Читать книгу Blood, Tears and Folly: An Objective Look at World War II - Len Deighton - Страница 31

After a slow start in 1941 the U-boat building programme began to bear fruit. By the end of the year Dönitz had 247 boats to command. His losses were going up slowly: 9 in 1939; 26 in 1940; 38 in 1941. His building rate was 64, 54, 202.

In the opening months of 1941 the long-range German reconnaissance aircraft showed their teeth. In January aircraft sank 20 ships, while U-boats sank 21. In February the U-boats sank 39 ships while aircraft added 27 and surface raiders brought the total to over one hundred (and over 400,000 tons for the first time since October 1940). More than half the ships lost during this period were stragglers, alone and defenceless.

Dönitz calculated that sinkings (including those by the Luftwaffe) must reach 750,000 tons before Britain could be forced to surrender. The British set the red-line at 600,000 tons. On the charts at his headquarters at Kernéval, the rate of Allied sinkings for early 1941 was shown as 400,000 tons per month. In fact his captains – awarded medals on the basis of tonnage sunk – were giving him outrageous estimates of the size of their victims.¹⁸ But the losses were grave nevertheless, especially when augmented by the depredations of aircraft and surface raiders (see Table 1).

Table 1

Allied shipping losses May–Nov. 1941 (total gross register tonnage)

In the early part of 1941 RAF Coastal Command was put under the operational control of the navy, and a reconnaissance squadron was sent to be based in Iceland. British air activity, as little as it was, persuaded Dönitz that he too must have air cover for his submarines. He had the experienced bomber group I/KG 40 put at his disposal. After January 1941 Condor aircraft regularly ranged far out into the Atlantic between Bordeaux and Stavanger in Norway. As time went on, Allied ships had enough anti-aircraft weapons to deter bombing attacks. It then became the task of these four-engined planes to scout specific convoy routes, provide Atlantic weather reports and cooperate with the U-boats.

In fact there were too few Condors to make much difference, and despite using radio beacons, few Luftwaffe navigators could pinpoint a position exactly enough to bring a U-boat within sighting distance of a convoy. To add to the confusion, the Luftwaffe map grids did not tally with the navy’s charts. At this time, anyone standing at the bar in a U-boat mess could get an easy laugh from any joke about ‘air support’. The unseen value of aircraft in the Atlantic battle was the morale boost they gave to their own side and the disturbing sight they made for any enemy seaman.

At first the convoys outward-bound from Britain had been given RN escorts on only the first stage of their journey, about 15 degrees west longitude. Then the escorts stayed as far as 25 degrees west and then – by July 1941 – convoys were given continuous escort. Relays of escorts operated from Britain, from Iceland and from Newfoundland. But warships were scarce, so that even by the end of 1941 the average convoy had no more than two escort ships.

The escort ships were not immune to torpedoes either. I make no apologies for the extra length of this excerpt from one of the most graphic accounts the Atlantic battle provided:

The sky suddenly turned to flame and the ship gave a violent shudder … Looking ahead, I could see something floating and turning over in the water like a giant metallic whale. As I looked it rolled over further still and I could make out our pennant numbers painted on it. I was dumbfounded. It seemed beyond reason. I ran to the after-side of the bridge and looked over. The ship ended just aft of the engine room – everything abaft that had gone. What I had seen ahead of us had really been the ship’s own stem. There were small fires all over the upper deck. The First Lieutenant was down there organizing the fire parties. He saw me and called, ‘Will you abandon ship, sir?’ ‘Not bloody likely, Number One … We’ll not get out till we have to.’

But a ship with its stern blown away does not stay afloat for long:

The deck began to take on an angle – suddenly – so suddenly. She was almost on her side. I was slithering, grasping all kinds of unlikely things. My world had turned through ninety degrees … I jumped for the galley funnel which was now parallel with the water and about two feet clear, and flat-footed it to the end. I paused at the end of my small funnel to look at the faces. They were laughing as if this were part of some gigantic fun fair. The men called to me.

‘Come on, sir. The water’s lovely.’

‘I’m waiting for the Skylark,’ I shouted back. But the galley funnel dipped and I was swimming too – madly … We swam like hell. I turned once more, but now there were very, very few bobbing heads behind me. I swam on. The destroyer of my old group was passing through us. I could see her men at action stations. They were attacking. They were attacking the wreck of the Warwick! I screamed at them in my frenzy. Wherever else the U-boat might have been it could not have been there. The depth charges sailed up in the air. Funny how they wobbled from side to side, I’d never noticed that before. When, I wondered, would they explode? It was like being punched in the chest, not as bad as I had expected. I swam on. Things were a bit hazy. I was not as interested in going places as I had been. I could only see waves and more waves, and I wished they would stop coming. I did not really care any more. Then I felt hands grasp my shoulders and a voice say, ‘Christ, it’s the skipper. Give me a hand to get the bastard in,’ and I was dragged into a Carley-float which was more than crowded to capacity.¹⁹

To make the most of their pitifully few escorts, the RN had started ‘Escort Groups’, which usually meant in effect nothing more than RN captains getting together – under one of their number named as escort group commander – to exchange ideas about anti-submarine tactics.

