Other German surface raiders now began to make their presence felt. On Christmas Day 1940, the cruiser attacked the troop convoy WS 5A, but was driven off by the escorting cruisers. "Admiral Hipper" had more success two months later, on 12 February 1941, when she found the unescorted convoy SLS 64 of 19 ships and sank seven of them. In January 1941, the formidable (and fast) battleships and , which outgunned any Allied ship that could catch them, put to sea from Germany to raid the shipping lanes in Operation Berlin. With so many German raiders at large in the Atlantic, the British were forced to provide battleship escorts to as many convoys as possible. This twice saved convoys from slaughter by the German battleships. In February, the old battleship deterred an attack on HX 106. A month later, SL 67 was saved by the presence of .