Every year during the college entrance examination season, various sectors of society strive to create a quiet environment for candidates to take the exam. As an important part of urban transportation, railways also bear the responsibility of noise reduction. The selection of track sleepers directly affects the noise level of train operation. Anti corrosion wooden sleepers, especially pine wood, have become a key support for the "silent mode" of railways due to their natural structure and special treatment processes.
Pine wood: a naturally endowed noise reducing base
Pine wood is a common raw material for making anti-corrosion sleepers, with a loose and porous fiber structure that can effectively absorb vibration energy. When the train wheels come into contact with the steel rails and generate high-frequency sound waves, the air chamber inside the pine wood will act like a sponge to buffer the sound energy, converting some mechanical vibrations into heat energy for dissipation. This characteristic makes wooden sleepers better at suppressing noise propagation than concrete or steel sleepers.
The anti-corrosion treatment further extends the noise reduction life of pine wood. After cutting and shaping the logs, anti-corrosion oil is injected into the deep layers of the wood through high-pressure impregnation technology, which can resist insect infestation and moisture decay without significantly changing the sound absorption performance of the wood. In contrast, although concrete sleepers have strong rigidity, their acoustic reflectivity is high; Although composite sleepers are lightweight, they are prone to aging and cracking after long-term use, which may increase abnormal noise.
Shock absorption design: silent collaboration from single point to system
The noise reduction advantage of wooden sleepers not only comes from the material itself, but also from its coordination with the track system. The steel rails are fixed to the sleepers with elastic fasteners, and the flexibility of pine wood allows for slight deformation of the track when the train passes by, reducing the impact noise between the wheel and rail in a "soft against hard" manner. At the same time, the distributed support system formed by the interval laying of multiple sleepers can evenly distribute the train load and avoid local vibration amplification.
With the assistance of ballast (crushed stone layer), the noise reduction effect of anti-corrosion sleepers is more significant. The ballast fills the gaps between the sleepers and together with the wood, forms a sound barrier, further blocking the propagation of vibrations to the ground. However, due to their heavy weight, concrete sleepers often require a stronger roadbed, which may actually transmit vibrations to a wider range.
The social value behind silence
During the college entrance examination period, the railway department often takes measures such as speed limit and reducing honking for trains passing through the examination area, and the popularity of anti-corrosion sleepers makes "passive noise reduction" possible. Even during non speed limit periods, pine sleepers can reduce the noise level of trains passing by by 3-5 decibels - a seemingly small value, but enough to turn the environmental volume of residential areas along the line from "interference" to "acceptable".
In addition, the sustainability of wooden sleepers deserves attention. Pine wood, as a renewable resource, has lower carbon emissions in its production compared to concrete; After anti-corrosion treatment, the service life can reach more than ten years or even decades, and it can be recycled and reused in other environments after retirement. This combination of environmental attributes and noise reduction function is in line with the concept of modern railway green development.
conclusion
From the primitive tranquility of pine forests to the technological quietness of railway tracks, anti-corrosion sleepers have solved the noise problem of the industrial era in the most natural way. With the advancement of technology, wooden sleepers may continue to upgrade in sound-absorbing coatings and structural design in the future, providing more assistance for "silent protection" and urban noise reduction. When candidates are focused on answering questions, they may not notice the quiet changes of the railway tracks outside the window, but this is precisely the silent protection of railway engineers.
