Army-Corps (15 March – 12 August 1917), and Signal-Adviser of the General-Staff of the Army-Group “Deutscher Kronprinz” until the End of WW I.
From 1 February – 29 April 1919 he served as Group-Signal-Commander with the Special-Purpose-General-Command 52, Border-Protection East, followed by the assignment to leader of the 104th Brigade-Signal-Battalion.
In the capacity as communications engineer, he worked as representative of the “Deutsche Reichsbahn” (en: German Railway-Company) in Yugoslavia (1920 – 1933).
His primary mission was handling of the Wire-Signal-Affairs of the newly established “Luftnachrichtentruppe” (en: Air-Signal-Troop), supported to the “Reichsluftfahrtministerium” (RLM) (1934 – 1938).
The final mission of Walter Surén was Signal-Leader with Generalfeldmarschall Erhard Milch, General-Plenipotentiary of the Deutsche Reichsbahn (15 March 1945 – … May 1945).