This photograph shows the submarine's four bow torpedo tubes and hydroplane on the port side.
The following images, provided by Tyne & Wear Archives, show the heart of a World War I German submarine that sank in 1918 after it was rammed by a torpedo boat destroyer.
During WWII, Germany built 1,162 destructive "U-boats," which is short for the German word "Unterseeboot," or undersea boat. By April 1917, 430 Allied and civilian vessels were sunk by German U-boats.