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For the first time ever, a railway bridge in Wales has been raised away from rising river waters to prevent flooding on the track.

Black Bridge with workers
Work taking place at Black bridge

Black Bridge, on the Cambrian Line, near Machynlleth, now stands one metre taller than before, after Network Rail engineers and contractors AmcoGiffen worked day and night to lift it away from a river flood zone.  

This resilience project will improve passenger journeys and secure the future of this vital transport link between Mid Wales and the rest of the UK.

During periods of heavy rainfall, the bridge has repeatedly flooded in the past, causing regular closures on the Machynlleth to Shrewsbury route, leaving large sections of the Cambrian lines in central Wales isolated. The bridge has been closed 30 times in the last decade, and ten times in 2020 alone, for emergency repairs caused by flood water.

What we did

A total of 360 engineers clocked up more than 32,000 hours to deliver this innovative project, in just six weeks, with the line reopening on June 28 2021.  

Engineers opted to lift the 80-tonne bridge manually, rather than using hydraulics, to ensure there was no twisting or buckling of the structure. Eight, 20 tonne chains were used in total and for every 10 meters of chain pulled, the bridge was raised just 10mm.  

This resulted in more than 12,800 metres (12.8km) of chain being pulled through the lifting blocks for this challenging lift.

This project will protect the bridge from high river levels and significantly reduce disruption for passengers in the future.

The bridge goes over the River Dulas in Powys, which is a fish spawning river. This means there is a limited time period when we can carry out the resilience work. We are working in collaboration with Natural Resources Wales and ecological specialists, doing everything possible to protect the sensitive local environment.

Get in touch

If you have any additional questions or concerns about this work, please call our dedicated 24-hour national helpline on 03457 11 41 41 or email

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