A clean-up operation was under way across much of Britain’s railway network on Monday, after Storm Isha’s heavy rain and winds of over 90mph caused severe disruption.
The storm’s impact highlights the problems facing Britain’s ageing railway network with climate change predicted to increase the frequency of severe weather events hitting the country.
Isha is the ninth named storm to hit the UK this winter, setting a record for this stage in January since the introduction of the naming convention by the Met Office in 2015. A tenth, Jocelyn, is brewing in the Atlantic and looks set to make landfall on Tuesday night.
The persistent severe weather has already caused misery for tens of thousands of travellers over Christmas and New Year. Heavy rain led to widespread flooding, including in the Thames tunnel used by high-speed Eurostar services for the first time since they opened in 2007.
“We’re definitely seeing the impact of climate change. It’s happening now, it’s real, and it is having a significant impact,” said Martin Frobisher, group safety and engineering director at Network Rail, the owner and operator of the UK’s railway infrastructure.
The railways were just one part of what the UK government terms “critical national infrastructure” which, along with energy, telecommunications and water networks, face an “urgent” and growing challenge from the worsening effects of climate change, according to a 2022 parliamentary report.
But the scale and age of the infrastructure on the railways make them particularly vulnerable.
Intense rainfall can lead to floods which block or wash away parts of the track, damage the embankments and cuttings that are common across the network and, in extreme cases, cause landslides.
High winds bring down power cables on the electrified parts of the network and blow debris on to tracks. In the summer, extreme heat can cause the steel rails to buckle and sag as they absorb heat, increasing the risk of derailments.
The two most recent serious rail accidents have involved bad weather, including a fatal derailment in north-east Scotland in 2020 caused by a landslide following heavy rain.
Network Rail has set aside £1bn to spend on adapting the network to climate change in its regulatory period between 2024 and 2029, double the £500mn spent in the previous five years.
But the state-owned body has also admitted it is impossible to protect all of the UK’s 20,000 miles of track and has warned it expects the railway infrastructure to become less reliable because of weather-related damage.
The biggest problem is that unlike most other European countries that rebuilt their networks after they were extensively damaged during the second world war, much of the UK’s rail infrastructure largely survived intact.
On top of that as the country that brought the world the railway, much of Britain’s network still follows the same routes built over a 70-year period beginning during the Victorian era in 1850.
The building boom gave the country one of the most extensive networks in the world, but many of its structures were now reaching “end of life”, according to a Network Rail report published last year.
“The reality is that you cannot rebuild the entire Victorian railway infrastructure of the UK, that is just not practical,” Frobisher said.
The report found a 50 per cent rise in “adverse weather impacts” over the past five years compared to the decade before that, and said it expected “asset condition and performance” would slip.
The impact on the ageing infrastructure was worsened because of how busy the UK railway is, with operators running faster, more frequent and heavier trains as the industry has grown, said Gareth Dennis, a railway engineering writer and academic. “If you are running more trains you have less time to get on and do maintenance. We try to sweat the asset,” he added.
Network Rail has prioritised spending on the most safety-critical areas, including signalling, and the busiest lines. It has invested in weather forecasting to better predict where the most intense rainfall will hit and installed sensors to generate real-time information on the state of the track. The data should allow for more targeted interventions such as line closures or speed restrictions, and reduce delays.
“We’re able to make better decisions than ever before. So we can’t rebuild everything . . . but we can use science to allow us to make the best operational decisions in difficult circumstances,” Frobisher said.
HS2, the truncated new high-speed link that will now run only between London and Birmingham, illustrates how modern railways differ from a network designed in a bygone era.
The designers have allowed for the effects of climate change on the new track, tunnels and signalling that are being built to handle a one-in-1,000-year flood event.
The project has been massively cut back as its costs have spiralled, but Nick Sartain, HS2’s head of geotechnical engineering, said he believed that designing the railway to be more resilient to bad weather would pay for itself eventually.
“My strong expectation is that the difference in capital costs . . . will be significantly outweighed by the savings we can get in terms of operational costs just in terms of maintenance,” he said.
Dennis said that it was inevitable given the age of most of the network that the government would need to ensure Network Rail had more funding to combat extreme weather.
“The way you make it less costly in the long run is by spending more money upfront to build a more robust and resilient system in the first instance. And that requires quite big money. But the do-nothing option costs a lot more money over a longer period.”
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