The Pistoia–Bologna railway is an Italian railway connecting Bologna to Pistoia and was the first line through the Apennines between Tuscany and Emilia-Romagna. It is also known in Italian as the Ferrovia Porrettana (Porrettana Railway, named after the spa town of Porretta Terme) or the Transappenninica ("trans-Apennines"). It was officially called the Strada ferrata dell'Italia Centrale (Central Italy Railway) and was officially inaugurated by King Victor Emmanuel II in 1864. At the time it was an enormous engineering project with its 47 tunnels and 35 bridges and viaducts, with a total length of 99 km. The most difficult section was the 14 km stretch between Pracchia and Pistoia, which had a drop of 500 metres. The project was put in the charge of the French engineer Jean Louis Protche who solved the problem by designing a spiral tunnel between Piteccio and Corbezzi. This solution was then used for the construction of the Gotthard Tunnel. In Porretta Terme a square was dedicated to Protche and Victor Emmanuel II, who opened the line. It was electrified on the three-phase system (3,700 V at 16.7 Hz) in 1927 and re-electrified with 3,000 V DC in 1934. Features Length: 99 km single track. Grades: Pistoia–Pracchia section: average gradient of 22 per thousand, up 26 per thousand at Valdibrana station; Pracchia–Porretta section: average gradient of 17 per thousand, up to 25 per thousand between Ponte della Venturina and Molino del Pallone; Porretta–Bologna section: average gradient of 5 per thousand, up to 11 per thousand. Tunnels: 48 totaling 18.480 kilometres: Vaioni tunnel, 533 metres, curve radius of 350 m, Piteccio-Vignacce-Fabbian tunnel complex, 1,708 m radius curves 300 m; Apennine tunnel 2,727 m with a gradient of 24.43 per thousand; Casale tunnel 2,622 m Riola tunnel 1,834 m. Bridges and viaducts: 64 with a total length of 2.240 km Level crossings: 29 Stations: 13 attended and 3 unattended Electric traction, 3,000 V DC. Trains Stadler FLIRT (ETR 350) Stadler FLIRT (Fast Light Intercity and Regional Train; German: Flinker Leichter Intercity- und Regional-Triebzug) is a passenger multiple unit trainset made by Stadler Rail of Switzerland. The baseline design of FLIRT is an electric multiple unit articulated trainset that can come in units of two to twelve cars with two to six motorized axles. The maximum speed is 200 km/h (120 mph). Standard floor height is 57 cm (22.4 in), but 78 cm (30.7 in) high floors are also available for platform heights of 76 cm (29.9 in). The FLIRT train was originally developed for the Swiss Federal Railways and was first delivered in 2004. The trains quickly became a success and were ordered by operators in Algeria, Azerbaijan, Belarus, the Czech Republic, Estonia, Finland, Germany, Hungary, Italy, the Netherlands, Norway, Poland, Serbia, Sweden, Switzerland, the United Kingdom, the United States, and, most recently (2018), Canada. As of 18 April 2018, more than 1,500 units have been sold. Other than electric (EMU), the FLIRT is produced in diesel-electric version (DEMU), and recently also as electro-diesel (bi-mode/BMU), first ordered by the Aosta Valley region in Italy (BTR.813), and then by Greater Anglia (British Rail Class 755), Norske Tog, and Wales & Borders ("tri-mode" version: diesel/overhead electric/battery). Diesel, bi-mode electro-diesel, hybrid diesel-battery, or battery versions are essentially baseline design with an additional one-third length non-passenger car inserted in the trainset – called a PowerPack car – which contains the electricity generating and storage components, such as diesel engines and batteries, that provide electricity to the train to run "off-wire". It has a gangway through the centre to allow passengers to pass Pistoia - Porretta Terme - Bologna
