The British Army’s part in the struggle against Nazism was vastly smaller than that of the Russians, as would also be the US Army’s contribution. Britain’s principal strategic importance became that of a giant aircraft carrier and naval base, from which the bomber offensive and the return to the Continent were launched. It fell to the Royal Navy to conduct the critical struggles of 1940-43 to keep the British people fed, to hold open the sea lanes to the Empire and overseas battlefields, and convoy munitions to Russia.
The Germans might have improved their chances of winning the war if they had never prosecuted the Battle of the Atlantic but had expended all their resources on the air and ground campaigns. The Third Reich lacked the resources to fight a world war on so many fronts, and war demands hard choices. But Hitler’s method of decision-making, coupled with the inability of the German military to think at the strategic level, made it impossible for leaders of the Third Reich to make the choices that might have brought them victory.
A decisive moment in the course of the Second World War was the Allied cracking of the German Enigma codes, producing a stream of decrypts known by their British special security classification, Ultra. This allowed the Allies, for much of the war, to read many of the communications sent and received by the Germans, amounting in total to several million items of intelligence. From the correspondence of the Führer himself right down to that of the harbor-master of Olbia in Sardinia, messages were routinely decoded by the Allies. Its importance can be gauged from the jokey acronym ‘BBR’ that the Americans gave to Ultra, which stood for Burn Before Reading.
In February 1940, however, the German submarine U-33 was attacked off the west coast of Scotland and two of the extra rotor wheels used by the naval Enigma were captured. Five weeks later, a brilliant, eccentric, accident-prone, Cambridge mathematics don called Alan Turing installed something known as a bombe machine, an electro-mechanical device which made hundreds of computations every minute, at the Government Code and Cypher School at Bletchley Park in Buckinghamshire, 40 miles north-west of London. Other heroes of Bletchley were to include the mathematicians Stewart Milner-Barry and Alfred Dilwyn (‘Dilly’) Knox. In modern computing parlance, while the Poles provided the Enigma hardware, the assorted civilian geniuses stationed at Bletchley provided the software that produced Ultra.
Part of the explanation for the heavy losses on the Atlantic and Arctic convoys was that the British convoy code had been cracked by German intelligence, something that was not discovered until after the war. In February 1942 the German Beobachtungsdienst (radio monitoring service) managed to crack about 75 percent of Naval Cipher No. 3. The Germans were reading Royal Navy codes, although only 10 percent of the intercepts could be used operationally because of the time taken to decipher them. If they had achieved real-time decryption, as Turing was to do, it could have been potentially as decisive an advantage to the Germans as the cracking of the Enigma code was for the Allies.
Most British battleships were old, slow and could not be adapted for bulky modern fire-control equipment. The Dutch navy’s triaxially stabilized Hazemeyer system represented the most advanced AA gunnery technology in the world, to which the Royal Navy gained access in 1940. It was fragile and unreliable, however, and a British version entered general service only in 1945; anti-aircraft fire-control remained ineffective meanwhile. Throughout the conflict, the Royal Navy displayed the highest standards of courage, commitment and seamanship. But until 1943, it struggled against odds to fulfil too many responsibilities with too few ships, all vulnerable to air attack.
When the war broke out, both the British and German Admiralties assumed that the great German surface ships would be crucial in deciding whether Britain survived or starved. It was thought that if these capital ships could dominate the Ocean Gap, the New World would be incapable, to adopt Churchill’s phrase in his ‘fight on the beaches’ speech, of stepping ‘forth to the rescue and liberation of the Old’. If, on the other hand, the Allies could sink these huge vessels, the danger was thought to be far less great. On the outbreak of war Graf Spee and Deutschland were already stationed to attack the trade routes, and Scharnhorst and Gneisenau put to sea in November 1939. Yet both Admiralties were wrong in assuming that the big battleships would be decisive. In fact, it very soon became clear that the U-boats posed the primary threat.
