by Clay Blair
While U-160 was still well to the north of U-487$ position, a Wildcat-Avenger team from the Santee spotted her on the morning of July 14. H. Brinkley Bass in the Wildcat dived to strafe. John H. Ballentine in the Avenger came behind with depth charges and a Fido. In violation of the new standing orders, von Pommer-Esche dived, presenting a Fido target. Ballentine let go the Fido and it was assumed to have hit U-160, which was never heard from again. Her loss further complicated the excruciatingly tight refueling situation.
By this time, eight boats had arrived at the rendezvous site, expecting to meet U-487 and/or her backup, U-160. Some boats had been at the site several days. One or more boats notified Control of the missing U-487 and U-160 and Control queried the U-487. When it received no reply from U-487, Control assumed she (but not U-160) was lost and issued a new refueling plan, designed to favor boats of the important group Monsun. The (lost) backup U-160 was to refuel four Monsun boats (U-516, U-532, U-533, and the lost U-509). The IXC U-155, outbound to the Americas, was to refuel the other three Monsun boats (U-168, U-183, U-188) then come home. The VII U-648, outbound to the Americas, was to cancel her mission, refuel the IXC40 U-527, inbound from the Americas, then come home in company with U-155.
The three Monsun boats that were to resupply from the lost backup 17-160 reported her missing on July 19-20. Control correctly assumed she had been lost and assigned one of those four Monsun boats, 17-516, which had reported irreparable mechanical difficulties, to refuel the other three on July 26: the lost U-509, 17-532, and U-533. Then, as related, she was to go farther south to give the Americas-bound boat, 17-662, ammo and a Metox. The 17-516 refueled the 17-532 and 17-533 but, of course, never found (7-662, which, as related, was sunk on July 21. The 17-516 returned to France on August 23.
As directed, the IXC backup refueler 17-155, commanded by Ritterkreuz holder Adolf-Cornelius Piening, who was diverted from a patrol to the Americas, met and refueled the other three Monsun boats (17-168, 17-183, 17-188) on July 23. The next day Piening made contact with von Trotha in 17-306, homebound from Freetown. Piening gave von Trotha some fuel and the two boats returned to Lorient on August 11.
Per orders, the outbound VII17-648, commanded by Peter-Arthur Stahl, met the 17-527, commanded by Herbert Uhlig, inbound from the Americas and transferred fuel on July 20. Control directed both boats to proceed in company to France.
Alerted to this rendezvous by Enigma decrypts and Huff Duff, aircraft from the “jeep” carrier Bogue, which was supporting eastbound convoy UGS 12, found 17-527 and 17-648 sailing side by side on the morning of July 23. An Avenger pilot, Robert L. Stearns, attacked the two boats. In violation of doctrine, Stahl crash-dived 17-648, went deep, and escaped, returning to St. Nazaire on August 10. Uhlig in 17-527 remained on the surface, racing for a patch of fog and firing at the aircraft with 20mm flak guns. Stearns dropped four shallow-set depth charges that straddled the boat and blew open the pressure hull aft. The boat sank instantly, leaving Uhlig and a dozen other Germans in the water. Later, one of Bogue’s screen, the four-stack destroyer Clemson, fished the thirteen Germans from the water. Stearns, who helped sink the XB 17-118, won a Navy Cross for this kill.
Assigned to Monsun, the new IXD2 U-cruiser 17-847, which had incurred ice damage in the Denmark Strait and had aborted to Norway for repairs, was too far behind the surviving group to patrol with them and, as related, was assigned to be a refueler and was lost. Thus group Monsun, originally eleven boats, was reduced to the five Type IXC40s that had been lucky enough to escape from Biscay and to obtain fuel from provisional tankers 17-155 and 17-516.
These five Monsun boats rounded the Cape of Good Hope into the Indian Ocean. On September 8, the day Italy capitulated, they met the German tanker Brake. As a precaution against the possibility that the Italians might reveal the rendezvous to the Allies, U-boat Control directed all German vessels to leave that area at once and proceed to a new rendezvous several hundred miles south. On September 12, Brake replenished the five Monsun boats and Control issued them patrol areas.
By that time American codebreakers had mastered naval Enigma by the use of the new four-rotor bombes, mathematical theory, and intuition. One result was that Allied authorities were able to keep track of the five Monsun IXC40s and to avoid them, minimizing merchant-shipping losses. The other results:
• Assigned to the Gulf of Cambay (near Bombay, India), Helmut Pich, age twenty-nine, in U-168 sank the 2,200-ton British freighter Hatching by torpedo, and six cargo sailing vessels by deck gun. On the night of November 4, an as yet unidentified Catalina bombed U-168, thwarting an attack on a convoy.
