongside, and David, torpedoman Arthur W. Knispel and radioman Stanley E. Wdowiak went down the conning tower hatch with grenades and submachine guns, expecting to meet the crew. They found the boat empty except for Fischer’s body on deck.

What they found below was worse. Water was pouring in through an open bilge strainer about eight inches across whose cover had been knocked off, and the vents were open (Gallery, Naval History). The boat was settling by the stern. The boarders found the strainer’s cover and screwed it back on, closed the vents and valves they could find, and disconnected the scuttling charges the crew had set (MSI). The party gathered up code books, signal publications and other secret material and passed them up to the whaleboat (NHHC).

Medal of Honor

Lt. (j.g.) Albert L. David, USS Pillsbury

His citation records that he “boldly led a party from the Pillsbury” aboard the German submarine “as it circled erratically at 5 or 6 knots on the surface.” Knowing the boat might “momentarily sink or be blown up by exploding demolition and scuttling charges,” he braved enemy gunfire to “plunge through the conning tower hatch” and, with his small party, kept her afloat until help arrived. It calls the action the “first successful boarding and capture of an enemy man-o-war on the high seas by the U.S. Navy since 1815.” David, born in Maryville, Missouri, in 1902, was a former enlisted man. He died of a heart attack at Norfolk on 17 September 1945, before the medal could be presented; the Congressional Medal of Honor Society records its presentation to his widow at Great Lakes, Illinois, on 9 November 1945. It is displayed with U-505 in Chicago.

Citation →

Keeping her afloat was another matter. When Pillsbury tried to come alongside to pass a towline, stopping the U-boat’s engines let her stern sink dangerously, so the boarders restarted them and the stern planes lifted it again. The submarine’s bow planes then tore a long gash in Pillsbury‘s side below the waterline, flooding two main compartments, and the destroyer escort had to back away (Gallery, Naval History). U-505 rode so low that the hatch was shut over the men working inside to keep the swells out; had she gone down, Gallery noted, they would have had no way out.

Gallery decided that only the carrier could tow her. He brought Guadalcanal close aboard, had the U-boat’s engines stopped and a towline passed, and got her moving again. A second boarding party from the carrier, led by her chief engineer, Cmdr. Earl Trosino, USNR, took charge of the salvage (Gallery, Naval History). Trosino worked in the bilges for hours to make her watertight (MSI). Damage-control parties recharged the boat’s nearly flat batteries, which let them run her pumps, emptied the flooded compartments and restored her proper trim (NHHC).

Meanwhile the escorts picked up the crew; Chatelain alone took aboard 48 men, including Lange. The National WWII Museum and MSI count 58 survivors; uboat.net gives 59. The capture position was 21°30′N, 19°20′W by uboat.net’s reckoning; Chatelain‘s report logged it as 21°30′N, 19°10′W at 1127.

U-505: the long tow and the long secret

Guadalcanal towed the U-boat for three days. On 7 June the fleet tug Abnaki (ATF-96) took over the tow, and the oiler Kennebec came out to refuel the escorts (Guadalcanal Task Group 22.3 Association, “Third ASW Cruise”). The museum calls the 2,500-mile passage to Bermuda the longest tow of the war. U-505 arrived in Bermuda on 19 June 1944, where she was kept in secret for trials and training (uboat.net).

The haul made the capture matter. The boarders brought out classified publications, code books, an Enigma cipher machine with current rotors and her radio equipment (NHHC). The National WWII Museum’s account says the captured material helped American cryptanalysts break the special codes the U-boats used to disguise grid positions in their signals, improving the Allies’ picture of where U-boats were patrolling. Its value depended on the Germans not knowing, and the salvage of a whole boat worried officers who feared it would give the secret away (NHHC).

The crew paid for that secrecy. The prisoners went to an isolated compound at Camp Ruston, Louisiana. Their names were withheld from the International Red Cross, and they were not allowed to write home, contrary to the Geneva Convention (National WWII Museum, “Louisiana’s Camp Ruston”; MSI). By August 1944 the German Navy had told their families that the men must be presumed dead. The capture was announced publicly only in a press release of 16 May 1945, after the war in Europe was over, and the last of the crew did not get home until 1947 (MSI).

