Track Dualling on Milan-Lecco Rail LineThe dualling of the Carnate Usmate-Airuno section on the Milan-Lecco rail line will improve the suburban train service provided by Line S8 from Milan via Carnate to Lecco. About 72 trains will travel on the future line compared to 56 at the moment, as well as 36 direct trains daily (one every hour) from Milan to Valtellina valley and return (instead of 20 today). In addition, the dual track will create the conditions to provide a new service to Malpensa airport on the Carnate-Seregno-Saronno corridor. The overall cost amounts to EUR187 million, whereof EUR26 million financed by the region of Lombardy. The second track built between Carnate and Airuno is 12.3 km long and mostly follows the existing track, moving away from it at only two different spots where two tunnels are being built to reduce as much as possible the impact on the environment and save the valuable landscape in this area of the Brianza valley. They are the 260 m Roncaglia tunnel, south of Olgiate, and the 2,155 m Beverate tunnel, near Airuno. The objective of the Beverate tunnel is also to make journeys faster and to overcome the difficult crossing of the Brivio municipality. The Beverate tunnel, value at around EUR27 million, is located between chainages 21+768 and 23+970 and bypasses the existing path. The route crosses the terriroties of Olgiate Molgora and Airuno municipalities and crosses the hillock where are erected the Monastirolo hamlet in Olgiate Molgora and the Airuno hamlet in Airuno. North portal The twin-track single bored tunnel features a circular cross-section with invert and a 6.20 to 7.10 excavated radius, that varies according to the four types of cross-sections. The final internal radius to the crown is 5.30 m. Rete Ferroviaria Italiana (RFI) commissioned its construction to the Rome-based contractor Todini. Click it/90. Visit www.todini.itThe tunnel crosses sedimentary formations made up of turbiditic and flysch materials, characterised by a predominantly arenaceous and/or silty and pelitic lithology. There are tectonic fractures where oozing and water ingress of variable intensity had to be tackled or is expected.Crews have excavated so far 1,922 metres from the north portal and six metres from the south. The drill-and-blast method was used from the north, drilling 100 blast holes of 4.9 m in length with explosive charge of 450 kg. At the south drive, a jackhammer is used. The machinery used includes two micropiling drill rigs and one diaphragm walling system supplied by Casagrande, a Manitou 1432 lift platform, a Puntel piling rig, a Tamrock jumbo (only for advance from the north portal), a Caterpillar CAT 966 wheeled loader, three dumpers (1 Caterpillar and 2 Astra), a Caterpillar CAT 330B excavator with hammer, a Fiat Hitachi 215 excavator equipped with bucket, one to three Mercedes concrete mixers, two CIFA CSS 2 shotcrete pumps, two Tata pick-ups, a Volvo excavator equipped with bucket and four to eight four-axle Iveco tipper trucks. Visit www.casagrandegroup.com, www.manitou.com, www.miningandconstruction.sandvik.com, www.cat.com, www.astraspa.com, www.hitachi-c-m.com, www.mercedes-benz.it/industriali/default.htm, www.cifa.com, www.volvo.com/group/ and www.iveco.comAt the north drive portal, a micropile wall has been built. The bored tunnel has been previously supported with umbrella vaults of steel tubes and valved glass fibre nails on the face. Further to each blast, steel arches and welded mesh have been installed, then shotcrete has been sprayed and the steel arches have been fastened with bolts.At the south end, the bottom in open trench and false tunnel requested to build a concrete tap and to use jet grouting to create columns of fortified or strengthened ground, diaphragm walls and struts and full round waterproofing. Support of the bored tunnel involves forepoling, jet grouting columns around the tunnel circumference and under the benches, strengthening of the face with glass-fibre reinforced grouting and glass-fibre rods, active and passive drainage, steel arches, shotcreting, bolting of the benches, shotcreting of the face and full round waterproofing. To view a table summarizing the different sections, the methods and machinery used, click here. South portal During tunnelling, water ingress has been encountered, higher than expected by the executive project. It has been therefore necessary to study and implement adequate technical solutions and increase the capacity of the decantation and sludge dewatering plant to treat waters polluted by the excavation works.An alternative project has been submitted for the south portal stretch, which predominantly involves the reinforcement techniques in the bored tunnel throughout the digging works to guarantee a better protection to the overlying building along the tunnel axis. The spoil is mucked away by three dumptrucks, one Caterpillar and two Astras. 39/07.