When the temperature of the rail increases greatly, it will expand to a certain extent, leaving a certain gap to prevent the rail from expanding and squeezing each other to cause accidents; The general law of thermal expansion of objects: Generally, objects expand when the temperature increases and contract when the temperature decreases. Under the same conditions, the expansion of gas is the most obvious, followed by liquid and solid.
Extended data:
The earliest "slab track" used for railway tracks was made of thin iron sheets nailed to wooden tracks. However, the bearing capacity of this kind of track is very low, so although the construction cost is very low, it is not cost-effective in the long run.
Later, railways began to switch to rails. After decades of improvement, the material used was changed to steel, and the quality of steel was greatly improved. Rails used in railways must bear great pressure, so high-quality steel must be used. The requirements of railway rails for steel are higher than those for other purposes.
The same small flaw, the steel bar used in the building, may not be a problem; However, the appearance of railway rails will lead to rail fracture and train derailment at any time.
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