The Bull of Scapa Flow

by Donald A. Hollway

In the very first months of World War II the Royal Navy learned the hard way that German U-boats could penetrate even their most impenetrable base.

© 1993 Donald A. Hollway

On the peaceful Sunday afternoon of October 1, 1939–exactly a month into World War Two–a small launch motored across the harbor at Kiel, Germany, to tie up beside the depot ship Weichsel. Kapitänleutnant Günther Prien of the German Kriegsmarine disembarked, and was presently met by a runner. "Will Captain Prien please go to the C.O?"

The "C.O." was Commodore Karl Dönitz, Commander of U-Boats. Prien was about to begin "Special Operation P," one of the most audacious missions of the World War II. Winston Churchill would call it "a remarkable exploit of professional skill and daring."

The Commodore was an old submarine hand from the First World War, when Unterseeboots had very nearly starved England to death. He believed a force of 300 subs would finish the job this time around. But stealthy U-boats didn’t conform to Hitler’s vision of noble German naval might, so Dönitz began the war with just 56 boats, only about half of which were the open-water Types VII and IX. He’d planned to deploy them in "wolfpacks" of six to nine boats each, but it was all he could do to keep that many at sea at any time. Where could a German submarine, perhaps even operating alone, strike fear into the heart of the Royal Navy and cause repercussions all out of proportion to actual effect?

The answer lay in the British naval base at Scapa Flow, the impregnable deep-water anchorage in the Orkney Islands, almost in the path of German naval traffic coming out of the North Sea. This held a special place in the hearts of German sailors, as the place where their High Seas Fleet went to die–scuttled rather than handed over–in 1919. Now, over the corpses of former German naval might floated the British Home Fleet. The vision of row upon row of battleships, helplessly moored side by side at anchor and awaiting only the delivery of a few torpedoes, made German military mouths water as much as it would Japanese, two years later at Pearl Harbor. Even if an attacking submarine itself was lost, if it was able to sink just one British battleship (and cause panic in the Royal Navy) the trade-off would be well worth it to the Germans.

Unfortunately the British weren't ignorant of the submarine threat. Two U-boats had attempted to infiltrate Scapa Flow during the Great War. Both had been detected and sunk. Since then the defenses had only been strengthened. A successful U-boat attack would require a captain with both skill and nerve.

Kapitänleutnant Günther Prien
Commanding Officer, U-47. Despite a short career, one of the greatest U-boat aces of the war.

To Dönitz’ mind "Prienchen" Prien, at 31 a seven-year veteran of U-boats, was the ideal skipper for the job. An accomplished seaman, he’d won his master’s papers in the German merchant marine at 24 but could find no work, which compelled him to join the National Socialists in 1932 and the Kriegsmarine in 1933. He’d served in the waters off Spain during the civil war; a submarine captain for less than a year, he’d scored the U-boats’ first official victory (not counting the liner Athenia, sunk on the first day of the war; even the Nazis denied that publicly). He’d sunk three ships totaling over 66,000 tons on his first war patrol and won the Iron Cross, Second Class. The American war correspondent William Shirer, who met Prien in Berlin, described him as "clean-cut, cocky, a fanatical Nazi, and obviously capable."

Now, standing before Dönitz in the Weichsel, Prien glanced at the charts on the table and saw the map of Scapa Flow on top. He could barely contain himself as Dönitz outlined his "Special Operation P." Finally the Commodore asked, "Do you think a determined commander could get his boat inside Scapa Flow and attack the enemy’s forces lying there?" He gave Prien 48 hours to look over the accumulated charts, photos, and intelligence and deliver a carefully thought-out estimate.

After supper at home Prien sent his wife and young child out for the evening and spread the various documents out on his writing table. There was a wealth of intelligence on the Flow; Dönitz had planned the venture for some time. Aerial photos taken as early as September 6 showed the entire Home Fleet at anchor, and antisubmarine booms and sunken ships blocking the bay’s seven entrances. A U-boat scouting the inlets had found scant defenses but ten-knot rip tides. Navigation, even in daylight, would be tricky at best. In Kirk Sound, the northernmost of the Flow’s three eastern inlets, the blockships Thames, Soriano and Minich lay just far enough apart that a U-boat might zigzag through, in the still water just after high tide. The tides on the night of the 13th/14th should be one of the highest that year, and there would be no moon.

