Complex sentence: Construction began on 10 January 1954 and continued for 20 months and the tower was placed in service on 5 February 1956 by Süddeutscher Rundfunk (today Südwestrundfunk--SWR).
Split into simpler sentences: Construction began on 10 January 1954 and continued for 20 months. The tower was placed in service on 5 February 1956 by Süddeutscher Rundfunk (today Südwestrundfunk--SWR).