History of the Second World War (67 page)

On the German side Hitler was enraged by the ineffective result of a New Year’s Eve attack on an Arctic convoy by the
Hipper, Lutzow
and six destroyers, emerging from Altenfiord, and this had important effects. In his disgust he expressed his ‘firm and unalterable resolve’ to pay off his big ships. This brought about the resignation of Grand Admiral Raeder a month later, and his replacement, as Naval Commander-in-Chief, by Donitz — who at the same time retained his title and office as Commander, U-boats. Donitz had a better knack of handling Hitler, and in the end obtained Hitler’s agreement to the retention of the
Tirpitz
,
Lutzow
, and
Scharnhorst
in Norway as ‘a fairly powerful task force’.

There was a lull in the Atlantic during December and January, when U-boat sinkings fell to barely 200,000 tons. That was largely due to stormy weather. But the respite was offset by the dispersing effect and havoc caused to the merchant ships in convoy, especially the more weakly powered ones.

In February the U-boat sinkings were almost doubled, while in March they amounted to 108 ships of 627,000 tons — thus approaching once again the peak figures of June and November 1942. Most worryingly, nearly two-thirds were sunk in convoy. In the middle of March thirty-eight U-boats were concentrated on two homeward-bound convoys, which happened to be close together, and sank twenty-one ships of 141,000 tons, for a loss of only one U-boat, before air cover was resumed on the 20th. This was one of the biggest convoy battles of the whole war.

In retrospect, the Admiralty recorded that ‘the Germans never came so near to disrupting communication between the New World and the Old as in the first twenty days of March, 1943’. Moreover, the Naval Staff was brought to the point of wondering whether convoy could continue to be regarded, and used, as an effective system of defence.

But in the last eleven days of March — the last third of that fateful month — a great change came over the scene. Only fifteen ships were sunk in the North Atlantic compared with 107 in the first two-thirds. In April the month’s toll was halved, and in May it was much less still. Max Horton’s co-ordinated counteroffensive had come into effect — and fulfilled its desired effect in a remarkably short time.

The Americans, at the most critical time in March, had asked to withdraw from the North Atlantic escort system, taking responsibility for the South Atlantic routes, particularly to the Mediterranean. They also had the Pacific much in mind. However, the practical effect was not great. The U.S. Government put the first support group carrier under British Command and provided the vital V.L.R. (very long range) Liberators. So from April 1, Britain and Canada had taken complete charge of all convoys between the American continent and Britain.

During the spring of 1943, the U-boats met defeat in a series of convoy battles, and suffered heavy losses in them. In mid-May Donitz perceptively reported to Hitler: ‘We are facing the greatest crisis in submarine warfare, since the enemy, by means of new location devices . . . makes fighting impossible, and is causing us heavy losses.’ For U-boat losses in May had more than doubled, rising to 30 per cent of those at sea — a rate of loss that could not be borne for long. Hence on May 23 Donitz withdrew his U-boats from the North Atlantic until he had new weapons to use.

By July, more Allied merchant ships were being built than were being sunk. That was the crux of the matter and the proof that the U-boat offensive had been defeated.

Yet, looking back, it is evident that Britain had herself narrowly escaped defeat in March. It is also evident that the primary cause of her danger was the lack of long-range aircraft for the protection of convoys. From January to May, only two ships were sunk in convoy, in the Atlantic, while an air escort was present. Once adequate air cover of this kind was provided for convoys, particularly by the long-range Liberators, it became increasingly difficult for U-boats to operate in ‘wolf-packs’. They might now at any moment suddenly find an aircraft over them, directing a support group to their position.

But radar, on the new 10-cm. wavelength that the U-boats could not intercept, was certainly a very important factor, as Donitz realised and emphasised. New weapons such as the ‘Hedgehog’, an anti-submarine rocket device, and heavier depth-charges, also contributed. So did the analytical work of the Western Approaches Tactical Unit set up early in 1942 to evolve the best tactical system for dealing with U-boats, and Professor P. M. S. Blackett’s operational analysis of convoy deployment. Moreover a new cipher, for shipping control, introduced at the end of May 1943, deprived the Germans of their most valuable source of Intelligence.

