by Clay Blair
• The IXC40 U-534, commanded by Herbert Nollau, was next to sail from Bordeaux on the night of August 25. She, too, had only just completed her first war patrol—ninety-eight days in the North Atlantic as a weather boat—and had arrived on August 13. There had been no chance for a refit but remarkably, in the brief stop at Bordeaux, technicians had jerry-rigged a snort to U-534, a rigid pipe that could not be raised or lowered.
When Nollau sailed on the night of August 25, he also kept the crew on deck wearing life preservers. Dodging mines and/or detonating them with temporarily streamed noisemakers and diving to escape swarms of Allied aircraft, Nollau finally reached the open waters of the Bay of Biscay. When the snort was activated, it malfunctioned and filled the boat with exhaust gases, which felled Nollau and many crewmen. When Nollau surfaced to get fresh air, Allied aircraft attacked the boat. Nollau returned fire with his flak guns—claiming one aircraft destroyed—but was soon forced to make an emergency crash dive, during which the boat accidentally shipped about twenty-five tons of seawater and plunged to an extreme depth before Nollau and his engineer could regain control.
After this close call, U-534 proceeded well westward to skirt the British Isles, all the while learning to snort on this temporary fixed apparatus. On the way, Control directed Nollau to serve as a provisional weather boat. After a sixty-one-day trip, the boat reached Norway on October 24 and sailed for Flensburg the next day. Nollau retained command, but the boat did not resail for a war patrol until May 3, 1945.*
• The IXC40 U-857, commanded by Rudolf Premauer, age twenty-five, sailed from Bordeaux the same night as U-534, August 25. She was the last of the big boats to leave that base for Norway.
This new boat also had just completed a ninety-seven-day weather patrol, arriving in Bordeaux on August 13. She, too, had been fitted with a temporary, rigid snort and also had to tediously negotiate the mined Gironde River, harassed by Allied aircraft. After the boat finally reached the open waters of the Atlantic, Control directed Premauer to carry out another weather-reporting task. Forty-four days later, on October 7, the boat arrived in Norway and sailed the next day for Flensburg. Premauer retained command but he did not leave for another war patrol until February 8, 1945.
The last of the seven Type IXs to leave France directly for Norway was the famous veteran IXC U-155. Commanded by Johannes Rudolph, age twenty-eight, she had made a patrol of 105 days to the Gulf of Guinea, arriving off Lorient on June 24, where, as related, Allied aircraft killed two men, wounded seven, and damaged the boat. When it was learned that Rudolph was unable to return to Lorient from leave in Germany, the first watch officer of the IXC40 U-548, Ludwig-Ferdinand von Friedeburg, age twenty, was given temporary command and he sailed on September 9, the youngest officer yet to command an oceangoing U-boat in the Atlantic war zone.
Von Friedeburg brought U-155 into Norway on October 17, completing a harrowing voyage of thirty-nine days. From there he resailed to Flensburg, where Rudolph reassumed command and von Friedeburg went on to command a small Type XXIII electro boat. The U-155 made no more war patrols.
The voyages of these last thirteen Type IXs to evacuate from French bases were designed principally to save the boats from capture, battle-harden the crews for duty in electro boats, and provide weather reports and transportation to Germany for flotilla commander Kuhnke. In 581 days at sea, the six snort boats in this group that mounted war patrols to the waters of West Africa and America sank or caused the destruction of only two ships, the 7,200-ton American Liberty ship George Ade and the 2,100-ton British freighter Livingston,
These minuscule results and those of the Type VIIs belie the rosy reports on the offensive effectiveness of snort boats emanating from Admiral Dönitz and U-boat Control. The only advantage the snort of that era gave a U-boat was the ability to avoid detection by radar-equipped Allied aircraft and survive—it did nothing to aid in successful attacks on Allied shipping.
TYPE VII SNORT BOAT PATROLS FROM NORWAY: 1944
During the evacuation of the U-boat bases in France in August 1944, the Red Army summer offensive (Bagration) advanced steadily westward into Poland toward the Vistula River and Warsaw. On September 4, German-occupied Finland formally surrendered to the Russians. This “defection,” as Berlin viewed it, deprived the Germans of naval bases that had been used to maintain the minefield sealing off the Gulf of Finland and to support a few Type VII U-boats operating in that area. On October 13, Riga fell to Soviet forces, forcing the Germans to evacuate Estonia and to reorganize farther south in Latvia and Lithuania.
