The end of the U-boat war

On 4 May 1945 the German navy’s radio stations transmitted a short order to all submarines at sea: cease fire immediately and stop all operations against Allied shipping. It was signed by Grand Admiral Karl Dönitz – for the past few days Hitler’s successor as head of state, but still, above all, the man who had directed the German submarine fleet throughout the war. So ended the U-boat war in the Atlantic, the longest campaign of the Second World War, waged without a break since the first day of the war with Britain in September 1939.

The day before, on 3 May, in the port of Kiel, the heavy cruiser Admiral Hipper, badly damaged by RAF bombers in April, was scuttled by her own crew. It should be added that the order of 4 May did not yet settle the fate of the German submarine fleet: in defiance of it, crews scuttled more than two hundred boats in harbours and roadsteads, and the last Allied ships were sunk only on 7 May.

A fleet in its death throes

By the spring of 1945 only remnants were left of the once great Kriegsmarine. The battleship Tirpitz had been sunk off Tromsø in November 1944; in April 1945 a raid on Kiel capsized the heavy cruiser Admiral Scheer; and the remaining large ships lay damaged in port or – like the Prinz Eugen – were giving fire support to the last bridgeheads on the Baltic coast and covering the evacuation of refugees and soldiers from the east. The only part of the fleet still able to wage war on the ocean was the submarine arm.

In numbers it was still formidable. According to figures cited in the literature, at the beginning of May 1945 Germany had about 470 submarines. Some 170 were operational boats, most of them based in Norway; around 200 more were under construction, on trials or in training in German ports and in the Baltic. Among them were the new Type XXI boats – large, streamlined vessels with huge batteries, capable of long, fast underwater runs – and the small coastal Type XXIII boats. They were meant to turn the tide of the war at sea, but the bombing of the shipyards, the air-mined waters of the Baltic and technical problems meant that by May 1945 only one Type XXI and a few Type XXIII boats had gone out on war patrol.

The Germans had lost the tonnage war long before. The turning point was “Black May” 1943, when, after losing more than forty boats in a single month, Dönitz withdrew the wolf packs from the North Atlantic. From then on U-boat losses grew faster than their successes. Fitted with snorkels, the boats could stay submerged for longer, and in the last months of the war they operated mainly in the coastal waters of the British Isles, where they still sank individual ships but no longer threatened Britain’s supplies. Allied air superiority now reached into the bases themselves: in the last weeks of the war RAF aircraft and American bombers destroyed boats in the ports of Kiel, Hamburg and Bremen, while Coastal Command hunted vessels making the passage from Germany to Norway through the Kattegat and Skagerrak. According to the records, 23 boats were destroyed or badly damaged on the way to Norway in the first week of May.

The end of the Admiral Hipper

The fate of the Admiral Hipper illustrates well what happened to the German surface fleet. The ship, the first of her class, took part in the invasion of Norway in 1940, hunted convoys in the Atlantic and in December 1942 fought in the Battle of the Barents Sea. The failure of that battle enraged Hitler, who demanded that the large ships be scrapped; Dönitz, the navy’s new commander, secured their reprieve, but the Admiral Hipper was decommissioned in February 1943. From 1944 she served at Gdynia as a training ship for officer cadets.

The approach of the front forced the Germans to move her west, even though only one of her turbines was working. On 29 January 1945 the cruiser left Gdynia with nearly 1,400 refugees on board. The following evening she picked up a distress call from the sinking liner Wilhelm Gustloff, torpedoed by a Soviet submarine, but for fear of attack did not stop to rescue survivors. On 2 February she reached Kiel and entered the Germaniawerft yard for repairs.

In April the ship was badly hit by the RAF. On 3 April 1945, during a raid on the port, a bomb struck the cruiser; it did not penetrate the armoured deck but killed six sailors. On the night of 9–10 April, during a heavy Lancaster raid, the Admiral Hipper took three more hits, which put her out of the war for good. The command still intended to use the wreck as a floating battery and loaded her with ammunition for the main guns. But as British troops approached Kiel, at 4.25 a.m. on 3 May 1945 her crew scuttled her at the quayside by setting off charges inside the hull. That same night and over the following days other warships and dozens of U-boats were also scuttled at Kiel.

