Royal Oak

Sinking of HMS Royal Oak

"The place where the German U-boat sank the British battleship Royal Oak was none other than the middle of Scapa Flow, Britain's greatest naval base! It sounds incredible..." William L Shirer, journalist, 18 October 1939.

In 1938, with the threat of war looming, surveys showed that Kirk Sound (part of Holm Sound) had a perfectly clear and deep passage running through it, 300 to 400 feet wide. This posed a real danger to British ships stationed in Scapa Flow. Indeed, a 2,000-ton vessel was said to have made it through in 1932 (Hewison, 1985, p.209-210).

In an attempt to block the channel more effectively the old merchant ship Seriano was sunk as a blockship on 15 March 1939. Nevertheless, navigable channels remained through both Kirk Sound and Skerry Sound (Hewison, 1985, p.210). The survey vessel Scott even reported this as a navigable channel in May 1939, 400 feet wide with a depth of two fathoms at low water. In spite of this it was concluded that the sounds would be too hazardous for a vessel passing through on the surface.

Admiral Sir William French, commanding Orkney and Shetland, refuted this judgement. He travelled through Kirk Sound and Skerry Sound in a picket boat in June 1939 and determined that a submarine or destroyer could make it through at slack water (Hewison, 1985, p.211).

Costs slowed the sinking of more blockships until the outbreak of war when SS Cape Ortegal was sunk in Skerry Sound. SS Lake Neuchatel was destined to be a blockship in Kirk Sound, but was still afloat on the night of 13/14 October 1939 (Hewison, 1985, p.212).

The attack

Konteradmiral Döenitz, Commander of the Submarines, said on receipt of a survey to find Scapa Flow's weakness: "I hold that a penetration at this point [Kirk Sound] on the surface at the turn of the tide would be possible without further ceremony." Kapitänleutnant Günther Prien was to prove how inadequate the British defences were when he made one of the most daring attacks ever recorded (Wood, 2008, p.91).

A sortie by units of the Kriegsmarine, or German Navy, including the battlecruiser Gneisenau, the cruiser Köln and nine destroyers, was staged to tempt units of the British Home Fleet out of Scapa Flow for attack by the Luftwaffe. Although many ships of the Home Fleet did respond, the Luftwaffe did not engage and this tactic left Prien with just a few ships in Scapa Flow as targets. HMS Royal Oak had returned early from the Home Fleet sweep and took up its role as anti-aircraft defence for the Scapa Flow anchorage and the Radio Direction Finding station at Netherbutton.

The German submarine U-47, under the command of Prien, approached Scapa Flow through the narrow approaches at Kirk Sound with surprising ease. It was high tide and a little after midnight on 14 October 1939. U-47 first sailed towards Lyness but, finding no ships in the area and encountering no resistance, then turned to the north where HMS Royal Oak, HMS Pegasus and possibly HMS Iron Duke were spotted (Wood, 2008, p.92). A total of 51 ships were in Scapa Flow at the time, 18 of which can be described as fighting ships (Weaver, 1980, p.39).

When the first torpedo struck HMS Royal Oak at 12.58am, the dull thud confused the sailors – they thought the muffled explosions were an on-board problem, perhaps an explosion in the paint store. They certainly did not think it was a U-boat attack. A second salvo failed to deliver a hit but the confusion surrounding the first hit gave Commander Prien an additional 20 minutes to return to his firing position, reload, and fire a third salvo. This third discharge landed direct hits amidships.

Such was the ferocity of the explosions, the ship heeled over alarmingly and all the lights went out. It had been fine weather so all of the ship's hatches were open. Undoubtedly Royal Oak would have taken longer to sink and more lives would have been saved if the watertight hatches had been closed; but it is not normal procedure to have all hatches closed when in a supposedly safe harbour with no alerts.

When the ship rolled its gun barrels shifted, pulling the ship faster beneath the surface. Water crashed through the open hatches and men asleep in their bunks were unable to get out in time. It took just minutes for the battleship to sink. Hundreds fought for their lives in the water, trying to swim for shore through thick fuel oil and in freezing temperatures. A total of 834 men lost their lives. Many of the men are buried in the Lyness Royal Naval Cemetery on Hoy (Wood, 2008, p.92).


The sinking of HMS Royal Oak was a notable German propaganda coup. However, there is conjecture that she may not have been the only British ship struck by the German forces that night.

Prien's account stated that he hit another ship – the battlecruiser HMS Repulse. This warship had, in fact, left that day with the rest of the fleet. However, it is possible that U-47 hit the British Atlantic Fleet's Flagship, HMS Iron Duke. On 17 October a Luftwaffe squadron attacked HMS Iron Duke as she lay beached at Lyness. When the attack commenced it is claimed that the ship was already listing heavily and had a large hole in the bow. Metal Industries were engaged in pumping out the vessel and patching the hull. The British Admiralty never confirmed that HMS Iron Duke had been hit but it has been argued that it was deemed too sensitive to report that the Fleet's Flagship had also been torpedoed on the same night as Royal Oak was lost (Wood, 2008, p.93).

Later it was discovered that Prien never subscribed to many of the claims attributed to him. His ghost-written account was inevitably embellished by propaganda and it has taken some work to untangle his original account. In 1978 Karl Dönitz, who became head of the German navy during World War II, said that Prien’s identification of the HMS Repulse at anchor came from the German High Command:

"Lt Prien arrived home safely, was told he had torpedoed Repulse, heard the evidence and didn’t like it. Except when cornered by questions he avoided positive identification of Repulse wherever possible." (Weaver, 1980, p.135).

Despite conspiracy theories that HMS Royal Oak sank as a result of sabotage, involving a bomb in the explosives store, the damage to the ship has been confirmed as external. Moreover, the gaping torpedo holes reveal why she sank so quickly.

The vessel's torpedo bulge, although modernised in 1934, had been fitted in 1922 and was designed to withstand torpedoes with 450 to 500 pounds of explosives (Rickard, 2007). By World War II torpedoes were more powerful and so ships like HMS Royal Oak could fall prey to a few well-placed torpedoes.

In a film recording of Prien discussing his actions he says:

"Inside of Scapa Flow, the harbour of the English sea force, it was absolutely dead calm in there. The entire bay was alight because of bright northern lights. We then cruised in the bay for approximately one and a half hour, chose our targets, fired our torpedoes. In the next moment there was a bang and the next moment the Royal Oak blew up. The view was indescribable. And we sneaked out, in a similar fashion as we got in, close past the enemy guards, and they did not see us. You can imagine the excitement and happiness we all felt, about the fact that we managed to fulfil our task and achieve such a huge victory for Germany."

The realisation that U-47 had entered Scapa Flow through Kirk Sound prompted the immediate sinking of further blockships. By 1940 the Churchill Barriers were under construction and, when completed, they permanently blocked the eastern entrances to Scapa Flow.

History of U-47

U-47, a type VII submarine, was laid down in Kiel on 27 February 1937, launched on 29 October 1938 and commissioned on 17 December 1938 under command of Günther Prien. He was awarded the Knight's Cross of the Iron Cross First Class by Adolf Hitler. He commanded U-47 through 10 patrols, sinking 30 ships in the process.

The last radio message from U-47 was received on the morning of 7 March 1941 from the North Atlantic near the Rockall Banks. The sinking of U-47 has always been attributed to the British destroyer HMS Wolverine. What actually happened remains confusing, but accounts indicate that the destroyer kept up a sustained attack on an unknown U-boat resulting in its probable destruction. All that is definitely known is that U-47 failed to report back to headquarters after 7 March 1941.

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