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Visualisation of proposed design for Chesham Road intervention shaft
Visualisation of proposed design for Chesham Road intervention shaft

Chesham Road intervention shaft

The Chesham Road intervention shaft is one of five shafts being constructed as part of the Chiltern tunnel.  The 10 mile long Chiltern tunnel comprises four ventilation shafts (at Chalfont St Peter, Chalfont St Giles, Amersham and Little Missenden) to regulate airflow, and the Chesham Road intervention shaft.  Each of the shafts have shaft “headhouses”, which house electrical equipment.

The intervention shaft at Chesham Road, located off the B485 at Hyde End, near Gt Missenden, will provide access for emergency services.

Chesham Road intervention shaft design engagement

We have published the proposed design for the Chesham Road intervention shaft headhouse, landscape and our construction plans.

We are currently asking for your feedback to help shape our final plans. We would like your views and ideas on the following topics:

  • Landscape design
  • Ecology
  • Design of the intervention shaft and headhouse
  • Construction

For more information, please view or download our Chesham Road intervention shaft information boards August 2021.

Please also complete our Chesham Road intervention shaft online questionnaire.  The closing date for all submissions is Sunday, 19 September, 2021.

Join our online webinars

These online “webinars” have been set up to give the local community the opportunity to hear from the team designing and building the railway in your area.

During the sessions we will discuss:

  • our approach to the proposed design for the intervention shaft headhouse
  • our approach to landscape design and ecology at the site
  • our traffic management measures and the construction method

Our team of experts will also be available to answer any questions you may have during the event.

The events are being held on two dates. Please select which date to you would like to attend when registering.

Tickets are available via Eventbrite for the events on the following dates:

  • Monday 6 September 18:30 to 20:00
  • Wednesday 8 September 12:30 to 14:00

These events are free of charge.

Please click here to choose your date and to reserve your place.

Please note that these are guided presentations and you must register at least two hours before the start.

Design engagement – next steps

Your comments will be considered in the next stage of review.  We will keep you informed of any design changes at future ‘you said, we did’ engagement events and webinars.

Design of the intervention shaft and headhouse

The function of the headhouse is to provide:

  • Mechanical and electrical equipment to support the operation of the railway
  • Intervention access point for emergency services

A clear set of design principles have been employed to achieve sensitivity and aesthetic consistency with surroundings. The building colour and detail has been designed to blend into the landscape, using a simple palette of materials inspired by the local agricultural buildings. Historic agricultural buildings in the surrounding area have influenced the design proposals, in particular the simple pitched roof forms and horizontal cladding. The material palette will be durable and designed to age naturally over time without compromising robustness or quality. Dark, neutral colours will ensure the buildings appear recessive within their surrounding context.

Visualisation of proposed design for Chesham Road intervention shaft
Visualisation of proposed design for Chesham Road intervention shaft

The form and orientation of the buildings have been designed to reduce their scale when seen from key viewpoints. The openings within the buildings have been sized in proportion to the buildings, whilst the ridge line of the pitched roofs help to lower their apparent height. Chesham Road is one of four headhouses located on rural sites within the Chilterns. All headhouses and ancillary structures have been designed to be recessive and form part of a common family of buildings. The buildings are distinguished by the colour of painted louvres, selected to reflect the specific features of each site.

The form and position of the buildings have been designed to reduce their scale when seen from key viewpoints. The lower part of the compound and security fencing are screened from views as you walk along the public footpath by new hedging. Proposed trees frame key views through to the


We will build the intervention shaft safely, ane minimise our inpact on the local community. We will manage air quality by:

  • Regularly inspecting and monitoring site and equipment
  • Cleaning onsite roads and vehicles
  • Managing earthworks to contain dust
  • Monitoring air quality on site

We will control noise and vibration by:

  • Tackling noise at source and reviewing location of equipment
  • Screening and enclosing noisy activities

Landscape design

We have studied the site and its natural environment to help shape our landscape restoration works. We want to reflect the character of the native trees and hedgerows found in this part of the Area of Outstanding Natural Beauty to positively integrate the new building into the landscape. The landscape proposals complement the recessive approach adopted in the architecture, hedgerow and tree planting is used to screen the buildings and integrate the site into the surrounding landscape context.


The ecological design is based on the site being one of five Chiltern Tunnel shaft sites that would form ecological stepping stones through the Chiltern Hills AONB. It will significantly improve biodiversity by integrating with the existing surrounding habitats and through the creation of contextually appropriate species-rich grassland with areas of planting and basking banks further increasing the value of the habitat for wildlife.

Delivering a new tunnel beneath the Chilterns to carry high speed trains

Find out more about Chiltern tunnel