When Hitler declared war against the United States, the bulk of the German submarine force was committed, directly or indirectly, to the support of Axis forces in North Africa, a task for which it was not suited and which Dönitz believed to be a wasteful diversion from the “decisive” task of shutting off the flow of imports to Great Britain in the North Atlantic.
Kerneval rejoiced over the formal declaration of war with the United States. It provided Dönitz with the strongest possible arguments for a curtailment of the dangerous and unremunerative Mediterranean/Gibraltar operations and a resumption of full-scale U-boat war in the North Atlantic without restrictions. It offered the possibility of launching a devastating attack on Allied shipping in American waters before the Americans could organize convoys or effective ASW forces, perhaps decisively disrupting the flow of war materials from the Arsenal of Democracy on its very doorstep.
The German problem—the all too familiar problem—was the acute shortage of U-boats. Owing to battle losses and retirements, diversions to the Arctic and the Mediterranean, and the mounting delays in new production and workups, on January 1, 1942, the Atlantic U-boat force numbered only sixty-four oceangoing U-boats: nineteen Type IXs; forty-four Type VIIs; and U-A.*
The Atlantic U-boat force was not only short of boats but also relatively green. Forty-four of the sixty-four boats (69 percent) had been in the Atlantic six months or less. Fourteen of the forty-four recent arrivals (32 percent) had only just joined the force in December 1941. Six of the Type VIIs were transfers from the Arctic force and had yet to make a full war patrol in the Atlantic.
Many authors have described a “great growth” of the U-boat peril in 1942, often put at an increase of “twenty boats per month.” If this figure is meant to describe newly commissioned attack boats, it is only a slight exaggeration. In the first five months of 1942, the Germans commissioned seventy-eight new attack boats, a monthly average of 15.6. In the remaining seven months of 1942, when new commissionings actually reached and slightly exceeded twenty boats per month, the total figure was 148, or a monthly average of 21.1. For the entire year the figure was 226, a monthly average of 18.8 boats.
That, however, is merely one part of the story. Some of these new attack boats were assigned to the Submarine School or to R&D projects and never reached a war front. A few were lost to mines or in accidents in the Baltic. Owing to delays in workup or to commissioning dates late in 1942, about half of the 226 new boats commissioned in 1942 did not reach war fronts until 1943. About fifty of these were lost on first patrols from Germany or Norway, most of them having achieved nothing noteworthy, and, of course, they were only a brief “paper” addition to the war-front flotillas.
The only meaningful figure in this welter of numbers is the actual “growth” of the Atlantic U-boat force. This was nowhere near the oft-implied “twenty boats per month.” Owing to the delays in the Baltic, diversions to the Arctic and the Mediterranean, and combat losses, in the first six months of 1942 the Atlantic U-boat force grew by only thirty-four attack boats, or an average of 5.6 per month. Doubtless by coincidence, the growth was divided exactly between Type VIIs and Type IXs:
Owing to the vast distances from France to North America—3,000 miles from Lorient to New York—only the twenty Type IXs were suitable craft for the impending campaign in those waters. One of the twenty was the older U-43 and eight were Type IXBs with a range of only 8,700 miles at 12 knots. The other eleven were Type IXCs with a range of 11,000 miles at 12 knots.
At the time Berlin authorized the U-boat attack on North America, eight of the twenty Type IXs were not available for that purpose. The weary IX U-43 was under orders to return to Germany for a prolonged overhaul. Four IXs (U-68, U-124, U-126, U-129) were returning from patrols to the South Atlantic and required long overhauls. Three IXs (U-67, U-107, U-108) were committed to the arduous battle with convoy Homebound Gibraltar 76 and had to return first to France to replenish fuel and torpedoes and give the crews some rest.
Only six Type IXs could be made ready for launching the U-boat war in American waters. Contrary to some published accounts, Dönitz did not handpick U-boat “aces” for the initial attack. He made do with six Type IX boats and skippers at hand in France. These were:
• Richard Zapp in the IXC U-66. Zapp had arrived in the Atlantic in May 1941 and had made three patrols: one in the North Atlantic, cut short by a mechanical breakdown, and two long patrols to the South Atlantic, during which he had sunk five ships.
• Heinrich Bleichrodt in the IXB U-109. Bleichrodt had won a Ritterkreuz in two patrols on the famous U-48 in the fall of 1940, sinking fourteen and a half ships. Subsequently he had commissioned the Type IX U-67, which was temporarily diverted to sonar R&D. Assigned to command U-109 in June 1941, Bleichrodt had made two Atlantic patrols, both bedeviled by mechanical problems, and had concluded the second on escort duty. He had sunk no ships on U-67 or U-109.
