"The feasibility project of the sub-port tunnel crossing the city of Genoa extends for a length of approximately 4.2 km, of which 3.49 km in the tunnel, consisting of two separate main pipes, with a diameter of 15, 4 meters each, made by mechanized excavation by TBM. The section below the seabed will cover 400 meters at the port basin, between Calata alla Sanità and Calata Gadda, with a minimum ground cover of 13 meters and a hydraulic head of 33 meters. "

https://www.primocanale.it/porto-e-trasporti/15657-tunnel-subportuale-inchiesta-regione.html