As Operation Sealion petered out during the autumn of 1940, Admiral Raeder and his colleagues in the Kriegsmarine began to focus on the kind of warfare they believed in. Following the damage sustained in the spring of 1940, a sense of optimism was renewed when many ships returned from the shipyards. Among the ships expected to be fully serviceable soon were the battleships Gneisenau and Scharnhorst. They had formed a task force during the attack on Norway in April 1940, when Admiral Marschall had been in command. If sent to the Atlantic together, they would form a powerful group, menacing British merchant shipping. The long winter nights would also improve chances of them being able to break out undetected into the Atlantic. Finally Raeder could embark on the large-scale warfare against merchant shipping that he had advocated for so long. His intention was not only to sink merchant ships; Raeder hoped that the countermeasures that the Royal Navy would be forced to take would also disrupt British trade.
The German Navy had deployed surface ships against British merchant shipping since spring 1940, but these were not regular warships. Instead, the Germans had employed Hilfkreuzer—armed merchant ships not unlike the British Rawalpindi. By fitting the weapons behind doors and other forms of cover, they could be effectively disguised, yet quickly made ready to fire on prey as it appeared. Mostly, the ships sailed under false colours, to avoid recognition. Their combat capabilities were far too low to engage regular warships and the German Navy did not expect any grand achievements from them. However, by sailing outside normal convoy routes, the Hilfzkreuzer could search for merchant ships sailing alone, approach disguised and when they had approached close enough, sink or capture them. Usually the Germans preferred to employ their armed merchant ship in areas like the Indian Ocean and the South Atlantic, where many ships sailed unescorted. Protected convoys were left to the regular German warships, which had not appeared in the Atlantic since the autumn of 1939.
The first German warship to reach the Atlantic Ocean in 1940 was the pocket battleship Admiral Scheer. She had been at Wilhelmshaven when the war broke out, as she needed a major overhaul. Her antiaircraft artillery shot down a Wellington bomber while she was at the yard, but otherwise she took no part in combat during the first year of the war. When she was at last fully refitted, her crew needed training to attain combat readiness. She was sent to the Baltic for a month of intensive exercise, before finally being declared ready for operations. On 23 October, 1940 she weighed anchor at Gdynia and steered west on the Baltic. After passing Denmark, she sailed north. Undetected she continued towards the Atlantic and a week after departing from Gdynia, she passed through the Denmark Strait between Greenland and Iceland. The first phase, regarded as the most difficult part of the operation by the Germans, had been successfully completed. The Admiral Scheer could begin searching for prey.
She did not have to wait long. Early on 5 November she discovered the lone Mopan and promptly sank her. A few hours later the lookouts on board the Admiral Scheer caught sight of an even more tempting quarry, the convoy HX84—a British convoy numbering no less than 37 merchant ships. The escort consisted of only a single ship, the armed merchant ship Jervis Bay. Since the sun was about to set, the commander on board Jervis Bay, Captain Edward Fegen, decided to accept battle with the Admiral Scheer, hoping that the convoy could scatter and as many merchant ships as possible disappear in darkness before the German ship got too close. Fegen’s decision doomed his ship. The battle was hopelessly uneven. A sailor in the convoy thought the action resembled a bulldog attacking a bear. The 40 year old, 152mm guns fitted to Jervis Bay did not even have the range needed to successfully engage the German warship. Nevertheless, the British fired incessantly, while laying smoke to protect the ships of the convoy. The battle could only end in one way and after 24 minutes it was over. The Jervis Bay had become a burning wreck. Admiral Scheer sank five merchant ships and another three were damaged, but the rest of the convoy escaped. Later, 65 men from the gallant crew of the Jervis Bay were saved by the Swedish freighter Stureholm.
A few uneventful days followed, until on 12 November Admiral Scheer met with the tanker Eurofeld and the supply ship Nordmark. A few days were spent bunkering diesel oil and taking on supplies. Also, 68 prisoners from the Mopan were transferred to the supply ship, before the Admiral Scheer resumed her search for prey. The results were not impressive. After almost a month had passed, she had only been able to add another two ships to her tally. Again, the pocket battleship met with the supply ship to bunker. On this occasion, the opportunity was used to perform some maintenance on her diesel engines, before the Admiral Scheer set course for the southern Atlantic on 15 December.
