Leven Viaduct
The project upgraded a historic railway viaduct with innovative scour protection and structural improvements, delivering a safer, faster and more resilient solution for Network Rail in a challenging tidal environment, and setting a new standard for proven, efficient delivery.
Winner of the Small Project Award at the ICE North West Awards 2025.
Network Rail
£6m
The project involved the following main phases:
- Removal of sea growth and loose material for inspection
- Installation of 26 Proserve grout mattresses
- Installation of 2 Precast Concrete (PCC) caissons around Piers 20 & 21
- Reinstatement of rock armour
- 11 spans apron repairs completed
- Local spalling and cracking repairs
Conventional access and repair techniques were not viable in the extreme marine environment, with a 10‑metre tidal range, shifting sands and strong currents. Delivering the works relied on bringing specialist expertise together, leading to a close collaborative partnership with marine specialists GPS MACS and ScaffFloat.
A detailed understanding of the estuary’s topography and tidal behaviour was critical to developing a safe and efficient solution. Analysis of flow data, aerial imagery and on‑site surveys identified narrow working windows, powerful tidal flows and plant exclusion zones, directly shaping the design, methodology and sequencing of the works.
By challenging the original outline solution, which relied on a 1.7km temporary access road and limited low‑tide working, the team developed an innovative, industry‑first approach.
This involved installing PCC collars using bespoke ScaffFloat pontoons. Marine specialists GPS MACS were engaged early in the design phase, with their detailed understanding of tidal behaviour maximising safe working windows and driving a pivotal design change: replacing in‑situ concrete pours, proposed by an alternative contractor, with precast collars manufactured off‑site.
This approach significantly reduced environmental disturbance, cut the construction programme from 18 months to just five, and delivered savings of over £11m against Network Rail’s original cost forecast. Off‑site prefabrication improved quality and consistency, achieving first‑time acceptance at handover, while sustainability objectives were fully met.
Early engagement and fully integrated working were central to the project’s success. Story brought together designer MHB and the wider supply chain from the outset, ensuring buildability, environmental constraints and tidal risks were embedded within the design. Regular collaborative reviews with Network Rail supported timely approvals and maintained clear alignment on cost and programme impacts.
Safety was paramount throughout. Robust tidal flow controls, safety boats and comprehensive workforce training enabled the five‑month construction phase to be completed without incident.
As a Site of Special Scientific Interest with protected bird habitats, the project required a rigorous and proactive environmental approach. Close collaboration with the Marine Management Organisation and Natural England included a year‑long biodiversity survey, ensuring works were delivered in full compliance while safeguarding sensitive habitats.
A major sustainability breakthrough was achieved by replacing the planned 1.7km stone access road (which would have required 5,280 tonnes of material) with a fully marine‑based logistics solution.
This decision delivered significant benefits:
• Carbon savings of 39.6 tCO₂e, equivalent to 39 return flights from London to New York
• Minimal disturbance to wildlife, avoiding nesting seasons and protecting sensitive habitats
• No temporary bridge required, reducing the overall programme by 12 months
Beyond the construction works, Story Contracting demonstrated a lasting commitment to the local community by reinstating a viaduct access road for walkers and fishermen, donating £6,000 in materials alongside a week of volunteer time.
£10.225m
cost saving
14 week
programme reduction
39.6 tCO₂e
saved
The site at Leven Viaduct had challenging risks, working on a fast-flowing estuary. The Story team made the work look easy with highly competent specialist teams. The work was well managed, and risk was controlled well from both a safety and sustainability perspective.
Nicola Uijen, Director of Routh Health, Safety, Quality and Environment
Network Rail