Probably the most important factors in the victory, however, was the improvement in training standards of the escorts and aircraft, and the increased co-operation between sailors and airmen.

Among individuals, the outstanding part in the defeat of the U-boats was played by Admiral Sir Max Horton, as already emphasised. Much was also due to Air Marshal Sir John Slessor, who became Commander-in-Chief of Coastal Command in February 1943, the crucial period of the battle. Among the fine band of escort group commanders, two deserve special mention for their exploits — Captain F. J. Walker, from 1941 on, and Commander P. W. (later Vice Admiral Sir Peter) Gretton in 1942-3.

No convoys were attacked in the North Atlantic during the month of June 1943, while July was very costly for the U-boats, particularly in the Bay of Biscay, where Coastal Command’s air patrols had a rich harvest. Of eighty-six U-boats which tried to cross the Bay that month, fifty-five were sighted, seventeen were sunk (all save one by aircraft), and six forced to turn back. Their only outward route had become a narrow line in the Bay of Biscay, hugging the Spanish coast, as Donitz gloomily reported to Hitler. The anti-submarine patrols, however, paid a considerable price for their successes, fourteen planes being lost.

During the three months June to August 1943, the German U-boats sank no more than fifty-eight Allied merchant ships in all waters excluding the Mediterranean, and nearly half of them were off South Africa and in the Indian Ocean. They gained that very moderate result at a cost of seventy-nine U-boats — of which no less than fifty-eight were sunk by aircraft.

In the hope of regaining the upper hand, Donitz pressed Hitler for more long-range air reconnaissance in the Atlantic and stronger air cover on the transit routes — and did get a more sympathetic hearing than Raeder had for his arguments towards overcoming Goring’s unwillingness to provide air co-operation. Donitz also obtained approval to increase U-boat production from thirty to forty a month, and to give priority to new types of submarine which would be capable of higher speed when submerged. But the very promising ‘Walter’ type submarine, driven by a combination of diesel fuel and hydrogen peroxide, suffered so many ‘teething’ troubles that none was ready for service before the war ended in 1945. A new and important development, however, came with the fitting of the ‘Schnorkel’ air intake and diesel exhaust mast, a device of pre-1940 Dutch origin, that enabled submarines to charge their batteries while remaining at periscope depth. Thirty of them were fitted with it by the middle of 1944.

Two other new German devices of the mid-1943 period were the ‘homing’ torpedo, acoustically guided to ships’ propellers, and the glider bomb. But during September and October, the first two months of the renewed U-boat campaign, the Allies lost only nine merchant ships — out of the 2,468 which sailed in sixty-four North Atlantic convoys — whereas twenty-five U-boats were sunk. After that further heavy defeat Donitz gave up working the U-boats in large mobile groups.

On October 8 Britain took over two air bases in the Azores, by agreement with Portugal, and from then onward air cover could be provided over the whole North Atlantic.

In the first three months of 1944 the U-boats suffered still worse losses. Only three merchant ships were sunk — out of 3,360 which crossed the North Atlantic, in, 105 convoys — whereas thirty-six U-boats were lost. Donitz now cancelled all further operations against convoys, telling Hitler that they could not be renewed until the new types of U-boat and new defensive devices were available, and better air reconnaissance provided.

At the end of March, 1944, Donitz was ordered to form a group of forty U-boats for inshore operations in the event of an Allied invasion of Western Europe. By the end of May he had concentrated seventy in Biscay ports, and only three remained in the North Atlantic, while these were merely kept on the task of weather reporting.

The German abandonment of the U-boat campaign in the North Atlantic was a relief to Coastal Command, whose aircraft, of No. 19 Group, had sunk fifty U-boats and damaged fifty-six (out of 2,425 passages in and out from the Biscay bases) by May 1944, during forty-one months of anti-submarine operations. No. 19 Group had lost 350 aircraft in the Bay during that period. Its losses would probably have been less, and its effect even greater, if Coastal Command had been allotted a larger scale of aircraft, more appropriate to the key importance of its task.