While the Admiral Scheer operated in the Atlantic, the heavy cruiser Admiral Hipper was prepared for the same purpose. In fact, she had sailed already on 24 September, with the intention of reaching the Atlantic, but before passing the Skagerrak she had problems with her machines. She was forced to return to Germany and spent two months in the yard, until she was finally fit again. On 30 November she left harbour, commanded by Captain Wilhelm Meisel, to attack convoys in the Atlantic. The operation was called Nordseetour. At first she searched in vain for Allied shipping and had to survive extremely bad weather. Problems with her machinery ensued, but they could at least be temporarily repaired. The Admiral Hipper bunkered fuel oil from German supply ships, first on 12 December, then on 16 and 22 December, but after three weeks at sea not a single enemy ship had been seen. However, on the night before Christmas Eve, her radar finally picked up an echo. She had found the British troop convoy WS5A about 600 miles west of Cape Finistere. Unlike HX84, which had been attacked by Admiral Scheer seven weeks earlier, the WS5A was escorted by regular British warships: the heavy cruiser Berwick and a few smaller ships. Captain Meisel did not become aware of the British escort, and shadowed the convoy with the intention of attacking it after dawn. While it still was dark, Meisel closed the distance to the convoy and fired a number of torpedoes, but none hit. The German commander was not deterred and pursued his intention to attack at dawn, this time relying on his guns. Almost immediately the lookouts on the Admiral Hipper found the Berwick. Meisel decided to attack the British cruiser. In the ensuing battle, Berwick was damaged and forced to withdraw from the battle, but enough time had passed to allow the convoy to scatter and all merchant ships evaded the Admiral Hipper. The German cruiser had not been hit, but nevertheless Meisel decided to break off the operation and steer towards Brest. His decision was based mainly on the defects in the machinery, which he wanted to correct. On Christmas Day the lone freighter Dumma was found and sunk. It was the only success scored by the Admiral Hipper during Operation Nordseetour. She reached Brest on 27 December.
Operation Nordseetour and the battle between the Admiral Hipper and the Berwick exposed shortcomings in the German Navy’s concept of cruiser warfare. Although the German ship came out unscathed, the action had certainly put her at risk. When encountering an escort of equal strength, the German ship might at least suffer damage and impaired mobility. This was a serious risk, considering the kind of warfare Raeder intended to conduct.
On the very day the Admiral Hipper reached Brest, a meeting took place in Berlin, attended by Hitler, Raeder and a few other high ranking naval officers. The German Navy was already planning for the Admiral Hipper’s next voyage and Hitler wanted to know the purpose. Raeder explained that the Admiral Hipper was only to attack enemy supply lines, concentrating on the convoys as the main target but avoiding the escorts. She should only accept battle with the escort if it was clearly inferior in armament. Hitler concurred. It is possible that this discussion resulted from discontentment with Meisel’s decision to engage a British heavy cruiser.
The Admiral Scheer spent the last weeks of 1940 without much drama. The only exception was on 18 December, when her floatplane found the refrigerator ship Duquesa, which carried food, including about 15 million eggs and 3,000 tons of meat. She was captured and her cargo came in handy for the German ships operating in the Atlantic. In addition to the Admiral Scheer and the Admiral Hipper, the armed merchant ships Thor and Pinguin, several blockade runners and captured ships were also operating in the Atlantic. The Duquesa supplied several German ships with food, before she was finally sunk after two months.
While the Admiral Scheer and Admiral Hipper ravaged the Atlantic, the two battleships Gneisenau and Scharnhorst also prepared for an operation in the same waters. They sailed on 28 December, but very bad weather caused damage to the Gneisenau and both ships had to return at an early stage. The Gneisenau was quickly repaired, but the operation was postponed for a month.
Meanwhile the Admiral Scheer patrolled the South Atlantic. She did not score any notable successes. No convoy was found, but a Norwegian tanker was captured and sent to Bordeaux on 17 January. Three days later two freighters were sunk, but subsequently the Admiral Scheer ran out of luck. Late in January she set course for the Indian Ocean, hoping to find better opportunities for success there. On 3 February the Admiral Scheer passed south of the Cape of Good Hope.
