improved version of Germaniawerft's design for the Imperial German Navy's first U-boat, , and featured a double hull with internal saddle tanks. The Germaniawerft engineers refined the design's hull shape through extensive model trials. and were both laid down on 12 March 1907 at Germaniawerft in Kiel and were launched in August and November 1908, respectively. After completion, each was towed to Pola via Gibraltar, with U-3 arriving in January 1909 and U-4 arriving in April. The was built to the same design as the C-class for the US Navy and was built by Robert Whitehead's firm of Whitehead & Co. under license from Holland and his company, Electric Boat. Components for the first two Austrian boats were manufactured by the Electric Boat Company and assembled at Fiume, while the third boat was a speculative private venture by Whitehead that failed to find a buyer and was purchased by Austria-Hungary upon the outbreak of World War I. The U-5-class boats had a single-hulled design with a teardrop shape that bore a strong resemblance to modern nuclear submarines. The boats were just over long and displaced surfaced, and submerged. The torpedo tubes featured unique, cloverleaf-shaped design hatches that rotated on a central axis. The ships were powered by twin 6-cylinder gasoline engines while surfaced, but suffered from inadequate ventilation which resulted in frequent intoxication of the crew. While submerged, they were propelled by twin electric motors. Three boats were built in the class: U-5, U-6, and . World War I Austro-Hungarian Naval Budget: 1901–1914 (in millions of Austro-Hungarian krone) After the assassination of Archduke Franz Ferdinand and his wife in 1914, the Austro-Hungarian Navy honoured them with a lying in state aboard . During the First World War, the navy saw some action, but prior to the Italian entry spent much of its time in its major naval base at Pola, except for small skirmishes. Following the Italian declaration of war the mere fact of its existence tied up the Italian Navy and the French Navy in the Mediterranean for the duration of the war. Following the declaration of war in August 1914, the French and Montenegrin forces attempted to cause havoc at Cattaro, KuK Kriegsmarine's southernmost base in the Adriatic. Throughout September, October and November 1914 the navy bombarded the Allied forces resulting in a decisive defeat for the latter, and again in January 1916 in what was called the