In July 1945 the British raised the wreck and towed it to a bay off Heikendorf, where she was broken up for scrap in 1948–1952. Her bell went first to the National Maritime Museum in Greenwich, later returned to Germany and is now in the Naval Memorial at Laboe near Kiel.

The order from Flensburg

After Hitler’s death Dönitz moved his headquarters from Plön to the naval academy at Mürwik, a district of Flensburg near the Danish border. His policy in the first days of May was to resist the Red Army for as long as possible while surrendering piecemeal in the west, so that as many soldiers and refugees as possible could get across to the British and American side. On 3 May he sent Admiral Hans-Georg von Friedeburg, his successor as Commander-in-Chief of the Navy, to the headquarters of Field Marshal Bernard Montgomery near Lüneburg.

Montgomery agreed to accept the surrender of the German forces in north-west Germany, Denmark and the Netherlands, but he set a condition: the surrender was also to cover warships, which were to be handed over intact, without being destroyed or scuttled. The instrument was signed on the evening of 4 May and came into force at 8 a.m. on 5 May. For the submarine fleet this meant the end. Still on 4 May, the command transmitted to the boats at sea an order to cease fire and stop operations against Allied shipping, combined with a ban on destroying boats and weapons. The next day Dönitz sent the U-boat crews a longer farewell: he wrote that after six years of submarine warfare they had “fought like lions”, but that the enemy’s crushing material superiority had driven them into a small area from which further fighting was not possible. Sources differ on the order and exact timing of these signals; all agree that offensive U-boat operations were to cease on 4–5 May.

The order reached boats scattered from the English Channel to the coast of North America. One of them was U-2511 – the only Type XXI boat to go out on war patrol. Her commander, Adalbert Schnee, was on his way from Bergen to the Caribbean when on 4 May he received the instruction to break off operations; on 5 May he returned to Bergen. According to his account, later repeated by Dönitz in his memoirs, on the way back he crept unseen up to a British cruiser and carried out a mock attack on her – historians treat this story with caution, but it became part of the legend of the new boats that came too late.

“Rainbow” – the scuttling of the fleet

Since the start of the war the German navy had followed the rule that a ship in danger of falling into enemy hands was to be scuttled. In 1943 this was given the code word “Regenbogen” (“Rainbow”) for the submarine fleet: on receiving it, crews were to scuttle their boats. According to German studies, Dönitz confirmed the order on 30 April 1945, on taking power after Hitler. Accepting Montgomery’s terms meant that he had to revoke it – and on 4 May he did so.

Many U-boat officers, however, regarded handing their boats over to the enemy as a disgrace. Even before 4 May, as the Allies approached the ports, crews scuttled or blew up their boats so that they would not fall into British or Russian hands: on 1 May at Warnemünde, on 2 May at Travemünde near Lübeck, on 3 May at Kiel and Hamburg. On the evening of 4 May a group of U-boat commanders turned up at the headquarters in Mürwik to hear from Dönitz in person that “Rainbow” had been cancelled. They were not allowed to see him; his adjutant, Korvettenkapitän Walter Lüdde-Neurath (PL), is said to have told them that if he himself were a U-boat commander, he would know what to do. Some historians see this as tacit consent; others point out that the episode is known mainly from later accounts.

What is certain is that on 4 and 5 May, in breach of the surrender terms, crews scuttled several dozen more boats. Most – several dozen vessels – went to the bottom in Flensburg Fjord and the neighbouring Gelting Bay, and a dozen or so each at Wilhelmshaven and in the Weser estuary. On 7 May two experimental Walter-propulsion boats were blown up at Cuxhaven. Those scuttled included new Type XXI boats, training boats and even vessels long since withdrawn from service or not yet completed. This is why the figures in the literature differ: the German historian Axel Niestlé counted 195 boats scuttled by their own crews, the British authors Paul Kemp and V. E. Tarrant 218, and the American historian Clay Blair 222, which matches the tallies drawn up by the Allies in September 1945.

Not everyone at sea complied with the surrender either. On 8 May U-2365 was scuttled by her crew in the Kattegat; two boats that reached the coast of Portugal in May and June were scuttled there instead of being handed over; and two others – U-530 and U-977 – reached Mar del Plata in Argentina and surrendered to the authorities there only in July and August 1945, which for years fuelled rumours of Nazi dignitaries escaping to South America.

