Case story - Danfoss SEM-SAFE Istanbul metro line in Turkey

Case story - Danfoss SEM-SAFE Istanbul metro line in TurkeyCase story | SEM-SAFE® high-pressure water mist system in Turkish metro tunnel Istanbul metro line achieves fire protection in challenging conditions with a Danfoss SEM-SAFE® solution Danfoss Fire Safety A/S Serving one of Europe’s busiest airports Since opening in 2019, Istanbul Airport has evolved into one of Europe’s busiest airports, serving 64.3 million passengers in 2022. Efficient public transportation is therefore very important, and accordingly a new metro line was opened in 2023. The new M11 line connects the airport with central Istanbul and has a capacity of 800,000 travellers daily. Soil conditions prevent escape routes Passenger safety is critical in public transportation, but the developers hit a problem when building the M11. Metro systems usually feature escape tunnels or shafts allowing passengers to evacuate in the event of a fire, but because the soil in the region is a natural source of underground water, it was not possible to construct cross-passages. An alternative procedure was found: in the event of a fire, a fixed fire suppression system will be activated to control it, after which passengers can leave the coaches. Such a system must be efficient towards fires and harmless towards humans, and it must be compact and economical. All these criteria were met when the developers selected a Danfoss SEM-SAFE® high-pressure water mist system – the world’s first water mist system to be installed in a metro. Efficient fire protection A high-pressure water mist system works by releasing a water mist that simultaneously lowers the temperature and removes oxygen, suppressing the fire. The SEM-SAFE® solution on the M11 line covers two tunnel segments with two tubes each. The first segment is 3,083 meters long and has 3,150 open nozzles connected by 4-inch water pipes divided into sections using 150 section valves. The second segment features 1,596 nozzles and 76 section valves. In case of a fire, the Danfoss pumps start up and rapidly provide water for the affected areas through the section valves. The water is forced through nozzles at high-pressure to create a fine mist. To ensure efficient fire protection and prevent the fire from propagating quickly, the system is activated in the affected zone plus the adjacent zone. The water mist is completely harmless to staff and passengers on the metro. www.semsafe.danfoss.comPage 2