Neptune: holding the Channel

Two days after U-505 was taken, the Allies landed in Normandy. The ships of Operation Neptune, the naval part of the invasion, and the cross-Channel convoys that followed were the richest target the U-boats would ever have. Dönitz had held a group of boats ready in the Biscay ports for just this, and on 6 June he ordered them toward the invasion area (Roskill, vol. III).

The Allies had planned for them. Coastal Command filled the western approaches to the Channel with closely spaced air patrols, and support groups covered the sea lanes beneath them. The boats without schnorkels, forced to surface to charge their batteries, were bombed again and again, and within days they were withdrawn (Roskill, vol. III; Blair, vol. 2). Only schnorkel boats could stay down long enough to work their way into the Channel.

They had some successes. On 15 June 1944 schnorkel boats sank two British frigates in the Channel approaches: U-767 sank HMS Mourne, and U-764 sank HMS Blackwood (uboat.net). But the cost was high. U-767 was hunted down by the destroyers Fame, Inconstant and Havelock southwest of Guernsey on 18 June, with one survivor among her 50 men (uboat.net, U-767). Against the scale of the invasion traffic, the U-boats’ results were small (Roskill, vol. III).

The invasion also took away the U-boats’ best bases. As the American armies broke out of Normandy and into Brittany in August 1944, the boats that could still sail left Brest, Lorient, St. Nazaire and La Pallice for Norway. German garrisons held several of the ports as fortresses until the end of the war, but from the autumn of 1944 the U-boat war was fought from Norway and Germany.

The schnorkel and the inshore war

A U-boat that no longer had to surface to charge its batteries was very hard for radar to find, and that undid much of what had won the battles of 1943. The price was mobility. A schnorkel boat could not shadow a convoy or join a wolf pack; it crept to a patrol area and waited. So the U-boats came inshore, to the coastal waters of Britain, Canada and the United States, where shipping passed through narrow channels and wrecks, rocks and tide rips confused sonar.

U-482, Kptlt. Hartmut Graf von Matuschka, showed what a schnorkel boat could do. Working the approaches to the North Channel between Scotland and Ireland, she sank the American tanker Jacksonville on 30 August 1944, the corvette HMS Hurst Castle on 1 September, the Norwegian Fjordheim on 3 September, and Empire Heritage and Pinto from convoy HX 305 on 8 September (uboat.net, U-482). She was lost with all hands in November.

The same tactics came to North American waters. U-1228 sank the Canadian corvette HMCS Shawinigan in the Cabot Strait on 25 November 1944 (uboat.net). In December U-1230 landed two spies, William Colepaugh and Erich Gimpel, on the coast of Maine; both were soon captured (NHHC, H-Gram 047). The numbers sunk were not large, but the schnorkel boats tied down huge numbers of escorts and aircraft, which found them much harder to kill.

The electro-boats

Germany’s real hope was a new kind of submarine. The Type XXI was designed in 1943 to spend almost its whole patrol submerged: a streamlined hull, three times the battery capacity of a Type VIIC and a top submerged speed of 17.2 knots, faster than many convoy escorts and faster than its own surface speed of 15.6 knots. It needed to run its schnorkel for three to five hours every two or three days to recharge (uboat.net, Type XXI). The small Type XXIII, built for coastal waters, carried just two torpedoes, loaded from outside in harbor, and could make 12.5 knots submerged (uboat.net, Type XXIII). Both were built in prefabricated sections and assembled at Hamburg, Bremen and Danzig.

