Railway transportation equipment 2021-06-20 08:28:01 Railway lines bear the quality of rolling stock and trains, and guide their running direction, so it is the basis of operation. The railway line is composed of three parts: subgrade, bridge and tunnel, and track. The track is composed of steel rails, connecting parts, sleepers, track beds, anti-climbing facilities and turnouts. In the past, the steel rails used in my country were 38kg per meter, mostly 3kg and 50kg. At present, most of the main trunk lines have been laid with steel rails with a mass of 60kg per meter. Rails with a mass of 70kg per meter are under development. The use of heavy rails can help increase the strength and stability of the line, reduce the amount of maintenance, and improve the passing capacity. The lengths of rails laid on general lines are 12.5m and 25m. When rails are laid continuously, 'rail gaps' should be left between adjacent rails in order to adapt to thermal expansion and contraction when temperature changes. In order to reduce the shock and vibration of the train to the rail joints, increase the smoothness of the train operation and reduce the amount of maintenance, countries are rapidly promoting the 'seamless track': the 'seamless track' is generally made up of 25m-long steel rails connected by high-strength bolts. , Gusset-type fasteners or elastic fasteners are 'locked' on the sleeper to prevent thermal expansion and contraction of the rail. The rails are fixed on the sleepers (wood sleepers or reinforced concrete sleepers) with connecting parts. The distance between the inner sides of the two rail heads and the track centerline is called the gauge. The gauge of most railway lines in our country is 1435mm, which is also the common gauge in most countries in the world and is called the standard gauge. The larger one is called wide-gauge. For example, there are a large number of wide-gauge railways in the CIS, Pakistan, Bangladesh, and India, with a gauge of 16.76mm; the smaller one is narrow-gauge, such as Malaysia, Vietnam, Myanmar, Pakistan, Bangladesh, India and my country's Yunnan Province have meter gauges with gauges of 1000rFm, inch gauges with gauges of 762mm and 610mm.