Sean Harrington Architects Shortlisted for Lower Thames Crossing Low-Carbon Footbridge Competition

Seán Harrington Architects, in collaboration with Arup London, has been shortlisted in the Lower Thames Crossing low-carbon footbridge competition. Their innovative design features a two-span bridge with twin haunched glulam girders, a steel central pier, and reinforced earth embankments, showcasing sustainable materials and construction methods.

Launched in July, the contest is seeking innovative, sustainable designs for a crossing over the A127, a key strategic road connecting Southend and London, and located close to the northern end of the Lower Thames Crossing. The winning design could also form the new footbridge standard and be replicated across roads country wide.

Over 30 entrants were received and assessed anonymously, and judged on their proposed use of low carbon materials and construction methods, and evidence of good design principles to allow ease of access and a pleasant crossing experience. The winning design is due to be announced in late Spring 2025.

The five shortlisted teams are:

• Arup and Seán Harrington Associates: A two-span bridge with twin haunched glulam girders, with an all-steel central pier and steep reinforced earth embankments for the approaches.
• COWI and Moxon: A slender timber bridge supported on a V-shape stainless steel pier, minimising span lengths for an efficient low carbon solution.
• Davies Maguire Ltd: A timber bridge with twin haunched girders, an inclined steel prop as the main pier and stone columns for the approach piers.
• Useful Studio Architects and Expedition Engineering: A modular truss bridge designed on the basis of regeneration and circularity, re-using steel materials and adopting an industrial process for repeatability and efficiency.
• Webb Yates Engineers: A prestressed stone bridge, with the internal tendon profile reflected in the treatment of the façade. A modern interpretation of the traditional stone bridge.

The Lower Thames Crossing is a proposed new road and tunnel connecting Kent and Essex that will tackle congestion on the Dartford Crossing and create a reliable new connection between the north, the midlands and the ports of the south-east. As a carbon pathfinder project, the Lower Thames Crossing is aiming to reduce its predicted carbon emissions and set a new standard in the industry for low-carbon construction by scaling up the use of low-carbon construction methods and materials.

It was the first project to make the limit legally binding by locking it into its application for planning consent. Set to become the UK’s greenest road, the scheme will also encourage active travel as it creates almost 40 miles of new or enhanced pathways for walkers, cyclists and horseriders; two new public parks – Chalk Park and Tilbury Fields on either side of the Thames – and a new community woodland, Hole Farm near Brentwood, Essex. If the project is granted planning permission and is funded, construction is expected to take six-years, with road opening targeted for 2032.