by Clay Blair
During his interrogation at Fort Hunt from May 4 to 14, Henke recanted his signed agreement to give truthful information and clammed up. The naval interrogators wrote:
Henke proved extremely security-conscious. He professed preference for American captivity rather than British but this fact made him no more accessible. His interrogating officers found him sullen and embittered. His conceit was limit less although he somewhat grudgingly gave some credit for his success to his crew. ... The feelings of U-515’s crew toward their commander were mixed. Some ad mired his personality; others held his extreme strictness against him. The surviving officers, although admitting his ability, acknowledged his frightful conceit. It seems that ashore Henke was particulary disliked and few in the 10th Flotilla and on the staff of the Admiral U-boats could forgive his boundless ambition and egotism…
To punish Henke for his recantation of a signed pledge and to prevent him from bragging to his crew that he had defied the Americans and was therefore to be regarded as a POW hero, the Allied authorities concerned decided to make good on the original threat to turn Henke over to the British, ostensibly to stand trial for sinking the troopship Ceramic. Although there was never any intent to try Henke for that sinking, which was perfectly legal and proper, Henke did not know this and, as Mulligan writes, he must have viewed the proposed transfer to British control as “a death sentence,” resulting in a “show trial” that “could only end on the scaffold.”
Henke apparently decided that he would not allow himself to be subjected to that supposed humiliation and disgrace. During an exercise period on the evening of June 15, he suddenly bolted for the Fort Hunt security fence. An official report from Fort Hunt described the rest:
At about 1855 ... a guard saw Henke attempting to climb the enclosure wire Fence …. In easily audible tones the guard twice called halt. Henke continued to climb and the guard called halt a third time just before subject reached the top of the fence. As Henke mounted the fence, the guard fired. The prisoner was hit and hung motionless on top of the fence. The officer of the guard, hearing the shot, went immediately to the scene and upon seeing Henke called the camp doctor. Injured prisoner was promptly placed in an ambulance and driven to [a] hospital, while the doctor administered first aid en route. Upon arrival at the hospital at approximately 2018, Henke was pronounced dead. A thorough investigation disclosed that the guard had acted properly and that death was due to prisoner’s own misconduct.*
The sorriest U-boat in the Atlantic force, the IXC U-505, which had aborted at least a dozen starts since December 1942—one occasioned by the suicide of the skipper, Peter Zschech—finally sailed again on March 16. She was still commanded by Zschech’s replacement, Harald Lange, age forty, the oldest captain of an attack U-boat on active service. Her first watch officer remained Paul Meyer, age twenty-six, who had brought the boat home when Zschech killed himself.
After he gave U-123 new Enigma keys, Lange in U-505 patrolled for about six weeks between Freetown and its neighboring seaport, Monrovia, Liberia. The Allies tracked his movements, diverted shipping, and in all that time he sank nothing. “The hex was still with us,” the crewman Hans Decker wrote, unaware of the Allied break into Enigma. “It was maddening. Absolutely nothing turned up.” The prolonged operations in the warm, humid tropics disgruntled and debilitated the crew and sapped the batteries. Low on fuel, Lange commenced the homeward voyage on May 27, electing to take a shortcut, hugging the Cape Verde Islands.
Allied codebreakers provided the approximate homeward track of U-505. Dan Gallery’s hunter-killer group—the “jeep” carrier Guadalcanal and five destroyer escorts—attempted to locate U-505 but failed. Low on fuel, on June 4 Gallery issued orders to steer for Casablanca.
One of the well-trained destroyer escorts, Chatelain, reported a possible sonar contact at 11:10 that same morning. Her new captain, Dudley S. Knox, a lawyer and son of the prominent naval historian Dudley Wright Knox, ran down the bearing, evaluated the contact as a “submarine,” and fired a Hedgehog salvo that missed. Gallery promptly directed two airborne Wildcats and two destroyer escorts, Jenks and Pillsbury, to assist Chatelain and hauled Guadalcanal out of torpedo range, screened by the other two destroyer escorts, Pope and Flaherty. He then turned Guadalcanal into the wind and launched a Wildcat-Avenger “killer team.”
