Thermal Expansion Management in Railway Tracks
To address the challenges posed by thermal expansion and contraction, conventional railway tracks are equipped with expansion joints, special gaps between the rails typically measuring about 6mm in width. These joints allow for the controlled expansion and contraction of the rails in response to temperature fluctuations. Additionally, the small holes through which the track bolts pass on the rail fishplate are elliptical in shape. This design enables the track bolts to displace slightly when the rail expands during hot weather conditions.
This displacement capability is crucial for preventing excessive stress on the rails. Without adequate expansion space, the rails would be subjected to significant pressure or tension with every degree of temperature change. For instance, a temperature difference of 1 degree could translate to 1.6 tons of pressure or tension on the rails. In areas where the temperature fluctuates by 30 degrees over the course of a year, the cumulative stress on the rails could amount to 50 tons. Such excessive stress levels can lead to rail skewing and pose serious safety risks for train operations.