The SPS tunnel with and without shuttering

Inside the tunnel of the SPS where work on the final concrete lining is beginning. The metal structure which produces this striking photograph is the shuttering for pouring the vault. The mole had bored around half the ring in December, reaching access shaft PP4. It is here that the tunnel lining is now taking place, advancing in the opposite direction to that taken by the mole — in other words going back towards PP1. The mole itself is continuing its boring way around the ring towards the same PP1.