More than 20 tunnel-boring machines have been put to work so far to build lines 15, 16, 17 and 18 as part of a Grand Paris Express metro expansion in the French capital. Among the latest, a 9.87-m-dia earth pressure balance tunnel-boring machine (TBM), is due to be launched this month by Italy-based Webuild S.p.A.

By the end of last month, Société du Grand Paris, responsible for oversight of Paris’ public transit network, had awarded more than $8 billion in civil engineering contracts on the four new lines. The agency is scheduled to add nearly 180 km to the Paris system by 2030.

The whole program, including upgrades to existing sections, is budgeted at $42.6 billion, including $8.4 billion in contingencies.

At $2.2 billion, the largest contract, including 19.3 km of tunnels, went to a consortium led by locally based Eiffage Génie Civil S.A. The six-year contract was awarded in February 2018.

Another big winner is Germany's Herrencknecht A.G., which by 2019 had won orders for 19 of the Paris TBMs, including 16 EPBs.

As part of Webuild’s $860-million contract, its machine will drive 5.3 km of the northern line 16 between Bel-Air à Chelles and Mare au Chanvre à Sevran. The contract includes 11.1 km of tunnel, four stations and 11 ventilation shafts. Webuild is the only non French contractor to win major civil engineering work on the program.