Among other events of the period were two damaging attacks on the
Tirpitz
at her moorings in northern Norway — by three midget-submarines in September, 1943, and by the Fleet Air Arm in March 1944 — which preceded her eventual sinking by R.A.F. heavy bombers in November that year. She had only once fired her main armament in earnest (in a raid on Spitzbergen), but the amount of damage she survived was testimony to the design and strength of German naval construction. Moreover, her mere existence as a ‘ship in being’, and threat in the offing, had a great influence on Britain’s maritime strategy, while absorbing a remarkably large amount of her naval strength.

The threat of the
Scharnhorst
had been brought to an end in the previous December, when she was intercepted and sunk by a strong force from the British Home Fleet, when herself attempting to intercept an Arctic convoy.

During the first half of 1944, Britain’s chief trouble in home waters came from the small motor torpedo-boats, called ‘E-boats’, which the Germans had developed. Although their number was never more than about three dozen, they could be switched rapidly from one convoy route to another and, by choosing suitable opportunities, became a harassing nuisance.

The U-boats that had been concentrated in the western ports of France to oppose an Allied cross-Channel move proved of little effect, although they benefited from having been fitted with the Schnorkel device by the time the Normandy invasion came in June, and were thus less vulnerable to air attack.

When the American Third Army, breaking out from Normandy, arrived close to these western ports — Brest, Lorient, and St Nazaire — in mid-August, most of the U-boats were moved to Norway. And from then shipping to and from Britain could again use the old, and normal, route round the south of Ireland, as well as the route round the north coast.

From the later part of August onward, a stream of U-boats started to come out from Norway, and Germany, by passing round the north of Scotland and Ireland, and positioned themselves close inshore, at busy comers — as far south as Portland Bill on the south coast of England. But they achieved little by this inshore campaign — although, thanks to constant submergence and use of their Schnorkels they suffered fewer losses than before. During the four months September-December 1944, they sank only fourteen ships in British coastal waters.

THE ARCTIC CONVOYS

British convoys to North Russia were started at the end of September, 1941. Ice blocked Archangel in the winter, so Murmansk was used, Russia’s only important ice-free port. The Germans’ failure to capture that port by a strong overland move was a strange strategic omission as it lost them the chance to strangle this northern supply-route when it was most vulnerable.

As the Germans came to realise the large scale on which British, and then also American, ships were carrying aid to Russia by this route, they hastened to reinforce their naval and air strength in Norway, and developed a series of powerful attacks on the Allies’ Arctic convoys in March, April, and May, 1942. The worst hit was eastbound convoy PQ 17, sailing at the end of June. The Admiralty, believing that the convoy and its escort were about to be overwhelmed by German warships, ordered the convoy to scatter in the Barents Sea on July 4. The helpless merchant ships were attacked by aircraft and U-boats, only thirteen out of thirty-six surviving. Of the aircraft which this convoy was carrying eighty-seven were delivered, but 210 lost; of the tanks 164 were delivered, but 430 lost: of non-fighting vehicles 896 were delivered, but 3,350 lost — along with two-thirds of the other cargo, some 99,316 tons.

After that disaster, the next convoy to Russia was not despatched until September. It was given a much stronger escort and Admiral Raeder, warned by radio intelligence, cautiously held back his larger warships — which might have overwhelmed the escorts. As it was, twenty-seven of PQ 18’s forty merchant ships got safely through to Archangel, while the German aircraft and U-boats suffered badly. Never again did the Germans deploy such great air strength in the far north.

After another interval, a few smaller convoys were sent in the winter. But the Russians, while repeatedly pressing for more convoys to be run, gave no help in protecting them on the long ocean passage and only a little at the receiving end. From March 1943 onward the C.-in-C., Home Fleet, Admiral Tovey, was unwilling to risk further convoys as the daylight lengthened. The critical situation in the Atlantic decided the argument, and the Arctic escorts were diverted to the Atlantic, where they played a great part in the decisive defeat of the U-boats that spring.

By November, when the Arctic convoys were resumed, much stronger escorts were available, and included the new escort carriers. These inflicted heavy loss on the weakening Luftwaffe as well as on the U-boats, while bringing huge cargoes safely through to Russia.