Seizing the Enigma (28 page)

Perhaps under the supervision of the director of the Operations Division (Home), Captain Ralph Edwards, Haines planned the attack. He determined the forces, the time of day, and the angle of approach that gave the best chance of success. He studied the three-page report on German weather ships that Hinsley had compiled on April 26, 1941, from various sources. The report made clear to any naval officer the isolation of the weather ships. Perhaps from later intercepts, the British concluded that the
München
was to sail May 1 to relieve the
Ostmark
in grid square AE 39, east of Iceland.

The same source may have revealed the presence of the other weather ship that Hinsley knew about, perhaps the
Sachsen
, in the other preferred observation area, AB 72. Edwards figured that seven ships would be needed to search the grid square. Since AE 39 extended about 1° of latitude from north to south, or 69 statute miles, and since ships would be able to stay in sight of one another at a spacing of 10 miles, seven ships would adequately sweep the area. Presumably one warship, quickly reinforced by others, could swiftly capture a surprised and lightly armed weather ship.

So it was decided. Edwards detached three cruisers and four destroyers from the Home Fleet for the assignment. In command of the forces was Vice Admiral Lancelot E. Holland, a gunnery specialist, head of the Eighteenth Cruiser Squadron. A short, slim man with sharp features and nearly white hair, Holland, intensely ambitious, was regarded as one of the most competent senior officers in the service. He flew his flag from the
Edinburgh
; the other two cruisers were the
Birmingham
and the
Manchester
, both armed with twelve 6-inch guns and capable of speeds greater than 30 knots. Also aboard the
Edinburgh
was Haines, who knew what the cryptanalysts needed and was assigned to search for it aboard the seized vessel.

The destroyers were the
Nestor
and three of the large, fast, and tested Tribals: the
Eskimo
, the
Bedouin
, and the
Somali.
All three had, barely two months before, participated in the Lofotens raid, in which the
Somali
had sunk the
Krebs
and captured Enigma rotors and keys. Now they and the cruisers, together with the other gray warships of the Home Fleet, held in readiness as a strategic force at Scapa Flow, tugged impatiently at their anchor chains.

On Monday, May 5, the seven ships raised anchor and steamed out of the basin. The destroyers took one route, the cruisers another to their rendezvous next morning north of the Faeroes. That afternoon the flotilla practiced a battle action. The
Manchester
acted as an enemy pocket battleship, with the
Nestor
laying a smoke screen to
help it escape. During much of the day the force pretended to cover for some minelaying west of the Faeroes. At 3
A.M.
on Wednesday, May 7, the group altered course from north-northwest to southeast. This was to disguise its intentions in case it was seen by that morning’s German meteorological flight. At 6
A.M.
, the flotilla again altered course, this time to a little east of north. It was heading for its starting position for the sweep, which it reached a little after noon. At 12:55 Holland turned his ships east and eight minutes later spaced them at 10-mile intervals along a north-south line a little bit west of AE 39. Visibility was only 7 or 8 miles, which made it a little harder for the ships to remain in contact but enabled them to approach the weather ship more closely before being detected.

They steamed at 17 knots for two and a half hours, then Holland increased speed to 20. The sky was clear, the sea, slightly ruffled by a light breeze, calm. The temperature stood around freezing. The sun declined slowly on its shallow oblique to the sea. At 4
P.M.
, the
Birmingham
sent up an observer aircraft. Its pilot and the lookouts on all ships strained their eyes for the trawler’s smoke or for the needle of her mast above the horizon. Aboard the
Somali
, the physician, Surgeon-Lieutenant Dr. M. G. Low, retired to the wardroom to read
Country Gentleman
while awaiting the action.

Suddenly, a few minutes after 5
P.M.
, someone aboard the
Edinburgh
saw smoke off the starboard bow between
Edinburgh
’s course and
Somali
’s
.
At about the same time the man who had shot open the locked drawer on the
Krebs
, Lieutenant Warmington, on the bridge of the
Somali
, spotted the smoke. The rattlers sounded action stations. Low threw down his magazine and ran out on deck. He, too, saw the smoke. The
Somali
increased speed to her maximum 32 knots and raced toward the ship that appeared to rise above the horizon.

Aboard the
München
, Radioman Wiggeshof was transmitting a weather report when the cry rang out, “Mastheads on the horizon!” The little ship put on way and ran. The crew began rushing about. The wireless noncom came into the radio shack, grabbed the
Enigma machine, put it and the current keys into a canvas bag with a lead bottom, added papers and instruments that Rebelein brought up from below, and slung it overboard. At 5:28, Wiggeshof transmitted on 7769 kilocycles, in the clear, “
Werde gejagt
” (Being chased).

By then the
München
had emitted a dense white smoke screen and was dodging to and fro trying to stay behind it. On the
Somali
, Low felt a pang of sympathy for the little ship and her crew, suddenly seeing the bow waves of a flotilla of enemy warships heading toward her.

