The slaughter inflicted by the twenty-nine U-boats that sailed to the Americas in April was undeniably a spectacular German naval victory: 133 confirmed ships sunk (thirty-three tankers) for 641,100 gross tons and fourteen ships damaged (six tankers) for 81,000 gross tons. The number of the victims sunk or damaged was thus 147 ships (thirty-nine tankers) for 722,000 gross tons.
The great majority of these ships were sunk and damaged in the Gulf of Mexico and the Caribbean Sea or in the approaches to those areas in the western Atlantic. The German victory was made possible by a swift and adroit shift of U-boats from the United States East Coast to those two areas, which were not yet prepared for U-boat warfare. Had the Allies been able to read four-rotor naval Enigma on the U-boat net Triton (Shark), almost certainly they would have detected this shift as well as the refueling operations early enough to have taken special precautions and more effective ASW measures. For example, the destruction of the tanker U-459 doubtless would have disrupted U-boat operations and spared many Allied ships in May and June.
In the five months, January 1 to June 1, 1942, the Germans and Italians sank 129 tankers in the Atlantic, Caribbean, and Gulf of Mexico. Of these, forty-nine were of American registry, thirty-seven were British, nineteen were Norwegian, and twelve were Panamanian. The other twelve were Canadian, Dutch, Venezuelan, Mexican, and Russian.
With the introduction of the Halifax-Boston-Halifax and Norfolk-Key West-Norfolk convoy systems, admirals King and Andrews had reduced tanker losses in the Eastern Sea Frontier to near zero (one loss in May; one in June). The difficult problem areas remained the Caribbean Sea and the Gulf of Mexico. King was not yet able to provide sufficient air and surface escorts to establish convoys between Trinidad and Key West and between the Texas and Louisiana oil ports and Key West.
Per plan, the British and Canadians established two convoy systems in the Caribbean Sea during May:
• A British route running between Aruba-Curaçao and Trinidad. One British group (B-5) of the Mid-Ocean Escort Force (MOEF) shifted from the North Atlantic run to the Caribbean to provide surface escort, reducing the MOEF from twelve to eleven groups: six British, four Canadian, and one American.* American aircraft provided additional cover; the British ordered Coastal Command Squadron 53 (twenty Hudsons) to Trinidad. As related, from Trinidad British tankers sailed to Freetown, Sierra Leone, unescorted, thence in convoy to the British Isles.
• A Canadian route running between Trinidad and Halifax via Bermuda.
Four (later six) Canadian corvettes shifted from the MOEF to provide surface escort. American aircraft on Trinidad and Bermuda furnished additional cover. Canadian warships of the Western Local Escort Force (WLEF) escorted the tankers on the trip from Halifax to Portland, Maine, the Atlantic terminus of a pipeline to refineries in Montreal, which had come into operation in November 1941.
One reason that King was unable to establish American convoy routes in the Caribbean and Gulf of Mexico in May was the failure of President Roosevelt’s much-touted 110-foot SC building program (“Sixty Ships in Sixty Days”) to live up to its billing. By May 1, this program had encountered many difficulties and was embarrassingly behind schedule. So was the 175-foot PC building program; from January 1 to May 1, only a dozen PCs were completed and half of these were still in workup.* As one consequence, on May 21, Admiral King asked Admiral Pound for the loan of “fifteen or twenty corvettes” from the British “Home Station” so that he could initiate American convoys in the Gulf of Mexico and Caribbean. Pound replied that the British had no corvettes on the “Home Station”; however, he was willing to reduce MOEF groups from eleven to ten to meet this request, provided the Admiralty could be assured that American and Canadian escort groups “worked as hard” as British groups. Believing that a further reduction in MOEF groups would almost certainly invite a renewal of intense U-boat attacks on the North Atlantic run, King let the matter rest, but not happily.
In the first week of June, as the great Battle of Midway loomed, King convened yet another Convoy Conference in Washington to deal with the Caribbean and Gulf of Mexico shipping crisis. The conferees decided that a proposed convoy system, Guantánamo Bay-New York-Guantánamo Bay,† be postponed in favor of a temporary Key West-Trinidad-Key West system to be initiated on July 1. In addition, a temporary Key West-Panama-Key West system and a Gulf of Mexico system were to follow as soon as possible. The British agreed to retain the British MOEF group B-5 in the Caribbean to facilitate the start-up of these convoys.
At this time King renewed the Navy’s long-standing request for destroyer escorts (DEs). On June 15, he wrote Roosevelt that “We need modified DEs [i.e., the American, not the British version] at the earliest possible moment. If we cannot get them soon,” King continued, “it will be necessary to put some important [shipping] routes ‘out of bounds’ in order to prevent prohibitive losses.” However, at that time Roosevelt believed that the emergency invasion of France (Sledgehammer) in late summer of 1942 was still a strong possibility and the construction of landing craft of various types remained priority number one for several more months.
In addition to this frustrating situation, King also had to wage continuous bureaucratic warfare with the Army and Army Air Forces over methods of employing land-based aircraft for ASW purposes.
In compliance with the agreement of March 26 between the Army and Navy, the Army Air Forces had parceled out units of the 1st Bomber Command to the Eastern and Gulf Sea Frontiers and had placed its Antilles Air Task Force under control of the Caribbean Sea Frontier. The several sea frontier commanders, Andrews, Kauffman, and Hoover, had assigned these land-based Army aircraft to two principal tasks: air escort for convoys and/or important ships sailing alone, and search patrols in likely U-boat operating areas.