The Atlantic was the dominant naval battlefield, forever the cruel sea. While Germany’s capital ships commanded headlines and their sorties inflicted some injuries, Axis submarine and air forces represented a much graver long-term threat, and the men of both arms displayed courage and skill. U-boats achieved striking early successes, such as sinking the old battleship Royal Oak in Scapa Flow, and wreaking havoc upon vulnerable merchantmen. Merchant ships were obliged to waste weeks waiting for convoys to assemble. Once ocean-bound, they travelled painfully slowly, and were offloaded on arrival by a lethargic and sometimes obstructive British dock labor force.
In May 1941 the Germans took the initiative, unleashing the battleship Bismarck and the new heavy cruiser Prinz Eugen into the Atlantic shipping lanes, in the hope of asphyxiating Britain and forcing her to sue for peace. These two warships left port at Gotenhafen (present-day Gdynia) in Operation Rheinübung (Rhine Exercise), a break for the Atlantic. The British fleet pursued the two German monsters and, after a bloody engagement, Bismark, the pride of the German Navy, was sunk. The British also lost an important ship, the HMS Hood. Bismarck had been launched in Hamburg by the Iron Chancellor’s granddaughter, Dorothea von Löwenfeld, in February 1939, and Göring, Goebbels, Hess, Ribbentrop, Himmler, Bormann, Keitel and of course Raeder were all present; the Führer gave a speech. The ship was one-sixth of a mile long, recalled the British writer Ludovic Kennedy, who was a junior reserve lieutenant when he took part in the operation to try to sink her, ‘120 feet wide, designed to carry eight 15″ guns and six aircraft, with 13″ armour made of specially hardened Wotan steel on her turrets and sides. Listed as 35,000 tons to comply with the London Treaty, she would in fact be 42,000 tons standard displacement and over 50,000 tons fully laden. There had never been a warship like her: she symbolized not only a resurgent Navy but the whole resurgent German nation… Warships combine uniquely grace and power, and Bismarck, massive and elegant, with the high flare of her bows and majestic sweep of her lines, the symmetry of her turrets, the rakish cowling of her funnel, her ease and arrogance in the water, was then the most graceful, most powerful warship yet built. No German saw her without pride, no neutral or enemy without admiration.’ Furthermore she had twelve boilers, her four gun turrets each weighed 1,000 tons – they were nicknamed Anton, Bruno, Caesar and Dora – she could sail at 29 knots and her crew numbered 2,065. Prinz Eugen, meanwhile, displaced 14,000 tons, had eight 8-inch guns and a speed of 32 knots.
The sinking of the Bismarck – although of course it cost the Hood – saw the last of the German surface-fleet raiders threatening the Atlantic sea-lanes, and in that sense marked a major turning point in the battle. Bismarck’s and Prinz Eugen’s supply ships were immediately targeted, using the German Home Waters key of the naval Enigma code called Dolphin, and hardly any made it back to port. That meant that the Germans had henceforth to rely on underwater tankers and supply carriers, which had much smaller capacities and slower speeds.
Until 1943, the Royal Navy was desperately short of escorts and effective technology to hunt U-boats. The British sank twelve German submarines in 1940, and just three in the six months between September that year and March 1941; intelligence and skilful convoy routing did more to frustrate Admiral Karl Dönitz than did anti-submarine escorts. The Royal Navy was slow to realize the vulnerability of merchantmen off the African coast, where in 1941-42 just two long-range Type IX U-boats achieved some spectacular destruction, partly because they maintained wireless silence and partly because few defensive resources were available.
Dönitz had been a highly decorated U-boat commander in World War I until captured by the British in 1918. After a successful career in surface vessels that lasted into the mid-1930s, he took over the effort to rebuild the U-boat force. Dönitz believed that submarines offered the best avenue to defeat the British. Dönitz’s operational aim for his offensive was simple: to sink the maximum number of Allied ships possible, without regard to their cargo, their destination, or even whether they had any cargo on board at all.
A major problem with British strategy at the start of the war was that too much attention was paid to taking the offensive against the U-boat threat, and not enough to protecting convoys, which the Great War had proved was the best way of keeping the sea-lanes open. It was not until May 1941 that convoys were escorted all the way across the Atlantic, and even then they were often woefully under-protected. The Americans took even longer to institute a proper convoy system. After Enigma had been cracked in April 1941, between July and December 1941 Allied convoys were re-routed so expertly that not one was intercepted in the North Atlantic. Although there were still significant losses, these were heavily reduced.
