Rail pad, is a rail rubber plate between the rail tie plate and foot of the rail, made of elastic polyurethane, which is interposed between steel rails and sleepers to reduce friction and impact. Rail pads are fastened within a fastening system by screw spikes or rail bolts into the sleeper ties. It is designed to increase the elasticity of the superstructure, reduce shock and vibration in the rail system.
What is the operating temperature range of rail pads?
Rail pad operating temperatures vary by material but generally span from -50°C to +70°C (-58°F to 158°F) for standard rubber/EVA pads, offering wide usability, while specialized polyurethane (PU) pads can extend to -40°C to 70°C, and even tougher materials handle wider extremes, ensuring performance in diverse climates from cold winters to hot summers.
Common Temperature Ranges by Material:
- Rubber & EVA Pads: Often cited as -50°C to 70°C (-58°F to 158°F).
| Rubber Rail Pad | ||
| Technical Parameter | Unit | Value |
| Stiffness | KN | 90-130 |
| Hardness Shore A | ℃ | 72-80 degree |
| Electronic Resistance | Ω | ≥ 106 |
| Tensile Strength before Aging | Mpa | ≥12.5 |
| Elongation before Aging | % | ≥250 |
- Polyurethane (PU) Pads: Can reach wider ranges, like -40°C to 70°C (-40°F to 158°F), with consistent stiffness.
- Specific EVA Products: Some EVA pads target -40°C to 60°C (-40°F to 140°F), suitable for light rail.
| EVA: Polyethylene 80%, Vinyl Acetate 20%. | |||
| Technical Parameter | Unit | Technical Requirement | Value |
| Density | g/cm3 | 0.95-0.98 | 0.95 |
| Tensile Strength | Mpa | ≥15 | 16 |
| Elongation | % | >500 | 550 |
| Melting Point | ℃ | 170-190 | 170 |
| Insulation Resistance | Ω | ≥1×1010 | 5.0 ×1010 |
| Hardness | A | ≥90 | 92(A) |
What precautions should be taken when using a rail pad in extreme temperatures?
When using rail pads in extreme temperatures, ensure pads are made from high-quality, resilient materials (rubber/polyurethane) designed for temp variations, choose thicker pads for big swings, maintain proper tension (re-tighten fasteners after temp changes), implement speed restrictions during peak heat to prevent buckling, and store pads away from heat/chemicals to preserve their function, as extreme heat softens pads (worsening vibration dampening) and extreme cold makes them rigid.
Precautions for Extreme Heat (High Temps)
- Material Choice: Use pads made from materials like polyurethane or specialized rubber that resist softening and maintain stiffness in heat.
- Thicker Pads: Opt for thicker (12-15mm) pads to better absorb expansion and stress from big temperature swings.
- Speed Restrictions: Reduce train speeds during hot periods; slower trains exert less force, lowering buckling risk.
- Fastener Maintenance: Re-tighten fasteners and check rail joints, as heat causes expansion and increased stress.
- Track Coatings: Consider painting rails white to reflect heat and reduce rail temperature.
Precautions for Extreme Cold (Low Temps)
- Material Resilience: Ensure pads remain flexible and don't become excessively rigid, as cold increases their stiffness.
- Damping: Be aware that while cold improves damping slightly, very rigid pads can channel vibrations into sleepers rather than dampening them
What is the thickness of the rail pad?
Rail pad thickness varies significantly by application, typically ranging from 5 mm to 20 mm (or even thicker for specialized uses), with standard rubber pads often around 5-10 mm, while heavier applications (cargo/high-speed) use thicker pads (12-20mm) for better cushioning, and thinner pads (4.5-6mm) might be used for lower-profile needs, all designed to reduce vibration and protect sleepers.
As a professional rubber rail pad manufacturer GNEE RAIL can produce various standards of rubber rail pads and other rail fasteners. If you want to build a railway line, do not hesitate to contact us, we can supply all types of rubber rail pads with different materials. If necessary, we can make customized rubber rail pad production.