The double-track, twin-tube tunnel will bore through expected geology of fine sand and medium coarse sand, silt, silty clay. It will be lined with a concrete segmental lining with an OD of 10.2m and an ID of 9.3m.

A spokesperson for the manufacturer said that the TBM was designed and manufactured in nine months, is capable of active articulation and negotiating a 180m curve radius.

The contract also covers nine stations and 10 ventilation shafts. Excavation is due to begin in mid-2019 and the project should be commissioned in 2021.