• Reinhard Hardegen in the IXB U-123. The boat had come to the Atlantic in September 1940 commanded by Karl-Heinz Moehle, who won a Ritterkreuz. Since taking command in May 1941, Hardegen had made two patrols, one to Freetown, one to Newfoundland. He had sunk one confirmed ship on the duck U-147 and five confirmed ships on U-123—none on his second patrol in U-123.
• Ulrich Folkers in the IXC U-125. The boat had reached the Atlantic in July 1941, under command of Ritterkreuz holder Günter Kuhnke, who took her on one luckless patrol to the South Atlantic. Promoted to command U-125 on December 15, 1941, Folkers had not yet made a patrol or sunk a ship as skipper.
• Ernst Kals in the IXC U-130. Sailing from Kiel on his first patrol, Kals had run into the eastbound Slow Convoy 57 on December 10. Attacking alone, he had fired six torpedoes and sunk three freighters for 15,000 tons. Recalled from patrol to prep for the attack on America, he reached Lorient on December 16, after merely seventeen days at sea.
• Jürgen von Rosenstiel in the IXC U-502. The boat had made one Atlantic patrol, September 29 to November 9, during which von Rosenstiel sank no ships but severely damaged the whale-factory ship Svend Foyn.
These six Type IXs comprised the first wave. A second wave of Type IXs sailed to United States waters about two weeks after the first. A third wave of Type IXs put out shortly after the second, to patrol the West Indies and the Caribbean Sea. Other IXs followed.
Although the first boats to American waters enjoyed the advantages of surprise and weak ASW forces, patrols to that area were not without great dangers and difficulties. Apart from the vast distances to and from the areas, the chief drawback was the extremely shallow water along much of the United States East Coast, the “continental shelf,” which in the New York area extends seaward nearly 100 miles. To avoid any possibility of being trapped in these very shallow waters by ASW forces, the big clumsy IXs were advised to attack only at night, leaving time to run out to the 200-meter curve (656 feet of water) before daylight, a fuel-wasting but prudent procedure. Since it was likely that the Americans would divert all coastal shipping to these shallow waters and patrol them with aircraft, and possibly order shipping to put into the many convenient ports along the East Coast at night, the succeeding waves of U-boats, lacking the element of surprise, might face even greater difficulties.
There was one very promising spot in this otherwise hostile subsurface geography: the Outer Banks of North Carolina, whose chief feature was Cape Hatteras. At that protrusion, the continental shelf is less than thirty miles wide, merely a two-hour run to deep water at full speed on the surface. Hence, if shipping hugged the coast, as might be expected, to take advantage of air cover, Cape Hatteras offered the possibility of dense traffic with easy access to a deep-water sanctuary and probably lightships and lighthouses to provide precise navigation.
Farther to the south, off the coast of Florida, the subsurface geography was likewise favorable. From Palm Beach south to Miami the continental shelf extends seaward only about ten miles. However, the Florida coastline is a long way from Lorient and the waters are highly phosphorescent. A Type IX patrolling those waters could stay only a short time and ran the danger of its glittering wake being spotted by aircraft at nighttime.
To add physical and psychological punch to the assault on North America, Dönitz suggested that a group of Type VIIs should patrol Canadian waters near Halifax, Nova Scotia, and St. John’s, Newfoundland. Apart from ships these boats might sink, their mere appearance would hold in place Allied escorts and ASW forces on the North Atlantic run and in Canadian waters, which otherwise might be transferred to United States waters. It was even possible that this group of U-boats might force the Allies to abort eastbound convoys, just as they had aborted the besieged Slow Convoy 52 in early November. If so, some ships taking supplies to the Soviet Union via Murmansk might be delayed or might not arrive at all, a setback for the Red Army at a crucial time.
Not everyone at Kerneval or the OKM approved of the commitment of the Type VIIs to Canadian waters. The weather in the North Atlantic—and the Newfoundland area—was certain to be hideous and radio-communications poor. The Type VIIs could barely reach Newfoundland in good weather at one-engine speed with enough fuel left to make a productive patrol. Under the best of circumstances, at one-engine speed, it would take each boat about two and a half weeks to reach the area and two and a half weeks to return, leaving only fuel and food enough for about ten days of patrolling in Canadian waters, and even less if a protracted convoy chase became necessary. If they encountered stormy seas en route to Canada, further delays could be expected, drastically curtailing the time available for covering patrol zones. Moreover, the continental shelf seaward of Newfoundland and Nova Scotia was no less shallow and wide than that in United States waters. The Grand Banks, with an average depth of about 250 feet, extends about 200 miles to the east of Newfoundland.