Booms, blockships, tides–"I worked through the whole thing like a mathematical problem," Prien wrote. The next day he reported in ahead of deadline. Dönitz was at his desk. "He did not acknowledge my salute; it seemed as if he hadn’t noticed it. He was looking at me fixedly and asked, 'Yes or no?'"

Prien answered, "Yes, sir."

"Very well." Dönitz came around to shake Prien’s hand. "Get your boat ready."

Prien's ship, the U-47, was one of the ocean-going Type VIIB boats with which Dönitz planned to sink Britain within the scant budget granted him by Berlin. She displaced 750 tons, with distinctive saddle tanks amidships fueling a range of 8,700 miles, enough to circumnavigate Britain or reach mid-Atlantic. She could hit 16 knots on the surface, seven under water, and more than 100 meters in the dive. She packed four 21-inch torpedo tubes forward and another aft, an 88mm gun on the foredeck and a 20mm antiaircraft gun behind the conning tower.

Oblt. z. S Englebert "Bertl" Endrass
1st Officer, U-47. Later a U-boat ace in his own right.

Oberleutnant zur See Englebert "Bertl" Endrass, the First Officer, would later become a U-boat ace in his own right in U-46 and U-567. Oblt. z. S. Amelung von Varendorff, the Second Officer, would captain U-213. Navigator Wilhelm Spahr, chief engineer Wessels, engine-room artificer Bohm, helmsman Schmidt and the rest of the 42-man crew were all volunteers, products of the grueling U-boat school which required 66 simulated attacks on the surface and 66 more submerged before the firing of a single torpedo.

On October 8th, a week after Prien first assumed Operation P, U-47 made ready to depart Kiel. There was no ceremony, no fanfare, except for a salute from Kapitan zur See (later Admiral) Hans-Georg von Friedeburg, the submarine genius who at the end of the war would take over direction of Dönitz’ U-boat campaign. "Well, Prien, whatever happens you are sure of many thousands of tons–and now–the best of luck, my boy."

U-47 departing Kiel. Original conning-tower insignia soon to be replaced.

U-47 steered around the Denmark peninsula and into the North Sea. Prien divulged nothing of his destination. Sighting potential quarry he dived rather than attacked. They traveled at night, lying submerged during the day. "The crew looked at me questioningly but nobody said a thing," he noted. They trusted der Alte–the Old Man–implicitly.

On the evening of the 12th, having steered all the way by sounding and dead reckoning, they surfaced to get a fix on their position. The weather had steadily worsened; heavy overcast and drizzle obscured the stars. Going by coastal lights, which the British had kindly lit, Prien ascertained they were just off the Orkneys, within 1.8 nautical miles of their intended position–no mean feat of navigation.

Endrass asked, "Are we going to visit the Orkneys, sir?"
"Take hold of yourself. We are going into Scapa Flow."
After a moment the first officer said simply, "That will be OK, sir, that will be quite OK."

At four AM they buttoned up and put the boat on the bottom, 270 feet down. "Tomorrow we shall enter Scapa Flow," Prien told the crew. "We must economise on current; no one is to move unnecessarily, for we shall be lying aground for this evening and must be careful with the air."

The men went to their bunks. The lights were extinguished. The only noise was the whisper of the control room watch, the drip of condensation off the pipes, and the occasional burble of the water, just a few feet away, pressing in on all sides.

Prien could not sleep. He finally got up and went to the wardroom, where he found Spahr poring over the illuminated map table, on which was spread the hydrographic plot of Scapa Flow. For what no doubt seemed a long time they stood there together, contemplating the chart. Finally Spahr said, "Do you believe, sir, that we can get in?" "Do you think that I am a prophet, Spahr?"
"And suppose it goes wrong?"
"Well, then, we will have had very bad luck."
About this time Endrass peered out from his bunk. "I can’t sleep any more, sir, and you can court martial me if you like."
"Shut up and save the air."
Prien went back to his bunk. Presently somebody stumbled past; the radio operator across the passageway snarled, "Quiet! The Old Man’s sleeping."
"The Old Man never sleeps," answered Prien from the shadows. "He just rests his eyes."

By 4 PM the thick stench of diesel fuel and unwashed bodies thinned with the smell of as great a feast as the Kriegsmarine could provide. Walz, the ship’s cook, had outdone himself: soup, veal cutlets, pork ribs and gravy, potatoes and green cabbage and strong coffee to wash it down. A "hangman’s dinner" the men called it, and relished it anyway. Prien sat with Wessels and von Varendorff, who kept everybody laughing.