The two airborne Wildcats, piloted by John W. Cadle, Jr., and Wolffe W. Roberts, provided cover for the destroyer escort Chatelain. When the pilots saw the outline of the submarine at periscope depth, Cadle radioed: “Ship that just fired Hedgehog reverse course.” Thereupon Cadle twice “marked the spot” of the submarine with machine-gun bursts. Gallery later wrote that the “intelligent,” “quick-thinking,” and “courageous action” by Cadle and Roberts was decisive to the events that followed and was “one of the few cases in which an aircraft actually directed the attack” on a U-boat. Later, skipper Dudley Knox in Chatelain emphatically denied that was the case. He wrote that after his failed Hedgehog attack, he regained sonar contact on U-505 at one hundred yards and never lost it. The observations and target marking by the Wildcats, Knox insisted, were “valuable” but only in that they enabled him to cut short standard procedure and commence a depth-charge attack at a range of five hundred yards rather than the prescribed one thousand yards.
Knox ran down the sonar bearing and at 11:21 commenced firing fourteen shallow-set depth charges. By that time Lange had discovered that U-505 was in great peril and had ordered his engineer, Joseph Hanser, to take the boat deep. The depth charges shook U-505 and caused some flooding, but they did not severely damage the main structure of the boat. However, it plunged “out of control” to about 755 feet, according to the account by crewman Decker. He went on to say that Lange then cried “his last organized order” to Hanser: “Take us up—take us up before it’s too late!”
Merely twelve minutes after the original sonar contact, at 11:22, the U-505 popped to the surface about seven hundred yards from Chatelain. Dudley Knox, who was on fullest alert, stopped and immediately opened fire with his 3750 caliber guns, shooting forty-eight rounds, some of which hit U-505. When it appeared that U-505 was turning toward him—and a lookout shouted that a torpedo was coming toward Chatelain—Knox responded by shooting a single torpedo at U-505, but it missed, as did the German torpedo. Joining in the attack, Jenks, commanded by Julius F. Way, fired thirty-two rounds of 3750 caliber and Pillsbury, commanded by George W. Casselman, fired twenty-one rounds. At the same time, the two Wildcats ran in and strafed, drawing flak, the pilots reported (perhaps inaccurately). All this gunfire killed one of the fifty-nine Germans on U-505 and wounded others, including skipper Lange and first watch officer Meyer.
The Wildcat pilots reported that the Germans were streaming topside with hands raised in surrender or jumping into the sea. Gallery, who had encouraged his captains to plan for a possible U-boat boarding, radioed all hands: “I would like to capture that bastard if possible.” At 11:27, he ordered all elements to cease fire.
The subordinate commander of the five destroyer escorts, Frederick S. Hall, flying his flag in Pillsbury, reacted promptly. He directed Pillsbury’s captain, George Casselman, to close on the U-boat and lower away a whaleboat with a boarding party. At the same time, Knox in Chatelain and Way in Jenks were to launch whalers and recover survivors. Pope, commanded by Edwin H. Headland, was to continuously circle the scene at a range of two miles to thwart or kill any other U-boats that might be in the vicinity. Flaherty, commanded by Means Johnson, Jr., remained with Guadalcanal as plane guard and screen.
The Pillsbury’s boarding party, commanded by the ship’s first lieutenant, Albert L. David, was composed of nine men. When the party boarded U-505, which was circling on electric motors slowly to starboard, David and two others, radioman Stanley E. Wdowiak and torpedoman Arthur W. Knispel, disregarding possible booby traps, demolition charges, or armed fanatical Germans, rushed below to the control room. It was deserted. Seeing a six- to eight-inch geyser of seawater
spouting from an open strainer (one method of scuttling), the men found the valve cap nearby and shut off the flooding, a decisive measure in the capture of U-505. However, they were unable to immediately shut down the electric motors or unjam the rudder in the control room or at the emergency hand-steering station in the stern torpedo room, which they believed to be flooded and the watertight door to be booby-trapped. Instead, the three men, who thought the U-boat was on the verge of sinking, concentrated on salvaging secret “publications” (current Enigma keys, short-signal books, and so on) and “encoding machines” (Enigmas), which they passed topside to other members of the party. The haul was large—and priceless.*
Since Guadalcanal was no longer threatened by U-505, Gallery brought her and her screen, Flaherty, close to the U-boat. He then called away a ten-man Guadalcanal boarding party, led by a veteran engineering hand, Earl Trosino, and, somewhat later, a second party of seventeen men. Lifted by a wave, Trosino’s first boat crashed down on the forward deck of U-505, making a great noise, which terrified the three Pillsbury men belowdecks, who did not know Guadalcanal had sent a boarding party.