They came too late. Uboat.net counts 118 Type XXI and 61 Type XXIII boats commissioned, but bombing, hurried construction, mined training areas and a shortage of trained crews kept almost all of them out of action. The NHHC counts only five Type XXI and one Type XXIII that actually set out on combat patrols. The Type XXIII boats that did sail, around the British Isles from early 1945, sank four ships of 7,392 tons between them (uboat.net). Only one Type XXI, U-2511 under Korvkpt. Adalbert Schnee, made a war patrol, leaving Bergen on the evening of 30 April 1945. On 4 May, after receiving the cease-fire order, Schnee said he had slipped undetected to within about 500 meters of the British cruiser HMS Norfolk and could have torpedoed her, then withdrew. Later writers have questioned his account (uboat.net, U-2511).

Operation Teardrop

The last big American operation of the Atlantic war was fought against a weapon that did not exist. From the autumn of 1944 rumors spread, some of them from the spies landed in Maine, that the Germans would fire V-weapons from submarines at American cities. In January 1945 the German armaments minister, Albert Speer, said in a broadcast that V-weapons would strike New York by February, and on 8 January Adm. Jonas H. Ingram, commanding the U.S. Atlantic Fleet, told a press conference that rocket attacks on the East Coast were possible (NHHC, H-Gram 047). The Tenth Fleet and the Admiralty doubted it, but when decrypts in March showed a group of U-boats heading for the American coast, the Navy prepared for the worst.

The group was called Seewolf: six Type IXC schnorkel boats, U-518, U-546, U-805, U-858, U-880 and U-1235, which left Norway in mid-March 1945 bound for the U.S. East Coast. Ingram set two barrier forces of escort carriers and destroyer escorts across their path in mid-ocean. The First Barrier Force, with Mission Bay to the north and Croatan to the south and 20 destroyer escorts, formed a line about 120 miles long along the 30th meridian south of Iceland in early April (NHHC, H-Gram 047). Fog and mountainous seas grounded the aircraft much of the time.

The destroyer escorts did the work. At 2135 on 15 April, in fog, Stanton (DE-247) picked up U-1235 on radar, running on the surface because the seas were too heavy for her schnorkel; with Frost (DE-144) she made three Hedgehog attacks, and at 0333 on 16 April the U-boat blew up. At 0406 Stanton‘s Hedgehogs destroyed U-880 nearby with an explosion felt aboard Croatan 15 miles away. Both boats were lost with all hands. Late on 21 April Carter (DE-112) sank U-518 with a Hedgehog attack at 2309 (NHHC, H-Gram 047).

The Second Barrier Force, with Bogue (Capt. George J. Dufek) and Core (Capt. R. S. Purvis) and 22 destroyer escorts strung across 120 miles at five-mile intervals, took over on 21 April and swept east. On 23 April Dönitz, not knowing that half the group was gone, broke up Seewolf and ordered its boats to operate independently. The next morning, 24 April, U-546 (Kptlt. Paul Just), stalking Bogue, was detected by the destroyer escort Frederick C. Davis (DE-136). At 0830, before the escort could attack, Just hit her with an acoustic torpedo at about 650 yards, on the port side forward of the engineering spaces, though she was streaming her Foxer gear. She broke in two and sank within minutes, taking her commanding officer, Lt. James R. Crosby, USNR, with her (NHHC, H-Gram 047; uboat.net).

Eight destroyer escorts hunted U-546 for the rest of the day. Flaherty, one of U-505’s captors, made the decisive Hedgehog attack at 1810, holing the pressure hull and releasing chlorine gas from the batteries. At 1838 U-546 surfaced and fired a last torpedo at Flaherty, which missed; the escorts’ guns opened up, and at 1845 she sank. Just and 32 of his men were rescued (NHHC, H-Gram 047; uboat.net, U-546). At Argentia, Newfoundland, and later at the Fort Hunt interrogation center in Virginia, Just and several of his men were beaten by interrogators trying to learn about rocket submarines; the skipper of Varian protested what he saw. They had nothing to tell. U-546 carried no rockets. Philip K. Lundberg, a junior officer among the survivors of Frederick C. Davis who became a naval historian, later called the treatment of the prisoners “a singular atrocity” (NHHC, H-Gram 047).

