by Clay Blair
Prolonged and sometimes heated debates ensued. Against the advice of his military chiefs, Roosevelt sided with Churchill and approved further Allied operations in the Mediterranean Basin. The conferees finally agreed that:
• After the defeat of the Axis in Tunisia, the Allies were to promptly invade Sicily (Operation Husky), probably in early July during the new moon, which favored paratroopers. Proposals for the invasion of Italy were tabled.
• Owing to the delays in the capture of Tunisia and the decision to invade Sicily—and possibly Italy—Overlord was to be postponed to about May 1944. George Marshall, Dwight Eisenhower, and other American Army strategists regarded this postponement in favor of the Mediterranean operations a major mistake.
• The Allies were to mount an all-out offensive against the German U-boat force. At the insistence of Admiral King, who was still loath to place American ships under “foreign” (i.e., Commonwealth) command, there was to be no single Allied ASW commander, on the Atlantic, presiding over a unified force.
• Concurrent with the campaign against the U-boats, Bomber Command and the U.S. Eighth Air Force were to begin the combined bomber offensive (Sickle) against Germany.
• Military forces of the Soviet Union were to be supplied materiel, but not at “prohibitive cost” to other operations. However, during the period of complete daylight in the Arctic and the invasion of Sicily, shipments via the Arctic route were to be curtailed.
• Operations against Japan were to be intensified in five ways: in the Southwest Pacific, a two-pronged assault on the stronghold of Rabaul, staged from New Guinea and the Solomon Islands; an island-hopping campaign across the central Pacific, beginning at Tarawa in the Gilberts; the recapture of Burma by Allied forces staging from India; materiel support to the Chinese Nationalists, who were fighting Japanese armies on the Asian mainland; and maximum support of the American submarine force in the Pacific.
• The Allies were to accept nothing less than the “unconditional surrender” of the Axis.
Throughout the Casablanca conference, the acute shortage of Allied shipping remained the “controlling factor” in most decisions. The loss of Allied merchant shipping to all causes in 1942 had been a hard blow: 1,664 vessels for 7.8 million gross tons. Of this number, it was calculated, Axis submarines sank about 1,160 ships for about 6.25 million gross tons, well over half of that in North American waters. All Allied shipyards had worked frenetically to overcome the losses. American yards turned out an astounding 760 ships for about 5.4 million gross tons in 1942. British Commonwealth yards had produced about 1.1 million gross tons, raising the total to 6.5 million gross tons by all Allied yards, almost exactly offsetting losses to Axis submarines. The net loss in Allied shipping in 1942 was therefore about 1.3 million gross tons.*
Convoying and the shipping losses to U-boats in 1942 plus diversions of shipping for offensive operations (Torch, Guadalcanal, Papua New Guinea) had sharply reduced imports to sustain the people and war-production facilities in the British Isles. From a comfortable prewar level of fifty million tons, British imports had fallen to forty-two million tons in 1940, to thirty-one million in 1941, and to an absolutely intolerable twenty-three million tons in 1942. In response to a strongly worded request from Churchill that additional shipping be allotted for British imports, Roosevelt had replied on November 30, 1942, that he had ordered an increase in American shipbuilding goals for 1943 from about sixteen million (deadweight) tons to about 18.8 million (deadweight) tons, and if the steel could be spared he might possibly order twenty million (deadweight) tons.† He had assured Churchill that the United States would Lend-Lease the British sufficient extra shipping from the increased American production to guarantee that imports to the British Isles would not fall below twenty-seven million tons in 1943.
Owing to a breakdown in communications—and to loose language and terms—the American military chiefs came to Casablanca with a large misunderstanding of Roosevelt’s guarantee of extra American shipping to raise British imports to twenty-seven million tons in 1943. The Americans not only thought the increase in Lend-Lease shipping for that purpose was to be far, far less, but also that the British were to provide extra shipping for military operations. Because there were no shipping experts at Casablanca, the conferees did not discuss maritime allocations in any significant detail and therefore the misunderstanding remained un-revealed for several weeks. When it finally came to light, it was to cause temporary difficulties in Anglo-American relations and force revisions in some plans agreed upon at Casablanca.
