HS2 A421 London Road Overbridge, Buckinghamshire, UK

New Overbridge for the A421 enabled by Mek-Dek GRP Permanent Formwork Panels

A new overbridge on a busy Buckinghamshire road was built as part of the HS2 railway project by EKFB, a joint venture of major engineering firms. Mekina Industries supplied custom GRP Mek-Dek panels, which simplified installation, reduced resource use, and enhanced safety. This collaboration ensured seamless integration with existing infrastructure and improved accessibility across the railway line.

With over 50 years of experience in the GRP industry, we bring extensive expertise to projects of this nature.

The construction of new overbridges is an integral part of HS2’s goal to create a modern, efficient, and safe high-speed railway system that can coexist seamlessly with the existing transport infrastructure. The installation of this new overbridge in Buckinghamshire was managed by EKFB – a collaborative joint venture harnessing international expertise from prominent civil engineering and construction leaders: Eiffage, Kier, Ferrovial Construction, and BAM Nuttall.

Located on an extremely busy A road, the newly constructed overbridge allows vehicles to pass over the newly built HS2 railway, improving access to both sides of the track. The primary challenges of constructing this overbridge involved managing the project’s complexity whilst ensuring safety throughout, particularly in spanning the rail tracks without causing any interference.

The formwork demanded specialised adaptations, as conventional solutions would have proved insufficient to meet the technical requirements. Mekina Industries, an expert formwork designer, manufacturer, and supplier, was selected to supply the overbridge due to our ability to provide a bespoke solution using GRP Mek-Dek Formwork panels. Mek-Dek Haunched Panels were chosen to ensure the continuation of the haunch from the underside, with specific measures implemented to prevent accidental dislodgement, thereby enhancing both safety and overall reliability.

Modular and lightweight, Mek-Dek Panels are highly manoeuvrable, requiring less person-power and fewer resources for transportation and installation. They offer a safe working platform, installed from above, streamlining the construction process and enhancing safety on-site. Because they remain in place, there is no need to dismantle and remove them, saving valuable project construction time. After determining the required panel specification to carry the concrete deck, Mekina initiated our custom manufacturing process.

Throughout this project, we maintained close collaboration with the EKFB design team, ensuring constant communication to promptly address on-site challenges and maintain a clear understanding of project requirements from start to finish.