HS2 reveals finals designs for the Amersham vent shaft headhouse
HS2 today revealed the design for the Amersham vent shaft headhouse – one of five structures that will be built to provide ventilation and emergency access to the high-speed rail line’s 10 mile-long Chiltern tunnel.
Set in the middle of a road junction just outside the town, the circular single-storey building will be surrounded by a spiral shaped weathered steel wall designed to echo the shape of the site and the natural tones of the surrounding landscape.
Robust and durable, weathered steel fades naturally over time to a dark brown colour. In order to let light through, the upper parts of the wall will be lightly perforated with a pattern inspired by woodland foliage.
On top of the building, a crown of aluminium fins will help disguise the shape of the building and soften views when viewed from further away.
Below ground level, a 18 metre deep ventilation shaft will reach down to the twin tunnels below, with fans and other equipment designed to regulate air quality and temperature, remove smoke in the event of a fire and provide access for the emergency services.
HS2 engaged with the Chilterns AONB Review Group and Buckinghamshire Council during the development of the designs and this week launched an online virtual engagement site to gather views from the local community.
Kay Hughes, HS2 Ltd’s Design Director said:
“The reveal of the latest designs for the Amersham vent shaft and headhouse is an important milestone for the project.
"Inspired by the location and the form of the shaft beneath, the headhouse will be one of the few parts of the Chiltern tunnel visible to residents living nearby so it was important that we get the design right. Align and their design partners have put an incredible amount of work into these proposals and I hope the design will be welcomed by the local community.”
The plans have been drawn up by HS2 Ltd’s main works contractor Align JV – a team made up of Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick - working with its design partners Jacobs and Ingerop-Rendel, architects Grimshaw and landscape designers, LDA Design.