A tunneller stands on the cutterhead of Lovat TBM Helen as the machine broke through on the $6m Holland Park tunnelling project in London, UK, last autumn.
Contractor Murphy & Sons started excavating the 1.2km long, 2.9m diamter water main tunnel for client Thames Water in May 1999.
Excavation was carried out at depths of 20-50m, with TBM progress reaching 25m/dy. The tunnel has been lined with precast concrete segments.