It was the 5th Escort Group which in March 1941 was in the same area as the German navy’s three most famous U-boat captains: Günther Prien, Joachim Schepke, the celebrated and colourful captain of U-100, and Otto Kretschmer of U-99. At their collars these men wore the Ritterkreuz, to which the insignia of the oak leaves had been added to celebrate 200,000 tons of ships sunk. Kretschmer and Schepke were both determined to be the first to sink 300,000 tons of Allied shipping. Kretschmer had left his base at Lorient credited with 282,000 tons (although, as we have seen, such German figures were usually very much inflated).

It was Prien in U-47 who sighted the outward-bound convoy OB 293 and summoned his colleagues: Kretschmer, Matz in U-70 and Hans Eckermann in UA.²⁰ Although a primitive seaborne radar set played its part, this encounter marked little change in the methods or technology of either side. But there was a change in the men: the Germans, solidly professional, were at the zenith of over-confidence, while the Royal Navy’s landlubbers and weekend yachtsmen had discovered a new determination.

Kretschmer started the sinkings. Firing while surfaced, he hit a tanker which burst into flame and a Norwegian whaling ship Terje Viken which remained afloat. Using the same tactics in U-70, Matz hit a British freighter and the Mijdrecht, a tanker, which with true Dutch resilience steered at him and rammed as U-70 dived. The UA was detected and dived, its course followed by asdic. Depth charges damaged it enough to make the German set course for home.

Matz in U-70 had submerged. He now came under coordinated attacks from two corvettes. Wallowing and unstable he went to 650 feet: far deeper than the submarine was designed to endure. The damage sustained from the Dutchman which rammed him, together with the depth-charging, started leaks and made the U-boat impossible to control. Despite the crew’s efforts the U-70 surfaced and was fired upon. The crew surrendered as the stricken boat reared, bow in the air, and slid under, taking 20 of the crew with it.

Even the stubborn Kretschmer dived deep and sat ‘in the cellar’. He watched the rivets pop and the lights flicker as the explosions came and went. Carefully he withdrew, with half his torpedoes still unused. The convoy sailed on, having lost two ships, and had two damaged.

Prien followed the convoy and tried again at dusk, his approach covered in fitful rainstorms. But in a clear patch he was spotted by a lookout on HMS Wolverine and his crash-dive failed to save him from the depth charges that damaged his propeller shafts. Instead of turning for home, he surfaced after dark for another attack, perhaps not realizing how clearly the damaged propellers could be heard on the asdic. This time Wolverine, which had tenaciously waited in the vicinity, made no mistake. As the U-boat crash-dived, an accurately placed depth charge caused the submarine to explode under water, making a strange and awful orange glow. ‘The hero of Scapa Flow has made his last patrol,’ said the obituary notice personally dictated by Admiral Dönitz when, after 76 days had passed, they finally told the German public of their hero’s death. Even then stories about him having survived circulated for months afterwards.

A few days later on 15 March 1941, south of Iceland, Fritz-Julius Lemp, now promoted to Korvettenkapitän, signalled the approach of a convoy. It was an attractive target but the escort was formidable. The escort commander was Captain Macintyre RN, who was to become the war’s most successful U-boat hunter. He was in an old First World War destroyer, HMS Walker. There were four other old destroyers with him, and two corvettes. The homeward convoy HX 112 consisted of almost 50 ships, in ten columns half a mile apart. They were heavily laden tankers and freighters, and even in this unusually calm sea they could make no more than 10 knots (11.5 mph).

Lemp’s sighting signal was intercepted by direction-finding stations in Britain. Such plots could only be approximate, but Captain Macintyre was warned that U-boats were probably converging on HX 112. Without waiting for other U-boats, Lemp’s U-110 surfaced and used darkness to infiltrate the convoy. Two torpedoes from his bow tubes missed, but one from his stern hit Erodona, a tanker carrying petrol, and the sea around it became a lake of flames.

The next day other U-boats arrived. The uncertainties of U-boat operations are illustrated by the way in which U-74 never found the rendezvous and U-37, having surfaced in fog, was run down by a tanker and had to return to base for repairs. But Schepke (U-100) and Kretschmer (U-99) provided enough trouble for the resourceful Captain Macintyre. Having spotted Schepke’s boat, the escorts started a systematic search which kept it submerged and allowed the convoy to steam away. At this stage of the war the escorts had not discovered that U-boats impudently infiltrated the convoys to fire at point-blank range. The search for the attackers always took place outside the convoy area. So the chase after Schepke was Kretschmer’s opportunity to penetrate the columns of the virtually unprotected convoy, and at 2200 hours there was a loud boom which marked the beginning of an hour during which Kretschmer hit six ships. Five of them sank. The hunt for Schepke’s U-100 was abandoned as the escorts closed upon their charges.

