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Sea change: protecting coastal railways from rising sea levels

In 2014, the devastating impacts of climate change almost proved fatal for the railway line running in the English town of Dawlish, which was partially destroyed by extreme weather conditions. As works start to repair the damage, Adele Berti  finds out how Network Rail is protecting its coastal railways from high waves and predicted rising sea levels.

Image: Paul J Martin | Shutterstock

W

hen Isambard Kingdom Brunel engineered the UK’s South Western Railway in the early 19th century, he saw great potential in the British coastline - a flat piece of land that, he thought, would make for a good value/price ratio.


On paper, England’s southwestern coast indeed looks like an ideal spot to build a railway, requiring very few tunnels and relatively simple design. What Brunel could have not forecast, however, are the consequences of climate change.


Years of carbon emissions and compulsive plastic consumption have left this idyllic part of the English coastline at high risk of floods and extreme weather conditions caused by a sharp rise in sea levels.


This threat was brought to national attention in February 2014, when the sea wall at Dawlish – a picturesque seaside town in southwestern England – collapsed into the sea as a result of heavy storms and floods that washed away some rail tracks and disrupted services for eight weeks.


Five years later, UK rail infrastructure owner Network Rail has finally kicked off works to build a new sea wall and make the tracks more resilient. But with 2018 estimates from the Committee on Climate Change suggesting England will need to prepare for a 1m rise in sea levels in the future, the fate of its coastal rail lines is still very much a cause for concern.

The likelihood of climate change-related accidents is forecast to grow even further

A widespread problem 

The Dawlish accident represents what could happen to British coastal railways and the communities they serve in the coming decades.


As professor Robert Duck from the University of Dundee told The Guardian in 2015, railways in Cumbria, Wales and Devon are all at risk of severe floods as a result of climate change.


“Much of our coast has railway lines at the edge forming the first line of defence from the sea. This leads to spectacular scenery for passengers to enjoy but increasing difficulties for franchise operators and government,” he said ahead of the release of his book, ‘On the Edge’, about this topic.

Image: Storm waves breaking over the railway track at Dawlish

Supporting his claim, a 2018 study by the Committee on Climate Change titled “Managing the coast in a changing climate” stressed the need to intervene immediately to guarantee the future of hundreds of coastal properties, roads and railways.


It warned that some 520km of railway line are currently at 0.1% or greater risk of coastal flooding in the foreseeable future.


According to the report, the likelihood of climate change-related accidents is forecast to grow even further by the 2080s, when some 650km of railway lines and 92 railway stations will be exposed to major coastal flooding and erosions.

Learning from the Dawlish accident

If anything can be learned from a dangerous weather-driven event like the Dawlish accident, it is that stronger measures need to be adopted.


As far as Dawlish is concerned, works have now started to build new, improved sea wall protection along the damaged part of the line as part of a £30m scheme funded by the UK Government.


As Network Rail senior programme manager David Lovell explains, the project will continue throughout the coming months, with the new wall set to be completed by January next year.


“We will build a new sea wall roughly in line with the current alignment that will be between 7m and 7.5m high,” he explains. “We are doing the foundations now and in September, we will start putting concrete-facing panels attached on to the existing sea wall.”


Other vulnerable parts of the southwestern line passing through Dawlish – and which connects Plymouth and Cornwall to the rest of England – are also being upgraded as part of a wider scheme called the South West Rail Resilience Programme.

Image: Storm wall | Network Rail

Focusing on three intervention areas – among which is the Dawlish sea wall – the scheme hopes to make the rail line running between Exeter and Newton Abbott safer and more resilient to extreme weather conditions.


As part of the programme, Lovell says, Network Rail has collaborated with marine, coastal and geotechnical engineers, as well as railway consultants, to draw a set of plans that will need to be implemented to address current and future climate change-related problems.


“The South West Rail Resilience Programme is going to be delivered over multiple control periods to make sure that the railway is resilient over the next 100 years,” he explains. “We need to implement all those interventions as and when they're required.”

Works have now started to build new, improved sea wall protection

We have taken the latest government guidelines on sea level rises and built that into our solutions

Future-proof protection for coastal railways

Looking ahead, plenty of work still needs to be carried out to make coastal railways more resilient.


And while high-risk areas are rightfully top priorities for Network Rail, Lovell says that wider, future-proof strategies are equally being implemented across the country’s sea-facing lines.


“Sea levels are going to rise and that's clear,” he says. “The climate is changing and we'll get less rain in the summer and more in the winter and we've built these factors into our designs and developments so that we consider all the aspects.”


Works such as the ones currently underway at Dawlish will undoubtedly help protect the railways, but when it comes to preventing it, Network Rail’s capabilities are for more limited.

Image: VP2 Render | Network Rail

“The only thing that we can do at the moment is, when there is a severe storm event, we will increase our inspections,” says Lovell.


“We get daily updates from the Met Office [national weather service] about tides, wave heights, wind speed and such and we have a traffic light system that signals risks, so if we're getting all this information and it's high risk, we will stop trains running.” He adds that during extreme weather conditions, the only way of checking the state of the tracks is though inspections.


Future-proofing the tracks will be complicated, but Lovell says that Network Rail is working to keep on top of the situation.


“We have taken the latest government guidelines on sea level rises and built that into our solutions and built physical models, as well as design models, to prove that these things will work in the future,” says Lovell.