Network resilience to climate change

Lots of flooding around the country at the moment and lots of disruption to rail services. It will be interesting to see how the Conwy Valley line holds up this week.

Do forum members feel we are reaching a point with any of these flooding/landslip problems where we can say, 'this is now unprecedented, take an period in railway history and we are getting far more of these incidents than we ever have had before' or, are we still in territory where this is normal.

It feels difficult to be completely objective as historic data does not seem that robust, the internet causes you to hear about far more individual problems that you wouldn't have heard about in previous times and most railway infrastructure is really old now and that has implications.

Looking at a single line, like the Conwy Valley, it does feel like it is easier to say we might have hit a tipping (or tipping it down) point.

If we are already beyond normal times, that has huge implications. The cost and disruption of preventative and remedial works will be huge, especially as flooding often attacks expensive parts of the infrastructure such as bridges.

Rising sea levels could well take out the northern part of the Cambrian Coast line, for one.

Bletchleyite said:

Rising sea levels could well take out the northern part of the Cambrian Coast line, for one.

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And the SE main line between Dover and Folkestone ....

robert7111a said:

And the SE main line between Dover and Folkestone ....

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That could be very interesting as third rail flooding incidents have generally involved relatively non-conductive fresh water. Let's just say you could expect fireworks long before that happens!

But weren't we all supposed to be under water by now?

As well as direct flooding there is the risk to earthworks, with landslips either blocking or undermining the line. The Victorians didn't understand soil mechanics and tended to pile up any old stuff at any old angle, and I get the impression age or increased rainfall are taking their toll (although again this may be because we are now more likely to hear when something goes wrong). The sheer number of vulnerable areas means there will be more failures even if most of them remain stable.

This, incidentally, is another reason to build HS2 rather than try to increase capacity by upgrading what we have now. Like the motorway network it's costly but part of that is to incorporate the state of the art in staying above flood levels and building robust structures and earthworks.

edwin_m said:

As well as direct flooding there is the risk to earthworks, with landslips either blocking or undermining the line. The Victorians didn't understand soil mechanics and tended to pile up any old stuff at any old angle, and I get the impression age or increased rainfall are taking their toll (although again this may be because we are now more likely to hear when something goes wrong). The sheer number of vulnerable areas means there will be more failures even if most of them remain stable.

This, incidentally, is another reason to build HS2 rather than try to increase capacity by upgrading what we have now. Like the motorway network it's costly but part of that is to incorporate the state of the art in staying above flood levels and building robust structures and earthworks.

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Absolutely spot on.