Of the many decisions reached at Casablanca, none ranked more urgently in the minds of the conferees than the protection of shipping and the destruction of the German U-boat force. That mission was explicitly and officially granted “first charge” (or priority) on Allied military assets. Among the numerous measures to be taken:
• American and British heavy-bomber forces were to greatly intensify the attacks on the U-boat bases on the French Atlantic coast.
• American and British heavy-bomber forces were to bomb German cities known to have U-boat building yards or factories producing important U-boat components, such as diesel engines and batteries.
• Coastal Command was to remount hunter-killer operations in the Bay of Biscay in order to interdict U-boats going to and from the French bases. The two Army Air Forces squadrons (numbers 1 and 2) of the Antisubmarine Command, based at St. Eval in southwest England and equipped with B-24 Liberators fitted with centimetric-wavelength radar, were to operate in cooperation with Coastal Command in the extension of the Biscay hunter-killer missions.
• Because of the shortage of surface escorts, beginning in January 1943, east-bound cargo convoys on the North Atlantic run were to sail from New York on a ten-day cycle rather than eight days, guarded mostly by British and Canadian warships but still including one American escort group, A-3. The British and Canadians were to increase convoy defenses by providing a minimum of five offensive or hunter-killer groups (support groups). Comprised of about six to eight ships each (destroyers, sloops, ex-American Coast Guard cutters, frigates, and, when available, “jeep” carriers) the hunter-killer groups were to patrol the convoy routes and rush to the support of those convoys threatened by U-boats, killing as many as possible, rather than merely suppressing them as in prior years.
• North Atlantic convoys known to be under direct threat of U-boat attack were to be provided with air escort to the maximum extent possible. The early model B-24s of Coastal Command’s Squadron 120 were to be upgraded to very-long-range aircraft by the addition of extra fuel tanks in the bomb bays, and other measures. Meanwhile, the B-17 Flying Fortresses and Halifax bombers and the less lethal, more vulnerable, shorter range Catalina and Sunderland flying boats were to provide the main weight of long-range coverage, operating as far as possible toward the Greenland “Air Gap.”
• The newly established Middle Atlantic convoys from the United States to Gibraltar and the return (UG and GU Fast and Slow), in support of Torch operations, were to be escorted exclusively by American warships. These were mainly cruisers, Treasury-class Coast Guard cutters, and a host of destroyers, but since many troopships sailed in the UGF convoys, the escort also included the old battleships Arkansas, New York, and Texas, the carrier Ranger, and later, offensive “jeep” carrier hunter-killer support groups.*
• The Allies also established two other convoy routes in the Middle Atlantic area, protected by American destroyers. These were exclusively “oil” convoys, comprised of seven big, fast tankers, which cruised at 14.5 knots. The first, OT (“Oil for Torch”), sailed directly from the Caribbean to Gibraltar and the Mediterranean, returning in ballast to the Caribbean as convoy TO. The second, CU (“Oil from Curaçao for the United Kingdom”), sailed directly from the Caribbean to the British Isles, returning in ballast to the Caribbean as UC convoys. Scarcely ever mentioned in popular accounts of the Battle of the Atlantic, the Middle Atlantic convoy system grew to be an enormous enterprise
and was to require large numbers of American warships and aircraft for escort.†
• By decision of the highest British officials, Coastal Command was to be allotted forty H2S centimetric-wavelength aircraft-radar sets, theretofore designated for Bomber Command.* Fearing that the Germans would recover an H2S from a crashed British bomber and quickly devise a centimetric-wavelength radar-detection device (FuMB) for U-boats before Coastal Command could exploit the new radar, John Slessor, the new chief of Coastal Command,§ requested that Bomber Command not fly H2S sets over Germany or German-occupied territory for at least several months. The request was denied. The Germans recovered an H2S from a Stirling that was shot down near Rotterdam on the night of February 1-2, only the second time the H2S was employed in combat.