Then the table was cleared, the dishes stowed. Bunks were folded out of the way. Three men went the length of the boat, placing explosive charges in case of scuttling. Everyone checked his life jacket and ripped the flotilla ID off his cap to prevent identification of the unit in case of capture. (This was assuming they lived to be captured; there was a running joke about potato-picking in a Scottish POW camp.) It was 7 PM. Time to go into the enemy’s lair. Prien ordered, "To diving stations."

"Pump ballast to sea," ordered Wessels, watching the depth gauges. "Boat rising...1 meter up, 2 meters up. Fore planes hard a-rise, after planes up five! Boat rising. 200 feet...160 feet..."

The electric motors came up to speed. A hydrophone search from 80 feet detected no noise from the surface; at 45 feet Prien ordered the periscope up. It was night above, and all clear. "Surface."

"Blow all main ballast tanks," ordered Wessels. The boat came bobbing and rocking to the surface. Prien, wearing oilskins, popped the hatch and went up into the cool Orkney air, with Endrass, von Varendorff and the lookouts behind him.

Prien wrote in the U-47’s log: Surfaced at 7:15 PM.

Diesels clutched in, U-47 eased forward on the tide, northwest toward Holm Sound. "By now our eyes had become accustomed to the night and we could see everything clearly–almost too clearly." The hills to the north were silhouetted as if by a bonfire.

The Northern Lights were ablaze above Scapa Flow.

Oblt. z. S. Amelung von Varendorff
2 nd Officer, U-47. Later died commanding U-213 on its third patrol.

For a moment Prien considered aborting the mission, if only for 24 hours. Von Varendorff muttered, "Man, it’s going to be a sticky night, tonight."

But Endrass said, "Well, sir, it is a good light for shooting."
Prien ordered, "Both engines half-speed ahead."

For the next four hours the U-47 worked its way through Holm Sound, submerging to let surface traffic pass, struggling to stay on course in the turbulent water. Their timing had not quite been perfect; a strong tide still moved into the Flow. The boat rode into Kirk Sound like a canoe into rapids, with Prien steering for the gap between the Thames and Soriano, hoping to ride up over the cables stretched beneath the surface. The hawsers scraped along the boat’s bottom (the crew wondering if they’d fouled a mine), and then slewed U-47 hard astarboard, and aground.

Prien had brought the boat in partially flooded to stay low in the water; now he ordered all tanks blown. U-47 floated off the sand bar, rudders hard to port to head her back into the current. The channel gradually widened, the water slowed, and at 12:27 Prien made a new log entry: We are in Scapa Flow.

Suddenly a brilliant light bathed the submarine. A car on the shore near the village of St. Mary’s had turned its headlights on U-47. The bridge crew could make out trucks and sentries on the shore, and knew they would be fired on at any second.

But as abruptly as it appeared the light faded. The car swung around and raced away toward Scapa Flow. Had they been spotted? Prien couldn’t know. (In fact it was just a taxi turning around.) But the incoming tide would permit no escape now, and in any event having gotten into the lion’s den he was determined to find a target.

12:55...No ships are to be seen, although visibility is extremely good. U-47 cruised west, almost three and a half miles across the placid surface of the Flow. Somewhere out ahead lay the remains of Germany’s High Seas Fleet–but where was the British Home Fleet? The Germans came about and felt their way back to the shoreline, astounded to have found in this bastion of the Royal Navy not a single warship.

(Though Prien didn’t know it, the lack of targets was due to poor planning on the part of the Kriegsmarine. Less than a week previous the battleship Gneisenau, escorted by the cruiser Köln and nine destroyers, had sallied into the North Sea with the specific goal of luring the Home Fleet out of Scapa Flow and into the reach of the Luftwaffe. The British dutifully steamed forth; the Germans retreated. Göring’s bombers (not for the last time) proved ineffective, but the British, aware of the vulnerability of Scapa Flow to submarine attack, retired instead to Loch Ewe in western Scotland. The only effect of the operation was to rob Günther Prien of his choice of targets.)

Turn to port is made. We proceed north by the coast.

U-47 crept silently along the Mainland coast beneath the blazing Northern Lights. Still the most they saw were sleeping tankers, and Prien hadn’t come this far for such lowly prey.

