data acquisition (SCADA), platform-edge doors, and the signalling system. The route's tunnels were constructed by Seli Tunneling Denmark ApS, subsidiary of Seli SPA, and subsequently acquired by Salini Impregilo. Consultancy services regarding rolling stock and the automated train depot were sourced from Ramboll and WS Atkins. The line incorporates various live data feeds for the purpose of highlighting hazards and recording any accidents using project compliance software ComplyPro, produced by software company Comply Serve. Construction During 2013, boring of a pair of 15.5km parallel tunnels commenced using a total of four tunnel boring machines (TBMs) named Eva, Minerva, Nora, and Tria. These tunnels were bored with an inner diameter of 4.9 meters and at a depth varying between 35 meters and 20 meters. The tunnels have been built by Seli Tunneling Denmark, that also manufactured two out of four machines in Denmark, at a facility especially prepared for the task. The interior walls of the tunnel have been coated with concrete and multiple emergency shafts have been installed for the purpose of providing ventilation and maintenance access. The extracted earth produced by the construction effort was routinely used to fill the Nordhavn reclamation project in Øresund. During the construction process, it was commonplace for geological sensors to be deployed in the general vicinity to monitor ground movements for the purpose of protecting buildings and other structures in the city. During 2014, the line's control and maintenance centre buildings were completed (at Vasbygade, ). That same year, various other works were finished, including the walls around all of the stations, and three of the shaft structures. Reportedly, the final construction activity was centered upon the refurbishment of the surrounding areas around the new stations. Stations and route Overview The 15.5 km City Circle Line serves 17 stations. It crosses the M1 and M2 lines at Kongens Nytorv and Frederiksberg stations, and suburban train services at København H, Østerport and Nørrebro. It extend the Metro network to the Nørrebro and Østerbro areas and København H (the Copenhagen central station). The City Circle Line services to many of the major areas of Copenhagen, including the Danish Parliament, the Central Station, City Hall, and multiple stations of the S-train and existing metro stops. Access to the region and commuter heavy rail network is also deliberately provision for at several places along its route; furthermore, a twin-track line provides a connection between the City Circle