by Clay Blair
Not described in the Wenger memo was mention of another communications item found in the secret papers of U-505. This was a reference (in a table of contents) to “Short-Signal Procedure Kurier.” Of itself, this was not particularly alarming; Allied codebreakers had seen a prior reference to Kurier in late 1943. However, this new reference led the codebreakers to deduce that the Germans might be—or were—contemplating a new short-signal procedure. All hands involved with Enigma breaking kept a sharp lookout for further Kurier information or procedures.
Allied codebreakers had confirmed by August 26, 1944, that “a radically new communications system was being introduced into German U-boat operations.” This was Kurier, which the Allies dubbed “Squash” and, later, “Turnip.” It was a super-high-speed transmission device (Geber) for use by U-boats at sea. It could transmit a seven-letter message in a burst of about half a second. It was therefore not only extremely difficult for the Allies to intercept but also virtually impossible to DF. Adding to the complexity, the Kurier could be transmitted daily over four wavelengths of varying frequencies. Two of these were available in any given hour.
The Allied “Kurier watch” had a very tough time spotting test transmissions from U-boats and assembling useful data. It was not until December 18, 1944, that British and American communications specialists had learned the “essential elements” of Kurier. Fearing that the Germans might give the Japanese Kurier devices to copy, in January 1945 the Americans gave MIT and Bell Telephone Laboratories contracts to develop sophisticated devices to intercept and DF Kurier transmissions.* Fortunately for the Allies, before the use of Kurier became widespread, the Germans capitulated. No evidence has come to light that the Germans gave the Japanese Kurier technology.
The IXC40 snort boat U-543, commanded by Hans-Jürgen Hellriegel, who won a Ritterkreuz on his one prior patrol in this boat, sailed from France to the Caribbean on March 28. On April 9, Hellriegel came upon a “small convoy” but escorts drove the boat off and depth-charged her, thwarting an attack. Ten days later Hellriegel refueled from the XIV tanker U-488. Aware of this rendezvous from Enigma decrypts, Allied authorities sent an American hunter-killer group built around the newly arrived “jeep” carrier Tripoli to the area. An Avenger from Tripoli, piloted by C. B. Humphrey, found and attacked U-543. In three runs into heavy flak, Humphrey’s depth charges hung up but he fired rockets, drove U-543 under, and dropped a Fido. Hellriegel went deep and escaped.
Later, when U-boat Control assumed (correctly) that the XIV tanker U-488 had been lost, it directed Hellriegel to abort his patrol to the Caribbean and reverse course to the area west of the Cape Verde Islands and serve as a provisional refueler. He was to supply Lüdden’s U-188, inbound from the Indian Ocean and/or Seehausen’s U-66, inbound from the Gulf of Guinea. On May 14, when Control assumed (wrongly) that U-188 and (rightly) that U-66 had been sunk, it released Hellriegel from refueling responsibilities and gave him a free hand. He elected to patrol off Freetown and in the Gulf of Guinea.
After several miserable weeks in tropical waters and no sinkings, Hellriegel headed north for France. Allied codebreakers calculated his homeward track from Enigma decrypts and, on June 28, a hunter-killer group built around another new American “jeep” carrier, Wake Island, got on the scent. On the evening of July 2, an Avenger, piloted by Frederick L. Moore, found U-543 on radar and attacked, notwithstanding flak. When Hellriegel crash-dived, Moore dropped a Fido on the swirl. It apparently hit. Nothing further was ever heard from U-543.
The other three attack boats that patrolled to Freetown and the Gulf of Guinea in March and April also fared poorly. The veteran IXC (7-755, commanded by a new skipper, Johannes Rudolph, who celebrated his twenty-eighth birthday en route, sank no ships. Nor did the IXC40 U-190, commanded by Max Wintermeyer, age thirty. The IXC40 snort boat U-547, commanded by a new skipper, Heinrich Niemeyer, age thirty-three, sank two freighters for 8,400 tons (the Dutch Bodegraven, the French Saint Basile) and the 750-ton British ASW trawler Birdlip. Wintermeyer and Rudolph returned to chaos in France on June 20 and 23, respectively; Niemeyer on August 11. The unpopular Wintermeyer left U-190 for other duty. While U-155 was joining her escort off Lorient, a Mosquito of British Squadron 248, piloted by Leslie Cook Doughty, attacked with Tsetse 57mm cannon, machine guns, and two depth charges, but the boat limped into port.
