The building is an example of industrial architecture,[2] built of stone, while its roof is constructed of wood covered with tile.

[3][2] In 1920 SPAP was briefly nationalized as part of the Hellenic State Railways but became an independent company two years later.

Normal levels of service resumed at about 1948, with the exception of the destroyed bridge of Achladokampos (between Argos and Tripoli), which was rebuilt in 1974.

In 1970 OSE became the legal successor to the SEK, taking over responsibilities for most of Greece's rail infrastructure.

In 2009, with the Greek debt crisis unfolding OSE's Management was forced to reduce services across the network.

Timetables were cut back, and routes closed as the government-run entity attempted to reduce overheads.

However, a short section through the port city of Patras remains open as a suburban railway.