Winter Woes for a (not very) resilient railway

This week, I had an interesting discussion with the asset management engineer at Network Rail who is responsible for all the earthworks between London and the Scottish border on the east side of the Pennines. On his wall, he had a set of Met Office maps which compare the rainfall in a particular month with the 30-year average: the South East and South West are completely covered in deep blue, indicating greater than 200% and 300% of the normal average rainfall for three months in a row (Dec 2013 to Feb 2014). Fortunately for my colleague, the East Coast Mainline has mainly kept out of the danger zone, so we've escaped the worst of the problems. But the weather has had a massive impact on the railway this winter. High winds and flooding closed some lines in December and January, but they were usually open again within a day or two (other than the Somerset Levels where the water stayed for weeks), even if some equipment needed replacing.
The really significant impacts have come from the long term effects which take months rather than days to restore a normal service.At some coastal locations, the January storms washed away the whole railway, at Dawlish in the south west and several places on the Welsh coast, meaning no service from Pwlhelli to Dovey Junction until May (5 months). In other places, floodwater washed out the ballast so that the rails were hanging in mid-air and the track had to be completely relaid.
Network Rail's chief executive Mark Carne put it this way:

“We have suffered enormous damage to the network. In Devon and Wales we lost a lot of railway. There was flooding at 280 sites. We suffered unexpected groundwater issues with the worst at Maidenhead. And landslips were a serious problem with over 50 in Kent alone when we expect two to three a year.”

I have written here previously about the direct causal link between a long period of high rainfall, groundwater levels and landslides, and there is an excellent graph from the British Geological Survey which shows how the last two years have seen a significant peak of landslide events at the end of the winter when the ground is completely saturated (ie from January to March).
The railway has been no exception: there was a large landslide at Chesterfield (Unstone), shutting the Midland Mainline from London to Sheffield for four weeks and three landslips between Tunbridge Wells and Hastings which have shut the line for the past two months (since 30th January).
At Botley in Hampshire, what has been described by Network Rail as “one of the worst landslips ever seen on the network” is still being fixed - this has involved rebuilding an 80m length of 15m high embankment which had failed, taking the railway with it. One of the problems we have with the existing railway infrastructure was that the equations which govern how soil behaves were only discovered in the 1920s, so the Victorians built their embankments out of whatever materials they had lying around. Since then, we keep running more and more trains ever faster over them - this means they tend to be unstable and we have to keep repairing them. This is also why it would be really good to build at least one high-quality new railway line up the country: capacity and resilience are the reasons why we need HS2, not speed!
There is even a landslip at a very large cliff just up the line from Dawlish where they have adopted a very unusual method to force a quick failure so that they can reopen the line: washing the soil away with high-powered firefighter's pumps. I was told that the earthworks engineers here in York were asked for their opinion when the guys in the South West came up with that one...
This brings us back to the real economic and human costs on our society: the South West is highly dependent on tourism and Network Rail have worked flat out to rebuild the railway and sea wall at Dawlish by 4th April, the start of the Easter holidays. It would be a disaster for the region if the line was fixed at Dawlish, yet still couldn't reopen on time because of the landslip!
So is the railway resilient enough to cope with climate change? The asset manager certainly didn't think so! In his opinion, the last few winters (snow, floods and now this) have demonstrated that it doesn't take much to make some parts of the UK railway network grind to a halt (sometimes for months rather than hours), and we are going to require significant investment to deal with the weather we already have – let alone the next 50 years! So I am glad to see the Government making noises that they may provide more than the original £300 million budgeted for resilience work in CP5, when Network Rail have completed a set of climate resilience studies for the rail network in September (including options such as reopening a disused inland route to the South West given the vulnerability of the coastal section at Dawlish).

See also:
Climate Politics - where are we now?
Storms, Floods and Landslides - an engineer's tale
Good News - the railways are getting better! (tells you all about NR's plans for the next 5 year investment period)
Towards a Sustainable Railway - Part 1 and Part 2