History of the Second World War (66 page)

At the end of that year the total of operational U-boats was eighty-six, and about 150 more were in training or running trials. But as fifty were now in the Mediterranean or its approaches, only thirty-six were left for use in the North Atlantic. A sweep for supply ships there in June had resulted in nine being intercepted, and to the withdrawal of U-boats from the South Atlantic. During the nine months April to December 1941 the total German and Italian submarine sinkings had been 328 ships of 1,576,000 tons, but only one-third of these had been sailing in convoy. Moreover twenty of the thirty submarines lost had been destroyed by convoy escorts. It was clear that stronger escorting, and evasive routing, had temporarily gained the upper hand over the U-boats.

It may be useful to give here a summary of the escort situation at the beginning of 1942. The three great operational bases of the Western Approaches Command under Admiral Sir Percy Noble were Liverpool, Greenock and Londonderry, and controlled twenty-five escort groups — totalling about seventy destroyers and ninety-five smaller craft.

They were in four categories: (i) short-endurance destroyers for Middle East and Arctic convoys on the first part of their passage, and for the liners when they started bringing American troops across; (ii) long-distance destroyers and corvettes for the North Atlantic convoys, from the Western Ocean Meeting Point to Britain, and for the Gibraltar convoys; (iii) long-range sloops, destroyers, and cutters for the Sierre Leone convoys on the main part of their journey; (iv) anti-aircraft groups to back up escort of convoys within reach of German bombers, and for the Arctic and Gibraltar convoys.

There were also the equivalent of two groups at Gibraltar for local escort, and the Freetown Escort Force of one destroyer flotilla and about two dozen corvettes. The Newfoundland Escort Force, provided mainly by the Canadian Navy, had fourteen destroyers and about forty corvettes, as well as a score of other vessels for local escort.

But the improving prospect in the Battle of the Atlantic suffered bad handicaps in the early part of 1942. One was a lack of aircraft. On taking over Coastal Command in the previous summer, Sir Philip Joubert de la Ferte had assessed its needs as approximately 800 aircraft of all types, and particularly emphasised the importance of long-range bombers. But in the New Year, Coastal Command’s bombers were transferred to Bomber Command, and all the new ones allotted to it, for the air offensive against Germany. The clash of priorities became intense. Moreover the Fleet Air Arm was having difficulties in obtaining fighters for the thirty-one new escort carriers that had been ordered.

Another handicap was that the new frigates that were being built in America for the British were not entering service as fast as was hoped — largely because priority was being given to the landing-craft needed for a cross-Channel operation, which the Americans still hoped to launch in 1943, if not in 1942. This priority contributed greatly to the continuing weakness of British Atlantic efforts, and to the further heavy shipping losses.

A third handicap came in the early months of 1942 from America’s own maritime troubles — troubles which came not only in the Pacific, from the Pearl Harbor disaster, but also in the Atlantic, from the extension of U-boat activities and America’s own consequent shipping losses.

Admiral Donitz and his staff estimated in May 1942 that to defeat Britain their sinkings must average 700,000 tons a month. They knew that in 1941 these had not reached such an average — although they did not know that the monthly average had actually been no more than 180,000 tons. But they had thought that America’s entry into the war would give them increased freedom of action in the Western Atlantic, and more opportunity of finding unescorted targets.

Only a small number of U-boats could be sent to operate off the American coast, but these achieved disproportionately large results. For the American admirals were slow, and reluctant, to start convoys — as the British admirals had been in the First World War. The Americans were also slow to take other precautions. Lighted channel markers and the unrestricted use of ship’s radio gave the U-boats all the help they wanted. Coastal resorts, such as Miami, continued to illuminate their sea-fronts at night with miles of neon-lighted beaches — against which the shipping was clearly silhouetted. The U-boats lay submerged offshore during the day, and moved in to attack, with guns or torpedoes, on the surface at night time.

Although there were never more than about a dozen U-boats operating off the American coast, they sank nearly half a million tons of shipping by the beginning of April — and 57 per cent consisted of tankers.

The reaction on Britain’s situation was serious. The United States Navy was having to withdraw its escort vessels and aircraft to its own coastal waters, and British merchant ships, after surviving the crossing of the Atlantic, became an easy prey in American waters.