The dominance of Soviet forces in the eastern Baltic and the intense Allied mining and bombing of the western Baltic severely hampered U-boat operations. AH school boats and new combat boats in workup that sailed into the Baltic were vulnerable to Allied air attack and to acoustic and other types of offensive Allied mines.
Allied air raids on Hamburg, Bremen, and Kiel continued to retard new U-boat construction. Production of the big Type XXI and the small Type XXIII electro boats slipped ever further behind schedule. Subsections of the big Type XXIs—potentially the greatest threat to Allied maritime assets—were built in the interior of Germany and barged to three main locations for assembly: Hamburg, Bremen, and (to escape Allied air attacks), Danzig. In the summer of 1944, from June through August, the three main assembly areas commissioned only ten Type XXI
boats: four at Hamburg (U-2501 to U-2504), four at Bremen (U-3001 to U-3004), and two at Danzig (US501 and U-3502). Advancing Soviet forces in the eastern Baltic posed an especially grave threat to Danzig, which produced only twelve more Type XXIs in 1944.*
The fact that Albert Speer and German engineers were able to serially produce at numerous dispersed manufacturing sites a new oceangoing combat submarine type in about fourteen months awed Allied navalists. What seldom has been emphasized, however, is that the design was merely a modification of an oceangoing Walter boat and that the sea trials of the Type XXI boat revealed numerous design flaws. Since there had been no time to build a prototype for testing, flaws were to be expected, but at least two flaws in the Type XXI were crippling.
• To conserve battery power for operations, the Germans introduced a system of hydraulic power in place of the electrical motors theretofore used to control the periscope hoist, bow and stern planes, rudder, torpedo-tube doors, and other gear. Lacking experience with hydraulics on submarines, the Germans produced a system that was much too complicated and much too delicate. Besides that, too many of the hydraulic lines and pistons were placed outside the pressure hull, where they could not be repaired when submerged and were highly vulnerable to close explosions. Moreover, inasmuch as the external hydraulic piping and fittings could not be made entirely leakproof, seawater constantly contaminated the system and diluted its power and the boats left an oil trace. Although pieces of the hydraulic system were improved and retrofitted, the most serious flaws could not be eliminated.
To offset the weight of and to make more space available for the huge (372-cell) battery, the Germans powered the XXIs with two newly developed six-cylinder, lightweight diesels, rated in design at 1,970 horsepower each with superchargers driven by the exhaust gases. The superchargers did not produce the design horsepower. Moreover, the temperature of the exhaust was far in excess of the safe operating limit of the metal in the exhaust valves (350 degrees above the limit imposed in American submarines). To assure safe and prudent operations, the superchargers had to be removed, thereby reducing the horsepower of each engine from almost 2,000 to 1,200. This necessary modification left the Type XXI vastly underpowered and increased the time required for a full battery charge from one hour to four hours. A maximum surface speed of 15.6 knots (less than the 16-knot corvette), inherent in the design, could not be improved.†
When the U-boats in France were preparing to evacuate in July 1944, Control conceived a “new U-boat war,” which was to be waged by new snort boats sailing from Norwegian bases.
Admiral Dönitz or a senior OKM sta
ffer apparently felt the need to justify this new campaign (and possibly the impending campaign by Type XXI and XXIII electro boats) to all hands in the Kriegsmarine with yet another exhortation. From Berlin came a long propaganda screed entitled “Why the U-boat War?” Briefly repeating the familiar strategic arguments for isolating the British Isles (buttressed by incorrect and inflated numbers), the statement proclaimed that “a new U-boat war must and shall be our most important goal in the war against the Western Powers.” Therefore the Kriegsmarine and industry “must work for that end with fanatical energy”:
This new war must have a decisive influence even in the current year of the war [1944]. If it does, success will not be denied our iron will and zealous labors. Thus every man in the Kriegsmarine can say with pride that his activity—his work in this war—is of an importance at least equal to that of the best armored defense or grenadier on the distant fronts. Yes, the final decision itself may depend upon the revived U-boat war.
