Innovative construction solution used by Network Rail in challenging Cardiff bridge project: Windsor Road Bridge 1

Friday 19 Feb 2016

Innovative construction solution used by Network Rail in challenging Cardiff bridge project


Innovative construction techniques have been used to overcome challenges replacing Windsor Road bridge in Cardiff.

Network Rail engineers replacing the 1902-built bridge had to re-design the foundations after starting work on site in January 2015, installing a lightweight polystyrene-block solution on the new embankments.

The extensive re-design works were required as a result of challenging site conditions.

Mark Bull, project manager for Network Rail Wales said: “This solution was chosen over more traditional construction methods due to its high strength and versatility– proving suitable for the challenging ground conditions encountered at site. In addition these large white blocks are light enough to be moved by hand, minimising noise for our neighbours and reducing pollution levels requiring less machinery on site and fewer deliveries. ”

The bridge, which carries the road that connects Adamsdown with Splott and spans the South Wales Mainline, is being replaced with a larger and improved structure, which will not need to be replaced again for more than 125 years.  

The new structure will be able to accommodate modern-day city centre traffic and heavier road loads. The bridge will have improved access for pedestrians and cyclists, as well as better lighting.

The project was originally expected to finish in spring 2016, but has now been delayed until summer 2016, with the road expected to open in early July.

Through recent weeks, further delays have resulted from a combination of very high winds and extreme weather conditions that have affected crane operations on site. Key spans of the new bridge were due to be lifted into position in late 2015 however this crucial element of the work had to be cancelled on a number of weekends and rescheduled.

Mr Bull said: “This delay is intensely frustrating for our engineers and, more importantly, for the local community and we would like to thank them for bearing with us. When the scheme is completed, they will benefit from a new and improved bridge that is better able to cope with the demands of modern road and rail traffic and provides improved access for pedestrians and cyclists.

“Passengers will also benefit from more frequent, faster, quieter services once this wider programme of work is completed as part of our Railway Upgrade Plan.

“We are doing the best we can in difficult circumstances and we are sorry it is taking longer than we first thought, but our engineers face a huge challenge and we must allow them the time they need to tackle it safely”

The railway has remained open throughout the work, minimising disruption for passengers. However, as the new bridge is being built in the same position as the existing structure, the road is currently closed to traffic and will remain closed throughout the duration of the scheme.

Windsor Road bridge is a large structure, totalling 125 metres in length and 12 metres in width, and spans five railway lines, as well as road. It also carries a number of vital utilities – including electricity, gas, fibre-optics and water – which are buried in the structure. Engineers have been working carefully to ensure that these utilities remain largely undisrupted as the bridge is demolished and rebuilt.

The bridge will be raised as part of Network Rail’s Railway Upgrade Plan to provide the extra headroom needed for the future electrification of the railway. Electrification of the South Wales Mainline will mean faster and more reliable journeys for the rising number of passengers using the railway, as well as less noise and pollution for those who live close to the railway line.  It will also help stimulate economic growth across the region by better connecting towns and cities in South Wales and beyond.

Members of the public who require further information can contact Network Rail’s 24-hour helpline on 03457 114 141 or email

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Network Rail press office - Nichole Sarra
Media relations manager (Wales)
Network Rail

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Network Rail owns, manages and develops Britain's railway - the 20,000 miles of track, 40,000 bridges and viaducts and the thousands of signals, level crossings and stations (the largest of which we also run). In partnership with train operators we help people take more than 1.65bn journeys by rail every year and move hundreds of millions of tonnes of freight, saving almost 8m lorry journeys. We employ 36,000 people across Britain and work round-the-clock, each and every day, to provide a safe, reliable railway.

About the Railway Upgrade Plan

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  • longer, faster more frequent trains;
  • better, more reliable infrastructure; and
  • better facilities for passengers, especially at stations.

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