The sinking of HMS Royal Oak

On the night of 13–14 October 1939 the German submarine U-47, commanded by Kapitänleutnant Günther Prien, slipped through a shallow channel between sunken ships into Scapa Flow, the main base of the British Home Fleet in the Orkneys, and torpedoed the battleship HMS Royal Oak as she lay at anchor. The ship capsized and sank within a quarter of an hour or so. 833 men were killed – 835 counting those who later died of their wounds – among them more than a hundred boys not yet eighteen years old. U-47 left the anchorage the way she had come in and returned to Germany. The British had regarded Scapa Flow as an anchorage that no submarine could penetrate. In a single night Prien overturned that belief and became the first great hero of German propaganda in this war.

Some chronologies place the attack under 13 October. On the evening of that day U-47 did indeed surface on the approaches to the Orkneys and set course for the base, but she entered the anchorage only after midnight. She fired her torpedoes between 0.58 and 1.16 a.m. on 14 October, and the battleship sank on that day. The date of the sinking is therefore taken to be 14 October, although the whole operation began the previous evening.

The base in the Orkneys

Scapa Flow is a vast stretch of water enclosed by a ring of islands of the Orkney archipelago, off the north coast of Scotland. It can hold an entire fleet, and it is separated from the open sea by narrow sounds with strong tidal currents. In the First World War it was the base of the British Grand Fleet, from which the ships sailed in 1916 to the Battle of Jutland. It was here that the German High Seas Fleet was interned after the armistice, and here that on 21 June 1919 its crews scuttled their own ships on the orders of Admiral Ludwig von Reuter. For the German navy, therefore, the name Scapa Flow was a symbol of defeat and humiliation.

Submarines had been feared even during that war. Old ships, known as blockships, had been sunk in the narrowest passages, and the three widest sounds had been closed with net booms, which tugs opened for friendly vessels. Two German submarines had tried to break into the anchorage at the time, and both were lost: U-18 was rammed and captured in November 1914, and UB-116 was detected by hydrophones in October 1918 and destroyed with all hands by mines fired from the shore. In the inter-war period Rosyth on the Firth of Forth became the fleet’s main base, and the defences of Scapa Flow were allowed to decay. When in 1939 it was restored to the Home Fleet as its home base, the booms and blockships were in poor condition, and the additional ships that were to close the gaps were still being prepared.

Dönitz’s plan

The commander of German U-boats, Rear Admiral Karl Dönitz, had been thinking about an attack on Scapa Flow from the first days of the war. Success promised two benefits. One was military: driving the British fleet out of its best base in the North Sea would weaken the blockade and make it easier for German ships to break out into the Atlantic. The other was symbolic: a blow struck at the place where the Imperial Navy had met its end in 1919 would be revenge for that defeat. Dönitz was emboldened by the success of U-29, which had sunk the aircraft carrier Courageous on 17 September. He concluded that the British were not as effective at defending against submarines as they claimed. At the same time the Kriegsmarine command was gradually lifting the restrictions imposed on the U-boats.

Dönitz gathered the reports of U-boats that had been operating near the Orkneys, together with aerial photographs taken by the Luftwaffe. They showed that in the eastern entrance to the anchorage, Kirk Sound, between the archipelago’s main island, Mainland, and the small islet of Lamb Holm, a gap a dozen or so metres wide had been left between the sunken blockships. The shores there were thinly populated, and the passage had no net boom. A boat would, however, have to pass on the surface, at night, through a narrow channel with a strong current. As commander Dönitz chose the 31-year-old Prien, whose U-47 had sunk three British ships at the beginning of September, among them the freighter Bosnia. According to German accounts he gave Prien time to think it over on 1 October, and Prien volunteered the very next day. The attack was set for the night of 13–14 October: a moonless night, with high tide at the moment of passing through the sound. Secret documents were removed from the boat in case she fell into enemy hands.

U-47, a Type VIIB boat with a crew of about 44, left Kiel on 8 October. She crossed the North Sea cautiously, often lying on the bottom by day, and the crew learned of their objective only on the way. On 13 October the boat waited out the day on the seabed off the Orkneys, and at 7.15 p.m., after dark, she surfaced and headed for the base.

