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BARRIER PROJECT

A1 St Neots/Eaton Ford Noise Barrier

Improving quality of life for local communities

The A1 Eaton Ford Noise Barrier scheme was a high-profile project for National Highways, and its only noise barrier installation during the 2024/25 financial year. Located to the west of Eaton Ford in Cambridgeshire, the scheme was developed to replace a time-expired noise barrier within a designated Noise Important Area, identified through National Highways’ strategic noise mapping.

Working as principal contractor and civil engineering lot provider, Carnell mobilised in October 2024 and began construction in November. The project ultimately delivered 1,068 metres of new noise barrier across 357 bays, completing the main installation on 28 March 2025 – ahead of the end-of-financial-year deadline.

The scheme was delivered safely, with zero RIDDOR-reportable accidents and a zero AFR, while providing a long-term noise mitigation solution for the local community.

Overcoming Challenges

As with many infrastructure projects, we encountered several challenges along the way. Early in the programme, we discovered previously unrecorded drainage infrastructure beneath the existing barrier, requiring us to redesign and replace the drainage system before installation could continue. We also carefully adjusted the barrier alignment to accommodate nearby utility services while maintaining the overall design intent.

Working at the bottom of a batter in winter to replace a defunct drainage system didn’t lend itself to record breaking outputs! Ground conditions slowed the progress of an activity that wasn’t originally planned for. To overcome the issues created by a sodden embankment, a Menzi Muck spider excavator was brought in. It is a specialised piece of machinery designed for working in challenging terrains. It’s known for its unique “spider” leg system that allows it to navigate steep slopes, rugged landscapes, and areas inaccessible to conventional excavators.

Delivery

The barrier installation was delivered in collaboration with specialist installation partner Versco. As the works were located within a Noise Important Area and were being undertaken at night due to traffic management restrictions, the construction methodology needed to minimise noise while maintaining productivity.

The team used Continuous Flight Auger (CFA) piling to form the foundations – a relatively quiet piling solution suited to the working environment. Each foundation comprised a 2.5-metre-long steel foundation post bolted to a three-metre-long steel fence post. These were embedded within concrete pumped from the carriageway.

The bolted plate arrangement between the foundation and fence posts also provides a practical benefit beyond construction, making the system easier to maintain and service in the future.

Alongside the main barrier installation, Carnell adopted its self-delivery approach wherever possible, completing a range of civil engineering activities including access steps, signage and drainage works. This included gully and manhole construction, pipework installation and DDMS drainage surveys.

The wider supply chain also played an important role. HW Martin delivered traffic management, PJ Chaffin completed site clearance and arboriculture works, Colas installed 34 flex-beam road restraint systems, and Ringway used the closures to remove fly-tipped tyres and rubbish from the area.

Benefits

Safety

  • The scheme was completed safely without any RIDDOR reportable accidents and a zero AFR.

Customer
  • Before construction began, we supported a public information event, giving local residents and road users the opportunity to learn more about the project, its benefits and the planned road closures. Throughout the works, we listened to community feedback and adapted our programme.
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Delivery
  • 1068m (357 bays) was installed during the scheme.
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“Great to see the works progressing well. This scheme was a challenge to get on the ground but perseverance by all the team paid off.”
Shaun Moseley FIHEProject Manager, National Highways