At 3am, when the last high-speed train entered the maintenance workshop, track engineer Lao Wang was squatting beside the tracks, gently tapping the newly replaced sleepers with a rubber hammer. The sound is muffled, the rebound is fast, and this batch of pine anti-corrosion sleepers can withstand it. "He straightened up and patted his knees, and a few scattered lights were shining on the platform in the distance. The railway tracks had a cold and hard metallic luster in the moonlight. Few people know that these seemingly ordinary woods are the secret to the smooth operation of trains.
Shock absorption code inside the sleepers
Sitting in a high-speed train carriage, we often marvel at how smooth a train with a speed of 350 kilometers per hour can be. When the collision between the wheels and rails is inevitable, sleepers become the first line of defense to resolve the vibration. Unlike ordinary wood, sleepers that have undergone deep anti-corrosion treatment have a unique "softness with rigidity" characteristic - they can absorb wheel rail impacts and evenly distribute residual vibrations to the ballast layer.
The production of pine anti-corrosion sleepers begins with long-term high-pressure impregnation: anti-corrosion oil penetrates the wood fibers under high temperature and pressure, forming a stable anti-corrosion barrier. This treatment not only extends the lifespan of the sleepers, but also transforms the originally loose cellular structure of pine wood into countless micro shock absorbing units. When the train passes by, these wooden cells filled with anti-corrosion agents act like miniature springs, which can both counteract high-frequency vibrations and buffer low-frequency impacts.
The dilemma of cement sleepers
A section of the Beijing Guangzhou railway once attempted to use concrete sleepers. This gray component, weighing several hundred pounds, does demonstrate excellent stability on straight roads. But when the train enters a bend with a radius of 800 meters, the vibration generated is relatively noticeable. The track monitoring device shows that cement sleepers directly transmit the wheel rail impact to the track bed, with a vibration acceleration 2.3 times that of wooden sleepers.
The problem lies in the material properties. The compressive strength of concrete is 20 times that of pine wood, but its elastic modulus is over 100 times higher. This means it is more like a hard shield than a flexible buffer. In the northwest region where there is a large temperature difference between day and night, this rigid structure is also prone to micro cracks caused by thermal expansion and contraction, further exacerbating vibration transmission.
Invisible anti-corrosion technology
At Qingdao Tiehan Wood Preservation Co., Ltd., pine wood needs to undergo high-temperature and high-pressure anti-corrosion oil immersion in a steam pressure vessel. The anti-corrosion oil with a temperature controlled between 85 ℃ -90 ℃ can not only kill the insect eggs inside the wood, but also open the wood fiber channels through thermal expansion. The subsequent vacuum pressurization process allows the anti-corrosion oil to penetrate deeper into the wooden structure.
On the railway line under the moonlight, the black and shiny oil surface of the anti-corrosion sleepers shimmered with a faint reflection in the night, representing the light of anti-corrosion ability. The distant sound of the train's whistle entering the station, the sleepy passengers on the platform would not know that the smooth journey they were about to experience began with these oiled sleepers soaked in anti-corrosion oil. At the moment when the wheels meet the rails, those sleepers that have been injected with anti-corrosion oil are silently weaving a precise invisible shock-absorbing net.