• Priority for construction of destroyer escorts (DEs) in American yards, which had been downgraded in 1942 in favor of landing craft and merchant ships, was to be upgraded. However, as a result of the low building priority in 1942, only fifty-five DEs were to be commissioned in the first half of 1943. Twenty-one were to be sent directly to the Pacific to release fleet destroyers from convoy duties. Of the remaining thirty-four, seven were to go to the Royal Navy and five to U.S. Navy schools, leaving only twenty-two for Atlantic convoy escort.#
In the first quarter of 1943, Allied heavy-bomber forces carried out twenty separate raids on the U-boat bases in France, thirteen by Bomber Command and seven by the Eighth Air Force.* The combined air forces flew 3,124 sorties. Some of the Bomber Command raids were massive: 302 aircraft to Lorient on the night of February 7-8,437 to St. Nazaire on the night of February 13-14, 363 to Lorient on the night of February 16-17, and 413 to St. Nazaire on the night of February 28-March 1. These and the other raids destroyed the thinly built exterior base facilities and utterly leveled the cities of St. Nazaire and Lorient, but no bombs penetrated the U-boat pens or damaged any U-boats outside the pens. Similarly, the smaller raids on Brest failed to dent those pens.
The airmen dreaded and hated these missions. Invariably aircraft and aircrew losses were heavy. The failure to inflict any damage on the pens—even with 2,000-pound bombs—was humiliating and demoralizing. Berlin propagandists ridiculed the campaign, boasting of the invulnerability of the structures and steadfastness of the submariners. But, in fact, the Allied airmen made an important contribution to the anti-U-boat campaign, unrecognized at the time or later, even by the Air Force historians. The air raids significantly delayed or halted construction of other U-boat pens that were urgently needed to adequately accommodate the swelling Atlantic U-boat force.
Bomber Command continued to carry the weight of the Allied air attack on the U-boat pens and the building yards in Germany in the first quarter of 1943. In nine separate raids comprising 1,443 sorties, RAF bombers hit Wilhelmshaven four times, Hamburg three times, and Bremen and Emden one time each. These raids also failed: No bombs hit any U-boat building facilities or U-boats.
Owing to the slow arrival of aircraft and to the diversion of bombers to the Twelfth Air Force supporting Torch, the Eighth Air Force grew only slowly. It flew its first mission against German soil (Wilhelmshaven) on January 27, a token raid of fifty-three aircraft. In February and March, it mounted four other raids on Ger many, two more against Wilhelmshaven and one each against Bremen and Emden. Not until March 18 was it capable of mounting a raid of up to one hundred bombers and its fighter support remained inadequate. The raids in Germany, which also failed to damage any U-boat building yards or U-boats, were “largely experimental,” the official American Air Force historians wrote. Thus the combined bomber offensive (Sickle) against German targets other than the U-boat building yards proceeded haltingly. ;
1945: MYTHS VERSUS FACTS
For many years after World War II, naval historians and popular authors alike depicted the Battle of the Atlantic in the months January through April 1943 in a melodramatic fashion. The story line was that the Germans, having finally accumulated “four hundred” or “over four hundred” U-boats “in service,” came within a whisker of closing down the vital North Atlantic convoy nun in March, thereby “winning” that long-fought naval struggle, and that as a consequence, all Allied operations in that sector of the globe were thrown into peril. Then in May 1943, the U-boat war suddenly and almost inexplicably collapsed.
That view of this period in the Battle of the Atlantic apparently was first committed to paper in the British Admiralty’s authoritative and secret “Monthly Antisubmarine Report” for December 1943. Reviewing the year 1943, the author wrote:
Up to the 20th March 1943, there seemed real danger that the enemy would achieve his aim of severing the routes which united Great Britain with the North American continent. After that date his strength seemed to ebb....
Two paragraphs later, the author painted an even more apocalyptic picture:
The significance of the period up to the 20th March was that it appeared possible that we should not be able to continue convoy as an effective system of defence against the enemy’s pack attacks. …
In Volume I of Samuel Eliot Morison’s semiofficial fifteen-volume history of U.S. naval operations in World War II, published in 1947, Morison cited this Admiralty source and wrote:
The enemy never came so near to disrupting communications between the New World and the Old as in the first twenty days of March 1943.
