As a key equipment for train track conversion, the stability and safety of railway turnouts directly affect the operation of the entire railway system. In the turnout system, sleepers serve as the foundation components for load-bearing and force transmission, and their durability is particularly important. Ordinary sleepers are difficult to meet the complex working conditions of switch areas, so sleepers that have undergone special anti-corrosion, insect proof, and ant proof treatments are needed to meet higher technical and environmental requirements.
There are significant differences in function and performance between switch sleepers and ordinary anti-corrosion sleepers. Ordinary sleepers mainly bear vertical loads, while switch sleepers also need to withstand frequent lateral forces and vibrations. At the same time, due to their complex structure, susceptibility to water accumulation, and accumulation of impurities, stricter requirements are placed on the material's ability to resist biological damage.
Pine wood has become the main raw material for manufacturing switch sleepers due to its uniform fiber structure, strong and durable material, and easy handling. However, natural pine wood does not have the ability to resist biodegradation, and is susceptible to fungal erosion in humid environments, as well as damage from wood boring insects and termites. Therefore, it is necessary to enhance its durability through a systematic anti-corrosion treatment process.
The anti-corrosion treatment process of switch sleepers includes key steps such as drying, pretreatment, and pressure impregnation. After the raw wood is sawn and shaped, it is first dried to reduce the moisture content and create conditions for the penetration of anti-corrosion oil. Subsequently, the sleepers were placed in a high-pressure treatment tank, and the anti-corrosion oil was fully penetrated into the interior of the wood through vacuum and pressure operations. One of the core indicators of this process is the immersion depth, which must be above 13 millimeters. This depth ensures that even if the surface of the wood wears or cracks due to long-term use, the interior can still effectively resist biological damage.
In terms of insect and ant prevention, anti-corrosion oil has a good repellent effect on common railway pests such as termites and wood boring insects. Due to the numerous structural gaps and high humidity changes, the switch area is more likely to become a breeding environment for insects and ants. Untreated sleepers may be eroded, leading to instability of the turnout geometry and even causing traffic accidents in severe cases. Specialized anti-corrosion oil can effectively block the invasion path of insects and ants, ensuring the long-term integrity of the structure.
The anti-corrosion performance is mainly reflected in the barrier against moisture and microorganisms. Sleepers exposed to rain, snow, moisture, and even stagnant water for a long time are prone to decay. Anti corrosion oil penetrates deep into the wood under high pressure, effectively filling the pores, blocking the supply of water and oxygen, thereby inhibiting the growth of rot and mold. Compared with ordinary sleepers, switch sleepers have stricter processing technology, and their permeability uniformity and depth have higher standards to adapt to more demanding operating conditions.
In addition, the geometric shape and processing method of switch sleepers are also different from ordinary sleepers. They are usually larger in size and require pre drilling, slotting, and other mechanical processing according to the requirements of the turnout equipment. These processes must be completed before anti-corrosion treatment to avoid damaging the existing anti-corrosion layer. Therefore, from material selection to finished products, the manufacturing process of switch sleepers is more refined and integrated.
From the perspective of full lifecycle cost, although high-quality turnout sleepers have a high initial investment, their extended overhaul cycle and reduced maintenance frequency can significantly reduce operational interruptions and economic expenditures. Untreated sleepers may suffer from insect infestation or decay within a few years, while standard anti-corrosion sleepers can have a service life of over thirty years, demonstrating significant technological and economic advantages.
Switch sleepers are not only a type of wood product, but also an indispensable functional component in railway safety systems. In railway operation and maintenance practice, the emphasis on such details is directly related to the reliability of the line and the safety of passengers, and also reflects the profound pursuit of quality control in engineering practice.
