THIS MONTH is due to see the handover to Roma’s Sistema di Transporti SpA of detailed engineering designs for the first 12 km section of metro Line C. Project design for the route linking the Line A interchange at San Giovanni to Torrenova, where it would meet the Cotral suburban line to Pantano, is being undertaken by a consortium of Gibb, Team Engineering and Geoconsult.

Planning for the 29 km Line C was resumed earlier this year after a nine-month suspension, and definitive project design must be completed by October to meet STA’s deadline for planning approval. Construction work is expected to start on the first phase next year or early in 2001.

The initial phase will mostly be underground, with 20 km of running tunnel to be excavated using earth-balance TBMs and NATM techniques. Stations will be a mix of NATM and deep braced excavations. As part of the design process, Gibb is using GIS-based software to predict settlement and prepare mitigation strategies against building damage.