Once construction is complete, the seven ‘Key Design Elements’ will be the only parts of the tunnel visible to the local community.
Alongside the North Portal, which will be near South Heath in Buckinghamshire, they include the South Portal, near the M25, and headhouses above the ventilation and emergency access shafts, which are mostly designed to resemble agricultural buildings.
The design work has been completed by HS2’s main works contractor, Align JV – a team made up of Sir Robert McAlpine, Bouygues Travaux Publics, and VolkerFitzpatrick, working with its design partners Jacobs, Rendel-Ingerop and LDA Design, and its architect Grimshaw
Construction of the twin tunnels, which will stretch for 10 miles under the Chiltern hills, recently passed the halfway point, with two giant tunnelling machines currently between Amersham and Little Missenden.
The reveal of the last of the Key Design Elements for the tunnel represent a double milestone for Align who are also responsible for the Colne Valley Viaduct, meaning that they have completed their entire Detailed Design including designs for all of the Key Design Elements.