• Patrolling off Mombasa, Kenya, Heinrich Schäfer, age thirty-six, in U-183 sank no ships whatsoever. In extenuation, he reported that in the period from October 19 to October 24, he fired eight electric torpedoes at targets but all missed or malfunctioned.
• In the Gulf of Oman, Siegfried Lüdden, age twenty-seven, in U-188 sank the 7,200-ton American Liberty ship Cornelia P. Spencer and damaged the 10,000-ton Norwegian tanker Britannia.
• Near the southern tip of India, Otto-Heinrich Junker, age thirty-eight, in U-532 sank by torpedo and deck gun four freighters (two British, one Norwegian, one Indian) for about 24,500 tons.
• Assigned to the Gulf of Aden, Helmut Hennig, age twenty-nine, in U-533 sank no ships. On October 16, a twin-engine Bisley light bomber of British Squadron 244, piloted by L. Chapman, sank U-533 in the Gulf of Oman. Of the fifty-three crew, only one man survived: seaman Günther Schmidt, who washed ashore after twenty-eight hours in the water. Arabs found him and turned him over to a British patrol from Squadron 244.
The four surviving Monsun IXC40s went on to the new German-Japanese base on the island of Penang, Malaya. In aggregate they had sunk only six ships (and six sailing vessels) for about 33,800 tons, yet another humiliating U-boat failure, and another victory for Allied codebreakers. In Penang, Heinrich Schäfer in U-183, who had sunk no ships, was replaced by Fritz Schneewind, age twenty-six, who had earlier delivered the IXC U-511 (“Marco Polo I”) to Japan. Only two of these IXC40s (U-188, U-532) were to return to European waters. The other two (U-168, U-183) were to be sunk in the Far East by Allied forces.
THE U-BOAT STAND-DOWN OF AUGUST
Partly as a result of Coastal Command’s intense air offensive in the Bay of Biscay, the loss of U-boats in all waters had reached a catastrophic level by August 1. To repeat the Allied monthly kills:
April 15 (2 in Biscay)
May 40 (7 in Biscay)
June 17 (4 in Biscay*)
July 37 (12 in Biscay †)
Totals 109 ‡ (25 in Biscay)
U-boat Control intended to maintain the tempo of patrols to distant waters in August, but the loss in late July of four Type XIV U-tankers (U-459, U-461, U-462, U-487) and another (U-489) on August 4, as well as a Type XB provisional tanker (U-117) on August 7, forced the Germans to revise plans and tactics drastically. As a first emergency step, Control recalled four boats that sailed from France on August 1.* Only one boat sailed to distant waters from France between August 1 and August 16, the U-161, which had first to carry out an urgent special mission. Eight more boats then sailed to distant waters in the ensuing days of the month.
As a second step, Control issued three important changes, two doctrinal and one technical.
• Commencing on August 2, U-boats were no longer to cross the Bay of Biscay in groups and/or to remain on the surface and fight it out with enemy aircraft. Both inbound and outbound boats were to travel singly, remain submerged, and surface to charge batteries only at night. The one exception to this rule was the new flak boat U-621, which put out on August 22 and was, of course, to remain on the surface in the Bay of Biscay deliberately to trap unsuspecting Allied aircraft.
• Commencing on August 12, all new boats sailing from Germany to join the Atlantic force were to stop at U-boat bases in Norway and top off fuel tanks. This was one measure to compensate for the heavy loss of U-tankers. Although a seemingly sim
ple operation, it was not. The Germans had to ship precious fuel oil from German refineries to Norway by tanker, arrange for air and surface escorts in and out of Norway, and provide protection from air attacks while the boats were in Norwegian ports. Moreover, Norway gradually became a place where U-boats conducted final training, machinery and electronics retrofits, and voyage repairs, theretofore carried out in the Baltic. This practice overcrowded the Norwegian bases and led to delays in sailings.
Of the nine U-boats that sailed from Kiel to Norway from August 12 td August 31, none continued on in August. Six laid over in Norway for nearly a month. One got away after merely two weeks, but the average layover for the nine boats was 26.4 days. Control delayed the sailing of some of these boats for tactical reasons, but most simply became ensnared in the red tape of the new procedures and some were damaged during the layover. The layovers, of course, delayed considerably the reinforcement of the Atlantic force that had been savaged during the summer months.