Besides that, the critics argued, was it not wiser to use the VIIs to continue the U-boat war against North Atlantic convoys closer to home? Owing to the diversion of boats to the Mediterranean (and to British evasion tactics, based on Enigma), the North Atlantic convoys had scarcely been hit in the fall of 1941. Thousands of ships loaded with weaponry, oil, and food had reached Iceland and the British Isles unmolested, some proceeding onward to Murmansk. Operating much closer to home bases, the VIIs could almost certainly be employed more efficiently and with less physical and psychological strain on the crews against these convoys.
Dönitz prevailed. The Type VIIs were to augment the Type IXs in American waters, regardless of risks and inefficiencies. By ingenious use of some of the ballast and fresh-water tankage, the VIIs could extend their range by about 1,000 miles, gaining a little more mobility in Canadian waters. The VIIs attempting to patrol the more distant hunting grounds off Cape Hatteras would have no mobility. To conserve fuel, they would have to lie doggo on the bottom most of the daylight hours and hope shipping came their way.
The upshot was that ten Type VIIs comprising a first wave were to sail to Canadian waters in December. Two were commanded by Ritterkreuz holders: Rolf Mützelburg in U-203 and Erich Topp in U-552. However, five of the ten were new boats sailing from Germany on first patrols.*Other waves of VIIs were to follow.
On December 17, Dönitz summoned to Kerneval the six skippers of the Type IXs of the first wave, which bore the code name Paukenschlag (Drumbeat). It was a new war, a new opportunity to strike an unwary and untested opponent a heavy blow. In view of the depressing failures of the Wehrmacht in the Soviet Union and North Africa, a dramatic U-boat victory in American waters would help lift morale in Germany and rekindle Hitler’s and the OKM’s support for the U-boat arm, which had achieved so little in the Atlantic in the second half of 1941.†
Tactically, Drumbeat was to be a replication of the opening U-boat campaign of September 1939. The boats were to operate not in groups, or wolf packs, but in dependently over a wide area, striking simultaneously on a signal from Kerneval. As in 1939, the aim was to cause the greatest possible physical and psychological jolts. The Ritterkreuz holder Heinrich Bleichrodt in U-109 and the inexperienced Ernst Kals in the new U-130 were to patrol in the Newfoundland-Nova Scotia area, backing up the ten Type VIIs. Richard Zapp in U-66, Reinhard Hardegen in U-123, Ulrich Folkers in U-125, and Jürgen von Rosenstiel in U-502 were to patrol American waters between New York and Cape Hatteras. As in 1939, the skippers were to give priority to largest possible targets—preferably loaded tankers—which were sailing independently. Escorted convoys were to be avoided. To achieve maximum impact, Dönitz suggested that the skippers attempt to sink ships with two-fan shots and authorized the use of deck guns when the conditions for such action were safe.
Folkers in U-125 and von Rosenstiel in U-502 sailed for the United States on December 18. Outbound from the Bay of Biscay, Folkers in U-125 encountered the besieged Gibraltar 76, but when he reported the convoy, Kerneval told him to avoid the battle and continue to America. Von Rosenstiel in U-502 developed a heavy oil leak which left a telltale trace on the surface of the water, and he aborted and returned to Lorient on December 22. Hardegen in U-123 sailed December 22. Zapp in U-66 sailed on Christmas Day. Bleichrodt in U-109 and Kals in U-130, who were Canada-bound, sailed on December 27, by which time all ten Type VIIs assigned to patrol to Canada were at sea. Total force of the first wave: fifteen boats, of which three Type IXs, U-66, U-123, and U-125, were to attack shipping in United States waters.
Some historians have asserted that British codebreakers detected the sailings of these boats and that London flashed quite specific warnings to Washington and Ottawa, which were largely ignored. These assertions are only partly true.
Based on daily information supplied by Rodger Winn in the Admiralty’s U-boat Tracking Room, the naval staff in Washington issued daily U-boat position reports to the Commander in Chief, Atlantic Fleet. The reports were not very helpful. Almost all contained caveats and disclaimers:
General situation obscure and good information lacking.
Situation vague and no indicated activity in North Atlantic.
Sub situation still obscure. No indications of any great activity in North Atlantic but at least two subs are probably west of 40 degrees west….
Situation in Western Atlantic is vague and obscure. There are possibly 2 or 3 west of 40 degrees west, present position unknown.
In his weekly summary of December 29 for the Admiralty, Rodger Winn wrote that “There are indications of an inconclusive character that several U-boats may be moving to the Western Atlantic, possibly to operate in the Caribbean or off Halifax.” There was no suggestion that any U-boat might operate off the United States East Coast.
These vague reports from London came intermingled with word of one horrific disaster after the other in the Pacific and Far East. Besides these setbacks, about ten Japanese submarines, operating close off the coasts of California and Oregon in December, sank the American tankers Emidio and Montebello, damaged five other American tankers, and damaged two American freighters. They also shelled an oil field near Santa Barbara, intensifying rumors that the Japanese were on the point of invading California.*