The night in Scapa Flow

The night turned out to be far brighter than expected. A vivid aurora borealis lit up the sky, and in its light, as Prien recorded, the whole anchorage was “disgustingly bright”. At one point Prien took the wrong course and steered the boat towards Skerry Sound, a shallow, blocked channel further to the south. He realised his mistake in time and turned back to the north-east. In Kirk Sound U-47 squeezed through on the surface between two blockships, the Seriano and the Numidian, briefly caught on the steel cable of one of them and broke free only at full engine power. On the shore she was momentarily caught in the headlights of a passing car, but the driver raised no alarm. At 0.27 a.m., by now on 14 October, Prien wrote in his log: “We are in Scapa Flow!!!”

The anchorage was almost empty. A few days earlier German reconnaissance aircraft had flown over the Orkneys, and the Commander-in-Chief of the Home Fleet, Admiral Charles Forbes, fearing an air raid, had dispersed the fleet among safer ports on the west coast of Scotland. The main force had sailed to Loch Ewe. Prien first headed south-west without sighting any target, although according to British findings several warships, among them the new cruiser Belfast, lay a few kilometres further on. He turned back, and it was then that the lookouts spotted to the north, about four kilometres away, the silhouette of a battleship, correctly identified as a Revenge-class ship. Beyond her the bow of a second vessel could be seen, which Prien took for a Renown-class battlecruiser. In fact it was the old seaplane carrier Pegasus.

Royal Oak was one of the five Revenge-class battleships, built during the First World War and commissioned in 1916. She had fought at Jutland. Despite several modernisations, by 1939 she was an obsolete ship, too slow to sail with the newer units of the fleet. A few days earlier she had taken part in a fruitless pursuit of the German battleship Gneisenau, which had put out into the North Sea, and on 12 October she had returned to Scapa Flow battered by storms. She remained at the base because her anti-aircraft guns were meant to strengthen the anchorage’s weak air defences. There were some 1,230 men on board, including Rear Admiral Henry Blagrove, commander of the 2nd Battle Squadron.

Two attacks

At 0.58 a.m. U-47 fired a salvo of three torpedoes from her bow tubes; a fourth jammed in its tube. Two missed, and one struck the battleship’s bow and severed the starboard anchor cable. On board Royal Oak nobody thought of a submarine. It was believed to be an explosion in the forward inflammable store, where paraffin among other things was kept. The sailors remembered the unexplained explosion that had blown apart the battleship Vanguard in Scapa Flow in 1917, so orders were given to check the temperature in the magazines. No action stations were sounded, and not all the watertight doors or scuttles were closed. Many sailors went back to their hammocks.

Prien turned and fired a torpedo from his stern tube, which also missed. Since all was still quiet in the base, he had the bow tubes reloaded, came in again and at 1.16 a.m. fired a second salvo of three torpedoes. All of them struck the battleship amidships. The explosions tore through the armoured deck, wrecked the stokers’, boys’ and Royal Marines’ messes, cut the power and ignited cordite charges in one of the magazines. Fire swept through the inside of the ship. Royal Oak heeled 15 degrees to starboard, bringing her open scuttles under water, and then the list reached 45 degrees. At 1.29 a.m., thirteen minutes after the second attack, the ship rolled over and sank.

U-47 was not pursued. For some time the British still believed the cause to have been an internal explosion or aerial bombs, and only later did they begin to search for a submarine. Prien left through Kirk Sound, this time between the blockships and the shore of Lamb Holm, and by 2.15 a.m. he was in the open sea. In his log he recorded his regret at having destroyed only one ship. He believed he had also hit the Repulse, but the Pegasus was undamaged. As was established after the war, four of the seven torpedoes fired had hit, and at least some of the others had failed because of defects in the German G7e torpedoes. The German command kept this information secret.

Rescue

Moored alongside the battleship’s port side for the night was the small drifter Daisy II, commanded by Skipper John Gatt of the Royal Naval Reserve. As Royal Oak began to capsize, the drifter was briefly lifted out of the water by the anti-torpedo bulge on the battleship’s hull, but she managed to free herself. Gatt switched on his lights, and for two and a half hours, until almost four in the morning, his crew pulled survivors out of the water. They saved 386 men, including the battleship’s captain, Captain William Benn. For this Gatt received the Distinguished Service Cross. Boats from the Pegasus and from the harbour also helped.