The last patrols: Eagle 56, Black Point and U-853

Not every U-boat on the American coast was part of Seewolf. U-853, under 24-year-old Oblt. z. S. Helmut Frömsdorf, was patrolling the Gulf of Maine. Shortly after noon on 23 April 1945 the old patrol boat Eagle 56 (PE-56), towing targets three miles off Cape Elizabeth, Maine, blew up and sank. Survivors saw a submarine with a red and gold emblem, but a court of inquiry blamed a boiler explosion. In 2001, after a Naval Historical Center review, the Navy concluded that U-853 had torpedoed her, the only time it has overturned a court of inquiry (NHHC, H-Gram 047). Most accounts give 49 men killed and 13 survivors.

On 4 May Dönitz, now Hitler’s successor as head of the German state, ordered all U-boats to cease hostilities (uboat.net, U-2511). Frömsdorf did not stop, or did not get the message. At 1740 on 5 May, about five miles southeast of Point Judith, Rhode Island, U-853 torpedoed the collier Black Point, carrying 7,759 tons of coal from Newport News to Weymouth, Massachusetts. The torpedo blew off about 40 feet of her stern, and she capsized and sank about 25 minutes later. Twelve of the 46 men aboard died, 11 merchant seamen and one Naval Armed Guard sailor (uboat.net, Black Point; NOAA Ocean Exploration). The NHHC names Boatswain’s Mate Second Class Lonnie Whitson Lloyd as the last U.S. sailor killed in the Battle of the Atlantic. Black Point was the last American merchant ship sunk by a U-boat in the war.

The Yugoslav freighter Kamen (Karmen at uboat.net) rescued survivors and radioed the position. A hunter-killer group under Cmdr. Francis C. B. McCune in the destroyer Ericsson was nearby, and the destroyer escorts Atherton (DE-169) and Amick (DE-168) and the Coast Guard-manned frigate Moberly (PF-63) began the search within about 90 minutes of the sinking. Atherton, Lt. Cmdr. Lewis Iselin, found U-853 in about 100 feet of water east of Block Island and attacked at 2028 and again at 2337. At about 0200 on 6 May Moberly made a full Hedgehog attack, and the U-boat stopped moving. Through the morning the ships, with the Navy blimps K-16 and K-58 overhead, dropped more than 100 depth charges. At 1230 a diver from the rescue ship Penguin reported the pressure hull split open (NHHC, H-Gram 047). None of U-853’s crew survived; the NHHC gives 54 dead, uboat.net and NOAA 55.

U-853 is often called the last U-boat sunk in the Battle of the Atlantic, but she was not quite the last. A few hours earlier, at 0413 on 6 May, the destroyer escort Farquhar of the Mission Bay group had depth-charged U-881 as she maneuvered to attack the carrier, and the U-boat was lost with all hands; the NHHC calls her the last U-boat sunk by U.S. forces. British aircraft sank more boats in European waters in the last days.

Surrender

Dönitz, head of state since Hitler’s suicide on 30 April, sent his cease-fire order to the U-boats on 4 May. In the early hours of 5 May his staff apparently sent the code word Regenbogen (“Rainbow”), the signal to scuttle rather than surrender; Dönitz recalled it within minutes because it would have broken the surrender terms being negotiated (NHHC, “Victory in Europe”). The NHHC counts 55 U-boats scuttled between 1 and 4 May ahead of the Allied armies, 87 more on 5 May, 98 surrendered in German and Norwegian ports and 52 at sea.

Not every boat heard in time. On 7 May, the day the surrender was signed at Reims, U-1023 sank the Norwegian minesweeper NYMS 382 off Lyme Bay at 2145; 22 of her 32 men died (uboat.net). Later that night, at 2303 and 2306, the Type XXIII U-2336, Kptlt. Emil Klusmeier, attacked a coastal convoy near May Island in the Firth of Forth and sank the steamer Avondale Park and the Norwegian Sneland I, killing two men in the first and seven in the second. Uboat.net records these as the last attacks by a U-boat in the Second World War. The surrender required all German forces to cease active operations at 2301 Central European Time on 8 May.

