The role of civil design in rail infrastructure projects is fundamental to their successful planning, execution, and long-term viability. Civil engineering solutions are critical in addressing the complex demands of maintaining and improving railway networks, ensuring both operational efficiency and sustainability.
In this article, we examine the role of civil design through the case study of the Downs Park Road Overbridge refurbishment. We will explore the civil engineering strategies implemented, the challenges encountered, and the key lessons learned — insights that are directly applicable to future rail infrastructure projects.
A bridge in crisis
Located in the borough of Hackney, the bridge, a 154-year-old structure, had suffered considerable structural deterioration and required immediate intervention to restore its integrity.
Whitfield Consulting Services (WCS) was tasked with this challenge, providing expert design services from the initial planning phase through to construction, ensuring a solution that adhered to Network Rail’s operational and environmental standards. Appointed by Murphy as part of Network Rail’s Control Period 6 (CP6) East Anglia Structures remit, WCS played a pivotal role in delivering a cost-effective and sustainable solution for the project.
Read the case study for more background on the project: Expert civil engineering to revitalise Hackney’s historic Downs Park Road Overbridge.
Key learnings for future rail projects
The Downs Park Road Overbridge project offers several important lessons for future rail infrastructure projects, particularly in the application of civil design solutions to complex challenges. These lessons emphasise the importance of strategic planning, collaboration, and innovative engineering techniques.
1. Value engineering for cost-effective solutions
One of the key takeaways from this project is the importance of value engineering in rail infrastructure design. Instead of opting for full demolition and reconstruction, WCS retained the existing abutments, reducing material waste and embodied carbon. By optimising the structural arrangement and incorporating precast concrete elements, the team cut both construction time and expenses. These efficiency measures resulted in an estimated 30% cost reduction compared to alternative solutions, demonstrating how civil engineering can achieve cost-effective and sustainable outcomes through careful design choices.
2. The importance of early contractor involvement
Early engagement with contractors and stakeholders facilitated improved decision-making and better coordination throughout the project lifecycle. Constructability workshops provided a platform to address potential challenges proactively. This early collaboration ensured the design could be built efficiently and safely while considering all practical constraints. A trial erection attended by WCS streamlined the installation, reducing the risk of delays during possession.
3. Using digital tools for design optimisation
The use of structural modelling software such as MIDAS CIVILS and Tekla allowed engineers to explore multiple design scenarios, optimise performance, and identify risks before construction began. These digital tools ensured precision in structural calculations and improved overall project efficiency.
3D modelling of the bridge, highway alignment, and surrounding features using MicroStation enabled early identification of clashes with existing services and supported the planning of suitable diversion routes, including their integration within the new deck.
WCS independently verified the analysis and design outcomes through hand calculations and bespoke spreadsheets. This rigorous cross-checking process ensured consistency with the software outputs and demonstrated WCS’s understanding of the tools used and their design competency.
WCS modelled and assessed time-dependent effects on the proposed bridge deck – such as creep, shrinkage, and thermal effects – to ensure long-term structural performance and durability.
4. Prioritising sustainability in rail infrastructure
Sustainability was a key focus of the project, with WCS’ design choices contributing to a 25% reduction in carbon emissions, equating to approximately 88.70 tonnes CO2e. This was achieved by optimising steel sections, incorporating precast elements, using fibre-reinforced polymer (FRP), and reducing construction time and machinery use. WCS used the RSSB Rail Carbon Tool to quantify and verify these reductions, ensuring a data-driven approach.
By carefully selecting materials, minimising waste, and reducing energy consumption during construction, WCS demonstrates how environmentally responsible design can be integrated into rail infrastructure projects.
5. Integrating temporary and permanent works
The integration of temporary and permanent works ensured the bridge deck was installed on schedule, reducing disruption to both railway operations and the surrounding community. This approach improved safety and efficiency, demonstrating the importance of planning for all stages of construction from the outset.
A key strategy involved minimising temporary works by integrating them into the permanent works — such as using the parapet girder as shuttering for the concrete parapet, optimising concrete thickness, and employing GRP panels as permanent formwork instead of conventional systems. These measures reduced material use and time on-site, minimising environmental impact and ensuring timely project delivery.
Industry implications and future applications
“Lessons learned from this project will inform future rail infrastructure developments, particularly in the areas of service integration, deck optimisation, and risk management,” says Mohamed Omar, Senior Structural Engineer at WCS.
“The project’s success reinforces the value of early contractor involvement, the use of advanced digital tools, and a strong focus on sustainability in civil engineering projects. By applying these principles to future bridge refurbishments and replacements, the industry can continue to improve the resilience and efficiency of the rail network.”
“The design approach taken in this project is directly transferrable for future bridge renewal initiatives,” adds Jeremy Barnes, Technical Director at WCS. “The project showcases how innovative engineering solutions can be used to overcome complex challenges while ensuring compliance with industry standards.”
Feedback from Network Rail and Murphy
Network Rail expressed high satisfaction with the outcome, highlighting the project as an exemplar of collaborative working, innovative design, and efficient delivery under time constraints. Jenny Fowler, Lead Portfolio Manager at Network Rail, shares more about the team effort on LinkedIn (click here).
Murphy commended WCS’s design expertise and technical support. The WCS team provided continuous support, from early-stage optioneering to on-site construction assistance.
“Thank you, Whitfield Consulting Services, for such a seamless design and for the technical support.” Kieran Moore, Engineering Manager – CRE-C at Murphy.
Watch Network Rail’s video telling the story of the bridge replacement project, filmed shortly before the reopening: Job done in Hackney: roads reopened and bridge replacement complete.
Future rail infrastructure projects
The Downs Park Road Overbridge project stands as a testament to the impact that well-executed civil design solutions can have on rail infrastructure. WCS delivered a cost-effective and resilient solution that will serve the community for years to come.
The lessons learned from this project — especially in the application of civil design strategies, value engineering, sustainable choices, and digital tools — are directly applicable to future bridge refurbishments and rail infrastructure developments in the years to come.
To find out more about our rail experience click here. Or, if you would like to discuss your next project, please get in touch by emailing info@wcs-consult.co.uk or calling +44(0)20 3581 7847.