In return for one boat captured (U-505) and four sunk, including those of Ritterkreuz holders Henke (U-515) and Hellriegel (U-543), the ten boats patrolling to Freetown and the Gulf of Guinea from January through May 1944 sank seven confirmed ships for about 29,000 tons—Seehausen in U-66, four; Niemeyer in U-547, three. American codebreakers, hunter-killer groups, and the contingent of B-24s from U.S. Navy Squadron VB 107 on Ascension Island had made patrols to that area not only unprofitable but also as dangerous for U-boats as the Northwest Approaches to the British Isles and the Bay of Biscay,
PATROLS TO THE AMERICAS
U-boat Control mounted twenty-one patrols to American waters in the period from January 1 to June 1, 1944; including two by the snort boat U-539. As related, Control recalled Ritterkreuz holder Hans-Jurgen Hellriegel in the snort boat U-543 to serve as a provisional tanker near the Cape Verde Islands, after which he elected to patrol in West African waters and was sunk on the return voyage.
Another of the boats of this group was sunk early on the outbound voyage. She was the famous IXC U-68, commanded by Albeit Lauzemis, age twenty-six, who had commissioned the boat as a watch officer in February 1941. Except for a six-month stint as a skipper of two school boats, Lauzemis had made all of the patrols of Ritterkreuz holder Karl-Friedrich Merten and had himself commanded U-68 for fourteen months.
Assigned to patrol off Panama, Lauzemis was first to meet the VIID minelayer U-214 on April 9 to give her new Enigma keys. After that he was to refuel from the XIV “Milk Cow” tanker U-488t but he did not arrive at the rendezvous. Allied codebreakers decrypted Enigma instructions for this meet. In the early hours of April 10, the day after the Guadalcanal hunter-killer group sank U-515 and captured the ranking ace, Ritterkreuz holder Werner Henke, one of the “jeep” carrier’s Avengers, piloted by Eugene E. Wallace, came upon U-68 close by. Wallace attacked twice, but U-68 dived and got away.
In response to this alarm, three other aircraft from Guadalcanal joined Wallace. At about dawn, Squadron Commander Richard K. Gould in a Wildcat spotted the resurfaced U-68 and strafed, drawing flak. Thereupon two Avengers, piloted by Samuel G. Parsons and Helmuth E. Hoerner, attacked with depth charges, rockets, and Fidos. These three attacks killed or wounded flak gunners and forced Lauzemis in U-68 to crash-dive. Avenger pilot Wallace, who was out of ammo, circled and relayed a blow-by-blow account to Dan Gallery in Guadalcanal.
Gunner Hans Kastrup at the 37mm flak station aft headed for the conning-tower hatch and stumbled upon another gunner who was badly wounded and dragged him along. When Kastrup reached the hatch, he found it slammed shut. He shouted into the bridge voice tube, but it, too, had been sealed off for the dive. The U-68 plunged beneath the sea, stranding Kastrup and the wounded man in the water. Kastrup and the wounded man survived the Avenger attacks, but U-68 did not. Pilot Wallace reported “debris, oil, battery acid, torpedo air flasks, and several survivors. …” Spotting Kastrup and his wounded companion in the water, Wallace dropped them a life raft.
About three hours later, several destroyer escorts arrived at the scene. One of these, Chatelain, found and rescued Kastrup on the raft, but the wounded man he tried to save was dead. Other destroyer escorts recovered pieces of three torpedoes as well as “cork, cloth, food, a canvas bag, a sofa pillow, a leather jacket and human remains” to confirm the kill The sole survivor, Kastrup was temporarily confined at Fort Hunt, Virginia, for interrogation and was the last German submariner to see Werner Henke alive.
As related, while outbound, the first snort boat into combat, the IXC40 U-539, commanded by Hans-Jurgen Lauterbach-Emden, age twenty-four, which sailed on January 3, was diverted
to give fuel to the inbound IXC U-516, Consequently U-539 could not safely patrol the Caribbean and with the fuel remaining went to frigid Canadian waters instead. Two other boats, both on maiden patrols, also went to the icy Canadian waters in January: the IXC40s U-802 and U-845, commanded by Helmut Schmoeckel, age twenty-six, and Werner Weber, age thirty-six, respectively.
Canadian ASW forces were on full alert for these three boats. In spite of foul February weather, aircraft harassed U-539 and U-845. The snort in U-539 helped Lauterbach-Emden to escape detection, but he worried about his dwindling fuel supply. On March 1, he sighted and attacked “part of a convoy,” but his torpedoes missed and he got nothing. He returned to France on March 21, completing a patrol of seventy-nine days that profited him nothing except snort experience.