U-boats still at sea were ordered to surface, fly a black flag, report their positions and steer for designated ports. Several of the boats that surrendered at sea in the western Atlantic were brought into American ports. U-858, Kptlt. Thilo Bode, surrendered to Pillsbury and Pope on 10 May and was escorted to the Delaware Capes on 14 May; as the first boarded, she is often called the first German warship to surrender to American forces (NHHC, H-Gram 047; uboat.net). U-805 was met by Varian southeast of Cape Race on 12 May and taken to the Portsmouth Navy Yard in Kittery, Maine, arriving on 14 May (NHHC) or 15 May (uboat.net). U-1228 surrendered to Neal A. Scott and reached Portsmouth on 17 May.

The most remarkable was U-234, a Type XB minelayer converted to carry cargo, which had left Norway on 15 April for Japan. Her commander, Kptlt. Johann-Heinrich Fehler, chose to surrender to the Americans, and on 14 May the destroyer escort Sutton met her south of the Grand Banks and brought her into Portsmouth on 19 May. Her cargo included about 560 kg of uranium oxide (the U.S. unloading manifest says 550 kg), Me 262 jet-fighter drawings, mercury, optical glass and diplomatic mail, but, contrary to persistent rumor, no aircraft (uboat.net). Her passengers included the Luftwaffe general Ulrich Kessler, Messerschmitt engineers and two Japanese officers, Lt. Cmdr. Hideo Tomonaga and Lt. Cmdr. Genzo Shoji, who took their own lives rather than be captured.

Timeline

Hunter-killers and victory, 1943–1945

1. 20 May 1943King creates the Tenth Fleet to direct the U.S. antisubmarine war.
2. 24 May 1943Dönitz withdraws the wolf packs from the North Atlantic convoy routes.
3. 30 July 1943U-461, U-462 and U-504 sunk together in the Bay of Biscay.
4. 19–23 Sept 1943First use of the Zaunkönig acoustic torpedo, against ONS 18 and ON 202.
5. 31 Jan–19 Feb 1944Walker’s 2nd Support Group sinks six U-boats in one patrol.
6. 29 May 1944U-549 sinks Block Island.
7. 4 June 1944Task Group 22.3 captures U-505 off French West Africa.
8. 6 June 1944D-Day. U-boats sent against the invasion achieve little.
9. Aug–Sept 1944U-boats leave the French bases for Norway; U-482’s schnorkel patrol off the North Channel.
10. 24 Apr 1945U-546 sinks Frederick C. Davis and is sunk.
11. 4 May 1945Dönitz orders all U-boats to cease hostilities.
12. 5–6 May 1945U-853 sinks Black Point and is sunk off Block Island; U-881 sunk by Farquhar.
13. 7 May 1945U-2336 makes the last U-boat attack of the war, in the Firth of Forth.
14. 10–19 May 1945U-858, U-805, U-1228 and U-234 surrender and are brought into American ports.
15. 17 Nov 1945–11 Feb 1946Operation Deadlight: 116 surrendered U-boats sunk off Northern Ireland.

Surrendered boats in British waters were gathered at Loch Ryan in Scotland and at Lisahally on the River Foyle near Londonderry (Roskill, vol. III). The Allies agreed to keep 30 of them, ten each for Britain, the United States and the Soviet Union; the U.S. Navy took the Type XXI boats U-2513 and U-3008 and commissioned them under their German numbers (NHHC). The rest were destroyed. In Operation Deadlight, between 17 November 1945 and 11 February 1946, the Royal Navy towed 116 U-boats to sea areas about 100 miles northwest of Ireland and sank them, mostly by gunfire; 56 foundered on the way (Paterson, Black Flag; Waller, uboat.net). U-505 escaped that end because she had been captured, not surrendered.

People

Capt. Daniel V. Gallery (1901–1977), a Chicagoan and a naval aviator, commanded Guadalcanal and Task Group 22.3. He planned the capture of U-505 in advance, brought the boat to his hometown after the war, retired as a rear admiral and wrote a series of books about the Navy.

