The Casalnuovo Tunnel, one of the most complex engineering works on the high-speed Naples-Bari railway line, has been completed.
Webuild used hyperbaric tunnelling to excavate 650m of the 3.3km-long tunnel on the Naples-Cancello lot. It is the first time the hyperbaric method has been used in Italy.
The technique uses pressurised air to keep the groundwater away from the work areas so excavation can be undertaken in a dry environment, preventing the stratum from coming into contact with cement mixes and chemical additives. All the equipment used was electrically powered.
The tunnel was hermetically sealed to allow works to be carried out. It was also divided into watertight compartments, and workers entered by passing through a compensation chamber, where pressure was gradually raised to allow them to get used to the hyperbaric environment.
Webuild, which built the tunnel on behalf of Rete Ferroviaria Italiana, said the complexity of the excavation required efficient logistics and an innovative and sustainable system.
“Specific health protocols, procedures and monitoring systems were also used to ensure workers’ safety and health during excavations,” the company said.
More than 10km of tracks have been laid on the Naples-Cancello section of the new Naples-Bari line and installation is due to be completed by the end of the summer. The Naples-Cancello and Cancello-Frasso sections will open at the end of this year, reducing journey times between Naples and Bari from four hours to two hours and 40 minutes, and without the need for passengers to change trains.
The opening of the Naples-Cancello section will also allow Naples-Bari trains next year to reach the Napoli Afragola station which, when the line is fully operational, will be a strategic hub to connect the north and south of Italy and regional and national transport systems.
The new Acerra and Casalnuovo stations will also begin to be used, which will allow greater access to the high-speed railway system for a large part of the Naples metropolitan area.
In total, the Naples-Bari high-speed line will be 145km long, with 15 tunnels, 25 viaducts and 20 stations. Once the entire route is open, it will be possible to connect Naples to Bari in two hours; Rome and Bari in three hours; and Lecce and Taranto towards Rome in four hours.
The line is part of the Scandinavian-Mediterranean Corridor of the TEN-T network, and a strategic axis to connect the south of Italy to the north of Italy, and then to Europe.