Admiral Donitz was so encouraged by the results that he wanted to send every U-boat he could to the American seaboard. Fortunately for the Allies, Hitler’s ‘intuition’ came to their aid at this critical moment. At his conference on January 22 he announced his conviction that Norway was ‘the zone of destiny’ and insisted that every surface warship and U-boat available should be sent thither to ward off an Allied invasion. Three days later Donitz received a completely unexpected order to despatch an initial batch of eight U-boats to cover the sea-approaches to that country. The new battleship
Tirpitz
was also moved to Norway in January, and was followed by the
Scheer, Prinz Eugen
,
Hipper,
and
Lutzow.

There was something in his foresight, as in April Churchill did tell the British Chiefs of Staff to examine the feasibility of a landing in Norway, with the aim of relieving German pressure on the Arctic convoys — but their doubts were reinforced by the Americans, and the project never matured.

Another piece of good fortune for the Allies was that the severe winter of 1941-2 delayed U-boat training in the Baltic, with the effect that only sixty-nine submarines in all were made ready for operations in the first half of 1942. Of these, twenty-six were eventually sent to northern Norway, two to the Mediterranean, and twelve replaced losses, so that the net gain in the Atlantic was only twenty-nine.

Even as it was, Axis submarine sinkings increased monthly — in February to nearly 500,000 tons, in March to over 500,000 tons; in April there was a drop to 430,000 tons, but in May 600,000 tons and in June sinkings reached the ominous figure of 700,000 tons. By the end of June the toll for the half-year was over 3 million tons out of 4,147,406 tons sunk from all causes — of which nearly 90 per cent was in the Atlantic and Arctic. It was not until July that the monthly loss from submarines fell to just under 500,000 tons, thanks to an all-round improvement in anti-submarine methods, and the American adoption of convoy.

The improvement in the summer of 1942 proved illusory. By August the advent of freshly built U-boats had raised the total strength to over 300, and of the total about half was operational. It comprised groups off Greenland, off the Canadian coast, off the Azores, off North-west Africa, in or near the Caribbean, and off Brazil. Sinkings by U-boats in August went above the 500,000 tons mark again. In the next few months they made a particularly large bag near Trinidad, where many ships were still travelling independently. A more dubious action, politically and in terms of grand strategy, was the sinking of five Brazilian ships in mid-August, which led to a prompt declaration of war by Brazil. The use of Brazilian bases enabled the Allies to exercise much stronger control of the whole South Atlantic, and drive out surface raiders from then on.

That, however, mattered less than it would have earlier, as the place of the German armed merchant ship for commerce raiding in the far oceans was being taken over by new and larger U-boats — the so-called ‘U-cruisers’ of 1,600 tons, whose radius of action was 30,000 miles.

U-boats were now able to dive much deeper, to depths of 600 feet, or even more in emergency — an advantage that was soon offset, however, by the fact that depth-charges were being set to explode at greater depths — as well as being produced in greater quantity. The U-boats were also benefiting from the way that the new U-tankers could refuel them on the oceans, and from increasingly efficient wireless Intelligence. Moreover the Germans were now able to read many of the British ciphered convoy control signals again, as they had done up to August 1940.

On the other side, the new 10-centimetre radar set — which the U-boats could not intercept — was paramount among all the achievements of British scientists. When it came into full use in aircraft early in 1943, in conjunction with the Leigh Light, it restored the Allied initiative by night or in low visibility, and defeated the U-boats’ radar search receivers working on 1½ metres.

Donitz’s war diary for this period shows how worried he was about the effect of this new British location device, as well as about the increased number of British aircraft in the Eastern Atlantic.

Throughout the campaign Donitz had shown himself a very able strategist, always probing for the soft spots and concentrating to strike when the defence was weak. He had held the initiative from the outset, and the Allied anti-submarine forces were always a stage behind.

In the second half of 1942 his plan focused on the air escort gap south of Greenland, aiming to locate Allied convoys before they reached it, to concentrate against them while they traversed it, and to withdraw when air cover was resumed.

Moreover by the autumn Donitz had sufficient U-boats to allow a ‘pack’ to strike on its own initiative whenever opportunity offered.

Thus U-boat pressure increased from July on, and in November sinkings rose to 119 ships of 729,000 tons. A large proportion, however, were caught by U-boats when sailing independently, out of convoy, off South Africa or South America.