The last sinkings

The ceasefire order did not reach everyone, or not everyone obeyed it. On 5 May, off Rhode Island, U-853 sank the American collier Black Point – the last merchant ship sunk by a U-boat in United States waters. The next day the U-boat was tracked down and destroyed by American escort vessels; her entire crew was killed.

The last Allied ships sunk by a U-boat went down on 7 May 1945, the day the surrender was signed at Reims, off the coast of Scotland. The coastal boat U-2336 under Kapitänleutnant Emil Klusmeier attacked convoy EN 491, sailing from Hull to Belfast, near the Isle of May at the mouth of the Firth of Forth, and shortly after 11 p.m. sank the Norwegian steamer Sneland I and the Canadian-built British freighter Avondale Park. According to the records, nine seamen in all were killed aboard them. Klusmeier later claimed that he had not received the order to cease operations. The last U-boat destroyed in action was U-320, bombed by a British Catalina flying boat off the coast of Norway on 7 May; she sank that day or the next.

Black flags

After Germany’s general surrender came into force on 8 May, the boats at sea received instructions from the British Admiralty: surface, hoist a black flag, report their position by radio and proceed to designated Allied ports. Over the following days and weeks U-boats appeared off the coasts of Britain, the United States and Canada, while in the ports of Norway, Denmark and Germany Allied sailors took them over. According to Niestlé’s figures at least 150 boats surrendered – 52 at sea and 98 in port; other authors give between 154 and 174. Most were assembled at Lisahally in Northern Ireland and Loch Ryan in Scotland.

The Allies agreed to keep 30 boats, ten each for Britain, the United States and the USSR, and to destroy the rest. From November 1945 to February 1946 the Royal Navy carried out Operation Deadlight: 116 U-boats were towed out to the open ocean north-west of Ireland and sunk – some foundered under tow, others were sunk by gunfire and torpedoes. Among them were U-2511 and U-2336. The captured Type XXI boats were studied after the war by the Americans, British and Russians; their features – large batteries, a streamlined hull, the snorkel – influenced the design of submarines in the early years of the Cold War.

The balance sheet of the U-boat war

With Germany’s surrender, the Battle of the Atlantic came to an end. Its toll was terrible for both sides. According to frequently cited estimates, the Allies and the neutral states lost in the Atlantic some 3,500 merchant ships of more than 14 million gross register tons and about 175 warships, most of them sunk by U-boats; tens of thousands of merchant seamen and naval personnel died in icy water, in burning oil or in lifeboats drifting for weeks across the ocean.

For the German submarine fleet the war ended in catastrophe. Of more than 1,100 boats commissioned, Germany lost some 750–780, most of them in the Atlantic. Of the roughly 40,000 men who served in U-boats, between 26,000 and 30,000 were killed, according to various calculations – the figure most often given is about 28,000. This is often regarded as the highest loss rate of any branch of the armed forces that fought in the Second World War. Most of these men died in 1943–1945, when the U-boat war was already lost and yet the command went on sending fresh crews to sea, often very young and poorly trained.

Significance

The order of 4 May was one of the first steps in a surrender of the Reich spread over several days: partial surrenders in the north-west, in Bavaria and in Austria preceded the instrument signed at Reims on 7 May and repeated in Berlin on 8 May. For the war at sea it meant the end of a threat that since 1939 had been – as Winston Churchill admitted – the only thing that truly frightened him. The last convoys reached port with no need of escorts to fight off submarines, and the Allies soon abandoned the convoy system in the Atlantic.

Responsibility for the U-boat war became one of the charges against Dönitz at the Nuremberg trials. The Tribunal found him guilty of waging aggressive war and of war crimes, but stated that it did not base its sentence on breaches of the law of submarine warfare – in view, among other things, of the written answers of the American Admiral Chester Nimitz that the US Navy had waged unrestricted submarine warfare against Japan in the Pacific. Dönitz was sentenced to ten years’ imprisonment. The scuttling of more than two hundred boats in defiance of the surrender, meanwhile, remained the last act of disobedience by the arm of the navy that had been most devoted to its commander throughout the war – and the last echo of a tradition going back to the scuttling of the German fleet at Scapa Flow in 1919.