Polyethylene Sleepers vs Wooden Sleepers: A Comparison of Performance, Advantages and Disadvantages, Price and Service Life

Railway sleepers are essential components of the railway track system that support the rails and distribute the wheel loads to the ballast layer. Traditionally, sleepers are made of hardwood timber, prestressed concrete, or steel, but in recent years, alternative materials such as synthetic composites, engineered plastics, and low-profile prestressed concrete have been developed and used to replace timber sleepers. One of the most promising alternative materials is polyethylene, which is a type of plastic that can be recycled and mixed with mineral fillers and industrial wastes to form composite sleepers. In this blog post, we will compare the performance, advantages and disadvantages, price, and service life of polyethylene sleepers and wooden sleepers based on the available literature and data.

Performance

Several criteria, such as load-bearing capacity, energy absorption, electrical resistance, durability, and compatibility with other track components can evaluate the performance of railway sleepers. Table 1 summarizes the performance characteristics of polyethylene sleepers and wooden sleepers based on some studies.

Criteria	Polyethylene Sleepers	Wooden Sleepers
Load bearing capacity	Higher than wooden sleepers; can withstand static and dynamic loads up to 142 MPa	Lower than polyethylene sleepers; can withstand static and dynamic loads up to 17 MPa
Energy absorption	Higher than wooden and concrete sleepers; can absorb more impact energy from wheel loads	Lower than polyethylene sleepers; can absorb less impact energy from wheel loads
Electrical resistance	Higher than wooden sleepers; can prevent electrical leakage and corrosion of rails	Lower than polyethylene sleepers; can cause electrical leakage and corrosion of rails
Durability	Higher than wooden sleepers; can resist environmental degradation, vermin attack, extreme weather, and fire	Lower than polyethylene sleepers; can be susceptible to environmental degradation, vermin attack, extreme weather, and fire
Compatibility	Compatible with timber sleepers; can be used in interspersed track with similar dimensions and mechanical properties	Compatible with timber sleepers; can be used in interspersed track with similar dimensions and mechanical properties

Advantages and Disadvantages

Based on the performance comparison, we can identify some advantages and disadvantages of polyethylene sleepers and wooden sleepers. Table 2 lists some of them.

Material	Advantages	Disadvantages
Polyethylene Sleepers	– More durable and resilient than wooden sleepers – More environmentally friendly than wooden sleepers as they use recycled plastics and waste materials  – More cost-effective than wooden sleepers in the long run as they have a longer service life and lower maintenance cost  – More suitable for parts of the track where large impacts from the wheel are experienced or where the reduction of stiffness is intended	– More expensive than wooden sleepers in the initial purchase cost  – More difficult to manufacture than wooden sleepers as they require special equipment and processes  – more sensitive to temperature changes than wooden sleepers as they have higher thermal expansion coefficient  – More prone to creep deformation than wooden sleepers as they have a lower modulus of elasticity
Wooden Sleepers	– Cheaper than polyethylene sleepers in the initial purchase cost  – Easier to manufacture than polyethylene sleepers as they require simple equipment and processes  – Less sensitive to temperature changes than polyethylene sleepers as they have lower thermal expansion coefficient  – Less prone to creep deformation than polyethylene sleepers as they have a higher modulus of elasticity	– Less durable and resilient than polyethylene sleepers  – Less environmentally friendly than polyethylene sleepers as they use hardwood timber that is scarce and inferior in quality  – Less cost-effective than polyethylene sleepers in the long run as they have a shorter service life and higher maintenance cost  – Less suitable for parts of the track where large impacts from the wheel are experienced or where the reduction of stiffness is intended

Price

The price of railway sleepers depends on various factors, such as material cost, manufacturing cost, transportation cost, installation cost, and maintenance cost. According to some data from the Australian market, the average price of polyethylene sleepers is 2-3 times more than wooden sleepers. However, the price of polyethylene sleepers may vary depending on the type and content of fillers used, and the price of wooden sleepers may vary depending on the quality and availability of timber. Moreover, the price of sleepers may change over time due to inflation, demand, and supply.

Service Life

The service life of railway sleepers is influenced by material properties, environmental conditions, loading conditions, and maintenance practices. According to some studies, the expected service life of polyethylene sleepers is around 50 years, while the expected service life of wooden sleepers is around 20 years. However, the actual service life of sleepers may differ from the expected service life due to various factors that affect their performance and durability.

 

Conclusion

In conclusion, polyethylene sleepers and wooden sleepers have different performances, advantages and disadvantages, prices, and service life. Polyethylene sleepers are more durable, resilient, environmentally friendly, and cost-effective than wooden sleepers in the long run. Still, they are more expensive, difficult to manufacture, sensitive to temperature changes, and prone to creep deformation than wooden sleepers in the short run. Polyethylene sleepers are also more suitable for parts of the track where significant impacts from the wheel are experienced or where the reduction of stiffness is intended. Therefore, polyethylene sleepers can be a viable alternative to wooden sleepers for railway track applications, especially in secondary lines where timber sleepers are being replaced by a spot replacement strategy.