Under-Sleeper Pads Approved for French Rail Network

 

Pandrol’s under-sleeper pads have been approved for use on the French rail network after an 18-month testing programme, confirming compliance with SNCF Réseau’s technical and operational requirements.

 

Approval process and test conditions

The approval followed a comprehensive qualification programme conducted in collaboration with SNCF Réseau. Track testing was carried out over an 18-month period on a dedicated test section designed to replicate real operating conditions on the French network. The trials assessed the mechanical behaviour of the under-sleeper pads under repeated axle loads, as well as their durability and long-term performance in service.

 

This process is intended to ensure that new track components meet stringent criteria for reliability, compatibility, and lifecycle performance before being authorised for widespread deployment on operational lines.

 

Technical function of under-sleeper pads

Under-sleeper pads are installed beneath concrete sleepers to modify the stiffness of the track system. By distributing wheel loads more evenly into the ballast layer, the pads reduce peak stresses acting on sleepers and ballast. This load distribution mechanism helps limit ballast degradation and slows the accumulation of track geometry defects.

 

From an infrastructure perspective, reduced ballast wear and lower sleeper stress contribute to extended service life of track components and longer maintenance intervals, supporting improved availability of the rail network.

 

Materials and installation characteristics

Pandrol’s under-sleeper pads are manufactured from recycled rubber, combining mechanical resilience with a lower environmental footprint. The use of recycled material supports sustainability objectives while maintaining the elastic properties required for track applications.

 

Anchoring of the pads into fresh concrete sleepers is achieved using Pandrol’s patented MFF^® (Micro Filament Fastener) process. This method improves bond strength between the pad and the sleeper during casting, reducing installation time and ensuring consistent positioning without additional mechanical fixing. Once installed, the pads require no routine maintenance and are compatible with a wide range of track designs.

 

Operational and maintenance implications

The approved under-sleeper pads are designed to significantly reduce ballast wear, which is a major driver of track maintenance cost. By limiting ballast breakdown and settlement, the pads help maintain track geometry for longer periods, reducing the frequency of tamping and associated possession time.

 

For infrastructure managers, these characteristics translate into lower lifecycle costs and improved asset availability, particularly on heavily trafficked routes where track degradation rates are high.

 

Relevance for sustainable rail infrastructure

The approval by SNCF Réseau positions Pandrol’s under-sleeper pads for use across the French rail network and potentially in future renewal and upgrade programmes. The combination of mechanical performance, reduced maintenance demand, and recycled material content aligns with broader industry efforts to improve sustainability while maintaining high standards of safety and reliability in railway infrastructure.

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