Headwall

The platforms of all stations from Shepherds Bush to Liverpool Street have been lengthened from 325 ft. to 427 ft. between tunnel headwalls, to take longer trains.

HS2 Ltd has built a 17-metre-high headwall and reinforced the ground at what will become the south portal of the ten-mile Chiltern Tunnel, as part of preparations for the arrival next year of tunnel boring machines (TBMs).