While this was going on, the three destroyer escorts were busy. In compliance with orders from Hall, Casselman in Pillsbury attempted to lash his ship to the circling U-505. His men got a line to U-505, but her rigged-out bow planes holed Pillsbury (flooding an engine room) and put her out of action temporarily, while another of her whalers captured seven German survivors. Knox in Chatelain captured forty-eight German survivors, including the wounded skipper Lange, the engineer Hanser, a photo-propagandist, Kurt Brey, and the ship’s doctor, Karl-Friedrich Rosemeyer. Jenks captured the wounded first watch officer, Meyer. The first lieutenant of Jenks, John D. Lannon, who visited U-505 in a whaler, returned with secret documents obtained from the Pillsbury and Guadalcanal parties and with two other German survivors. Later in the day, all fifty-eight Germans were put on board Guadalcanal.
Upon hearing from Trosino that U-505 would sink unless she was towed, Gallery directed Guadalcanal to put a line on her. Not without considerable difficulty, Trosino and Guadalcanal’s men got a 174-inch steel cable through the U-boat’s bullnose and tied it off. Thereupon Gallery went ahead with Guadalcanal gingerly, setting course north to Casablanca with three destroyer escorts, leaving Pope to stand by the stricken Pillsbury until her crew could complete emergency repairs. During the late evening, when engineers informed Gallery that they doubted the task group had sufficient fuel to reach Casablanca with U-505 in tow, he changed course to the nearest Allied port, Dakar.
When Washington received news of the capture, it was thunderstruck and deeply concerned. Should Berlin learn of the capture of U-505, the Germans would doubtless go ahead with the promised “major changes” to improve U-boat Enigma security, perhaps temporarily blinding Allied codebreakers on the eve of the postponed Overlord invasion. Allan Rockwell McCann, a onetime submariner fresh from command of the new battleship Iowa who was to replace Francis “Frog” Low as Chief of Staff, Tenth Fleet, recalled that Admiral King was so furious at Gallery for possibly jeopardizing the Allied mastery of Enigma that he threatened to court-martial him.*
Cooler heads prevailed. In the belief that Dakar and Casablanca were crawling with Axis spies, Washington told Gallery that if possible, he should go west to the well-isolated British island of Bermuda. In furtherance of that plan, with which Gallery concurred, Washington immediately dispatched from Casablanca the big (20,000-ton) fleet oiler Kennebec, the seaplane tender Humbolt, which embarked an experienced submarine skipper, Colby G. Rucker, the destroyer escort Durik, and the 1,200-ton oceangoing tug Abnaki.
During the first night, June 4-5, the towline broke. The four American vessels circled U-505 all night on a maximum U-boat watch. During the pause, the slow-moving Pope and patched-up Pillsbury had time to catch up to the main formation. After daylight, Guadalcanal’s men put over a 2V4-inch wire tow cable, but U-505’s rudder was still jammed full right and towing remained exceedingly difficult. Gallery himself boarded U-505 and after a careful inspection, declared that the stern torpedo compartment was dry and that he could see no booby trap on the watertight door leading thereto. Holding their collective breath, Trosino and his men opened the door, gained access to the hand-steering station, and put the rudder amidships.
The supporting armada from Casablanca rendezvoused on June 7. Kennebec provided ample fuel for the onward voyage to Bermuda. The Humbolt delivered Colby Rucker, who assumed “command” of U-505, got her shipshape and dry with portable pumps, and jettisoned loose, unnecessary gear. Abnaki took the U-boat in tow with the 2V4-inch cable. Jenks, with “ten mail sacks” of secret documents (weighing about 1,100 pounds) and “the submarine’s coding machines” raced ahead at maximum speed to Bermuda. All this material reached OP20G in Washington on June 12. Meanwhile, Washington and London ordered steps to keep absolutely secret the arrival of these ships in Bermuda. Aware of Gallery’s overweening thirst for publicity,*Admiral King admonished him to lie low and to absolutely seal the lips of the three thousand sailors and airmen in the task group.
