 "UB-45" was laid down by AG Weser at its Bremen shipyard on 3 September 1915.As one of six U-boats selected for service in the Mediterranean while under construction, "UB-45" was broken into railcar-sized components and shipped overland to the Austro-Hungarian port of Pola.Shipyard workers from Weser assembled the boat and her five sisters at Pola, where she was launched on 12 May 1916.