Safety systems in underground tunnels of the Bilbao Metro

A centralised system of active and passive measures protects the tunnels of the Bilbao Metro against possible incidents that might affect passengers and installations. Despite the system being centralised, response levels are scaled so that action may be taken from the control cabinet of each piece of equipment or incident point, from the nearest station or from the general command centre. The Bilbao Metro route is basically Y-shaped to adapt to the longitudinal shape of the valley of the river Nervion between the city centre and the sea. Each branch provides a service to one of the riverbanks while the common section serves Bilbao's commercial and financial centre with an extra prolongation beneath the medieval quarter and the outlying towns upstream. Except for the branch along the right bank of the river, the entire Metro route runs underground. Tunnels and stations are rock bored and are located as close to the surface as the overlying buildings will allow. Service frequency is 5 min on each branch, which means that the shared section receives trains every 2.5 min each way. Some wide-ranging risk scenarios have been taken into account and include water getting unexpectedly into tunnel low points, fires with or without smoke, the need to evacuate a train from a point in a tunnel roughly equidistant from the two nearest stations and the loss of general lighting levels. The fire fighting systems are probably the most interesting as regards safety control. Tunnels and stations were designed so that the detection of fire, either through the verification of rising temperatures or the production of smoke, is automatic, the signal being received at the command centre and in the nearest stations. The system is designed to bring into operation three ventilation chambers, each one equipped with two ventilators with the capacity to move 90 m3/s, in suction/blowing and an automatic blower gate with a chimney connecting to the exterior. Studies were based on the premise that platforms should be evacuated in less than four (4) minutes, even when two packed trains arrive almost simultaneously at the station, and that absolutely everyone should be in a safe place at street-level in less than (10) minutes. The way the system works is simple enough. Once the incident has been detected the closest ventilation chamber begins to function in suction mode, while the two chambers located on either side function in blow mode. The idea is to limit the route of the smoke and hot air to the closest ventilators while clean air is blown towards the evacuation routes. Every year the Bilbao Metro stages a simulacrum of a fire with real smoke to check the suitability of the system installed. Each simulacrum involves a train with volunteers that are stopped in the middle of a tunnel and from which the passengers are evacuated in conditions similar to those of a genuine incident. Ventilation to maintain air quality is another especially important system. The system activates automatically when the temperature or the presence of solids in suspension exceeds certain thresholds. The suction system is located at one end of each station, and as well as the ventilators it is equipped with a system of filters to ensure that the air coming into the atmosphere does not contain particles that have been produced in the tunnel. (A). "Reprinted with permission from Elsevier". For the covering abstract see ITRD E124500.

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  • Accession Number: 01011507
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Dec 19 2005 3:14PM