Works are now in full swing at Chalfont St. Peter installing the prefabricated diaphragm wall cages that will form the walls for the first tunnel vent shaft.
Produced by ArcelorMittal at their fabrication facility in Chatham Docks in Kent, the prefabricated cages are fabricated and then shipped to Chalfont St. Peter for installation by KVJV the Keller / VSL joint venture.
The headhouse building at the top of the 60 metre ventilation and emergency access shaft at Chalfont St. Peter, the first of four such buildings needed for the 10 mile tunnel, will be a single storey block, “taking its inspiration from the style of local barns and wrapped in a simple pre-weathered grey zinc roof with doors and vent openings picked out in dark bronze”.
The buildings will be surrounded by mature trees and fresh saplings to help them blend in, along with bird boxes, reptile basking banks, and a grass snake laying heap to help encourage wildlife.