Railway springs are among the most critical components of the suspension systems used in freight wagons, locomotives and other rolling stock. Their primary function is to absorb the dynamic loads generated during operation, ensure proper vehicle behaviour on the track, and contribute to the safety, ride comfort and service life of the entire suspension system.
Because of their safety-critical function, the design, manufacture and maintenance of railway springs must comply with stringent technical and quality standards. Choosing an experienced manufacturer is therefore essential to ensure components are fully compliant with industry regulations and subjected to rigorous quality controls throughout every stage of the production process.
Main types of railway springs
Modern rolling stock uses different types of railway springs, selected according to the vehicle type, axle loads and suspension system requirements.
The most common solutions include:
- Compression coil springs, manufactured using both hot and cold coiling processes for primary and secondary suspension systems;
- