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.²⁶

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.²⁷

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.²⁸ 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.²⁹

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.³⁰

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.³¹ However, once the battleships had reached the north Atlantic, Lütjens emphasized that he would make the decisions as the events unfolded.³²