With the last breakthrough, excavation of the Sant’Ambrogio Tunnel, one of the three tunnels under construction as part of the doubling of the Cefalù/Ogliastrillo – Castelbuono railway section on the Palermo – Messina line, was completed on 20 December. A contract was awarded by RFI to Toto Costruzioni Generali under the Project Management of Italferr.
The work, which extends for about 4 kilometres, connects the municipal territory of Cefalù with that of Pollina and is designed to house the double track of the new high-speed railway line. With a total length of 12.3 kilometres and almost entirely underground, the track runs completely on a variant to the old railway line.
The excavation of the tunnel, which is approximately 10.5 metres in diameter, was carried out with mechanical demolition equipment by highly specialised personnel. The two excavation sides joined at a midsection opening with the subsequent demolition of two diaphragms.
The new railway project, which includes tunnel works for a total of more than 17 kilometres, includes, in addition to the S. Ambrogio single-tube tunnel excavation, the mechanised excavation of a second twin-tube tunnel for a total extension of more than 13 km. Unlike the S. Ambrogio, this further tunnel, named Cefalù, is excavated with the 10-metre-diameter ‘Margherita’ Tunnel Boring Machine (TBM), which allows the tunnel to be lined at every advance.
The completion of the Ogliastrillo – Castelbuono section as an extension of the Palermo – Punta Raisi line (already in service) will make it possible to achieve a significant improvement in the efficiency of the transport system related to Palermo’s railway node, as well as the strengthening of the direct connection of the tourist hub of Cefalù with the Punta Raisi airport.