Then von Varendorff, peering through his night glasses, made out a dark shadow ahead. Prien discerned the funnel, tripod mast, and–as U-47 moved closer–the jutting guns of a battleship. "I believe she belongs to the Royal Oak class."

HMS Royal Oak

In fact it was the Royal Oak herself, 29,000 tons, bearing eight 15-inch guns and 13-inch armor. This proud old veteran of Jutland couldn’t keep up with the newer ships in the fleet; she’d been left out of the Gneisenau expedition, but was slated to depart Scapa Flow in the morning. Prien handed his glasses to Endrass. "Here, take a peep at that. There’s another one behind her."

Only the bow of the second ship could be made out, a mile or so beyond that of the Royal Oak. With little more to go on, the bridge crew took her for HMS Repulse. (Actually it was merely the 6900-ton seaplane carrier Pegasus.) Cruisers not visible, wrote Prien, therefore attack on the big fellows.

Still on the surface, U-47 closed in. Endrass stood over the master sight, plotting the attack. Since, as Prien put it, "the Royal Oak, right in front of us, was a certainty anyhow," the First Officer aimed to put his first shot just past her bow and into Repulse, nearly three miles away. He reserved two fish for the Royal Oak herself.

Distance apart, 3,000 yards. Estimated depth, 22 feet. "Flood tubes for surface firing."
"Tubes flooded."
"Open outer doors."
"All tubes ready."
Endrass centered the cross hairs on the torpedo aimer and leaned on the firing lever. "Tube fire!"

12:58...Impact firing. The boat lurched as one, two, three ton-and-a-half G7e torpedoes went overboard on blasts of compressed air, electric motors winding up, accelerating toward 30 knots. U-47’s hydrophone operator called, "Torpedoes on their way."

Then it was just Spahr, counting off the seconds: five, ten, fifteen....

Aboard the Royal Oak nearly the entire crew was asleep, including visiting Admiral H.E.C. Blagrove, commander of the Second Battle Squadron. Few of them were much disturbed by the first dull explosion, shortly after one A.M. Something had cut the starboard anchor chain, which ran out noisily into the water.

A bomb? A mine? Many thought something inflammable had exploded in the paint shop, though there was no fire. The ship did not seem to be listing or settling at the bows. Most of the 1200 men, getting no duty call, went back to bed. But several reported air venting under high pressure. Royal Oak was taking on water.

On U-47 Prien and his crew thought they’d hit the Repulse. The two torpedoes meant for the Royal Oak had either missed or misfired, a not-uncommon flaw. There was still the stern tube. About! Torpedo fired from stern.

Again Spahr’s voice counting; again no result. It wouldn’t be the last time Prien had trouble with faulty torpedoes.

A more timid captain might have decided fate was against him. Surely the alarm would be raised any second; to bring the boat about for another shot was pushing it. But Dönitz had chosen the right man. Prien turned U-47 around. The forward torpedo-room crew had hurriedly reloaded; Endrass centered the aimer’s crosshairs on Royal Oak’s midships. "Tube, fire."

Three torpedoes from the bow. Three long minutes for them to zero in on the hulking Royal Oak. At 1:16 A.M. all three slammed into her starboard side, and all three–2,400 pounds of TNT–exploded. Tons of water leaped the height of Royal Oak’s mast; black smoke gushed from the colossal hole in her midships. Her lights went out and she immediately began to heel over. "Flames shot skyward,," recalled Prien. "Like huge birds, black shadows soared through the flames, fell hissing and splashing into the water...huge fragments of the mast and funnels."

Royal Oak had taken a hit in an aft magazine. With the power out the only light came from blazing cordite searing through her vents–"like looking into the muzzle of a blow lamp" was how one Marine put it–illuminating a hellish scene of screaming, horribly burned men, stumbling about like lost souls in the flickering maze.

Royal Oak leaned over 45 degrees. The great gun turrets wrenched around, barrels splashing into the water. Her mast snapped off and smashed her big liberty launch, which might have carried hundreds of men to safety. A last few men managed to scramble out through the portholes onto the port side, even as water gushed in through those on the starboard. For maybe four minutes the ship hung near 90 degrees. Then, amid the hundreds of sailors floating in the frigid, oil-slick water, she rolled ponderously over. One survivor remembered "the tremendous noise; it was like a huge tin full of nuts and bolts, slowly turning over. Racks of shells must have been coming loose, and other gear, so that anybody still inside had no hope."

