 U @-@ 9 was laid down on 31 December 1913 , the third of the U @-@ 7 boats . Her construction was slated to be complete within 29 to 33 months . Neither U @-@ 9 nor any of her sister boats 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 , U @-@ 9 and her four sisters were sold to the Imperial German Navy on 28 November 1914 . 