Lt. (j.g.) Albert L. David (1902–1945), of Maryville, Missouri, had come up from the enlisted ranks before being commissioned. He led the boarding of U-505, received the Medal of Honor, and died of a heart attack at Norfolk in September 1945.

Cmdr. Earl Trosino, USNR, Guadalcanal‘s chief engineer, led the salvage party that kept U-505 afloat and made her fit for the 2,500-mile tow to Bermuda.

Capt. Arnold J. Isbell led Card‘s hunter-killer group through its run of kills in 1943. He was killed on 19 March 1945 aboard the carrier Franklin off Japan.

Capt. Frederic John Walker, RN (1896–1944), led the 2nd Support Group from the sloop Starling and was credited with about 20 U-boats, more than any other Allied commander. He died of a cerebral thrombosis, brought on by exhaustion, on 9 July 1944 and was buried at sea off Liverpool.

Grand Adm. Karl Dönitz (1891–1980) commanded the U-boat arm from 1935 and the whole German navy from January 1943, and succeeded Hitler as head of state in the last week of the war. Convicted at Nuremberg of war crimes and crimes against peace, he served ten years in Spandau prison.

Oblt. z. S. Harald Lange, a reserve officer, commanded U-505 from November 1943 to her capture. He spent the rest of the war as a prisoner in the United States.

Oblt. z. S. Helmut Frömsdorf, 24, commanded U-853 on her last patrol, which sank Eagle 56 and Black Point. He and his whole crew were killed off Block Island on 5–6 May 1945.

Losses and uncertainty

Uboat.net counts 244 U-boats lost in 1943, 249 in 1944 and more than 120 in the first five months of 1945, well over half of all the boats lost in the war. For the war as a whole, the figures usually given are about 1,150 to 1,170 U-boats commissioned and about 780 to 785 lost to all causes at sea and in port, and about 28,000 to 30,000 of some 40,000 U-boat men killed (uboat.net; Niestlé, German U-Boat Losses). The memorial at Möltenort near Kiel lists about 30,000 names. The Allied cost of the battle, about 3,500 merchant ships and some 72,000 seamen and airmen, is examined in Chapter 9.

By the numbers

U-boats lost each year, 1939–1945

U-boats lost to all causes, by year, as counted by uboat.net

1939 (Sep–Dec)9

194024

194135

194287

1943244

1944249

1945 (Jan–May)120+

Many individual figures vary. The number of U-505’s crew captured is 58 in the National WWII Museum’s and MSI’s accounts and 59 at uboat.net; the one man killed is named Gottfried Fischer by MSI. The deaths in Frederick C. Davis are given as 115 in the Dictionary of American Naval Fighting Ships, 113 of 195 aboard at uboat.net, and 126 of 192 in the NHHC’s H-Gram 047, differences that probably reflect different muster lists. U-853’s dead are 54 in the NHHC account and 55 at uboat.net and NOAA. Eagle 56‘s crew is given as 62 or 67, with 13 survivors either way; U-549’s dead are 57 at uboat.net and 54 in the NHHC account.

The end-of-war counts are the hardest. The NHHC’s figures add up to 296 boats. Uboat.net counts 238 scuttled and 155 surrendered; Blair gives 222 scuttled and 174 surrendered; Kemp and Tarrant give 218 and 154; Niestlé gives 195 and 150. Much of the difference depends on whether decommissioned, damaged or unfinished boats are counted. Even the number of electro-boats that sailed differs: the NHHC says five Type XXI and one Type XXIII, while uboat.net describes six Type XXIII boats on patrol and only one Type XXI war patrol.

Questions readers ask

What was a hunter-killer group?

An American task group built around an escort carrier, with a composite squadron of Avengers and Wildcats, and four or five destroyers or destroyer escorts. Unlike a convoy escort, it went where intelligence placed the U-boats and stayed on a contact until it was sunk. The groups sank dozens of U-boats, including most of the German supply boats.

