The capture of U-505

Before noon on 4 June 1944, in the eastern Atlantic some 150 nautical miles off the coast of West Africa, level with Cape Blanc, an American anti-submarine group built around the escort carrier USS Guadalcanal detected the German submarine U-505. Depth charges from the destroyer escort USS Chatelain damaged her so badly that she was forced to surface. The crew abandoned the boat in the belief that she was about to sink, but failed to scuttle her effectively. A boarding party from the destroyer escort USS Pillsbury went below, closed the valves, disarmed the demolition charges and carried off the Enigma cipher machine together with a full set of secret documents. The boat was taken in tow and, fifteen days later, brought into Bermuda.

According to the US Navy, it was the first time since 1815 that the US Navy had captured an enemy warship on the high seas. The capture of U-505 did not change the course of the war in the Atlantic, which had already been decided in 1943, but it became one of the most celebrated actions of the American fleet in that war, and the boat herself survives to this day as a museum exhibit in Chicago.

It is often said, briefly, that U-505 was captured by American forces and towed to Bermuda. That is so; one need only add that the tow took more than two weeks: the boat reached Bermuda only on 19 June, and for the first few days she was pulled by the carrier herself.

The Atlantic in 1944

By the spring of 1944 the Battle of the Atlantic looked completely different from two years earlier. After the defeat of “Black May” in 1943 Karl Dönitz had withdrawn the wolf packs from the North Atlantic, and attempts to return in the autumn brought further heavy losses. U-boats still put to sea, but increasingly as single boats operating in distant waters where they hoped the defences would be weaker: off the coast of Africa, around the Cape Verde Islands, on the routes to South America and in the Indian Ocean. Especially dangerous for them were the passage across the Bay of Biscay, patrolled by aircraft, and every surfacing within range of aircraft.

In the central and eastern Atlantic they were hunted by American hunter-killer groups built around small escort carriers. After the closing of the Atlantic air gap in the spring of 1943 these groups no longer had to stay with the convoys: thanks to decrypted German signals and radio direction-finding they could go wherever U-boats or Type XIV submarine tankers were expected, and hunt them with Grumman TBF Avenger and F4F Wildcat aircraft and with destroyer escorts.

One such group was Task Group 22.3 under Captain Daniel Gallery, a Chicago-born naval aviator who in 1943 had taken command of the newly built escort carrier Guadalcanal. It included five destroyer escorts – Pillsbury, Pope, Flaherty, Chatelain and Jenks – commanded by Commander Frederick S. Hall. The group already had successes to its name: on 9 April 1944, after a chase and depth-charge attacks lasting many hours, it forced to the surface and sank U-515, commanded by one of the leading U-boat aces, Werner Henke, and the following night its aircraft sank U-68. Gallery drew a lesson from that encounter: a submarine abandoned by her crew could be captured if someone was prepared for it. Before the next cruise he therefore had a boarding party selected and trained on each destroyer escort.

A boat with no luck

U-505 was an ocean-going Type IXC (PL) submarine, built at the Deutsche Werft yard in Hamburg and commissioned in August 1941. At first she did well: under Kapitänleutnant Axel-Olaf Loewe she sank seven ships off West Africa and in the Caribbean, and in November 1942, under a new commander, one more off Venezuela. There her successes ended: in the whole war she sent to the bottom eight vessels totalling some 45,000 gross register tons, all of them in 1942, among them the Colombian sailing vessel Urious, whose sinking was one of the incidents that led Colombia to declare war on Germany.

Then came a run of misfortune. In November 1942, off Trinidad, a British Lockheed Hudson patrol aircraft scored a direct hit on the boat’s deck with a bomb, itself perishing in the blast; U-505, badly damaged, barely limped back to Lorient. Her subsequent sorties in 1943 ended after a few days because of breakdowns and damage, which, it was established, were partly the work of sabotage by French dockyard workers. In October 1943, during a heavy depth-charge attack east of the Azores, her commander, Oberleutnant zur See Peter Zschech, shot himself in the control room in front of the crew. The first watch officer, Paul Meyer, brought the boat back to base.

