Increasingly we are seeing our National Rail Network under pressure from extreme weather events, and many of us, as recently as last month, were affected by delays and cancellations as result of flooding of lines in and around London.
According to the recently published RSSB T1009 report on “Tomorrow’s Railway and Climate Change Adaptation”:
- Excess precipitation and flooding can cause Earthworks failure and Scour of bridges
- Drought can lead to Earthworks failure due to desiccation and Movement of overhead lines (OHL) due to soil shrinkage around foundations
- Sea level rises and storms can cause coastal erosion of earthworks, structures and tracks as well as damage to sea walls
There is evidence that we are already seeing many examples of weather related impact on the rail network’s earthworks and of course, the failure of the Dawlish seawall, which swept away part of the railway in the south-west in the winter of 2014, made national headlines.
The RSSB T1009 Report, which can be downloaded at here, identifies a number of gaps in our understanding of earthworks failure mechanisms in a changing climate and makes a range of recommendations including:
gathering more information about specific thresholds or trigger levels for procedures to manage freeze-thaw effects for earthworks;
further work to investigate the effects of rainfall on groundwater, in the context of earthworks;
- further refinement of management procedures for earthworks assets during wet weather;
increasing our understanding of the long-term vegetation strategies that should be adopted to ensure the stability of earthworks and soil structure;
- clear guidance on the frequency of drought; and
- more guidance on the effects of dessication.
In the medium term it is also recommended that:
technologies for waterproofing of earthworks to keep water in, preventing soil desiccation, or out, preventing soil saturation(high precipitation, low precipitation) are identified; and
innovative approaches for new types of post-flood remedial work with other benefits e.g. using earthworks for enhanced flood risk mitigation(high precipitation,high sea levels and storm surge) are explored.
If you are interested in knowing more about how the weather affects our trains then you might like to watch the Pro-B Youtube video below, a documentary following railway workers across the UK dealing with the impacts of weather on the Network during 2015.