The call for escorts was increased by the naval requirements of ‘Operation Torch’, the American-British landings in North-west Africa, which was carried out that autumn. The Gibraltar, Sierre Leone, and Arctic convoys had to be temporarily suspended. There was also fresh demand for escorts to the troopship convoys carrying American troops from Iceland to Britain. These fast convoys had at least four destroyers to escort three troopships.

An exception to the demand for escort was provided by the conversion of the two giant 80,000-ton liners
Queen Mary
and
Queen Elizabeth
into troopships, with a carrying capacity of 15,000 men and more — the major part of a division. Their speed, over 28 knots, was too high for any destroyers to accompany them except at the start and finish of their voyages, so it was on speed alone, combined with zigzagging and ever-changing routes, that such giant liners depended for their safety. The hazardous policy succeeded so well that no submarine ever managed to intercept them on their many trans-atlantic journeys from August onward.

In general, the provision of naval escorts and air cover did not, and could not, keep up with the increasing menace from the output of U-boats. Of these an average of about seventeen had entered the service each month, and at the end of 1942 there were 212 operational, out of a total of 393 — compared with ninety-one operational, out of 249, at the start of the year. The number destroyed was eighty-seven German, and twenty-two Italian — a total quite insufficient to offset the construction rate.

During the year Axis submarines had sunk, in all waters, 1,160 ships totalling 6,266,000 tons — while the enemy’s other weapons had raised the total loss to 1,664 ships and over 7,790,000 tons.

Although about 7 million tons of new Allied shipping was put into service, even that left a further deficit of nearly a million tons to the adverse balance shown in each year’s accounts since the outbreak of war. British imports during the year fell below 34 million tons — one-third less than the figure in 1939. In particular, stocks of commercial bunker fuel in Britain had fallen precariously low — only 300,000 tons, compared with a monthly consumption of 130,000 tons. Although it could be eked out from the Navy’s reserve stocks, that was a course to be avoided save in grave emergency.

Thus when the Allied Conference assembled at Casablanca, on the Moroccan coast, in January 1943, to settle the next steps in Allied strategy, it was faced with a very disturbing balance-sheet of mercantile tonnage. Until the U-boat menace was overcome, and the Battle of the Atlantic won, an effective invasion of Europe was not practicable. That battle had become as crucial as the Battle of Britain in 1940. The issue depended, basically, on which side could endure the longer, materially and psychologically.

The course of the struggle was affected by changes of command. In November, Admiral Sir Percy Noble was appointed head of the British Naval Mission in Washington, and thus became the First Sea Lord’s representative on the American side of the Combined Chiefs of Staff organisation. During his twenty months’ tenure as C.-in-C. of the Western Approaches he had done much to improve the anti-submarine measures, and to keep up morale among the escort and aircraft crews by the understanding he showed of their problems and the close personal touch he established. His successor, fortunately, was well chosen. This was Admiral Sir Max Horton, who had been an outstanding submarine commander in World War I, and in command of Britain’s home-based submarines since early 1940. He brought an expert knowledge of submarines, and submariners, to the anti-submarine campaign, coupled with driving energy and imagination. This combination of qualities made him a fit man to match Donitz.

Horton’s plan was to develop a more powerful and concentrated counterattack on the U-boats. The corvettes and other small craft had not got the speed sufficient to follow through in their fights with U-boats, for if they pursued them far they could not catch up with the convoys they were escorting. More destroyers and frigates were needed, working separately, to come to the aid of convoy escorts and, after making contact with the U-boats, hunt them to the death. Support groups for this purpose had already begun to be formed in September, but Horton at once developed them intensively, and even reduced the strength of the close-escort groups in order to do so. He aimed to surprise the enemy in mid-Atlantic with a co-ordinated counterattack by several of the new support groups and carrier-borne aircraft, working in co-operation with the escorts and with very long-range aircraft. He emphasised that the support groups should not waste time searching widely for the U-boats — the mistake in the past. The place to find them was near the convoys, and the support groups should work closely with the convoy escort groups. Each of these while in the Greenland air gap was to be reinforced by a support group, and whenever possible by aircraft. He reckoned that the U-boats, accustomed to being attacked from the direction of the convoy, would be thrown off balance when the support groups came in attacking from all quarters.