basis of an outdated operating program from 1995. For approximately 53 km kilometers the line run in the open, usually on embankments (in the Main valley) or in cuttings. The height of the embankments is limited to 15 metres and the depth of the cuttings is limited to 20 metres (under DB Directive 836). Bridges and tunnels are built where these limits cannot be met. According to the introduction of 1997 EBA Directive Anforderungen des Katastrophenschutzes an den Bau und den Betrieb von Eisenbahntunneln ("requirements of disaster relief for the construction and operation of railway tunnels), railway tunnels that are at least 1000 metres long am are used in mixed operation of passenger trains and freight trains must be operated as two separate single-track tubes. In coordination with the Federal Government, the states, the EBA and Deutsche Bahn, a concept was developed for the high-speed line with two tracks running through single tunnels, which allows a mixed train operation to be carried out on the line. The ETCS train safety system that has been used since 1997 prohibits the operation of passenger and freight trains together as a fail-safe. According to the Federal Audit Office in 2014, it is not clear how this ban on trains meeting in tunnels should be implemented. Where necessary, measures mitigating tunnel boom are also built in the portal area. Two new traction power lines are used to supply power to the line (110 kV). The 23.3 kilometre-long southern line is to branch off at Wörlsdorf from the existing Nuremberg–Weimar line and end at the new Roth substation at the north portal of the Müß tunnel near Welchendorf in Thuringia. The 21 kilometre-long northern line leads from the new Eischleben substation to the Wolfsberg substation. Over a length of about 4.4 kilometres, the railway power line is carried through the Wipfra valley on 13 masts of a 380 kV transmission line, which runs from the Vieselbach substation to the Altenfeld substation. This eliminated the need for 15 railway power line masts. For energy supply and data transmission, moreover, there are approximately 1,200 km of cable. The 22 tunnels (ca. 40 km) are equipped with, among other things, safety lighting, electrical equipment (power supply boxes) and test equipment for the overhead line voltage. The line's technical equipment was commissioned in December 2013. Safety In an "event in the tunnel", about 700 rescue workers from all districts