Herrenknecht yesterday presented the first of two double shield TBMs for Lot H53 Pfons-Brenner on the Brenner Base Tunnel.

The consortium of Porr and Marti will deploy the 10.37m diameter TBMs to excavate 7.5m of the West Main tunnel towards Innsbruck. The €959m (US$1bn) Lot 53 is the largest construction lot in Austrian history.

The double shield machines were specified for the complex geology and long drives in hard rock. Each has a 10.37m diameter, is 183m long and weighs around 2,700 tonnes.

Transportation of the first TBM – named Wilma – from Herrenknecht’s Schwanau factory is expected to start at the end of March. The machine will then be reassembled in the assembly cavern. Tunnelling is scheduled to commence in autumn this year.

The eighth, identical double shield TBM for driving the second tunnel tube in lot H53 Pfons-Brenner is currently being built and will be delivered in spring.

Lot H53 is Porr’s second contract for the Brenner Base Tunnel. The company is also building the approximately 600m-long link between the tunnel and Innsbruck’s main railway station through the Sill Gorge with construction Lot H21. The Sill Gorge section is planned for 2024.

The 64km Brenner Base Tunnel – the longest rail tunnel in the world – is being built under the Alps to connect Italy and Austria, reducing the journey time from Fortezza to Innsbruck from 80 minutes to 25 minutes. It will be a key part of the Scandinavian-Mediterranean Corridor of the Trans-European Transport Network (TEN-T).