Boring is complete on the first ‘Section 2’ tunnel on the UK’s Channel Tunnel Rail Link (CTRL), following the recent breakthrough of the 8.15m diameter Herrenknecht slurry TBM on the second of two tunnels under the River Thames.
Considered one of the more critical sections of the 39km long Section 2 between St Pancras in Central London and Ebbsfleet in north Kent, engineers on US$236M Contract 320 have shaved 50 days off the scheduled time.
The Hochtief/Murphy JV constructed the 2.5km long tunnel in six months. Passing through clay, gravel, chalk and flint, the JV posted excellent advance rates, including 170m in one week.