Taking this propaganda proclamation at face value, some writers have asserted that in the fall of 1944, Germany launched a new and telling phase of the U-boat war with snort boats, which were a major step toward a “true submersible “ as opposed to conventional but obsolete (and defeated) Type VIIs and Type IXs, dismissed as basically surface ships with the ability to submerge only briefly. It would be closer to the truth to describe the patrols of the new snort boats from Norway from July to December 1944 as a combination of propaganda strikes and advanced training exercises in combat snorting that it was vital to master if the Type XXI and Type XXIII electro boats were to be effective, when—or if—they ever reached readiness for combat.*
Owing to the absence of U-tankers and to the markedly increased distances from Norway to the convoy hunting grounds and to the dangers posed by the increased Allied ASW measures, it was not possible to mount group attacks versus
convoys by the Type VII snort boats or long-distance individual patrols to the Caribbean, the Gulf of Mexico, Latin America, or Freetown and the Gulf of Guinea by the Type IX snort boats. Excepting some weather-reporting patrols, which were deemed vital for Hitler’s planned Ardennes counteroffensive against Allied forces that were closing in on Germany from the west, the VIIs mostly patrolled close to the British Isles as in 1939 and 1940 and the IXs in the less distant Canadian waters.
To carry out this “new U-boat war,” Control mounted sixty-eight Type VII snort-boat patrols from Norway in the period of July through December 1944. Eighteen VIIs aborted; sixteen were lost.
The VII sailings by month:
The Type VIIs operated under difficult conditions. Refit facilities in Norway, which had to accommodate the thirty-odd boats of the Arctic force as well, were limited and often under heavy Allied air attack. Many of the new VIIs from Germany overlapped with the older VIIs evacuating from France, creating a traffic jam in the fjords and inshore leads used for interbase travel. All U-boats in northern waters in summer and early fall had to contend with the lack of darkness, the best time to snort to charge batteries and ventilate the boat.
It needs to be stressed yet again that the boats did not snort full time. They traveled on batteries for most of the day at about two or three knots. Once a day the boats snorted at five knots for four hours to recharge batteries, and surfaced for about a half hour to air the boat. Hence it was difficult for a snort boat to travel more than about fifty sea miles a day.
While the snorts afforded a welcome degree of protection from Allied aircraft, the VIIs deployed from Norway in the “new U-boat war” were greatly handicapped by the snail-like pace of the boat. Under the new tactical doctrines, it was to take a Type VII snort boat about twenty-five days each way to travel to and from Bergen to the English Channel, leaving only about ten days for operations in the assigned patrol zone. This was not unlike the limitations inherent in Type VII operations in the early days of the U-boat assault on America, Drumbeat. Snort imperfections and catastrophic failures made the travel to and from the patrol zone even more uncomfortable and often unbearable for the crews.
Aware from Enigma decrypts that this “new U-boat war” was afoot, the Allies took several important steps to thwart it. In hopes of destroying U-boats before they reached the Atlantic, they increased air and surface ASW patrols in the Shetland-Faeroes and Faeroes-Iceland “gaps” and planted new minefields in those passages. They mounted heavy-bomber raids against the naval bases in Trondheim, Bergen, Stavanger, and Horten, and also attacks against U-boats at sea in the Norwegian training areas. They switched the convoy routes into and out of North Minch and North Channel to the much more distant St. George’s Channel, going southabout Ireland, as in the early months of the war.
Four Type VII snort boats sailed to patrol North Minch, Scotland. Their stories in brief:
• The VIIC41 U-300, commanded by Fritz Hein, age twenty-four, the first and only Type VII snort boat to sail from Norway in the month of July, originally was to patrol the east coast of Iceland. On second thought, Control sent the U-300 to North Minch. But she never got there. On August 4, an Iceland-based Canso of the highly effective Canadian Squadron 162, piloted by W. O. Marshall, attacked U-300 with three depth charges. Contrary to policy—and good sense—Hein crash-dived. The explosions damaged both periscopes and cracked a ballast tank and a fuel tank, forcing Hein to surface and man flak guns. His 37mm gunners drove off the Canso, and Hein dived and got away. However, the damage forced Hein to abort to Bergen, arriving on August 28, and he did not resail until early October.