• Commencing on August 15, all boats were to cease using the Metox radar detector, or FuMB. Experiments had convinced the Germans that Metox did in deed radiate a signal—albeit a very weak one—on which Allied aircraft might be able to home. All outbound boats were to be equipped with a new radar detector, W Anz Gi, dubbed Wanze (Bed Bug), built by the German firm Hagenuk.
There was, however, a flaw in the substitution of Wanze for Metox, yet another technical mistake and commentary on the sad state of German science and engineering under Hitler. Unlike Metox, Wanze was not supposed to give off electronic emissions, which the Germans believed the Allies were able to detect on their radar. But Wanze did in fact give off the same (weak) level of emissions as Metox. More important, Wanze, like Metox, could only search in the broader, meter-wavelength bands, not in the centimetric-wavelength range. German scientists and engineers still did not believe that miniaturized centimetric-wavelength radar was possible!*
The weakness in German science and engineering was vividly revealed in a meeting between Dönitz and Hitler on August 19. According to the stenographer, Dönitz told Hitler that Metox emanations “may explain all the uncanny and unsolved mysteries of the past, such as the enemy avoiding traps set for him, and losses on the open seas.” Hitler listened with “utmost interest to these explanations,” the stenographer noted, then replied that “he believes that the [Metox-radiation] theory just advanced does account for many baffling facts, such as the ability of the enemy frequently to determine the exact number of [U-boats] in a patrol [line].” The “discovery” of Metox emanations, Hitler gushed, was “a great step forward” for the Germans.
During the August hiatus, U-boat Control, spurred by Admiral Dönitz, prepared to renew the U-boat war on the North Atlantic run that had been allowed to lapse since the previous May 24. The return to that decisive battleground in mid-September was to be a sudden dramatic blow, designed to create maximum psychological terror. An entire group, Leuthen, composed of twenty-one boats supported by the Type XIV tanker U-460, would sail secretly, assemble, and attack a convoy simultaneously. In a radical reversal in tactics, the boats were to first attack and destroy the surface escorts, then, secondly, the merchant ships.
To carry out this new tactical scheme with the greatest possible success, the twenty-one Leuthen boats (all Type VIIs) were to be equipped with the very best gear the Germans could provide. This package was to include:
• The new, somewhat faster, battery-powered T-5 Zaunkönig (Wren) homing torpedo, which the Allies called GNAT, an acronym for German Naval Acoustic Torpedo. U-boat skippers were to fire T-5s at the Allied escorts and wipe them out, then if any T-5s were left over, they could be used against the merchant ships, along with the regular air and electric and FAT looping and circling torpedoes with and without magnetic pistols.
• The new Wanze radar detector, replacing Metox.
• The Aphrodite radar decoy.
• The Bolde noisemaking sonar decoy.
• The quad 20mm and twin 20mm flak arrays for defense against Allied aircraft, mounted on improved bridge platforms.
• More sensitive passive-sonar arrays to enhance the ability of the boats to “hear” a convoy while submerged.
In its final configuration, group Leuthen was composed of eighteen experienced Type VIIs from France and three new Type VIIs from Germany. Nine VIIs and Ebe Schnoor’s supporting tanker U-460 sailed from France from August 23 to August 31, the other nine VIIs from September 1 to September 9. The three new VIIs from Germany that in accordance with new procedure had laid over in Norway (for almost a month) sailed from Bergen and Trondheim from September 5 to September 9. The operations of group Leuthen in September are described later in this narrative.
Apart from the new flak boat U-621, which remained in the Bay of Biscay, and the boats of group Leuthen, nine U-boats sailed from France in August, all to distant waters.
To get out of Biscay without attacks from the air, some of these boats closely hugged the coast of France and northern Spain as far as Cape Finisterre. Aware of this routing from naval Enigma decrypts, the Admiralty deployed two support groups in areas near the Cape. These were the 40th, commanded by John S. Dallison (frigate Exe and five sloops and corvettes, backed up by British cruiser Bermuda), and the newly created Canadian Support Group 5, commanded by the Britisher J. D. Birch (British frigates Nene and Tweed, five upgraded Canadian corvettes and a British corvette).
The Germans reacted to this bold gathering of surface ships by deploying special Luftwaffe attack forces. On August 25, a flight of fourteen Dornier DO-217s fitted with HS 293 radio-controlled “smart bombs” and protected by seven JU-88s, attacked Dallison’s Support Group 40. All the bombs missed but four near-misses heavily damaged the British sloop Languard, one of the ex-American Coast Guard cutters.
