Greek railway signalling

Other Greek trains at that time were controlled by signals given manually by station masters.

On lines currently operated by the Hellenic Railways Organisation (OSE), signalling was not installed until World War II.

There were few trains running and all traffic control was performed by the station masters (Greek: Σταθμάρχης).

In many cases the orders are transmitted over the radio by station masters, instead of being handed out in printed form.

[2] Today operations use four channels as follows: The suburban section from Acharnai Railway Center to the Athens International Airport station uses commercial TETRA radio instead of VHF/FM.

Currently the VHF/FM system is being phased out and replaced with a digital communications network based on the GSM-R technology which shall also carry ETCS-Level 1 cab signalling.

[3] In recent years the OSE undertook modernisation of the section from Piraeus to Thessaloniki and Idomeni.

Signals are tagged with an identity which consists of a three- or four-letter code denoting the station and a number (for example "OIN 3").

Details of the design and operation of the signals, the points, and the interlocking survive in Section D of the contract between the Greek Government and the railway company.

[5] In 1924 the new company "Hellenic Electric Railways" signed a new contract with Siemens & Halske to renovate the signalling system.

The line circuits operate with audio frequency alternating current (Siemens FTGS 17).

[8] In 2023 the fully installation of ATP in line 1 was completed and replaced the previous Indusi system.

[9] A VHF/FM simplex radio system, which operated on 161.325 and 161.375 MHz, was installed in stations and driving cabs in 1985.

Signals are tagged with an identity which consists of a three-letter code denoting the station and a number (for example "ΣΥΝ 11").

At some locations green wave signalling has been established, giving priority to approaching trams over road vehicles.

All Athens Tram driving cabs are equipped with GPS receivers and TETRA radio telephones.