At the start of the war, the company lost access to most of its overseas markets, but this was more than offset by increased demand for weapons by Germany and her allies ( Central Powers ). In 1902, before Krupp's marriage, the company leased a fuse patent to Vickers Limited of the United Kingdom. Among the company's products was a 94-ton howitzer named Big Bertha, after Krupp's wife, and the Paris Gun.[5] Gustav also won the lucrative contract for Germany's U-boats, which were built at the family's shipyard in Kiel.