Design for Chiltern Tunnel northern portals revealed
IMAGES have been released showing the intended look of the Chiltern Tunnel’s northern portals.
Trains will enter and leave the 10-mile tunnel, which is the longest on the HS2 route, at up to 200 miles per hour. To avoid sudden changes in air pressure and the resulting noise, perforated concrete hoods will cover the tracks beyond the portals.
Set low into the landscape between Great Missenden and South Heath in Buckinghamshire, they will only be visible from a footbridge over the railway.
The enclosed areas, which will consist of textured concrete with smooth tops, will differ from each other to allow for pressure variations. For the southbound line (on which trains will enter the tunnel), it will be 220 metres long. The northbound length (for trains leaving the tunnel) will be 135 metres.
Views are being sought by
HS2 for the final design of a single-storey building to house mechanical and electrical equipment, which will be alongside the portals.