Why was capturing U-505 such a big deal?

For two reasons. It was the first time since 1815 that the U.S. Navy had boarded and captured an enemy warship on the high seas, and it brought the Allies an intact Enigma machine with current rotors, code books and signal publications, which helped the code-breakers. It also gave American engineers a working U-boat to study. The capture was kept secret until after Germany surrendered.

Did Germany really plan to fire rockets at New York from submarines?

Not in 1945. Germany had experimented with rockets fired from a submerged U-boat earlier in the war, and spies and propaganda spread the idea, but none of the Seewolf boats carried rockets.

Was U-853 the last U-boat sunk in the war?

She was the last sunk off the American coast and among the last sunk anywhere, but not the very last. U-881 was sunk by Farquhar in mid-ocean a few hours earlier on 6 May, and British aircraft sank boats in European waters into 7 May. The last U-boat attacks of the war came on the night of 7 May, by U-1023 off Lyme Bay and U-2336 in the Firth of Forth.

Could the Type XXI have changed the outcome?

It was the most advanced submarine of the war and much harder to catch than a Type VIIC, but it came too late and in too few working numbers. Only one made a war patrol, and it sank nothing. Its real influence came after the war, as the model for American, British and Soviet submarines.

How it connects

This chapter picks up where Chapter 7, Crisis and Black May, leaves off: the convoy battles of spring 1943, the closing of the air gap and the first kills by Bogue‘s aircraft. The intelligence that let the hunter-killer groups find the supply boats, and the Enigma machine and code books taken from U-505, belong to the story of the code-breakers told in Chapter 5, Codes and Science. The schnorkel boats that came to the American coast in 1944 and 1945 were following the path of the first U-boats that reached North Carolina in 1942, told in Chapter 4, Torpedo Junction. The cost of the whole battle, and the ways the men who fought it are remembered, are the subject of the next and last chapter, Chapter 9, The Cost and the Memory. For the whole story, return to the Battle of the Atlantic collection, its timeline and the FAQ.

What happened afterward

After the war U-505 lay at the Portsmouth Navy Yard, where the Navy planned to use her as a target. Gallery led a campaign to bring her to the Museum of Science and Industry in his hometown, and Chicagoans raised the money to move her. The Navy turned her over to the museum on 9 March 1954 (uboat.net), and she was towed through the St. Lawrence and the Great Lakes and brought ashore beside the museum. She was designated a National Historic Landmark in 1989 (NHHC) and is one of only two surviving Type IXC U-boats.

The surrendered boats that reached American ports were tested and then disposed of. U-805 and U-1228 were sunk as targets off Cape Cod by the submarine Sirago in February 1946; U-858 was scuttled by Sirago on 21 November 1947; and U-234 was torpedoed by Greenfish in trials northeast of Cape Cod on 20 November 1947 (uboat.net). U-2513 and U-3008 taught the U.S. Navy what a fast submarine could do. Their lessons shaped the American GUPPY conversions of wartime submarines, and the hunter-killer group survived into the Cold War, aimed at Soviet submarines descended from the Type XXI.

The wrecks of U-853 and Black Point lie a few miles apart in Rhode Island Sound, and in 2019 the wreck of Eagle 56, found off Cape Elizabeth by civilian divers, confirmed the Navy’s 2001 finding (NHHC, H-Gram 047).

Walking the ground today

The best place to see this chapter is Chicago. U-505 is displayed indoors in its own climate-controlled gallery at the Griffin Museum of Science and Industry in Hyde Park, with the conning tower shell damage from 4 June 1944 still visible, an account of the hunt and capture, Albert David’s Medal of Honor, and an optional guided tour of the boat’s interior. In Germany, the Type XXI U-2540, now Wilhelm Bauer, can be visited at Bremerhaven, and the Type VIIC U-995 stands at Laboe near Kiel.