Most of the sailors had no chance. They had been asleep in hammocks or bunks and jumped into the icy water in nothing but their underclothes. The surface was covered with a thick layer of fuel oil, which got into their lungs and made swimming difficult. Of those who tried to swim to the shore 800 metres away, only a few survived. The battleship’s overcrowded motor launch capsized a few hundred metres from the ship. 833 men were killed, and 835 including the wounded who died over the following days. The latter figure is the one given by most British works; 833 is the number killed that night. Among the dead was Rear Admiral Blagrove, who according to witnesses had been helping with the evacuation. According to British records 134 boy seamen aged 15 to 17 were killed, the greatest such loss in a single incident in the history of the Royal Navy. After the disaster the navy virtually stopped sending under-age boys to serve in warships. The bodies of most of the dead were never recovered. The wreck, lying upside down at a depth of about 30 metres, is a war grave.

Reactions in London and Berlin

The BBC announced the sinking of the battleship before noon on 14 October. The broadcast was heard by German monitoring stations and by the crew of U-47 themselves. That morning divers had found fragments of a German torpedo on the seabed, which removed any doubt about the cause. On 17 October the First Lord of the Admiralty, Winston Churchill, announced the loss in the House of Commons. He called the attack “a remarkable exploit of professional skill and daring”, but gave an assurance that the loss of an old ship did not alter the balance of power at sea. An Admiralty board of inquiry sat from 18 to 24 October. Its report sharply criticised the state of the base’s defences, and Admiral Wilfred French, commanding in the Orkneys and Shetlands, was retired, although a year earlier he had himself warned of the weakness of the defences. A rumour also circulated that Prien had been guided into the anchorage by a German spy posing as a Swiss watchmaker in Kirkwall. It was published in 1942 by an American journalist, and post-war archival research showed it to be fiction.

In Germany the sinking of Royal Oak became a great propaganda event. U-47 entered Wilhelmshaven before noon on 17 October. Waiting on the quay were Dönitz and Grand Admiral Erich Raeder. Prien received the Iron Cross First Class and the entire crew the Iron Cross Second Class. The next day Adolf Hitler’s personal aircraft flew the sailors to Berlin, where in the Reich Chancellery Hitler presented Prien with the Knight’s Cross of the Iron Cross. It was the first Knight’s Cross awarded to a U-boat commander. Hitler stressed that Prien had achieved this at the place where, in 1919, a German admiral had saved the fleet from final disgrace. Joseph Goebbels’s ministry organised a press conference for foreign journalists. Prien earned the nickname “the Bull of Scapa Flow”, and the snorting bull that the crew painted on the conning tower was later adopted by the whole 7th U-boat Flotilla. Dönitz, a rear admiral since 1 October, won Hitler’s attention for his weapon.

The Churchill Barriers

The British reacted swiftly. Until the defences had been strengthened, the Home Fleet had to make do with substitute bases at Loch Ewe, on the Clyde and at Rosyth. These bases were not safe either: on 4 December 1939 the battleship Nelson was badly damaged in the entrance to Loch Ewe by a mine laid by U-31. The fleet returned to Scapa Flow only in March 1940, once new blockships had been sunk, new booms laid and the anti-aircraft defences reinforced. On Churchill’s orders the eastern sounds were permanently closed with concrete causeways linking Mainland with the islets of Lamb Holm and Glimps Holm and with the islands of Burray and South Ronaldsay. They were built in large part by Italian prisoners of war. The Churchill Barriers were essentially complete in September 1944 and were officially opened in May 1945, just after Germany’s surrender. To this day they carry the road to the southern islands of the Orkneys.

Place in the war

In military terms the loss of Royal Oak changed little. She was an old, slow ship, and the Royal Navy still enjoyed an enormous superiority over the Kriegsmarine. Yet she was the first of the five battleships and battlecruisers that Britain lost in this war, and she was sunk in the harbour that was supposed to be the safest place for the fleet. The sinking of Royal Oak, four weeks after the loss of the Courageous, showed that in the Battle of the Atlantic submarines could strike anywhere, even at a fleet base in British waters. British morale suffered badly, and the Germans gained the first great legend of the war at sea.

Further blows soon followed. On 16 October German bombers attacked warships in the Firth of Forth, and the next day aircraft appeared over Scapa Flow and damaged the old battleship Iron Duke, which was serving as a depot ship. For another year and a half Prien remained one of the most successful U-boat commanders, until in March 1941 he disappeared with the whole of U-47 in the North Atlantic. The first watch officer on that night in Scapa Flow, Engelbert Endrass, himself later became a well-known commander and was killed in December 1941. The memory of the Royal Oak’s dead is honoured every year: in St Magnus Cathedral in Kirkwall hangs a memorial with a book containing the names of the dead, and every year Royal Navy divers place an ensign on the wreck.