The Bismarck class was a pair of fast battleships built for Nazi Germany's Kriegsmarine shortly before the outbreak of World War II. The ships were the largest and most powerful warships built for the Kriegsmarine; displacing more than 41,000 metric tons (40,000 long tons) normally, they were armed with a battery of eight 38 cm (15 in) guns and were capable of a top speed of 30 knots (56 km/h; 35 mph). Bismarck was laid down in July 1936 and completed in September 1940, while her sister Tirpitz's keel was laid in October 1936 and work finished in February 1941.