Stimson and Marshall of the Army and Hap Arnold of the Army Air Forces were not in agreement with the Navy’s disposition and utilization of its land-based aircraft. As Arnold’s airmen saw it, the units of the 1st Bomber Command had been “chopped up” and meted out to the various sea frontiers for permanent duty. Aircraft assigned to one sea frontier were not allowed to cross boundaries into another sea frontier. The rotation of aircraft and crews from ASW patrols to training in navigation and high-level bombing, and vice versa, had not worked well. The aircrews hated area and convoy patrols. It was dull, defensive, and very difficult work, even with meter-wavelength ASV radar, and the rewards were few.
In five months of ASW operations, Hap Arnold and the air staff had settled on a firm doctrine to counter U-boats. Rather than decentralizing and delegating control of air units to the various sea frontiers as King insisted, Arnold and the airmen urged creation of a centralized single command in control of highly mobile air units which, in theory, could be shifted rapidly from frontier to frontier as the situation required. In place of defensive patrolling and escorting, the centralized command was to devote its resources principally to offensive ASW operations, pouncing upon a reported U-boat or group of U-boats with well-trained and equipped “hunter-killer” air units, capable of mounting persistent and prolonged chases.
In furtherance of this doctrine, on May 20 the War Department directed Hap Arnold to reorganize the 1st Bomber Command. “The reorganization should be of a character,” the directive specified, “that will fulfill the special requirements of antisubmarine and Allied air operations, in consonance with the Army responsibility in operating in support of, or in lieu of naval forces for protection of shipping.” Arnold was to provide 1st Bomber Command with every available twin-engine B-18 (medium) bomber in the United States and to equip these with centimetric-wavelength ASV radar as fast as the sets became available and with proper depth-charge and bomb racks for ASW. As the planes were so equipped, they were to be organized into “Submarine Destroyer Squadrons,” to operate from a network of new bases on the East and Gulf Coasts, employing tactics recommended by the ASW R&D group at Langley Field, and linked by first-class communication.
When Secretary of War Stimson informed Secretary of the Navy Knox and Admiral King of the Army Air Forces doctrine and reorganization plans for the 1st Bomber Command, the navalists were lukewarm and cautious. In a formal response that left Stimson almost incredulous, King welcomed the assignment of 1st Bomber Command exclusively to an ASW role but disapproved the idea of a centralized ASW command, even if the commander was to be an admiral. He recommended against any hurried and radical command-and-control changes that might interfere with ongoing operations.
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The loss of the 129 Allied tankers deeply dismayed and disturbed the British. It appeared that British petroleum stockpiles—or oil reserves—might fall to an unacceptable level. The situation had been worsened by the need to transfer about fifty British tankers to the Indian Ocean to support British operations there and in the Mediterranean Basin, and by the decision to route British-bound tankers the longer way from Trinidad east to Freetown, thence north in the slow Sierra Leone convoys.
To prevent a dangerous depletion of oil reserves, on May 2 the British petitioned the Americans for the “loan” (i.e., gift) of the equivalent of seventy tankers of 10,000 deadweight tons, a total of 700,000 deadweight tons. President Roosevelt “dramatically and almost unexpectedly” (as London put it) honored this request, despite America’s own tanker losses and the shortage of such vessels in the Pacific. The oil czar, Harold Ickes, notified the British on May 14 that the request (known as “Red Gap”) was to be met in the “next four weeks.” It was not only met, but exceeded substantially: a total of 854,000 deadweight tons, 170,000 for Canada and 684,000 for the United Kingdom.
This second generous gift of oil tankers to Britain was made possible by the following factors:
• The dramatic rise in deliveries of oil from Texas to the northeast United States by railroad tank cars. In January 1942, the oil industry delivered about 100,000 barrels a day to that area by rail. By June 1942, rail deliveries had risen to about 726,000 barrels a day.
• The start-up of the Plantation Pipeline. Running from Baton Rouge via Bremen, Georgia, to Greensboro, North Carolina, this line delivered about 50,000 barrels a day. From Greensboro, the oil moved further northeast by rail and barge. By June 1942, this pipeline, and those in the upper Midwest, delivered about 125,000 barrels of oil per day to the Northeast.*
• The initiation of gasoline rationing in the northeast United States on May 15, 1942.
• Far more efficient use of all means of conveying oil to the Northeast in 1942.
• Production of new tankers by Jerry Land’s Maritime Commission.
• The astonishingly rapid reconversion of many oil-burning industrial plants to coal-burning or to natural gas.
Nor was that all. To prevent a dangerous fall in oil reserves, on August 1, London again petitioned Washington for tanker assistance. This time (the “Blue Gap”) the British requested the equivalent of fifty-four tankers of 10,000 deadweight tons, a total of 540,000 more deadweight tons. President Roosevelt promptly met this request as well. Within thirty days—by September 1—oil czar Ickes had allocated to the British the equivalent of forty more tankers, or a total of 400,000 dead-weight tons. The rest of the British request was fulfilled in the months of October and November.
The total tanker assistance by the Americans to the British in 1942 (Red and Blue Gaps) was thus more than 124 “notional tankers” of 10,000 deadweight tons, or 1.24 million deadweight tons. In response to the first assist (Red Gap) Churchill cabled Roosevelt on May 27:
I must express my gratitude for your allocation of 70 tankers to build up United Kingdom stocks of oil. Without this help our stocks would have fallen to a dangerous level by the end of the year. This action is the more generous considering recent heavy American tanker losses and the sacrifices involved in releasing so many ships.