HS2 launches its second TBM under the M25 motorway

The second of two tunnel boring machines has been launched from just inside the M25 to dig tunnels for HS2 under the Chilterns.
The second tunnel boring machine (TBM), called Cecilia after Cecilia Payne-Gaposchkin, an astronomer, started a month after the first, called Florence, named after Florence Nightingale. Despite starting second, Cecila will run slightly faster, aided by geological data fed back from Florence, meaning that both machines are due to breakthrough at the end of the tunnels at