The TBM - six months to the day since it broke through the headwall at HRBT North Island - is on the move again. Mary began boring a twin eastbound towards Norfolk shortly after 17th October noon.

In early September, tunnel crews successfully lifted the fourth and final gantry out of the newly bored tunnel and onto North Island. The TBM Mary restarted boring almost 20 m (65 feet) below the road surface with only the first three gantries in place, making space for the last gantry as the machine advances. 

For further information on the project click here and us/125 for the tunnelbuilder archive and visit www.hrbtexpansion.org.  42/24.