Are railways prepared for more frequent heat waves?
Heatwaves with record-breaking temperatures made their impact on European railways in June and July this year, and it probably won’t be the last time. Are railways ready to cope with increasingly hot temperatures, and what measures are rail companies taking?
With temperatures reaching around and above the 40 degrees even in northern Europe and the UK this summer, the railways systems were tested to their limits. Several days after the heat wave, UK infrastructure manager Network Rail announced it would be setting up a hot weather taskforce, saying they have to “pull out all the stops to make the railway as resilient as possible”.
Line closures and equipment failures show that the railways are not always able to handle these extreme temperatures. “Definitely not enough action is taken at the moment to deal with heat waves”, says Frédéric Hénon, Head of Operations & Safety at the International Union of Railways (UIC).
The French SNCF has had to deal with a number of incidents in the past months, from fires along the tracks near Brittany to a chaotic train evacuation in the Ile-de-France region. “It is important to recognise that this has had a certain number of consequences for our customers”, SNCF management told AFP.
“With the abnormal heatwave, all the components of the system are pushed to the limit: rolling stock, infrastructure components, tracks, and catenaries. All this is going well and safety is guaranteed, but statistically we have more incidents than on other days”, said SNCF management.
Are heat waves like this still abnormal? “Look at the August weather forecast for 2022, it is again the case that there will be a quite strong heat wave everywhere”, says Hénon of UIC. “By looking at data from past years, and to the IPCC climate report, every railway stakeholder is now thinking on more intense and frequent heatwaves.”
Responding to what measures are taken, SNCF Réseau spokesperson Soune Serre says that during periods of very hot weather, SNCF Réseau is more vigilant, and agents are mobilised day and night to monitor the tracks. “Indeed, the rail network is likely to be affected when it is exposed to exceptional temperatures.”
According to Serre, the condition of the rails and catenary is monitored, and the number of inspections on foot in the field is increased before and during the summer. “Since 2021, SNCF Réseau has also been using a rail temperature prediction tool based on Météo France forecasts and several other parameters. In the event of an impact on the infrastructure, during very hot weather, the speed of the trains can then be reduced as a precaution to not put more pressure on the infrastructure.”
Testing of white tracks
Te press department of Adif says it is working on different projects in order to test different ways to prevent the possible effects of high temperatures on the railway, such as rail buckling.
For example, the Spanish infrastructure manager is testing the efficiency of painting some tracks in white. Adif has also treated some rails by applying a product called ‘Ice Paint’, a chemical compound with a specific formulation that “guarantees insulating properties and durability”. This product has been applied in a section line in Albacete and now Adif is studying and considering all data collected from it.
Also, Adif says it builds on its experience in the development and maintenance of railway lines that are able to endure continuously high temperatures, such as the Saudi-Arabian high-speed line from Mecca to Medina.
The risk of fires
The Italian railway manager RFI “constantly monitors its network to ensure the safe circulation of trains and to intervene in real time”, says RFI spokesperson Francesca Smacchia. Once a certain thermal threshold has been reached, the tracks and rails can expand and the circulation of trains can temporarily take place at a reduced speed or be suspended for ad hoc interventions on the rails.
However, fires in the vicinity of railway tracks did form a problem in Italy. Near Trieste, a railway line was closed because of fires, which blocked passenger trains as well as freight transport to the port of Trieste. There, the fire affected the railway and the road, and a traffic stop was requested by the Fire Department, says the RFI spokesperson. “The railway lines, when they are electrified, are surmounted by 3.000 volt power lines and water to fight the fire cannot be used in these environments”, thus the line had to be closed to traffic.
To lower the risks of fires and their impact on the railway, RFI periodically carries out interventions along the more than 24,500 kilometres of tracks to contain vegetation such as plants and trees. “These activities are intensified by at least 30 percent in spring and summer, precisely to mitigate the risk of fires”, says Smacchia. RFI did not respond to the question of whether any vegetation control was carried out recently near the stretch of railway near Trieste.
In addition, to counteract the high temperatures before summer along the main railway lines, the tracks are specially whitewashed. During the summer period, preventive checks and maintenance interventions are intensified.
Train airconditioning not able to withstand temperatures
On the train operator’s side, the high temperatures can lead to problems with the airconditioning on board, resulting in stifling situations for passengers and a load of complaints on social media. In Spain, there were reports of airconditioning failing on the high-speed trains between Madrid and Barcelona, both on Renfe trains and trains of newcomer Ouigo, a subsidiary of SNCF. In response, Renfe toldRailTech that “the heat wave in July caused specific problems in the airconditioning”.
The equipment was not capable of lowering the temperature to the usual levels, as excessive temperatures can cause a protection mechanism to activate. This stops the airconditioning when the pressure of the refrigerant gas that is used exceeds a certain limit, explained Renfe. It is then not possible to restart their operation until the refrigerant gas pressure is reduced, for which it takes a while for the equipment to cool down. The equipment currently has to be able to withstand temperature changes ranging from around -10 to 40 degrees, said the operator. Temperatures however surpassed 40 degrees in multiple places in the country in July.
Because currently not enough action is taken to handle extreme heat situations, many are in favour of the task force on high temperatures and desert-like conditions that UIC is launching in August, says Frédéric Henon. In this task force, practices will be shared and a work programme designed of what actions should be taken.
“The short term actions that UIC is proposing is to offer a deep share of good practices and short term measures that are delivering towards resilience of the system in the face of heat waves, from assets and infrastructures and rolling stock, to operational conditions and procedures to cope with.”