- Europe and the United States are experiencing record-breaking temperatures this summer.
- Intense heat causes steel railroad tracks to expand and to buckle under the extra stress.
- Trains reduce their speed in extreme heat to put less additional force on the tracks, resulting in delays.
Europe is experiencing record-breaking temperatures for the second time this season.London is forecast to reach 37 C (98.6 F) and Paris is expected to hit 42 C (107.6 F). Germany, Belgium, and the Netherlands are also being slammed by scorching temperatures. Meanwhile, large swaths of the United States are recovering from a heatwave last weekend that affected 147 million people.
Extreme heat is not just dangerous for people and planes. It also makes train travel hazardous by causing railroad tracks to bend.
When temperatures rise, steel tracks will expand, meaning they get longer. Heat-related expansion places a lot of stress on the ties, ballasts, and rail anchors that keep the tracks fixed to the ground. Eventually, the tracks will buckle under the force. These are called “sun kinks.” It makes the tracks look like spaghetti.
In the photo above, taken on July 24, 1978, extremely warped rail tracks in New Jersey led to the derailment of a passenger car, which can be seen in the background.
In direct sunshine, steel rails can be up to 20 C (68 F) hotter than the air temperature, according to Britain’s Network Rail. To prevent accidents when the thermometer goes above 46 C (86 F), rail networks require trains to reduce their speed, which is the cause for delays and cancellations. Slower moving trains exert less additional force on the tracks, which helps to prevent buckling.
A previous version of this article was published on July 1, 2013.
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