Polyurethane Under Sleeper Pad (USP)

The polyurethane sleeper pad is a customized elastic system. As a fixed elastic element at the bottom of the sleeper, it is installed directly under the sleeper to increase the vertical elasticity of the structure. It can be applied to ballasted tracks and solid track beds, functioning to delay ballast degradation and provide cushioning and noise reduction respectively, demonstrating good application results.

Main Functions and Characteristics

（1）Increase vertical elasticity, reduce wheel-rail impact force.

By increasing the vertical elasticity between the sleeper and the ballast, the load distribution among sleepers can be balanced, increasing the number of sleepers sharing the axle load, reducing the load acting on the ballast surface, slowing down ballast degradation and wear, meanwhile减缓 (slowing down) short-wave irregularities of the track and rail wear on small-radius curves, and extending the tamping cycle.

（2）Increase the contact area between sleeper and ballast.

Increasing the contact area between the sleeper bottom and the ballast layer improves the load transfer performance of the track bed, prevents track bed settlement caused by overloading and crushing of ballast particles, and alleviates sleeper hanging.

（3）Vibration reduction effect.

The positive effect of the sleeper pad is also reflected in its ability to maintain good track geometry, maintain high smoothness, reduce train impact forces, keep the track bed and components in good condition, and reduce maintenance requirements.

Applications

Polyurethane USPs are suitable for a wide range of railway environments:

High-speed railway lines for optimal ride comfort and safety

Urban transit systems with strict noise regulations

Freight tracks requiring enhanced load management

Curves, turnouts, and bridges to mitigate localized stress

Why Choose Polyurethane USPs?

Improve track longevity and performance

Enhance passenger comfort and ride quality

Reduce operational and maintenance costs

Environmentally resilient and long-lasting

Conclusion

Polyurethane Under Sleeper Pads provide a reliable, cost-effective solution to modern railway challenges. By integrating USPs into track design, railway operators can achieve quieter, safer, and longer-lasting tracks, while reducing maintenance efforts and costs.