From November 1943 U-505 was commanded by Oberleutnant zur See Harald Lange. Under his command she set out on 16 March 1944 on her twelfth war patrol, to West African waters. For nearly three months she sank nothing. At the end of May Lange turned back towards the French bases.

“Away all boarding parties!”

Task Group 22.3 sailed from Norfolk on 15 May 1944. From decrypted German signals the Allies knew that U-boats were operating around the Cape Verde Islands, although they did not know their exact positions. At the end of May the group combed these waters using HF/DF direction finders, air reconnaissance and the destroyer escorts’ sonar. For many days it found nothing, and on 4 June, running short of fuel, it was already heading for Casablanca to refuel.

At 11.09 a.m. that day Chatelain’s sonar picked up a contact only about 700 metres away. The escorts closed in on the target, while Guadalcanal made off at full speed, launching another Wildcat to join the two aircraft already airborne. Chatelain was so close to the target that ordinary depth charges would not have had time to sink to the right depth, so she first fired a salvo from her Hedgehog projector and then, after turning, dropped a pattern of depth charges on the spot that the pilots had marked with their guns. After the explosions an oil slick appeared on the water, and one of the airmen radioed that the submarine was surfacing.

Inside U-505 water was pouring into the engine room, the rudder was jammed, and Lange concluded that the boat was lost. Less than seven minutes after the first attack U-505 surfaced a few hundred metres from Chatelain and immediately came under fire from the destroyer escorts and fighters, which raked her deck to keep the crew from the guns. Lange was badly wounded, and so was his first officer. The commander managed to give the order to abandon and scuttle the boat. The sailors opened some of the valves and jumped into the water; one of them, the signalman Gottfried Fischer, was killed by the gunfire – the only fatality of the action. The engines, however, kept running, and the jammed rudder sent the abandoned boat circling at about seven knots. Chatelain’s captain, thinking the U-boat was turning to attack, ordered a torpedo fired at her; luckily for Gallery’s further plans, it missed.

Gallery, who had been waiting weeks for just such an opportunity, gave an order that, according to the US Navy, had not been heard on its ships since the War of 1812 (1812–1815): “Away all boarding parties!” While Chatelain and Jenks picked up survivors, an eight-man party from Pillsbury under Lieutenant (junior grade) Albert L. David approached the circling boat in a whaleboat and leapt aboard. David and the first two men behind him, Torpedoman Arthur Knispel and Radioman Stanley Wdowiak, went down through the conning tower into the hull, not knowing whether the boat was booby-trapped or about to go to the bottom. She was empty. The boarders closed the open valves (the most dangerous was an open bilge strainer through which water was pouring into the hull; its cover lay beside it, and Petty Officer Zenon Lukosius put it back), disarmed the charges set to blow up the boat, stopped the engines and began carrying charts, code books and the Enigma up on deck. The boat was low in the water and down by the stern, but she stayed afloat.

The tow to Bermuda

Keeping the prize afloat proved almost as hard as capturing it. Pillsbury tried to take U-505 in tow but collided with her hull several times and, with three compartments flooded, had to withdraw. The towline was therefore secured by a second party from the carrier herself, which included Guadalcanal’s chief engineer, Commander Earl Trosino. Trosino disconnected the boat’s diesel engines from her electric motors, leaving the latter coupled to the propeller shafts. As the carrier towed her, the boat’s propellers turned, and the electric motors acted as generators, charging the batteries. Their power ran the pumps, which pumped out the water, and the compressors, which blew the ballast tanks; U-505 slowly returned to a normal surface trim.

The nearest Allied port was Casablanca, but the command judged that it was swarming with German informers, and news of the capture must not reach Germany. On the orders of the Commander-in-Chief of the Atlantic Fleet, Admiral Royal E. Ingersoll, the group headed for Bermuda. As its ships were short of fuel, the oiler Kennebec was sent from Casablanca to meet them, and on 7 June the ocean-going tug Abnaki took over the tow. The documents and cipher machines found on board (two Enigmas according to the US Navy’s history, one four-rotor machine according to some other sources), packed into sacks, went ahead on the destroyer escort Jenks and were flown from Bermuda to Washington. U-505 herself entered Great Sound, home of the US Navy base in Bermuda, on 19 June, after a tow of some 1,700 nautical miles.

