This complex and high-profile scheme was led by Story Contracting’s in-house project management and engineering teams.
The GUN28 Green Overbridge is a flagship infrastructure project delivered as part of a broader package of works for the Eiffage, Kier, Ferrovial, and BAM Nuttall (EKFB) joint venture, supporting the development of the High Speed 2 (HS2) rail network.
Strategically located at Calvert, the overbridge spans 40 metres and is 46 metres wide, providing essential highway and pedestrian connectivity across the HS2 route. In addition to its transport function, the structure integrates utility corridors and a substantial green space, contributing to environmental sustainability and community value.
This complex and high-profile scheme was led by Story Contracting’s in-house project management and engineering teams. Direct delivery included pile cropping, earthworks, and drainage, while specialist subcontractors Murform (FRC) and Richters (Temporary Works Design) were engaged to execute the reinforced concrete works and all temporary works design. The project exemplifies Story’s collaborative approach, technical excellence, and commitment to delivering high-quality infrastructure solutions.
46m wide
main bridge deck
4000m3
concrete poured to form structure
The project involved the following main phases:
• Excavation to expose piles (installed by others)
• Pile cropping and construction of pile caps
• Construction of vertical bridge elements: approach containment units, wing walls, and abutments, using reinforced in-situ concrete
• Design and implementation of all temporary works, including falsework, formwork, and rebar stability
• Construction of the bridge diaphragm to secure the deck to the walls
• Installation of permanent formwork and construction of the reinforced concrete bridge deck
• Construction of the high-level approach containment structure
• Waterproofing and drainage works
• Backfilling and associated earthworks
From the outset, the Story team adopted a proactive and quality-driven approach to ensure the successful delivery of the GUN28 overbridge. A key aspect of this was the rigorous review of client-provided designs. The enhanced assurance process consistently identified and addressed design deficiencies early, enabling the mitigation of risks and programme momentum.
Integration with the client’s systems and workflows was seamless, allowing uninterrupted progress and fostering a collaborative working environment. Story’s engineering teams developed innovative temporary works solutions, particularly for the rebar stability of the 8m and 9m high abutment walls. These bespoke designs eliminated the need for independent propping, significantly reducing both time and cost while enhancing safety and constructability.
Story maintained a strong focus on quality and compliance throughout the project lifecycle. All handover documentation was completed in parallel with physical works, ensuring a smooth transition and full traceability.
Ayrshire Roads Alliance
Essential works took place to replace the unsafe road crossing over Dunure Road by reopening a former railway tunnel as a new underpass.
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