Metro line 4 in Budapest was implemented after dividing the project into several contractor’s contracts. One of its most complex elements covering the whole line is entitled ‘Interior fit-out’ (Tender No. Co-07). During the establishment of the stations, great emphasis was laid on fire protection. To this end, main ventilation equipment and built-in fire-extinguishing systems (sprinklers) were installed at the stations and along the lines.
In normal operation, the main ventilation systems of the stations supply fresh air to passenger areas and remove the heat generated under the floors of arriving trains (exhaust under the platforms). In case of fire, where the most ‘decisive’ and most dangerous is a train fire, the ventilation system at the station is automatically switched to exhaust above the tracks and maximum capacity within one minute. In normal operation, ventilation for the tunnels is provided by the piston effect generated by the running trains, which is mostly sufficient. In fact, in order to reduce the draught effect arising in the passenger areas of stations, the two line tunnels before and after the airspace of the platforms were connected to air ducts, which reach the ground surface. In certain cases, the tunnels need to be mechanically ventilated, thus main ventilation systems were installed on the lines before and after the stations, which, similarly to the main ventilation systems of the stations, also have an important role in handling fires. In order to ensure the appropriate operation and dimensioning of the main ventilation equipment, an airflow dynamics study was prepared and a 3D smoke flow simulation was carried out. The ventilation fans have reversible, frequency converter drives.
As part of the main ventilation system, our Company prepared the installation and cabling designs of the mechanical and electrical equipment at Kelenföldi Railway Station, in Tétényi út, Bocskai út and Móricz Zs. körtér, and at Keleti Railway Station on the basis of the system designs of the prime contractor Cegelec SA, and the as-built drawings required for technical delivery.