After nine years of waiting, the new M4 line of the Budapest metro was put into circulation on March 28, 2014.
Ten stations of the new line are now operational and serving the stations to the east to southwest railway station of Budapest. The opening of other portions of the line is expected by 2017.
If the work has been accelerated the last few months, particularly in view of the elections, safety has so far not been put aside. Siemens uses CLEARSY, a French company specialized in the design of safe software and systems certified SIL1 to SIL4, the highest levels of the railway sector, to contribute to the safety of Budapest’s subway.
Indeed, each platform has a PPE system (Platform Protection Equipment), developed by Honeywell, which detects through sensors (transmitter, receiver) falls of passenger on the tracks. The line is also controlled by two systems called ZC (Zone Controller), developed by Siemens, who manage the movement of trains through sensors that detect the presence of the train in the area.
A connection between two safety systems made possible by CLEARSY
These two safety systems are designed by two different suppliers, CLEARSY was called to develop a converter allowing both safe systems to communicate with each other without alteration of the safety, in particular to implement a safe communication protocol based on coding information from a technology developed by Siemens: DIGISAFE. Note that CLEARSY had already incorporated this protocol on a Siemens PLC from the Simatic line through the development of an opening and closing management function of line 9 platform doors from the fully automated metro in Barcelona, Spain.
Thus, through the CLEARSY system, if the PPE detects a person on the track, the ZC can secure the area. This security is reflected in the issuance of an order for emergency stop for the train arriving on track. This system, in addition to the link between the two security systems, detects failures and inconsistencies of connected devices and sends PPE alarms or anomalies to ZC (supervisory function). CLEARSY is a French company specialized in the production of safety critical software and systems, certified SIL1 to SIL4, the highest in the railway sector. Very present in the railway sector, CLEARSY has learned to work with companies such as Alstom, Bombardier, GE transportation, Siemens, Thales and RATP. This SME ensure safe system design, up to commissioning, and through the validation and verification.