Monthly Archives: February 2015

Unique safety system protects passengers in the Copenhagen underground

metro

Almost all evacuation stairways have been removed in the coming City Circle Line of the Copenhagen Metro. Nevertheless, the level of safety is at least as high as that of the existing Metro system.

A fire suddenly breaks out inside of a Metro car travelling on Copenhagen’s City Circle Line. The train comes to stop, the passengers evacuate to the emergency walkway and they move away from the train, in the direction indicated by the evacuation signs. The fire ventilation system inside the tunnel ensures that smoke from the train is drawn in the opposite direction. The emergency dispatch centre is immediately notified when the fire is detected, and shortly thereafter the fire brigade arrives at the Metro station from the nearest fire station. Using specially manufactured electric trolleys, the firefighters are transported along the tracks to the train’s location, where they rescue any injured passengers and battle the fire.

Hopefully, this scenario will never become a reality, but a rapid emergency response would nonetheless play out as described here in the City Circle Line, which is currently under construction and is expected to open in 2019.

Safety measures implemented in the City Circle Line are a further development of the Copenhagen Metro’s existing safety system, which was the first of its kind in Denmark.

– Fire and evacuation were an important premise from the very beginning of the project planning phase. We had no guidelines for safety in a Danish metro system, so our ambition was to ensure that it was just as safe as in other modern European metros, recalls Arne Steen Jacobsen, a senior consultant of Copenhagen Metro.

Jet fans and emergency stairways safeguard existing Metro lines
To achieve this, Danish authorities took into account existing foreign and international safety standards – particularly, the German BOStrab regulations (in German: Verordnungüber den Bau und Betrieb der Straßenbahnen) and the American NFPA 130 fire safety norm – which ultimately formed the basis of the Copenhagen Metro set of safety regulations.

– NFPA 130 states that passengers must be able to reach safety in a maximum of six minutes, which means that they are safe from both heat and smoke generation. That is why, if able, the train runs to a station before stopping to ensure optimal evacuation and extinguishing conditions. If the train is forced to stop in the tunnel, large jet fans have been installed to blow out heat and smoke. All tunnels are also equipped with emergency walkways with battery-powered emergency lighting and signs that point to the nearest station or emergency stairway, explains Lars Frisk, Rambøll’s chief risk and safety consultant.

Between stations, an emergency stairway with steps and elevators has been constructed to lead passengers to the surface level. This means that passengers never have to walk more than 600 metres to an emergency stairway or a station, and the stairway itself can also be used by emergency response teams to reach the tunnels. The emergency response teams, for their part, train for all imaginable scenarios.

– There are 12 emergency response scenarios, and full-scale exercises are conducted so that all parts of the response team are always fully aware of what, when and how to respond in the event of an emergency, Frisk says.

A high level of safety pays off
These solutions have lived up to the original ambition of implementing a high degree of safety. In the 12 years that the Metro has been in operation, there have been no notable events, and the safety measures that were originally put in place have not been modified.  As a matter of fact, the Copenhagen Metro was named the world’s best in 2008 due to, among other qualities, its high safety standards. These same technical solutions have since been further developed for the City Circle Line.

– Today, we the emergency response teams and Danish Transport Authority, which is the acting authority in the area, have a good amount of experience with safety in the Metro, and we’ve used our experiences to modify the safety measures for the City Circle Line, Jacobsen explains.

For example, only three emergency stairways have been built along the entire line. This means that if the train comes to stop in the tunnel, the passengers will instead have to walk to the nearest station and be evacuated from there. In some situations, this might entail having to walk up to 1,200 metres.

– With the ventilation system, passengers who might have to walk to the nearest station will be kept safe. However, with fewer stairways, response times can also be longer. To compensate for this, the emergency dispatch centre is contacted directly, whereas the alarm system in the existing lines initially notifies the Metro’s control centre, says Jacobsen.

– Copenhagen Metro is also purchasing closed-circuit breathing apparatuses (a breathing apparatus that is not dependent on the surrounding atmosphere, ed.) for a number of fire stations, so that firefighters stationed near the Metro all have the equipment needed for an emergency response situation. The fire-extinguishing equipment is located at the platform level at the Metro stations, so that they are accessible. The stations will also have electric trolleys that can transport emergency response teams and equipment to the site of an accident. Finally, the entire line has a water supply with constant pressure in all tunnels. All things considered, then, the response time of the emergency response staff has not increased when compared to the existing Metro lines.

15 fewer construction sites in the city centre
The new City Circle Line trains will also feature an upgrade in fire safety technology. More stringent material requirements have been put in place with respect to flammability and smoke generation, and the trains send live video feeds to the Metro control centre. The trains are furthermore fitted with sprinkler systems that can keep a fire from spreading and make it possible to remain inside the train until the emergency response team reaches any passengers who might not be able to evacuate on their own. Measures have also been adopted to ensure that no more than two trains at a time are present in the tunnel section, which means that one train can travel from one station to the next if another train is already in the tunnel, and the train ahead has not yet left the next station.

– All in all, what we have here is the further development of safety measures already found in the existing Metro lines. The result is a high degree of safety combined with reduced costs due to fewer emergency stairways. At least equally as important, though, is the fact that the overall solutions minimises the inconveniences associated with metro construction.  Just imagine what 15 extra construction sites in Copenhagen’s city centre would mean for inhabitants and traffic in the area, Jacobsen concludes.

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 Copenhagen Metro
The initial step was already taken in 1992, when the Danish Parliament decided that Copenhagen needed a ‘light rail system.’ Construction on the Ørestad elevated railway began in 1996, and by the next year the drilling machines began working on the Copenhagen underground. On 19 October 2002, the first Metro section began operating between the neighbourhoods of Nørreport and Vestamager, and the section from Nørreport to Vanløse became operational in 2003. The third section, which provides service to Kastrup Airport, opened in 2007. In 2013, the Copenhagen Metro transported some 55 million passengers.

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The City Circle Line
The next stage in Metro expansion is the construction of the City Circle Line, which will consist of 17 stations in the central Copenhagen area. The planning phase began in 2002, construction started in 2011, and the line is expected to open in July of 2019. The project’s budget is DKK 23.5 billion. A total of 15.5 km of track will be laid, and around 3 million tonnes of earth will be excavated. The total number of passengers for all Copenhagen Metro lines is expected to reach 130 million per year by 2025.

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Seagulls won’t stop the Metro in the future
To protect passengers from being hit by trains, all underground stations are fitted with doors to the tunnel that only open when a train is stopped at the station. At aboveground stations, the tracks are monitored by a laser system that stops the trains if they detect foreign objects on the tracks. This has, however, led to a number of unintentional service stoppages, as birds have been known to land on the rails, and the wind sometimes blows a stray newspaper into the protected area to trigger the alarm. To correct this problem, aboveground stations will be fitted with doors in the future, as seen in the underground model.