Lonato rail link TBM set for assembly in Italy 18 Jun 2020

A 10.03m diameter EPBM manufactured by CREG in China for the main contractor Cepav Due has progressed through its factory testing programme and is on site ready for assembly in Italy. The TBM will complete excavation of the twin tube Lonato Tunnel on the Milan to Verona high speed rail line. The JV, comprising Saipem, Pizzarotti and ICM, is main contractor for the 48km long Brescia East to Verona section of the line, after award of the Lot 2 contract by Rete Ferroviaria Italiana in 2018. Seli Overseas is hired by the JV to operate the TBM and complete the 4.75km long twin tube Lonato excavation works.

TBM on site and ready for assembly in Italy

Lot 2 of the Milan to Verona route is part of the EU (European Union) TEN-T Mediterranean high-speed rail corridor in Italy (Fig 1). Following resumption of work after Covid-19 limitations in Italy, work will get underway shortly to assemble the TBM ready for launch.

The JV ordered the EPBM through the CREG Italian agent Tunrock and the factory acceptance test took place at the CREG manufacturing plant in Zhengzhou in June 2019. It joins other CREG TBMs in the European market working on the Copenhagen and Paris Metros.

Bids for the Lonato tunnelling works were called by Cepav Due JV in late 2019 and Seli Overseas was awarded the contract in February this year. Geology along the tunnel route is glacial moraine with large boulders, which resulted in an EPBM design with a double screw and a boulder trap arrangement and a specification to withstand up to 6 bar operating pressure. The 8.8m i.d. tunnel has a segmental lining in rings of 450mm thick x 2m long.

Manufacture and factory acceptance ceremony in China

Construction of the Milan-Verona section of the TEN-T Mediterranean corridor began in the early 2000s, working progressively eastward from Milan (Fig 1). Two sections were completed in 2007 and 2016 bringing a total length of 79km of the route into operation. Lonato is the most significant tunnel on the route.

Beyond Verona to the east, the TEN-T Mediterranean corridor extends to Venice and runs onward to Budapest and farther. To the west, the corridor runs to the Lyon-Turin Mont Cenis Base Tunnel into France and on to Spain.

The wider TEN-T network will make Milan and Verona major rail hubs in northern Italy as they are located on two additional north-south high-speed corridors, the Rhine-Alpine and Scandinavian-Mediterranean routes.

Fig 1. TEN-T rail network across Europe

At the Milan interchange, the Rhine-Alpine corridor will fork off and pass through Switzerland connecting to routes through the Swiss Alps via the Ceneri and Gotthard baseline tunnels and via the Lötschberg base tunnel route. South of Milan the route terminates in Genoa.

At Verona, the Scandinavian-Mediterranean corridor extends the full length of Italy and northwards via the Brenner Base Tunnel into Austria and through Germany and on via the Fehmarn Fixed Link immersed tube tunnel to reach Denmark and on into northern Europe.

The Brenner and Lyon-Turin base tunnels are under construction, and so also is the high-speed route from Milan to Genoa on the Terzo Valico project. The Lötschberg tunnel is in operation and will see build-out construction to complete the currently incomplete parallel running tunnel to full capacity. Recently the Lötschberg tunnel suffered mud and inflows through a lining rupture as reported by TunnelTalk. The Ceneri and Gotthard tunnels are in operation and the Fehmarn Fixed Link is in the early stages of main construction.