In Volume II of Stephen W. Roskill’s four-volume history of Royal Navy operations in World War II, published ten years later in 1957, he quoted directly and extensively from the same Admiralty source, and wrote that this period was the “crisis of crises” and that
[f]or what it is worth this writer’s view is that in the early spring of 1943 we had a very narrow escape from defeat in the Atlantic. … [One cannot] look back on that month [of March] without feeling something approaching horror over the losses we suffered. … Where could the Admiralty turn if the convoy system had lost its effectiveness? They did not know; but they must have felt, though no one admitted it, that defeat stared them in the face.…
Although later scholarship showed that lugubrious story line to be quite wrong, vestiges of it still appear from time to time, even in the most serious works. For example, American naval historian David Syrett wrote* of this period:
The Allies’ strategic situation in the North Atlantic was bleak with no end in sight to the sinkings and U-boat attacks on transatlantic convoys. … March 1943 marked the point at which the German U-boats came closest to disrupting seaborne communications between North America and Great Britain [The shipping shortage was such that] the Allies found it almost impossible to provide the required vessels to maintain essential civilian programs such as imports of food and raw materials into Great Britain while at the same time provide the ships required to support military operations.
In order to put this matter in truer perspective, it is appropriate to set forth a number of relevant facts fully and clearly.
First, the strength of the U-boat force.
While it is true that by January 1, 1943, there were “400 U-boats in service,” according to the most reliable German sources, that figure demands close analysis. Less about twelve specialty boats (XIV “Milk Cow” U-tankers, XB minelayers, IXD2 U-cruisers), only about half of the “four hundred” were considered to be in “operational” status; all the rest were in workup or refit or icebound in the Baltic or assigned to the schools. Moreover, if we accept the repeated contention of Dönitz that the operational boats assigned to the Arctic and Mediterranean were wrongly placed and virtually useless except as a “threat in being,” then the only U-boats that posed a meaningful peril to the Allies were those of the Atlantic force, based at the five French Atlantic ports.
That force was still quite modest in size in January 1943. Counting gains and losses, the number of attack boats had grown by only thirty-three since late summer of 1942. This growth had developed as follows:
Nor was there to be a dramatic growth in the number of attack boats of the Atlantic
U-boat force in the first four months of 1943.
In the four months under analysis, January through April 1943, the Germans deployed the overwhelming majority of the Type VII and IX attack boats and XB minelayers in the Atlantic force to the North Atlantic convoy run:
Second, Allied losses.
In the same four months, the Allies sailed fifty-nine cargo convoys composed of about 2,400 merchant ships east and west across the North Atlantic run.** Over half, about 1,320 ships, left from New York eastbound in Halifax and Slow Convoys. The others, 1,081 ships, left from the British Isles to the Americas in Outbound North and Outbound North (Slow) convoys.
U-boats sank 111 of these 2,401 ships: seventy-three en route to the British Isles; thirty-eight on the return voyages to North America. This was about 5 percent of all ships that crossed the Atlantic in convoys in that area. Therefore, in these four months, 95 percent of the ships sailing in those fifty-nine convoys arrived at their destinations.
In the first twenty days of March, the U-boats operating against the North Atlantic run achieved unusual success against four eastbound convoys: Halifax 228 and 229 and Slow Convoys 121 and 122, sinking thirty-nine of the approximately two hundred merchant ships (20 percent) in these convoys and the British destroyer Harvester. It was this harsh blow that so rattled the Admiralty. The fact that eleven other convoys got through unscathed in the month of March in that area and only one other convoy lost one ship to U-boats is seldom if ever mentioned in the apocalyptic scenarios.
The loss of thirty-nine merchant ships in these four eastbound convoys in March cannot be dismissed lightly. No complete reckoning of the loss of life and food, weaponry, and raw material has come to light, but it was obviously serious. Yet not serious enough to cause, in Roskill’s words, the “crisis of crises.” In contrast to his assertions and those of other historians, the official historian of British merchant shipping during World War II, C.B.A. Behrens,* wrote that although stockpiles shrank throughout the first quarter of the year, “they began to rise” and “the United Kingdom import program suffered no disasters in the first half of 1943.”