A rail pad is inserted in between the rail and baseplate or sleeper. Rail pad is introduced to the railway fastening system because of its resilience or viscoelasticity which can be implemented in the intervention of fatigue cracking of sleepers. The dynamic stress from the wheel or rail impact from both regular and irregular movements is attenuated.
How does the railway pad work?
Railway pads work as elastic buffers between rails and sleepers, absorbing shock, dampening vibrations, distributing load, and preventing wear/noise by providing a cushioning layer, using specialized rubber or polyurethane to manage the intense forces from passing trains for smoother, quieter, and more durable tracks.
Key Functions
- Shock Absorption: They cushion impacts from wheels, preventing direct hard-on-hard contact that can damage rails and sleepers.
- Vibration & Noise Control: By absorbing vibrations, they reduce track noise for nearby areas and improve passenger comfort, stopping track elements from loosening.
- Load Distribution: They spread the heavy load of the train over a larger surface area of the sleeper, preventing stress concentration and fatigue.
- Wear Prevention: They act as a shield, stopping the rail from rubbing and grinding against the sleeper, which would otherwise cause abrasion and crushing.
- Electrical Insulation: Some pads provide electrical isolation, crucial for signaling systems.
How is the freeze-thaw resistance of railway pads tested?
Railway pad freeze-thaw resistance is tested by subjecting pads (or specimens from them) to rapid, repeated freeze-thaw cycles in a climate chamber, monitoring deterioration using ultrasonic velocity, mass/dimension changes, resonance frequency, and residual strength, often following standards like ASTM C666 or GB/T50082, measuring degradation like cracking, spalling, and changes in mechanical properties.
- Dynamic Modulus: Measuring fundamental frequency (transverse vibration) to calculate relative dynamic elastic modulus, indicating internal damage.
- Ultrasonic Pulse Velocity (UPV): Tracking changes in pulse velocity through the material to detect micro-cracking.
- Weight & Dimension: Recording mass loss and dimensional changes (length, volume) over cycles.
- Visual Inspection: Checking for surface damage like scaling or spalling (concrete) or cracking/tearing (rubber pads).
- Residual Strength: Performing splitting tensile tests after cycles to assess mechanical property loss.
What are the effects of low temperatures on rail elastic pads?
Low temperatures make rail elastic pads stiffer, reducing their ability to absorb vibration and impact, which decreases track elasticity, increases noise (rolling noise), and can negatively affect ride comfort and vehicle-track interaction, especially below the pad's glass transition temperature (Tg), leading to a more brittle, less damped state. This increased stiffness, particularly noticeable with materials like Natural Rubber (NR) and EPDM, can cause higher dynamic stress, potentially increasing track component failure risks in extreme cold.
GNEE RAIL provides exceptional elastic rail pads of various types for high-speed railways, normal-speed railways, and cranes. Especially the rail pads made of rubber, EVA, TPEE, and HDPE are very popular with customers. Our railway rubber pads fit the rails such as UIC54, UIC60, BS80lbs, BS100lbs, etc. We have more than 130set of machines in our production lines which can reach an annual production capacity of up to 2000, 000 pieces of rail pads. We offer a wide range of rail pads and other track materials at competitive prices.