The Guadalcanal and other ships arrived in Bermuda under extraordinary security on June 19. Kenneth Knowles of the U.S. Submarine Tracking Room, the outgoing Chief of Staff, Tenth Fleet, Francis Low, and seven others flew to Bermuda to inspect the boat and to interrogate the prisoners of U-505 (code-named “Nemo” or alternately, U-606).
Preoccupied with repulsing the Normandy invasion, the Germans assumed U-505 had been sunk by Allied aircraft and made no major changes in naval Enigma. Except for two special complete copies to King and Ingersoll, Gallery’s official patrol report mysteriously terminated on June 4, just prior to the capture. Remarkably, Allied personnel in the Guadalcanal hunter-killer group and the supporting armada and Bermuda kept their lips sealed until after the war. The IXC U-505 was the second U-boat to be captured intact during the war after the VII U-570, and first foreign man-of-war to be captured by the U.S. Navy since 1815.†
The intelligence haul from U-505 matched—or perhaps exceeded—the hauls from U-110 and U-559.* In a long memo of July 13, OP20G chief Joseph Wenger listed the cryptographic “benefits” from U-505. In summary:
• The Atlantic and Indian Ocean U-boat cipher keys for the month of June 1944. With these keys, the Americans were able to read that traffic as soon as the Germans did and, of course, no bombe time was required. The bombes that would have been used to find keys for that traffic were used to break Army and Luftwaffe keys, normally a British responsibility; four thousand extra hours on Mediterranean keys and nine thousand extra hours on other Army and Luftwaffe keys. Net gain: thirteen thousand bombe hours, as a result of which many new solutions “which would otherwise not have been possible,” were obtained.
• The “extremely important” current grid-chart—or geographic location— -cipher. In use by the Germans for about two years for position reporting, “this is the first time one has ever been physically compromised,” Wenger wrote. It eliminated a lot of guesswork and enabled OP20G to “determine exactly all positions expressed in the text of U-boat messages.”
• The “Reserve Short Signal” cipher, which was to go into effect on July 15, 1944. “This cipher,” Wenger wrote, “prescribes the internal machine setting to be used for tactical signals from U-boats and surface craft.”
• The “Reserve Bigram Tables “ which were to go into effect on August 1, 1944, replacing those of July 1943, which OP20G had “reconstructed” crypto-graphically. “These tables determine the internal set-up for each message,” Wenger wrote. “Hence, even though one message for the day can be read, all messages cannot be read until these Bigram Tables are available or reconstructed.”
The current “Short Weather” cipher for U-boats. This cipher enabled OP20G to determine accurately the position of weather-reporting U-boats. Prior to this capture, OP20G had only “partially reconstructed” this cipher. †
Another valuable discovery in the haul from U-505 was a desc
ription of and operating instructions for a new German electronic-navigation system for ships and aircraft, “Elektra-Sonne” Similar in principle to Loran and the RAF “Gee” electronic systems, widely separated shore-based German radio transmitters projected a “fan” or “cross pattern” of beams over the Bay of Biscay and the Atlantic Ocean that could be utilized to obtain a fairly precise “fix.”
In his memoir, the canny RAF scientist R. V. Jones‡ wrote that he learned (probably from Enigma) that to improve the Elektra-Sonne system, the Germans were building another land-based site at Lugo, in northwest “neutral” Spain. Jones asked Coastal Command whether it should be destroyed or saved for use by Allied aircraft. Coastal Command replied, in effect, “Save it.” The British code-named the system “Consol” and, Jones wrote, “used it with much success.” It was “beautifully simple,” much superior to the British “Gee.” In the postwar years, Elektra-Sonne replaced the British “Gee” system and spread all over the world.
After the interrogation process had been completed, the fifty-eight Germans from U-505 were carefully segregated from other German POWs at a U.S. Army facility, Camp Ruston, Louisiana. The Army’s Assistant Chief of Staff, G-2, Clayton Bissell, directed that “no reports of captures of members of this group of naval prisoners of war will be submitted either to the protecting power or to the International Red Cross.” Günter Hessler wrote that U-boat Control did not learn of the capture until late 1944 or early 1945, when a German officer in a Canadian POW camp managed to warn of “the probable capture of a U-boat, intact and complete with signal publications.”