Skip to main page content
Thame Valley Viaduct, artist's impression
Artist's impression of the Thame Valley Viaduct.

Thame Valley Viaduct

The Thame Valley Viaduct is located within the Northern Vale and crosses the low-lying Thame Valley, approximately 350 metres to the south-west of the Rabans Lane Industrial Area on the western periphery of Aylesbury. The viaduct is partially visible from Public Rights of Way to the south-west. 

Viaduct construction

We’ve begun assembling the UK’s first major railway viaduct to be entirely manufactured off-site, in a move that represents a major step forward for viaduct design and promises to boost safety and efficiency on site.

Unlike more traditional viaduct designs, every major element of the 880m long Thame Valley Viaduct is being manufactured in a factory before being slotted together on site like a giant Lego set, cutting its carbon footprint by around a third.

Ferrovial Construction and BAM Nuttall are working with their design partner, ASC (a joint venture between Arcadis Setec and COWI) and specialist architects Moxon.

Off-site manufacturing

The structure of the viaduct has been simplified, with every major element being made off-site, cutting the amount of embedded carbon. In a major step forward for viaduct design in the UK, the design features two wide ‘box girder’ beams per span instead of eight smaller beams, simplifying and speeding up assembly.

Unlike more traditional viaduct designs, every major element of the 880m long Thame Valley Viaduct will be manufactured in a factory before being slotted together on site like a giant Lego set.

The new lighter-weight structure is expected to save 19,000 tonnes of embedded carbon in comparison to the previous design, cutting its carbon footprint by around a third.

Traditionally, viaduct beams are secured together above each of the piers with a concrete diaphragm that is cast in situ. The larger pre-cast beams that will be used at Thame Valley can be secured directly to one another, removing the need for the diaphragm, improving durability and reliability, saving time, cutting cost and improving safety.

As well as cutting embedded carbon in terms of materials, this approach requires less lorries to deliver material to site, cuts waste and will reduce disruption for the community during construction.

Applying lessons from the construction of recent high-speed rail projects in Spain, the design team opted for a simple structural solution with two 25m long hollow beams per span, which cuts the amount of carbon-intensive concrete and steel, while simplifying work on site.

These enormous 97 tonne beams – and the 42 tonnes piers that support them – are being manufactured at PACADAR UK’s factory on the Isle of Grain, which also produces tunnel wall segments for HS2’s London tunnels.

Around the viaduct, the river floodplain will be enhanced to boost biodiversity and help better manage flood water. This will include replacing existing arable land with new wildlife-rich areas of woodland and wetland.

Off-site manufacturing also helps spread contract opportunities and supply chain jobs across the UK, with 200 people – including apprentices and graduate engineers from nearby Universities – employed on the Isle of Grain, delivering the viaduct and also making tunnel segments for HS2’s London tunnels.

Viaduct design

Thame Valley Viaduct is considered a Key Design Element (KDE) because it is close to a local residential area and because of the community interest around the River Thame corridor. KDEs are structures along the route that are recognised by HS2 to be important. This could be due to their size, their proximity to stakeholders or their location within sensitive areas.

The final designs for the Thame Valley Viaduct include pioneering pre-fabricated construction methods that will see the 880m-long structure slotted together like a giant Lego set, cutting its carbon footprint by an estimated 33%.

Crossing the flood plain of the River Thame, just outside Aylesbury, the viaduct will carry HS2 trains at speeds of up to 360km/h between London, Birmingham and the North.

Set low into the landscape with a simple and consistent profile, the underside of the viaduct will be just 3m above the ground, with thirty-six 25m-long spans crossing the river and surrounding wetlands. The piers will be extended to almost connect with the parapet edge, helping to enhance the appearance of a light and narrow structure.

Explore the In Your Area Map

Archaeology

Archaeology

The map displays information about our archaeological sites along the route.

Green Corridor

Green Corridor

The map displays information about our environmental sites along the route.

HS2 funded projects

HS2 funded projects

The map displays information about our funded community and business projects along the route.

Keeping you informed about our works

Stay informed about the works

Stay informed about the works

Find information about HS2 works and activities taking place in your area.

Managing impacts of construction

Managing impacts of construction

Find out information about how we manage construction impacts.

Construction look-ahead

Construction look-ahead

Read our three-month lookahead for associated work in Buckinghamshire and Oxfordshire.

Find out what HS2 means for Buckinghamshire and Oxfordshire

This section provides you with information about HS2 works and developments in your area.

Find out more

Further information

  • Join our mailing list

    To receive email updates about the HS2 project, including how it’s being planned and constructed

    Sign up here

  • Contact us

    If you contact the Helpdesk, our Community Engagement Advisors will try to answer your questions immediately.

    Contact us