Schepke’s U-100, damaged by the continuous attacks, soon caught up with the convoy. Although a surfaced submarine was immune to asdic, it was vulnerable to detection by radar, and despite the darkness he’d been detected a mile away by a primitive Type 271 radar set aboard the escort HMS Vanoc. A surfaced submarine, if spotted, did not have much time in which to dive to safety. This was Schepke’s predicament as Vanoc was suddenly seen accelerating to full speed. As she sped past HMS Walker, the escort commander ordered a signal made to caution her about speeding. He received the reply ‘have rammed and sunk U-boat’. By that time the shriek of the destroyer’s bow tearing through the steel U-boat came echoing through the night air. Schepke and the duty watch standing on the tower were all crushed and lost. Someone below gave the order to crash-dive but depth charges ripped the hull open and U-100 sank with all but seven of its crew.

While Vanoc was repairing its damage, and picking up German survivors, HMS Walker’s asdic showed another U-boat nearby, and then the set broke down. This brief encounter was with Kretschmer’s U-99. It was surfaced and heading home under cover of darkness. Kretschmer was below. On the conning tower there was the usual complement of four men: an officer, a petty officer and two ratings. Each man was assigned a quarter of the horizon to watch through his Zeiss 7×50 binoculars. Lighter, smaller and more waterproof than RN binoculars, such glasses were coveted by every Allied sailor who saw them. The officer occasionally swept the entire horizon: it was the routine. Suddenly they came upon the warships that had sunk Schepke’s boat. One of them was searching for survivors. One of the German lookouts on U-99 saw the moonlight reflecting off a gun turret: it was a destroyer about 100 yards away. Had they done nothing they would probably have escaped – standing orders said submarines sighting the enemy at night must stay surfaced – but the submariners were tired. Thinking he’d been seen, and contrary to orders, the officer on watch dived the U-99, and it was then that Walker’s asdic operator saw it briefly before his screen went blank.

The Walker’s depth charge attack had to rely upon skill, instinct and practice. Those first explosions brought Kretschmer’s damaged boat to the surface. Both destroyers opened fire. ‘With an understandable enthusiasm,’ rescued merchant seamen taken on board the Walker piled up so much ammunition around the guns as to cause confusion.

Kretschmer was forced back to the surface. All torpedoes expended and his boat crippled, he realized that his career was at an end, but his tonnage claims were foremost in his mind. He ordered his radio operator to send a message claiming 50,000 tons of shipping and telling Dönitz that he was a prisoner of war. When Kretschmer saw Walker lowering a boat he took it to be an attempt to capture his submarine. He sent his engineer officer to flood the aft ballast tanks so that the U-boat would sink stern-first. It reared up suddenly and steeply, and slid back into the ocean, leaving the crew swimming. When he climbed aboard the ship that rescued him Kretschmer still had his binoculars round his neck and wore the white-topped hat that had become a captain’s prerogative in the U-boat service. All but three of the U-boat’s crew were saved, but the engineer officer was one of those lost. Captain Macintyre, the escort commander, used Kretschmer’s Zeiss binoculars for the rest of the war.

Kretschmer, a prisoner aboard HMS Walker, remarked to George Osborne, her chief engineer, upon the coincidence that both ship and submarine had a horseshoe badge but one was the wrong way up. It was explained to him that in Britain a horseshoe pointing down is considered bad luck. An eyewitness said ‘it brought a rueful laugh from our prisoner.’

A destroyer was a cramped place, even without shipwrecked seamen and enemy prisoners aboard, and there was evidence of bad feeling. But the master and chief officer of J. B. White, a sunken merchant ship, and Otto Kretschmer an unrepentant Nazi, were persuaded by the chief engineer to join him in a game of contract bridge. Osborne said it was the only decent game he managed to get in the entire war.

Germany had lost her three U-boat aces and the Propaganda Ministry discovered that stardom for fighting men is a two-edged weapon. The loss of three ‘experts’ made Dönitz suspect that the British must have some new secret weapon. But then he changed his mind and decided it was just bad luck.

Dönitz had been right with his first guess. HMS Vanoc had used a primitive radar set, and in this same month, March 1941, a far more sophisticated 10-centimetre set was being tested at sea. It was the cavity magnetron which made such advanced radar possible and put the British work far ahead of the Germans. But in the summer of 1941 the range at which radar gave the first indication of an enemy’s presence was not always better than an alert observer could provide on a clear day. In May 1941 the pursuit of the Bismarck provided a better example of the contribution radar played in the naval encounters of that period.