Fresh from Kiel, Weber in the new U-845 was recklessly brave. Off St. John’s on February 1, he attempted to follow the British corvette Hardleigh Castle into the inner harbor but ran on a rock at Cape Spear and stuck fast. He finally broke loose, but the damage was severe: two ruptured tanks, both rudders, and two bow torpedo-tube outer doors jammed. When he saw the extent of the damage, Weber wanted to abandon ship and scuttle, but the thirty-seven-year-old engineer, Otto Strunk, who had served on Prien’s U-47 at Scapa Flow, dissuaded him.
After makeshift repairs, Weber returned to the hunting grounds. On February 9, he fired five torpedoes at the 7,000-ton British freighter Kelmscott, which was en route to join fast convoy Halifax 278. At least two torpedoes hit and Weber claimed a sinking, but it was not so. Other ships towed Kelmscott into St. John’s, where she was repaired and eventually reentered service.
This attack drew an intense response from Canadian aircraft. On February 14, a B-24 of Squadron 10, piloted by A.P.V. Cheater, found and attacked U-845, notwithstanding “intense” flak. In two runs, Cheater dropped eight depth charges and strafed, killing one German gunner and slightly wounding another two. Weber dived and escaped and, on the following day, shot at but missed the 6,100-ton freighter Pachesham.
Also low on fuel, Weber departed Canadian waters on about March 1, coincidentally near the track of the returning Lauterbach-Emden in U-539. About ten days later, on March 10, Weber came upon Slow Convoy 154. Although U-539 was close by, U-boat Control apparently did not want Lauterbach-Emden to join, and advised Weber that he was all alone and directed him not to attack the convoy unless conditions were entirely favorable.
Slow Convoy 154 was escorted by Canadian group C-l, commanded by the Britisher J. A. Burnett in the British destroyer Forester. In addition to that ship, the group consisted of eight Canadian vessels: the destroyers St. Laurent and Assiniboine, the frigates Swansea and Valley field, and four corvettes. Having dropped back to assist a burning freighter, George H. Stephen in St. Laurent got a good Huff Duff bearing on Weber’s contact and shadow reports. He and Burnett in Forester, the frigate Swansea, and the corvette Owen Sound, commanded by J. M. Watson, hunted and hounded U-845 for almost six hours, finally forcing her to the surface with an exhausted battery.
When Weber popped up, St. Laurent, Forester, and Swansea were close by. In a bold, dogged attack, Stephen in St Laurent pumped 119 rounds of 4.7” shells at U-845. This and the 40mm and 20mm fire from all three vessels killed Weber, his first watch officer, and all others on the bridge. Engineer Strunk assumed command, abandoned ship, and scuttled. The escorts rescued forty-five survivors of the fifty-four men who sailed on this one and only patrol of U-845.
A diversion to weather reporting delayed the arrival of Schmoeckel in the new IXC40 U-802. Off Halifax on March 22, he attacked a convoy of small coasters (SH 125), claiming three sunk for 5,000 tons and one for 1,500 tons damaged. Allied records confirmed one sinking: the 1,600-ton British freighter Watuka. This attack—and Schmoeckel’s report to Control that night—triggered another ASW hunt by Canadian forces, but Schmoeckel eluded his pursuers. On April 9, he intercepted and attacked the fast convoy Halifax 286 composed of fifty merchant ships. He claimed one 10,000-ton freighter sunk and another of 10,000 tons damaged, but Allied records did not confirm any sinkings or torpedo hits in that convoy. The U-802 returned to Lorient on May 2, completing a voyage of ninety-five days. While the crew was on leave in Germany, shipfitters equipped her with a snort.
Two more boats sailed to Canadian waters in February. Both came to grief.
• The new IXC40 U-550, commanded by Klaus Hänert, age twenty-six, which relieved U-802 as a weather reporter in mid-Atlantic. On February 22, a Canso (Catalina) of the Iceland-based Canadian Squadron 162 attacked U-550 with machine guns and four depth charges. The machine-gun fire killed one gunner and severely wounded another. The close depth-charge explosions holed a starboard fuel-ballast tank and washed a man overboard. After reporting weather twice a day for two weeks, Hänert headed U-550 for New York via Canadian waters.
Hänert reached an area east of New York and about seventy-five miles south of Nantucket Island by April 16. That day, while U-550 was submerged, tanker convoy CU 21, about twenty vessels en route from the Caribbean via New York to Northern Ireland, passed overhead. Hänert boldly rose to periscope depth and fired a salvo of three torpedoes at the 11,000-ton American tanker Pan Pennsylvania, which was loaded with 140,000 barrels of gasoline and had seven aircraft lashed on deck. Some torpedoes hit, and the tanker burst into flames and eventually sank.
