Thame Valley Viaduct

Nestled into the landscape, the underside of the viaduct will be just 3m above ground. Long, even spans will cross the river and surrounding wetlands, punctuated by 35 piers cradling the deck, each extended to the parapet edge. This will enhance the appearance of a light and narrow structure, which sits in keeping with surrounding meadows and farmland.

Assembled with modular pre-cast beams, slotted together on installation, the design eliminates the need for cast in situ concrete diaphragms which saves time and material. This methodology also simplifies the cross section from eight smaller beams to two wider U beams.

The major reduction of carbon intensive materials, combined with the ambitious modular design and the off-site prefabrication of major structural elements, the design accelerates assembly time and cuts projected embodied carbon by two-thirds.

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

Designed in partnership with EKFB and ASC, Thame Valley will be the first major UK railway viaduct to be almost entirely manufactured off-site. The advanced engineering and construction techniques developed by the team have since been adapted and applied for further sections of the high-speed line, helping HS2 meet its overarching ambition to drive sustainable travel.