On the American coast, the wreck of U-853 lies in about 127 to 130 feet of water east of Block Island, Rhode Island, and is a popular but demanding dive. It is a war grave, with many of the crew still inside, and should be treated as one; the wreck of Black Point lies about six miles away, near Point Judith (NOAA Ocean Exploration; uboat.net). The Portsmouth Naval Shipyard at Kittery, Maine, where U-805, U-1228, U-234 and other surrendered boats were brought in May 1945, is an active base with restricted access; its history is kept by the shipyard’s museum. Off Northern Ireland, the Deadlight wrecks lie in deep water northwest of Malin Head, and Lisahally on the River Foyle, where the U-boats were moored after the surrender, is now a working port.

In North Carolina, the Graveyard of the Atlantic Museum at Hatteras tells the U-boat war along the Outer Banks and displays the Enigma machine recovered from U-85, sunk off Nags Head in 1942. The Monitor National Marine Sanctuary’s Battle of the Atlantic research has surveyed U-boat and merchant wrecks off the state’s coast, and the British Cemetery at Ocracoke honors the crew of HMT Bedfordshire. Those sites belong to the 1942 campaign described in Chapter 4. Check each site’s current hours and access rules before you go.

Sources and further reading

• Naval History and Heritage Command, “Defeating the Sharks: The Capture of U-505” and “Imagery of U-505’s Capture and Salvage.”
• NHHC, Director’s Corner H-Grams: H-047-1, “The Last Battle of the Atlantic: Operation Teardrop” (Seewolf, Frederick C. Davis, U-546, Eagle 56, U-853, U-881 and the surrenders) and H-064-2, “Close Quarters Antisubmarine Warfare (Part 2)” (Card, Borie, Buckley, Block Island).
• NHHC, “Victory in Europe: Germany’s Surrender and Aftermath” (Regenbogen and the U-boat surrender figures).
• Medal of Honor citation, Lt. (j.g.) Albert L. David: NHHC; Congressional Medal of Honor Society.
• Daniel V. Gallery, “Wrangling a Runaway U-Boat,” Naval History, April 2021 (reprint of Gallery’s account); Gallery, Twenty Million Tons Under the Sea (1956).
• USS Chatelain (DE-149), action report on the capture of U-505, uboatarchive.net.
• Griffin Museum of Science and Industry, Chicago, “Capturing the U-505”; National WWII Museum, “Louisiana’s Camp Ruston and the U-505 crew”; USS Guadalcanal Task Group 22.3 Association, “Third ASW Cruise.”
• uboat.net: boat pages for U-505, U-853, U-546, U-234, U-858, U-805, U-1228, U-2511, U-461, U-482 and others; “What is a Milch Cow?”; Type XXI; Type XXIII; “The Schnorchel”; “Torpedoes”; “U-boat losses” and losses by cause; Black Point and Frederick C. Davis.
• NOAA Ocean Exploration, “Mapping and Assessing Rhode Island’s Historic Submarines” (U-853 and Black Point); NOAA, Monitor National Marine Sanctuary, Battle of the Atlantic research.
• Dictionary of American Naval Fighting Ships, Frederick C. Davis (DE-136), HyperWar.
• Samuel Eliot Morison, History of United States Naval Operations in World War II, vol. X, The Atlantic Battle Won, May 1943–May 1945 (1956); Stephen W. Roskill, The War at Sea, 1939–1945, vol. III (HMSO, 1960–61); Clay Blair, Hitler’s U-Boat War, vol. 2, The Hunted, 1942–1945 (1998).
• Axel Niestlé, German U-Boat Losses during World War II (1998); Paul Kemp, U-Boats Destroyed (1997); Lawrence Paterson, Black Flag: The Surrender of Germany’s U-Boat Forces (2009); Derek Waller, “Operation Deadlight,” uboat.net; Jürgen Rohwer, Axis Submarine Successes of World War Two; Marc Milner, The U-Boat Hunters (1994); Philip K. Lundberg, writings on Frederick C. Davis and the U-546 prisoners, as cited in H-Gram 047.

Photographs: official U.S. Navy photographs, National Archives and Naval History and Heritage Command, public domain.