• Two other boats that patrolled to North Minch were also forced to abort. Commanded by Konrad Bornhaupt, age twenty-four, the U-285 sailed from Norway on August 24, sank no ships, incurred heavy depth-charge damage, and returned to Bergen on September 18, after merely twenty-six days. Commanded by Erich Taschenmacher, age twenty-five, the U-775 sailed from Norway on November 18, sank the 1,300-ton British frigate Bullen, but had an engine failure and returned to Bergen on December 22, after a voyage of thirty-five days.
• The fourth boat, the Type VIIC41 U-296, commanded by Karl-Heinz Rasch, age thirty, conducted two patrols off North Minch. Neither resulted in any sinkings. On the first, from August 16 to September 29, Rasch reported that he remained continuously submerged on his snort and batteries for thirty-four days of the forty-five. For the second, of fifty-two days, he sailed on November 4 and returned to Norway on Christmas Day.
• Nine boats set out for patrols two hundred miles farther south, off North Channel (separating Scotland and Ireland). In brief:
The first to arrive there was U-482, commanded by Hartmut von Matuschka, age twenty-nine, who sailed on August 14. In merely nine days, from August 30 to September 8, he carried out far and away the most productive patrol of any Type VII in 1944: five confirmed ships sunk for 32,671 tons. His victims (from three different convoys) were the British corvette Hurst Castle, two big, valuable tankers (the 10,400-ton American Jacksonville and the 15,702-ton British Empire Heritage), and two freighters (the 4,100-ton Norwegian Fiordheim and the 1,300-ton British Pinto),
On a second patrol to North Channel in U-482 commencing on November 18, von Matuschka again found good hunting. On January 15, 1945, he damaged the 8,300-ton British “jeep” carrier Thane and the 7,400-ton Norwegian tanker Spinanger. Towed into Greenrock, the Thane was not repaired during the war. In wartime it was thought that on the following day, January 16, the British Support Group 22 (sloops Starling, Peacock Hart, and Amethyst; frigate Loch Craigge) sank U-482 with the loss of all hands. However, in a recent reassessment, the Admiralty declared that the cause of the loss of U-482 was unknown, possibly sunk by a mine.
The other eight U-boats that set out for North Channel during this phase of the “new U-boat war” fared poorly.
• British surface ships or mines caused the loss of two with all hands on about September 9, while en route to the area: the U-484, commanded by Wolff-Axel Schaefer, age thirty-three, and U-743, commanded by Helmut Kandzior, age twenty-four, sunk by British
frigate Helmsdale and British corvette Portchester Castle, Niestlé writes.
• The U-1200, commanded by Hinrich Mangels, age twenty-five, sailed on October 7 but aborted after one week with mechanical problems.
• Control berated and relieved the skipper of U-398, Johann Reckhoff, age thirty-three, for failing to act more aggressively and sent the boat back to the Baltic.
• The U-248, and the Type VIM Is U-1003 and U-1004, commanded by Bernhard Emde, age twenty-six, Werner Strübing, age thirty-seven, and Hartmuth Schimmelpfennig, age twenty-four, respectively, did not sink anything either. Emde left to command the nonsnort VIIC41 U-299 of group Mine; Schimmelpfennig left for other duty, but the oldster Strübing retained command of U-1003.
Only one of the eight boats hit a target: U-483, commanded by Hans-Joachim von Morstein, age thirty-five. He damaged the British frigate Whitaker, which was towed to port, a total loss, but he had to abort the patrol with a disabled hydroplane.
Four boats set out to patrol off Reykjavik, Iceland.
• The U-396, commanded by Ernst-Gunther Unterhorst, age twenty-five, whose first command, U-395, was destroyed in Kiel by Allied aircraft, sailed from Trondheim on August 6. A week thereafter, the snort failed, forcing Unterhorst to return to Trondheim after eleven days at sea. He did not resail until late October.
• While en route from Kiel to Norway, the U-244, commanded by Ruprecht Fischer, age twenty-seven, came under Allied air attack on July 25, as related. In this fierce engagement, Fischer incurred one dead and eight wounded. After repairs and remanning, he sailed from Bergen to Iceland on August 23. He patrolled off Reykjavik where on September 22, he missed a “destroyer” with a T-5, then returned to Bergen on October 10, a fruitless patrol of sixty-three days.