Keywords: North Sea Mine Barrage map 1918.png en Map of the North Sea Mine Barrage laid in the Summer of 1918 The mine barrage consisted of 18 rows of mines laid in an east-west direction between the Orkneys and Norway The minefield was laid by British and U S ship 56 571 of the 70 177 mines were deployed by the U S Navy http //www navy mil/ah_online/department_arch html U S Navy All Hands magazine http //www navy mil/ah_online/archpdf/ah198604 pdf April 1986 p 20 U S Navy 1986 PD-USGov-Military-Navy North Sea theatre of World War I |