Submarine warfare in the context of "U-boat Campaign (World War I)"

The London Naval Treaty, officially the Treaty for the Limitation and Reduction of Naval Armament, was an agreement between the United Kingdom, Japan, France, Italy, and the United States that was signed on 22 April 1930. Seeking to address issues not covered in the 1922 Washington Naval Treaty, which had created tonnage limits for each nation's surface warships, the new agreement regulated submarine warfare, further controlled cruisers and destroyers, and limited naval shipbuilding.

Ratifications were exchanged in London on 27 October 1930, and the treaty went into effect on the same day, but it was largely ineffective.

Leonardo Torres Quevedo (Spanish: [leoˈnaɾðo ˈtores keˈβeðo]; 28 December 1852 – 18 December 1936) was a Spanish civil engineer, mathematician and inventor, known for his numerous engineering innovations, including aerial trams, airships, catamarans, and remote control. He was also a pioneer in the field of computing and robotics. Torres was a member of several scientific and cultural institutions and held such important positions as the seat N of the Real Academia Española (1920–1936) and the presidency of the Spanish Royal Academy of Sciences (1928–1934). In 1927 he became a foreign associate of the French Academy of Sciences.

His first groundbreaking invention was a cable car system patented in 1887 for the safe transportation of people, an activity that culminated in 1916 when the Whirlpool Aero Car was opened in Niagara Falls. In the 1890s, Torres focused his efforts on analog computation. He published Sur les machines algébriques (1895) and Machines à calculer (1901), technical studies that gave him recognition in France for his construction of machines to solve real and complex roots of polynomials. He made significant aeronautical contributions at the beginning of the 20th century, becoming the inventor of the non-rigid Astra-Torres airships, a trilobed structure that helped the British and French armies counter Germany's submarine warfare during World War I. These tasks in dirigible engineering led him to be a key figure in the development of radio control systems in 1901–05 with the Telekine, which he laid down modern wireless remote-control operation principles.