Major accomplishments had thus far eluded the German naval ships in the Atlantic, but Raeder indulged in expectations of more success when the Scharnhorst and Gneisenau reached the transatlantic convoy routes. Due to the mishap with the Gneisenau, Admiral Lütjens, who commanded the squadron, was given more time to think about the best way to use his two battleships. As they were much more powerful than the Admiral Hipper and Admiral Scheer, Lütjens could attack escorted convoys without hesitating. When Meisel had attacked WSA5, despite the cruiser included in its escort, his action had bordered on the foolhardy. Considering the scarcity of German heavy vessels, it was imperative to keep them ready for action, or else it would be impossible for the German Navy to maintain the threat against the British convoy routes. With two battleships at his disposal, Lütjens would be in a very different position, as the British could hardly be expected to include stronger ships than cruisers in their escorts. However, damage to the German ships still had to be avoided. Prudence suggested that combat had to be conducted at long range, to avoid the menace from torpedoes.
Lutjens did not have to answer the question of how to attack convoys until his squadron reached the Atlantic, and he had a difficult journey ahead of him. The main problem was the ice in the Baltic, the Danish Belts and the Kattegat. The severe cold in January 1941 had resulted in ice with a thickness of about 30cm in the Danish Belts. Under normal conditions, Lütjens would have preferred to pass through the Belts in darkness, to avoid being seen from the coast, but in the present icy conditions it seemed impossible to sail through the narrow straits during night. The German squadron would have to make the passage in full daylight, when Allied agents as well as men and women from the Danish resistance could easily see the ships. When he had passed through the Great Belt, his two battleships would sail towards the Skagen, where escorts would join them, before continuing in the direction of Norway.
The forthcoming operation was given the name ‘Berlin’ and was a much more whole-hearted attempt to implement the cruiser warfare concept, compared to the small-scale operations conducted so far. Lütjens was a good choice to lead Operation Berlin, since he was the German naval officer with most experience at sea. In 1914 he commanded a torpedo boat unit and saw frequent action in World War I. When the Germans invaded Norway in April 1940, Lütjens commanded the Gneisenau and Scharnhorst, which had been tasked with the mission to protect the landings at Narvik and Trondheim.
Lütjens was a purposeful and calculating commander who carefully considered his alternatives. He preferred to retain freedom of action for as long as possible and was not given to impulsive decisions. Rather, he carefully weighed risks and opportunities. Success in Operation Berlin would depend greatly on the squadron’s ability to remain unobserved on the high seas and to maintain the element of surprise. The commander would have to display good judgement in estimating when the British convoys left ports, what course they followed and how fast they sailed, so as best to assess the risks of attack. Errors of judgement would severely curtail prospects of sinking a significant amount of British shipping. Lütjens seemed to possess exactly the traits needed to plan and conduct the kind of operation envisaged.
Operation Berlin provides the best example of the realisation of the German concept of cruiser warfare. The first phase of the operation was the actual break out into the Atlantic.
The passage from Kiel and, further on, the Kattegat and Skagerrak were narrow, icy and partly mined, requiring coordination with icebreakers, minesweepers, antisubmarine units and other escorts to get the squadron through safely, without jeopardizing secrecy. Tankers and supply ships had to be stationed in the Atlantic, to enable the battleships to remain there for months. Rendezvous places and signals had to be established well in advance, in order to minimize radio communication that could be intercepted by the British.
Radio traffic was a major concern. To reduce the risks of British interception the Germans used a large number of code names for various coordinates. A number of locations at sea had been assigned brief codes, such as ‘black 3’ or ‘red 15’. Without the specific tables needed, it was impossible to interpret the content of the messages. Furthermore, the actual transmissions could be briefer with the aid of the codes, making it more difficult to obtain bearings and estimate the position of the sender.
Several frequencies and types of transmitters were used. The two battleships used ultra short wave for communication between them, as it was very difficult to intercept at longer distance. For reporting between the ships and the shore staffs, other frequencies were used. The weather forecasting used its own specific frequency band, as did communication between the ships and the Luftwaffe. Considering the geography, it was unlikely that the battleships would cooperate with the Luftwaffe far out on the Atlantic, but during the initial and the final phases of the operation, coordination with air power might be needed. Communication with the supply ships was governed by special regulations, as was the use of special crews that were to sail captured ships to German-controlled harbours in the Bay of Biscay. All of these details had to be specified and included in the orders issued before the operation began. However, once the battleships had reached the north Atlantic, Lütjens emphasized that he would make the decisions as the events unfolded.