Jimu News reporter Pan Xiheng
Photojournalist Li Hui
Correspondent Li Dan Chuan Qidou
Intern Ray Purple
At about 6 p.m. on July 24, the setting sun shone obliquely on the dense outbound track of the Gutian depot of the Wuhan Metro, and the ground temperature was as high as 45 °C. More than 20 linemen were divided into 5 teams and raced against time to inspect the track lines and turnouts. About 3 hours later, the train that has completed the evening peak transportation task will pass through this "throat line" and return to the warehouse to rest.
At sunset, the ground temperature is still 45°C
As the throat connecting the parking garage to the main line, the importance of the track area of the depot is self-evident, and if there is a failure, it may affect the entry and exit of vehicles on the entire line. Therefore, it is necessary to carry out maintenance of this part of the track in a planned manner.
At about 6 o'clock in the afternoon of the 24th, after confirming that the maintenance area had been cut off and the power was checked and grounded, Ren Zhuojun, the leader of the professional Gutian work class of Wuhan Metro Line 1, and more than 20 members of the work team, wearing long clothes and trousers, wearing labor protection shoes and straw hats, carried the maintenance tools and entered the operation site in turn.
Jimu News reporters saw at the scene that their task that day was to conduct a comprehensive inspection of the lines and turnouts of the Gutian Depot. Wu Pengda and Ma Changjian used the ruler and chord line to measure the distance and height between the two strands of rails; Zhu Fan and Zhou Wang inspected the gaps at the rail joints; Ma Shuai, Kang Li and others measured and compared the turnout tracks......
Bend over, get up, lie on the ground...... The Jimu News reporter saw at the operation site that although the sun was setting, the scorching sun was still scorching the earth, and the thermometer showed that the ground temperature was 45 °C. The reporters' clothes gradually became sweaty, and the light blue overalls of the linemen had already become sweaty and turned dark blue.
"In hot weather, our maintenance operations are mainly based on inspection, and if we find abnormal data, we will record it and carry out special maintenance and rectification at night." Ren Zhuojun introduced, the internal stress of the rail in high temperature weather is large, if a large area of fasteners are loosened for maintenance operations, the rail will lose its binding force will appear to expand the rail, it is difficult to recover, so the high temperature weather is mainly inspected during the day and repaired at night. In the non-high temperature season, the maintenance work of the subway depot line and turnout is arranged at noon, and in the summer high temperature weather, in order to ensure the safety of personnel and equipment, this operation point will be adjusted to the evening period, and try to avoid the highest temperature period at noon without affecting the line of sight.
The clock turned to 8 o'clock in the evening, the sky turned dark, and after completing the maintenance task, the team operators counted the tools and left the track area in an orderly manner. In another hour, the trains that have ended the evening rush hour service will "go home" one after another through the tracks they have checked to confirm that they are safe.
In summer, it is necessary to focus on observing the width of the rail joint
The 10.3-kilometre track of the Gutian Depot consists of 824 steel rails, including 1,563 joints. In severe cold and high temperature weather, the line maintenance personnel should pay attention to observing and measuring the width of the gap between the rails, if the high temperature rail gap is 0 mm in summer, the internal stress of the rail can not continue to be released, and the phenomenon of rail expansion may occur, at this time manual adjustment is required; In winter, the steel seam of the low temperature rail is greater than 18 mm, and the rail is easy to bend the bolts, which affects the driving safety.
At the end of 2022, the Gutian Depot completed the overhaul and reconstruction of the line, and the track line frame is more stable after the transformation. "In summer, the rails are not tight, and in winter, the screws are not bent." The geometric size inspection data taken out by Ren Zhuojun shows that the current measurement data has changed little from the measurement data of the same period last year, and they are all within the range of maintenance standards.
Fan Hao, director of the first workshop of the public works center of Wuhan Metro Operating Company, told reporters that the overhauled line has been running all year round, and all indicators are normal; Now it is the second summer hot weather, and it is necessary to collect and summarize the indicators on the site again. "The data on the table is not only a string of numbers, but we also need to find out the change values from this millimeter, so as to explore the rules and use them as a basis for maintenance."
There are 27 depots and parking lots for the 486-kilometer operating lines of the Wuhan Metro, and the length of these sections of rail lines reaches 245 kilometers. In order to ensure that hundreds of trains can leave the warehouse and return to the section normally in hot weather, thousands of line maintenance workers are making every effort to meet the scorching heat, verify and verify during the day, accurately analyze, and repair and rectify at midnight to ensure the safety and stability of the line under high temperatures.
(Source: Jimu News)
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