The Project

21 September 2023

Journey in TBM Beyond the Colosseum

Journey in TBM Beyond the Colosseum

The operational section of Line C of the Rome Metro extends from the Monte Compatri/Pantano terminus to the San Giovanni Station, covering a distance of approximately 19 km and comprising 22 stations, half of which are located along the 8.5 km of tracks on the surface. Approaching Rome, near the Giardinetti station, the operational section continues in tunnels with 11 underground stations. Currently, the train frequency is 5 trains per hour (one train every 12 minutes) in each direction and can increase to 15 trains per hour (one train every 4 minutes) with the opening of the “Via Sannio” reversing loop, provided that a suitably sized fleet of rolling stock is available, which is not currently the case.

The current operating schedule includes the operation of 91 pairs of trains per day from Sunday to Thursday (05:30-23:30) and 101 pairs of trains per day on Friday and Saturday evenings (05:30-01:30).

The construction of Line C’s section T3 from San Giovanni (excluding San Giovanni) to Fori Imperiali began on March 21, 2013. It covers a distance of 3.6 km and includes 2 stations (Amba Aradam/Ipponio and Fori Imperiali/Colosseo) and 2 ventilation shafts (3.3 “Via Sannio” and 3.2 “Piazza Celimontana”) which will also serve as reversing points for trains: in the first case with the terminus at San Giovanni and in the second case when the terminus is Fori Imperiali. The ongoing project also envisions the extension of the tunnels beyond the Fori Imperiali/Colosseo station for approximately 500 meters.

On July 22, 2010, the Interministerial Committee for Economic Planning approved the final project and funding for the T3 Colosseo-San Giovanni section. It concurrently took note of the findings of the investigation conducted by the Ministry of Infrastructure and Transport, particularly emphasizing “the aggregation of the Venezia station to the T2 section due to the prolongation of archaeological excavations in the area of Piazza Venezia, the need to create a single shaft for connection with the future Line D, as well as the need to establish the second connection with existing lines, especially with Line B at Colosseo.”

Furthermore, considering the proximity between the Fori Imperiali and Venezia stations, it was decided not to construct an interstation shaft, as it was deemed unnecessary. This decision was also reflected in subsequent legislation with the approval of the Ministerial Decree on October 21, 2015, regarding the “Approval of the technical fire prevention regulation for the design, construction, and operation of subways” which stipulates the presence of at least one emergency access point in subways only for tunnels longer than 900 meters.

At the time of the approval of the T3 section, there was no doubt about the subsequent T2 section from Clodio/Mazzini to Venezia, nor about the Venezia station, where it was initially proposed to extract the two TBMs used for excavating the T3 section or to maintain them for further use towards Clodio/Mazzini.

Excavation of the new stations of Line C and the safeguarding of buildings and monuments

As it crosses the historic center of Rome, Metro Line C doesn’t just travel through urban space but also through time. A full agreement between the consortium of construction companies, the Municipality, and the Special Superintendency for Archaeology, Fine Arts, and Landscape of Rome has allowed for a complex plan of analysis, study, data processing, monitoring, and preservation to ensure the protection of millennia that underlie the structure of a city that continues to grow. Work on the section that stretches from the eastern quadrant of the city to its northwestern corner began in 2006, and in 2013, construction sites for two very “sensitive” stations, Amba Aradam and Fori Imperiali, were opened.

These four kilometers are saturated with history and artifacts, both below and above ground. Interactions with archaeological layers mainly concern the construction of stations and ventilation shafts because the tunnels always run below the archaeological strata, typically around 10-12 meters below street level.