There were over 800 men still inside, including 24 officers and Admiral Blagrove. For any yet alive there remained only darkness, cold, and small pockets of air gradually running out.

Prien had looked from the blazing innards of the Royal Oak down into the quiet, dark interior of his own boat. "I felt as never before my kinship with these men below who did their duty silently and blindly, who could see neither the day nor the target and who died in the dark if it had to be."

He called down to them, "He’s finished."

They broke out in a cheer. Prien gave an order for silence. They had yet to escape.

Less than half an hour had passed since the first torpedo had struck Royal Oak. Prien did not intend to observe rescue operations. "The bay awoke to feverish activity. Searchlights flashed and probed with their long white fingers...small swift lights low over the water, the lights of destroyers and U-boat chasers.... I could see no other worth-while target, only pursuers."

Actually there were no pursuers. The British weren’t even sure he was there. But the tide had changed; it was get out now or not get out at all. 1:28 A.M. At high speed both engines we withdraw.

Again Prien steered for Kirk Sound, and the twisting channel south of the Minich. "At high speed I pass the southern blockship with nothing to spare. The helmsman does magnificently. High speed, ahead both, finally three-quarters speed and full ahead out...and at 2:15 we are once more outside."

He called down to the crew, "All stations. Attention. One battleship destroyed, one battleship damaged–and we are through." This time he let them cheer.

The next day, when U-47 was safely out to sea, the British announced the sinking of the Royal Oak, adding that the attacking U-Boat had also been sunk. This was met with predictable amusement. Endrass scampered down on deck with a can of paint, and embellished the boat’s conning tower with his rendition of a snorting bull–the Bull of Scapa Flow. It would become Prien’s personal emblem, an ultimately that of his entire U-boat flotilla.

On her return to port U-47 passes the battleship Scharnhorst.
Courtesy of Naval Historical Center

They made Wilhelmshaven on the morning of the 15th, and were met at the dock by Dönitz and Grossadmiral Raeder. On the spot Dönitz awarded everyone the Iron Cross, and Prien the Iron Cross First Class; Raeder promoted Dönitz to Rear Admiral. That afternoon everybody flew to Berlin on the Führer’s personal aircraft, and the next day Hitler himself pinned the coveted Ritterkreuz–the Knight’s Cross of the Iron Cross–on Prien’s breast. He called the Scapa Flow raid "the proudest deed that a German U-boat could possibly carry out." (Dönitz seized the opportunity to buttonhole Hitler on the subject of increased U-boat production. Der Führer, a little annoyed, nevertheless agreed to Dönitz’ request.)

Prien receives the Ritterkreuz from Hitler, Oct. 18, 1939.

As for the British, the Scapa Flow scandal ended several naval careers. (In the entire war only one other British battleship–HMS Barham–was sunk by a U-Boat [U-331]; it and the liner Empress of Britain were the only U-boat victims larger than Royal Oak.) Churchill, as First Lord of the Admiralty, only escaped because he was new on the job. The Royal Navy was forced to resort to other anchorages, which the Germans quickly mined. The battleship HMS Nelson and the cruiser HMS Belfast were damaged and four other vessels sunk, all due in no small part to the U-47.

"Success had singled me out," wrote Prien in his memoirs. "But what after all is success? A matter of luck, of providence? That which matters among men is to have the heart of a fighter and to lose one’s self in the cause he serves."

Related material:
Largest ships sunk by U-boats
Knights Cross winner of the U-boat arm
Map showing Scapa Flow

This article was published on 9 Mar 2002.


Zetterling, Niklas

Buy this title at
£ 35.00

Books dealing with this subject include

Bismarck. Zetterling, Niklas, 2009.
Black Saturday. McKee, Alexander, 1966.
Fatal Decisions. Blandford, Edmund, 1999.
The Forth at War. Hendrie, William F., 2002.
Mein Weg nach Scapa Flow. Prien, Günther, 1940. (transl.)
Le Mystere de Scapa Flow. Korganoff, Alexandre, 1969. (transl.)
Nightmare at Scapa Flow. Weaver, H.J., 1980.
Operazione Marlene. Capello, Ezio, 1997.
The Royal Oak Disaster. Snyder, Gerald S., 1976. (transl.)
Slaget om Atlanten. Bauer, Eddy, 1978.
Der Stier von Scapa Flow. Frank, Wolfgang, 1958. (transl.)
Submarines!. Miller, Carey, 1971.

Return to Articles main page