Latest from Tunnels and Tunnelling


Herrenknecht TBM ‘Ellen’ holes through on Line 15 (South)
19 April, 2021 Tunnelling has been completed on Line 15 (South) of the Grand Paris Express subway expansion following the breakthrough on April 6 of TBM Ellen at Arcueil-Cachan station.
  • Harding Prize yields another young worthy winner
    Presentations from three promising young tunnel engineers kept an audience fascinated for the best part of two hours yesterday evening during the online Harding Prize final organised by the British Tunnelling Society Young Members (BTSYM). So, the winner of the 2021 Harding Prize is…
  • Breakthrough on Hudson Tunnel
    In what must be seen as a green light for the construction of the long-awaited tunnel beneath the Hudson River in New York, the Biden administration has given the go-ahead for a June 2021 completion of the Final Environmental Impact Statement (FEIS) and Record of Decision for the project.
  • Delhi Metro inviting bids for Phase 4 tunnelling works
    Delhi Metro Rail Corp (DMRC) is inviting bids from parties in eligible countries for the design and construction of twin tunnels by shield TBM on the 20.2km Aerocity to Tughlakabad Corridor of the Delhi Metro Rapid Transit (DMRT) Project Phase 4.


Collaboration, communication and competence updated
25 March, 2021 The following article by Bob Ibell, founder and director of London Bridge Associates, is based on a past Harding Lecture and has been updated by the author in celebration of the BTS 50th Anniversary
  • National grids
    Utility grid projects bring a variety of tunnelling challenges. Report by Patrick Reynolds
  • Review of ITA working group 12 PSCL linings
    Martin Knights, Independent Consulting Engineer, former ITA President and Chair of London Bridge Associates reviews the new ITA Working Group 12: Permanent Sprayed Concrete Linings guidelines
  • Grouting for ground improvement
    Grouting in underground projects refers to the injection of pumpable materials into soil or rock formations to change their physical characteristics. It is one of the most used ground improvement techniques for underground projects and tunnelling applications.
  • Brexit and its effect on standards
    Donald Lamont, a member of T&T’s Editorial Advisory Board and a member of ‘CEN/TC151 Construction machinery – safety’ looks at the impact of Brexit on machinery standards in the UK