The destroyer escorts Joyce and Peterson, commanded by Coast Guardsmen, Robert Wilcox and S. M. Hay, respectively, hurried to the scene to pick up survivors of the tanker. As they were doing so, Joyce got a sonar contact on U-550 and her captain, Robert Wilcox, carried out a depth-charge attack, firing eleven missiles. Hänert bottomed U-550 at about three hundred feet, but some of the depth charges ruptured air and fuel lines, causing serious flooding and other damage. Wrongly believing that he was being hunted by only one warship, Hänert decided to surface in broad daylight and fight it out.
When U-550 came up, Hänert had T~5s in two bow tubes ready. By that time, a third destroyer escort of the convoy, Gandy, manned by a Navy crew, had come on the scene to assist Joyce and Peterson. Shaken by the number of warships converging on him, Hänert nonetheless attempted to fire the T-5s. However, the torpedo tube outer doors were jammed shut and he could not shoot.
All three ships opened fire on U-550 with all guns that would bear. Seeing that his was the closest ship, W. A. Sessions in Gandy put on speed to ram. Owing to a last-second maneuver by Hänert, Gandy struck the submarine well aft, incurring four wounded and damage to her own bow. When Gandy hauled clear, all three escorts resumed the punishing fire from 3”/50 caliber guns and 40mm and 20mm cannons. Overwhelmed, Hänert gave orders to abandon ship and scuttle, thwarting a boarding party from Joyce, which picked up twelve German survivors, including Hänert, who was wounded. Wilcox in Joyce transported these prisoners to Northern Ireland, where he turned them over to British authorities.
• After duty as a weather boat, the new IXC40 U-856, commanded by Friedrich Wittenberg, age twenty-five, followed U-550 into Canadian waters. Forewarned by Allied codebreakers, Canadian ASW forces hunted for Wittenberg, but they had no immediate luck.
Upon learning from the codebreakers that U-856 intended to follow U-550 into the area off New York, American authorities mounted an all-out hunt for her by the “jeep” carrier Croatan and her five destroyer escorts plus two American hunter-killer groups comprising a total of seven destroyers.
In the early hours of April 7, one of two Avengers from Croatan, piloted by Wilburt A. Lyons, got U-856 on radar but could see nothing by eye. As the Avenger approached, Wittenberg made the mistake of firing at it with flak guns, giving away his position. In excited response, Lyons dropped a Fido rather than a flare, but U-856 was moving too fast for the Fido to home and Wittenberg escaped and went deep.
Other aircraft from Croatan and the armada of destroyers and destroyer escorts mounted a U-boat hunt to exhaustion. The destroyer Boyle got a sonar contact on U-856 and attacked with thirteen depth charges, but
Wittenberg escaped again. Ten hours later, the veteran destroyer Champlin, which had sunk the IXC U-130& year earlier, again found U-856, Assisted by the destroyer escort Huse, commanded by R. H. Wanless, who attacked with Hedgehogs, Champlin dropped twenty-one depth charges. These savaged U-856 and forced her to the surface.
Wittenberg ordered his crew to abandon ship and scuttle, but the conning-tower hatch was jammed shut and had to be pried open with a crowbar. While the Germans coped with this blockage, Champlin and Huse opened up with 5” and 3750 caliber guns. The captain of Champlin, John J. Schaffer III, then rammed U-856 solidly in the stern. Not to be outdone, Huse also steamed in to ram, but she missed. Presently U-856 upended and sank. Tragically, an errant 20mm on Champlin wounded four of her own men, skipper Schaffer mortally. The destroyers Nields and Ordronaux fished out eleven and seventeen Germans, respectively. The twenty-eight survivors of U-856 included Wittenberg and his first watch officer.
After a stint as a weather boat, the new IXC40 U-548, commanded by Eberhard Zimmermann, age twenty-seven, which sailed on March 21, was next to enter Canadian waters. Patrolling near St. John’s, Newfoundland, on the night of May 3, Zimmermann came upon the new British destroyer escort Hargood assisting the damaged freighter Baltrover of convoy Outbound North (Slow) 236. Zimmermann fired a T-5 at Hargood but missed. At that moment, a B-24 of Canadian Squadron 10 arrived, illuminated Hargood with a Leigh Light, and fired a recognition flare that failed. Convinced that he was the intended target, Zimmermann opened up with flak guns, then dived to the bottom and lay doggo. Believing Hargood had shot at the plane in error, the B-24 crew, justifiably miffed, hauled out of danger. Allied forces remained mystified by this encounter.
On the evening of May 6, Zimmermann lay submerged at periscope depth amid ice clutter. Control that night told him that his wife had given birth to a daughter and that all was well. Toward midnight the periscope watch caught sight of what appeared to be the shadow of a ship. Zimmermann shot a T-5 at a range of 1,500 yards and went deep.