German Type U 66 Submarine - Construction

Construction

After the Austro-Hungarian Navy's 1 February 1913 order, the first two boats, U-7 and U-8, were laid down at Germaniawerft on 1 November. U-9 was laid down at the end of December, and the final two boats, U-10 and U-11 were both begun in February 1914. Construction of the boats was slated to be complete within 29 to 33 months.

None of the submarines were complete when World War I began in August 1914. With the boats under construction at Kiel, the Austrians became convinced that it would be impossible to take delivery of the boats, which would need to be towed into the Mediterranean past Gibraltar, a British territory. As a result, the five boats of the class were transferred to the Imperial German Navy on 28 November 1914 after the advance payment of 2 million Kronen had been returned. Germaniawerft was then awarded Kriegsauftrag D, hence the type was known as UD.

After their purchase, the boats were assigned the numbers U-66 to U-70, and the class became known as the U 66 type. The Imperial German Navy had the submarines redesigned and reconstructed to German standards, which increased the surface displacement by 96 metric tons (106 short tons) and the submerged by 48 metric tons (53 short tons). The torpedo load was increased by a third, from 9 to 12, and the deck gun was upgraded from the 66 mm (2.6 in) gun originally specified to an 88 mm (3.5 in) one.

U-66 was launched on 22 April 1915, the first of the class, and was followed by the other four about one every three weeks, with the last boat, U-70, hitting the water on 20 July. The boats were all completed and commissioned into the Imperial German Navy between July and September.