Secrecy and awards

The capture of U-505 made sense only if the Germans never learned of it. Since 1941 the British, and later the Americans too, had intermittently been reading U-boat signals thanks to material captured from boats such as U-110 and the work of the cryptologists at Bletchley Park. Had U-boat Command grown suspicious, it could have changed its keys and procedures, and the Allies would have lost a source of intelligence at the very moment the invasion was to cross the Channel – an invasion postponed by a day because of the weather on that very day. That is why the Chief of Naval Operations, Admiral Ernest King, was, according to the historian Clay Blair, furious with the group commander for endangering the secret of the codes for the sake of a spectacular prize, and is said to have considered court-martialling him. Historians still judge the step differently: Samuel Eliot Morison saw it as an example of daring in the best traditions of the navy, Blair as an unnecessary risk.

In the end extraordinary precautions were taken. Some 3,000 sailors who had witnessed the boarding were sworn to silence, and souvenirs taken from the boat had to be handed in. The submarine was repainted to look like an American boat and named USS Nemo. The fifty-eight prisoners from U-505 (three of them wounded; Lange lost a leg) were isolated from other prisoners of war and held at Camp Ruston near Ruston, Louisiana. According to the US Navy’s history and the Museum of Science and Industry in Chicago, the International Committee of the Red Cross was neither notified of them nor allowed access to them, and the prisoners were not permitted to write to their families, although the Geneva Conventions required prisoners to be reported. In August 1944 the Kriegsmarine declared the crew lost with their boat, and the families received notices of the sailors’ deaths. Until the end of the war the Germans never learned that U-505 had fallen into enemy hands.

The value of the prize cannot be measured precisely. According to the US Navy’s history, the cipher machines and code books saved American cryptologists some 13,000 hours of decryption-machine time. The Americans also acquired modern German equipment, including G7es acoustic homing torpedoes, and spent the following months studying the boat in Bermuda, including on trial runs. Albert David received the Medal of Honor, the only one awarded during the war to a sailor of the Atlantic Fleet. He did not live to receive it: he died of a heart attack in September 1945, and the decoration was presented to his widow by President Harry Truman. Knispel and Wdowiak received the Navy Cross, Gallery the Navy Distinguished Service Medal, and the whole task group a Presidential Unit Citation.

Its place in the war

The capture of U-505 came two days before the Normandy landings, at a time when the German submarine arm could no longer threaten Allied sea lanes. Since the days of the U-boat aces of 1941 and the withdrawal of the boats from the US coast in 1942 the balance had been completely reversed: Allied hunter groups now pursued single U-boats even off the coast of Africa, and a boat that had sunk nothing in three months was heading home as the quarry. Neither the captured Enigma nor the code books decided the outcome of the Battle of the Atlantic, which had been settled a year earlier, but they helped the Allies to keep their intelligence advantage until the end of the war. The Royal Navy had made similar captures before – in 1941 it took U-570 and commissioned her into its own fleet – but for the US Navy it was a feat without precedent in more than a century.

U-505’s crew saw out the war in captivity. In 1945 the prisoners were moved to Britain; their families learned that they were alive only in 1946, and they returned to Germany in December 1947. After the war the boat was shown in American ports during war bond drives, then left in poor condition at Portsmouth Naval Shipyard and earmarked as a target ship. She was saved by Gallery, by then a rear admiral, who together with his brother, the priest John Gallery, persuaded the Museum of Science and Industry in his native Chicago to take her. In September 1954, after a tow through the Great Lakes, U-505 was installed at the museum as a memorial to the sailors who died in the Battle of the Atlantic. Since 2005 she has stood in an underground, climate-controlled pavilion and is one of only four German Second World War submarines preserved as museum ships. In 1964, at a gathering at the museum on the twentieth anniversary of the capture, Gallery returned to Harald Lange the binoculars taken from the boat twenty years earlier.