From 1865 until 1976, Berlin had an extensive pneumatic postal network, which at its peak in 1940, totaled 400 kilometers in length. After 1949 the system was split into two separated networks. The West Berlin system in operation and open for public use until 1963, and for government use until 1972. The East Berlin system which inherited the ''Hauptelegraphenamt'', the central hub of the system, was in operation until 1976