The first of two 9.4m diameter Lovat EPBMs started boring a 6.1km long twin-tube rail tunnel on 25 June under Bologna, Italy.
The 8.3m i.d. tunnels will run from San Ruffillo to Fascio Salesiani, with connecting tunnels every 250m. It will allow high speed trains to cross Bologna, and will form an important part of Italy’s high-speed rail network.
The TBM shields are 195m long, with 4,000kW of power, a thrust of 100,000kN, and weigh 550t.
The average daily progress rate is expected to be about 11m/day through Bologna’s reputedly tricky soils, which are made up of coarse-grained (gravel-sand) and fine-grained (silt-clay) deposits.
The Necso/Salini/Ghella JV, made up of domestic contractors, is expected to take two and a half years to construct the tunnel.
The US$220M project will be managed by Italferr and completed in 2007.
