Extreme weather

Rising sea levels, higher temperatures and extreme weather will have an increasing effect on railway operations.

THE railway is already being affected by climate change. The risks from higher temperatures, more frequent and more extreme weather, and rising sea levels will influence railway passengers, staff and operations.

These are the conclusions of a two-year study led by the RSSB (Rail Safety and Standards Board).

It finds that from 2050 the English climate will be similar to that of central France today. But there will also be greater disruption to rail operations and more damage to railway infrastructure because of increasingly severe winter rainfall.

“Climate change is a big issue for the railway and we need to consider how to prepare for it. We can develop specific actions to protect our assets,” RSSB Interim Managing Director Mark Phillips told RAIL.

The report - Tomorrow’s Railway and Climate Change Adaptation - also highlights the potential impact on railway workers through added heat stress, as well as problems for passengers stuck on stranded trains without air-conditioning.

It warns there will be increasing risk of earthworks failure due to the effects of rainfall and flooding. Conversely, higher summer temperatures and drought will also lead to earthworks failure due to desiccation - particularly clay embankments drying out in southern England.

There will be increased scouring of bridge foundations, such as by the River Clyde floodwater that closed the viaduct at Lamington on the West Coast Main Line last January and February ( RAIL 793).

And there will be more incidents of rail buckling, overheating of signalling equipment and sagging of overhead line equipment.

The report warns that vast areas of low-lying land currently served by the railway may be lost altogether. Coastal erosion will increase, and higher wind speeds will increase the incidents of trees falling onto tracks, as well as exacerbating autumn leaf fall.

RSSB calls for a new “vulnerability map” to record a database of railway assets that are at risk from climate change. This should include lineside equipment such as signalling. It says Network Rail must adapt for a changing climate whenever assets are renewed, taking a long-term view.

Perhaps its most challenging recommendation is to replace today’s ‘delay minutes’ system of attributing blame and the financial cost of disruption. RSSB argues that there should instead be a new “journey availability index” that would measure long-term performance of both infrastructure and rolling stock.

This journey availability system would need to be written into future franchises. RSSB accepts this could take five to ten years to implement, and require the support

of the whole industry.

The report cites Cowley Bridge near Exeter as a case study. Successive attempts to protect the railway from flooding there have failed, with an impact that stretches far wider than the rail industry. In 2014 the railway to the South West was severed for weeks by a combination of flooding along the rivers Exe and Culm, and the breach of the sea wall at Dawlish.

“Here we are seeking not to highlight the cost of putting it right, but the cost of not putting it right,” explained Phillips.

“Factoring in the wider economic impact gives a much more positive business case to take action.”

See feature, pages 74-77. Read the full RSSB report at: http://www.rssb.co.uk/Library/research-development-andinnovation/2016-05-T1009-finalreport.pdf