The submarine force commanded by Dönitz was far weaker than it could have been. Germany’s pre-war industrial planning envisaged a fleet which achieved full war-fighting capability only in 1944. Naval construction was skewed by a focus on big ships: a hundred U-boats could have been built with the steel lavished on the Bismarck. Until June 1940, Dönitz did not anticipate waging a major campaign in the Atlantic, because he was denied means to do so; the small, short-range Type VII boats that dominated his armory were designed to operate from German bases. Even when the strategic picture radically changed with Hitler’s seizure of Norway and of France’s Atlantic ports, the Kriegsmarine continued to build Type VIIs.
After April 1941 Dönitz pioneered Rudeltaktik (herd tactics), by which the first U-boat to spot a convoy shadowed it while sending out signals to headquarters and other U-boats in the area, prior to a concerted night-time, surface, close-range torpedo attack by them all, acting as a wolf-pack.
In 1942, by far the most alarming year of the U-boat war, 609 ships were sunk in the North Atlantic, a total of some six million tons. So prodigious was American shipbuilding capacity, however, that in the same period the Allies launched 7.1 million tons of ships, increasing their available pool of thirty million tons. Yet, as is the way of mankind, the Allies perceived most of the difficulties on their own side. While posterity knows that in 1942 the U-boats inflicted the utmost damage of which they were capable, and that thereafter the tide of the convoy war turned steadily against them, at the time Churchill and Roosevelt saw only a steeply rising graph of losses which, if it had continued, would have crippled the war effort.
In March 1943 there was another breakdown of U-boat radio traffic decryption. In consequence, for two months half of all Atlantic convoys suffered attack, and one in five of their merchantmen were sunk. Yet this proved the final crisis of the campaign. That spring, at last the Western Allies committed resources which overwhelmed the U-boats. Escort groups equipped with 10cm radar, VLR aircraft with improved depth-charges, small carriers and renewed penetration of Dönitz’s ciphers combined to transform the struggle. Dönitz found himself losing a U-boat a day, 20 percent of his submarine strength gone in a month. He was obliged to drastically curtail operations.
When Hitler invaded Russia, the British and American Chiefs of Staff alike opposed the dispatch of military aid, on the grounds that their own nations’ resources were too straitened to spare arms for others. The Royal Navy saw a further strategic objection: any material shipped to the Soviets must be transported through their Arctic ports, Murmansk and Archangel, the latter accessible only in the ice-free summer months. This would require convoys travelling at a speed of eight or nine knots to endure at least a week-long passage under threat or attack from German U-boats, surface warships and aircraft based in nearby northern Norway. Britain’s prime minister and America’s president overruled these objections, asserting – surely rightly – that support for the Soviet war effort was an absolute priority.
In 1942, however, as the British began to transport substantial shipments eastwards, Hitler’s forces intervened with mounting vigor. The experiences of the ‘PQ’ convoys, as they were designated, and of the return ‘QP’ series, became one of the war’s naval epics. On the Murmansk passage, almost every ship suffered weather damage, to which even the greatest ships were vulnerable. As the convoy battles of 1942 became progressively harder and more costly, merchant service officers voiced dismay about their treatment by the navy. Above all, they protested about the fact that they were expected to sail day after day through the most perilous waters in the world, knowing nothing of what was happening save what they could see from their ice-encrusted upper decks.
One of the most serious setbacks of the naval war occurred in July 1942, when Convoy PQ-17 was spotted by German submarines and aircraft. It was hard to miss, comprising thirty-five merchant ships, protected by six destroyers and fifteen other armed vessels. Four merchantmen were sunk by Heinkel torpedo-bombers, and, fearing that four powerful German warships – including the Tirpitz – were on their way, Admiral Sir Dudley Pound, the First Sea Lord, ordered the convoy to scatter, overriding the C-in-C Home Fleet Admiral Sir John Tovey. It was a virtual death sentence. The scattered convoy was picked off from the air and by submarines.
