Xinhua nanjing, may 24, question: how did the train's voice disappear? - i've heard about the steel rail adjustment
Xinhua news agency, journalist zhu guo liang
Railway maintenance workers are cutting steel tracks in the north turn-off of the ningi railway station. Xinhua news agency, journalist zhu guo liang
In the early hours of the morning, the station of the ning kai railway was completely silent and cold. In the north turn-off of the platform, there is another hot flash: headlights for workers, carlights for transport of steel tracks and flashlights between steel tracks, lighting of this small area, sparks of cutting and grinding of steel tracks, especially rotting in the night, flames of melted steel sand and aluminium oxide pieces of the aluminum welding, spreading heat around and the workers' “one, two, three” rings from time to time。
Between 2300 hours on 21 may and 3 a. M. On the following day, approximately 40 workers in the new long section carried out re-orbiting and stress adjustment works in the north turn-off of the hainan station with various operational tools。
The technicians present at the site, liu xie xin, told reporters that the temperature would stretch or reduce by about 1. 18 mm for each 100-metre length steel track at 1°c. In the past, subject to the conditions of the process, a steel track is set at 25 metres long, with approximately 8 mm of orbital stitches set aside for each of the two rail links to respond to thermal swelling and cooling of the steel track。
“when the train passes through the rails, the wheel collides with the steel rail, making the sound of `twilight, twilight'. For a long time, this voice has gradually become the iconic voice of the train that is remembered.” liu jie-chul says。
Today, the sound is gradually disappearing, not only is the high-speed motor vehicle not “swirling”, but it is also not heard on many super-fast and fast trains, and passenger comforts have increased dramatically。
Railway maintenance workers are welding steel tracks in the north turn-off area of the ningbai railway station. Xinhua news agency, journalist zhu guo liang
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“the re-orbiting and stress adjustment work carried out today is associated with the disappearance of this `square'.” according to chen hashi, the head of the construction work on the site, “this is behind the upgrading of the quality of the steel tracks, as well as technological advances in equipment, and the contribution of railway workers”
The new long segment is part of the shanghai railways bureau group limited, which is responsible for the maintenance of approximately 1,400 km of railway lines in jiangsu and anhui。
"in the past, our speed line used a `50 steel track', which is now `60 steel track'." according to liu, “the difference between `50 steel tracks' and `60 steel tracks' is that the same 1 metre long steel track, with almost no change in its appearance, weighs 50 kg each and 60 kg each.”
The change in the weight of the steel track is followed by an increase in resilience, strength and laying the foundation for seamlessness of the steel track. Liu xie xian described the previous standard steel track as 25 metres long and now a steel track is 100 metres long or even 500 metres long. And through seamless welding, the tracks become a whole。
Haian is located in the centre of jiangsu, where the maximum temperature of the steel track is 55°c, the lowest temperature is 5°c below zero, and the temperature of the steel track is about 60°c in a year。
Chen bridge explained that, based on the local maximum orbital temperature and the lowest orbital temperature, we would calculate a “locked orbital temperature” and use the length of the steel track under “locked orbital temperature” as a reference. When the temperature is lower and the steel tracks are replaced and laid, the worker will use specific equipment to stretch the steel tracks to the length of the "lock-on-orbit temperature" and release the steel-track temperature stress in advance. In this way, temperature rises within a given range and the steel tracks are not distorted by heat expansion. On the contrary, if the steel tracks are replaced and laid on a temporary basis at higher temperatures, and when the temperature is reduced to “lock-on” temperatures, workers will replace this part of the tracks in time to release the temperature stress in case the tracks are broken by cold contraction。
“the placement and replacement of steel tracks is generally chosen in the spring and autumn, at which point the temperature is closer to the `locking-on temperature'.” liu xie-chil says。
A steel-track welding point in the north end of ningi railway station and smooth and smooth on the wheel. Xinhua news agency, journalist zhu guo liang
The orbital pillows, the quartz, and the buttons that lock the steel track on the orbital pillow are also key to preventing the transformation and bending of the steel track due to thermal swelling and freezing。
Liu xie xin described the fact that every 60 centimetres on the railway line had a set of buttons, locking the tracks to the on-orbit pillows, which were then filled with quartz and, while bearing the impact of the train, produced horizontal and vertical resistance to the “hot and cold contraction” of the tracks to prevent their deformation and flight. As a result, in the course of line maintenance, if the pebbles on the line are found to be weak, they should be replenished in a timely manner; or if the orbital pillows, buttons are loose, they should be replaced and secured immediately。
According to statistics from the new long sections, in 2023 it maintained a total of 38,000 cubic metres of restocking lines, such as the ning kai railway and the cebu railway。
At the sea an station, journalists saw two steel tracks replaced by workers cut, retrenched, aluminum thermal welding, injury, fine grinding, sewn to the original steel tracks, almost completely melted into a whole and touched with their hands, with little or no confusion。
Chen hashi said: “line maintenance is less well known, but we owe it to the train to operate safely and to improve its comfort”
