Central Europe’s first CBTC automated metro opened on March 28 in the form of Budapest’s Line 4, marking a major milestone in Hungary, as Andrew Roden reveals.
When the first passengers travelled on Budapest Metro’s Line 4 it marked the culmination of an eight year programme to link the Southern boroughs of Buda with the centre of Pest, and the busy Kelenföld and Keleti pályaudvar stations. After being discussed for decades, a vital transport link in Hungary’s capital is now complete, with journey times of less than 25 minutes, a top speed of 80km/h for the Alstom Metropolis trains, and a 90-second headway at peak times.
Budapest’s Metro Line 4 is now open.
Construction – as with any underground railway – was something of a challenge. Two 7.34km single bore tunnels carry the tracks and associated structures, and although much of the route is fairly close to the surface, as it approaches the River Danube it dives down to a depth of 30m below ground. Turnouts are provided at the terminal stations to allow trains to begin their return journeys and there is also a crossover at Szent Gellért tér – one of 10 stations on the route – to allow a reduced service to operate in the event of train or infrastructure failures. A maintenance depot at Kelenföld incorporates an eight-storey control tower and offices. It is potentially possible for trains to be prepared before and powered down after duty remotely, though whether this is introduced is at the moment under consideration.
Siemens was tasked with installing and commissioning power supply, signalling, Communications Based Train Control (CBTC) and communication systems on the line, and although for the first year the trains will operate in supervised mode with a driver ready to intervene if needed, it is widely expected that fully automated unsupervised operations will start in 2015.
The power supply network had to be particularly resilient to meet the demanding fire safety requirements on Metro Line 4: a special 10kV fire retardant and resistant cable was developed by Siemens and its partners, while switchgear cells were designed with an armoured structure to protect operators should the cells malfunction. The system was designed from the outset for regenerative braking from trains, which offers potentially significant cuts in power consumption, though the exact figure depends heavily on the characteristics of the railway in question.
The CBTC installation – complete with TETRA radios – is fairly straightforward for a metro of this type, but one unusual aspect is provision of Passenger Protection Equipment. This radar based system detects when a passenger falls from a station platform onto the tracks (there are no platform screen doors) and cuts the power supply to trains. Integrated communications link supervisory and operational systems with train control, signalling and power supply sub-systems.
With Metro Line 4 now running, attention is now turning to the proposed 7km extension of Metro Line 1, extension of tram line 1, and improvements to that and tram line 3. With Metro Line 4 now open and CBTC in operation on Metro Line 3, Budapest’s transport network is undergoing a major upgrade that looks set to help this beautiful and historic city meet passenger demands for some time to come.