Difficulty: Challenger (Level 2)
A train in Rio de Janeiro, Brazil, went off track in February. The incident occurred after the tracks increased in size and buckled. The tracks were heated to a sizzling 71 degrees Celsius by the sun.
No one was hurt in the incident. However, it showed the need for a way to keep the country’s railway tracks cool during rising temperatures.
A railway company in Sao Paulo, Brazil’s largest city, says it has found a solution.
They suggested painting the tracks white to reflect sunlight and stop the steel from getting too hot.
Alan Santana de Paula is a maintenance manager for a company called ViaMobilidade. It operates two daily traveller train lines in Sao Paulo. He explained that they have recorded temperatures of up to 60 degrees on the tracks. This can cause the shape of the tracks to change and can be dangerous.
ViaMobilidade transports 800,000 passengers a day.
Last year, it counted 20 deformations on the tracks during very hot weather.
Brazil had its hottest year on record in 2024. Scientists say this is due to climate change.
The experiment of painting rails in light colours has already been carried out elsewhere in the world.
People have different ideas about whether this helps.
Tests carried out by ViaMobilidade showed that white paint could help lower the temperature of the tracks by six degrees. This is because white absorbs much less heat than dark colours (see graphic).
Santana de Paula said that the paint doesn’t completely remove the heat effect but does reduce it.
Think about it
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Why are high temperatures dangerous for train tracks?
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How does painting the tracks white help keep them cool?