When she was about 3 miles from the weather ship, the
Somali
opened fire with her 4.7-inch guns. The
Eskimo
followed. The
München
, with only a machine gun, did not return the fire. None of the British shells struck her, but, rumbling over the trawler and sending up towers of water next to her, they had the desired effect: the crew members were seen abandoning ship in two boats. Not all escaped that way, however. Some of the lifeboats could not be dropped to the water, and Wiggeshof, as soon as he had transmitted his warning signal, drew on another pair of pants and jumped overboard. Others remained on deck.

The trawler’s crew made no attempt to scuttle, in part because some of the seacocks had been cemented in when the sand ballast was replaced by concrete. The impression gained aboard the
Edinburgh
that the
München
was settling rapidly by the stern proved to be an optical illusion. The
Somali
readied her boarding party: Warmington; the second in command, Henry Stuart-Menteth, now a commander; and two seamen. She sped to the trawler at top speed, reversing to full speed astern to come to a thumping stop alongside. The boarding party, revolvers at the ready, jumped down from the destroyer onto the deck of the weather ship. One of the seamen shot himself in the toe with his pistol as he landed. Stuart-Menteth was nervous that the Germans had set explosives, but the party found none when it searched the ship. She was intact.

Warmington went to the radio shack, where he picked up a few bits of paper. He found nothing he thought worth taking; the Germans
had apparently thrown everything valuable overboard. Haines came over from the
Edinburgh
with the prize crew. He seemed to know just what he was looking for and that some cipher documents were kept in officers’ quarters separate from cipher documents in the radio shack. So he didn’t bother with that room but disappeared into the depths of the ship, apparently looking for something specific. Within a few moments he seemed to have found it, for he emerged from below carrying papers.

The
Edinburgh
and the
Somali
, meanwhile, were picking up the enemy crew. “What’s the name of that ship?” Captain Caslon bellowed down to Low, who spoke German.
“Wie heisst deine Schiff?”
shouted Low to the Germans. “
München,”
they replied. Wiggeshof had lost consciousness in the 35-degree water; the next thing he knew, a British seaman was slapping his face and asking whether he wanted tea or coffee. Wiggeshof, who had never in his life had tea, must have nodded his head at the wrong time because the sailor brought him a steaming mug of it.

After about twenty minutes the boarding party returned to the
Somali
, and the prize crew took over. By 6:45, an hour and a half after the trawler’s smoke had first been sighted, the
München
, escorted by the
Somali
, was on her way to a British port. Haines, meanwhile, transferred to the destroyer
Nestor
, which at 11:45 was ordered to bring him and his papers to Scapa.

Upon his arrival in Bletchley on Saturday, May 10, Haines turned over to Peter Twinn the Short Weather Cipher and the inner and outer Enigma settings for the home water keys for June. Holland had called them “rather undistinguished documents,” but they bore within them seeds of great power.

That their weather ship with its documents might have been seized seemed never to cross the Germans’ minds. They had received Wiggeshof’s frantic signal about being chased, and the Naval War Staff concluded two days later, when the
München
failed to respond to
a request to report her position, that she had been lost. The Germans picked up the intentionally misleading British official communique: “One of our patrols operating in northern waters encountered the
München
, a German armed trawler. Fire was opened, and the crew of the
München
then abandoned and scuttled their ship. They were subsequently rescued and made prisoner.” But though the German navy duly noted this in several war diaries, nothing was said of the possibility that secret documents had been captured, and no changes in German naval cipher procedure were ordered.

How could they not have thought about this? How could they have not taken ordinary precautions? In the first place, the previous losses of weather ships had led to no dire consequences. Second, the Naval Group Command North was getting ready for its role in Hitler’s vast ideological attack on the Soviet Union, less than seven weeks away. The group had to lay thousands of mines in the Baltic before the assault began and had to keep track of Soviet warships. It had to escort freighters carrying nickel from Finland, ward off raids like that on the Lofotens, protect U-boat departures—all duties linked to Norway’s being what Hitler called his “zone of destiny” in the war, and it would not be wise to fail the Führer. Finally, the high command had larger concerns. Only three weeks before the
München
was captured, Hitler and Admiral Erich Raeder, the head of the navy, discussed the perennial problem of the United States’ hindrance of the U-boat war and the newer issue of Japan’s planned attack on Britain’s major Asian base at Singapore.

In these realms of high strategy, it was easy to forget a single trawler, one of many tiny specks on the chart of the North Atlantic, doing a secondary job. Her fate was seen as insignificant in a struggle in which ships were sunk daily and many men died. For all these reasons, the
Kriegsmarine
ignored the loss of the
München
. Wrongly.

Britain’s target: an Enigma cipher machine of the German navy. The Enigma put German messages radioed to U-boats into secret form; an identical machine, identically set up, reconverted the ciphertext to plaintext in the submarines.

How the Germans set up an Enigma machine for enciphering messages.

From the eight rotors available, the three specified by the key list for current use are chosen. The alphabet ring on each rotor is turned to the position given in the key list and locked into place with a pin on a leaf spring.

The three current rotors are assembled on the shaft from left to right in the order given in the key list.