The British Support Group 1, commanded by Godfrey Brewer (sloop Egret, frigates Jed and Röther, backed up by destroyers Athabaskan and Grenville) relieved Dallison’s Support Group 40. On August 28, a flight of eighteen DO-217s fitted with smart bombs and protected by JU-88s, attacked Brewer’s Support Group 1. Most of the bombs missed the wildly dodging ships, but one hit and blew up the sloop Egret, Brewer’s flagship, with the loss of two hundred of her 225-man crew. Another hit and damaged the Tribal-class destroyer Athabaskan, which, after about two months of repairs, was recommissioned in the Royal Canadian Navy.
• The IXC U-161, commanded by Ritterkreuz holder Albrecht Achilles, sailed from Lorient to Brazil on August 8. As directed, Achilles met the France-bound Japanese U-cruiser 1-8 (code-named “Flieder” or Lilac) near the Azores on August 20. He handed over a German navigator/pilot, a new Wanze radar detector, radio personnel, and routing instructions for a rendezvous in Biscay with JU-88s and German destroyers.* This done, Achilles met Werner Hartmann in the home-bound U-cruiser U-198 in the middle of the South Atlantic on September 6, gave Hartmann a Wanze, obtained fuel, then proceeded to Brazilian waters.
Upon reaching his patrol area, Achilles sank two freighters in the week of September 20 to 26. The first victim was the 5,500-ton British St. Usk; the second, the 5,000-ton Brazilian Itapagé. On the day after he sank the second ship, September 27, a Mariner of U.S. Navy Squadron VP 74, piloted by Harry B. Patterson, found U-161 and attacked with machine guns and depth charges. Nothing further was heard from U-161.
• Two boats that had sailed on August 1 but returned to France, resailed in company to American waters on August 16. These were the famous old Drumbeat boat, the IXB U-123, and the IXC U-523, commanded by Horst von Schroeter and Werner Pietzsch, respectively.
In the dark early hours of the seventh day out, August 22, a Leigh Light-equipped Wellington of British Squadron 179 caught and bombed U-523. Pietzsch dived and escaped, but the Wellington’s report alerted surface ships passing in the vicinity, including the British close escort of a convoy en route from the British Isles to Gibraltar. Unaware of the proximity of enemy surface ships, on the night of August 24-25 Pietzsch ran on the surface.
The destroyer Wanderer and the corvette Wallflower of the convoy escort got U-523 on radar and caught her by complete surprise. Shaken, Pietzsch dived to elude, but Wanderer, commanded by Reginald F. (Bob) Whinney, immediately found the boat on sonar and commenced a dogged depth-charge attack, which Wallflower soon joined. Pietzsch went so deep (to 880 feet, some crewmen asserted) that the hull “groaned” and the interior wood trim “splintered” from the immense sea pressure. Finally Pietzsch gave up and surfaced to scuttle, taking gunfire from both warships. That fire killed about a dozen Germans before they could jump from the sinking boat. The destroyers Wanderer and Hurricane, the corvette Wallflower, and the convoy rescue ship Zamalek fished thirty-seven Germans from the water, including Pietzsch.
Near Cape Finisterre, Allied surface ships also found and depth-charged von Schroeter in U-123 but he got away. Control assigned the boat to patrol the Trinidad area, but later modified the orders to include the “bauxite route” farther south, if von Schroeter chose to go there. He did and on September 21, he found and attacked a convoy of tankers and Liberty ships off French Guiana that had a powerful sea and air escort. He claimed two definite hits and three maybes, but these have not been confirmed in Allied records.
Due to the lack of refuelers, on October 11 Control ordered von Schroeter to come home. While the boat was approaching St. Nazaire on November 7, a Mosquito flying with British Squadron 248 (on detachment from Squadron 618) attacked U-123. Piloted by a Canadian, A.J.L. Bonnett, the Mosquito was fitted with a powerful new 57mm (six pounder) cannon called a “Tsetse.” On the first run in, Bonnett fired eight 57mm rounds that struck U-123 on or near the bridge. On the second run, the “Tsetse” jammed and Bonnett could only fire machine guns. Reporting the attack, von Schroeter said he had a hole in the conning tower that precluded diving and requested air support. He reached St. Nazaire that day, completing an arduous but fruitless patrol of eighty-four days.