The turn of the year 1942 proved the critical landmark of the campaign. Weather and the enemy – especially U-boats armed with acoustic homing torpedoes – ensured that service on Arctic convoys never became less than a miserable and alarming experience, but losses fell dramatically. In 1943 the Royal Navy was at last able to deploy escort carriers and powerful anti submarine and anti-aircraft defenses. The Germans, hard-pressed in Russia and the Mediterranean, were obliged to divert much of their air and U-boat strength away from Norway. The US began to move massive supplies by other routes.
Between 1940 and 1943, the Mediterranean witnessed some of the bloodiest fighting of the Royal Navy’s war. British submarines, based on Malta when conditions there allowed, attacked Axis supply lines to North Africa with some success. Battle squadrons sought to assert themselves in the face of the Italian navy, U-boats and the Luftwaffe. In 1942, the hazards were increased by German deployment of U-boat reinforcements. But Churchill conducted the war effort on the basis that Britain must be seen to challenge the enemy at every opportunity, especially when the army accomplished so little for so long. Malta, within easy range of Axis Sicilian air bases, suffered almost three years of intermittent bombardment.
The requirement to sustain Malta became a priority for the Royal Navy, and every supply ship had to be fought through in the face of air, U-boat and surface attack. Each convoy demanded a supporting fleet operation: there must be battleships in case Italian heavy units sortied, carriers to provide air cover, and cruiser and destroyer escorts. Each venture precipitated an epic battle. The most famous, or notorious, took place in August 1942, when Malta’s shortages of oil, aircraft and food attained desperate proportions: Operation Pedestal was launched to bring relief. Despite heavy losses, the British navy managed to bring in enough supplies for the island to continue resisting.
The Pedestal convoy delivered 32,000 tons of stores, 12,000 tons of coal and two months’ supply of oil; five merchantmen survived out of fourteen. The navy’s aggressive posturing dissuaded the Italian fleet from joining the battle. The three-day drama of Pedestal was almost matched by the experiences and sufferings of other Malta convoys and their escorts. By the winter of 1942, the worst of Britain’s Mediterranean struggles were over. Ultra decrypts enabled Allied warships and aircraft to wreak increasing havoc on Erwin Rommel’s supply line. In November 1942, Bernard Montgomery was victorious at El Alamein and the Americans landed in North Africa. The siege of Malta was relieved soon afterwards.
After the siege of Malta was lifted in 1943 and 1944, Allied dominance of the Mediterranean remained contested and imposed continuing losses, but strategic advantage tilted relentlessly away from the Axis. The Royal Navy’s critical responsibilities in the last two years of the war became those of escorting Allied armies to new battlefields, and organizing and protecting a succession of massive amphibious landings.
The Soviet Union's navy was involved in important operations primarily in the Black Sea, but there is very little evidence of Stalin's recognition then of the extent to which Allied strategy was dominated by the problem of shipping. The role of the Soviet navy was primarily one of supporting land operations. In the north, the units of the fleet there assisted in the defense of Murmansk and played a small role in receiving the convoys from the West. The Russians had few merchant ships in the Pacific; the United States, therefore, began transferring ships to the Soviet flag so that they could cross the Pacific to the Soviet Union without escort, as the Japanese allowed Soviet ships to travel designated routes unmolested.
In the Baltic, the Russian navy units based at Kronstadt were of importance in two ways. The possibility of Soviet ships coming out of the Gulf of Finland into the Baltic and interfering with Germany's supply routes to Finland, her trade with Sweden, or her training of submarine crews always agitated the German navy. The Russians also used this route to supply a section of the front that had been cut off from the rest of the Red Army.
If the function of the Red Baltic Fleet was primarily one of army support, the same was true for most of the operations of the Soviet Black Sea Fleet. Its successful evacuation of the Odessa garrison was only one of many operations carried out by what was probably the most effective and efficient portion of Soviet naval forces in World War II. The Black Sea Fleet's role in the Soviet winter counter-offensive in the Crimea has also been mentioned. There the fleet not only reinforced the garrison but brought in other units, evacuated machinery, and generally organized under Black Sea Fleet Commander Admiral F.S. Oktyabskiy a very efficient defense.