Thursday 10 February 2022

ESFA 25: European standard freight axle for 25t

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In Europe, two harmonised axle designs (UIC types A and B) are primarily used in freight traffic. Recent years have seen various measures being introduced to improve wheelset maintenance in response to service experience.

In response to strong demand from the railway sector, including VPI, DB, SNCF, SNCB, ÖBB and FS at national level and UIP, UIC, CER and JSG at international level, as well as the freight business in particular, UIC has designed a new European standard freight axle for 25t (ESFA 25) within the framework of the 2015/RSF/406 project launched in 2015.

The aim of the project was to define requirements for a new, international, harmonised and low-maintenance axle with axle load of up to 25 tonnes and additional reinforcements to take further account of operational aspects.

UIC’s primary goal when designing the new axle type was to reduce its life cycle cost. This goal was achieved, in particular, by reducing the maintenance scheme.

The main challenge of this project was to demonstrate that a design with increased levels of safety could be achieved while reducing maintenance costs. This was ensured by means of an extensive failure mode, effects and criticality analysis (FMECA) based on EN 50126 and UIC IRS 80881.

Ultimately, the ESFA 25 axle benefits from a single design with four key features:

  • A standard, patent-free and TSI-compliant design suitable for axle loads up to 25 tonnes,
  • A full safety analysis compliant with CSM requirements,
  • Maintenance reserves for use and repair (machining margins),
  • Greater inspection capabilities.

The project deliverables are now available from the UIC ETF Shop:

The full specification for the UIC ESFA 25 is as follows:

  • A unique, optimised design that takes into account possible reserves on the shaft and seats for maintenance,
  • Fully compliant with European design standards (EN 13103-1) and product standards (EN 13261),
  • Material: EA4T,
  • Application: seven options in accordance with axle load and maintenance programme:
    • 25 t, painted, low maintenance (without NDT for medium maintenance/without EVIC)
    • 22.5 t, painted, low maintenance (without NDT for medium maintenance/without EVIC)
    • 18 t, unpainted, low maintenance (without NDT in medium maintenance/without EVIC)
    • 20 t, unpainted, standard maintenance

IRS 50510-6 was granted the IRS award for standardisation interfaces in March 2021.

In 2018, a project to design a wheel for 25 tonnes was launched – WES25 – the aim being to provide a full wheelset compatible with the ESFA 25 axle. This project is ongoing; collaboration with a wheel manufacturer began in 2022.

For further information, please contact Giulia Russo, Rail System Department, Junior Advisor Rolling Stock at

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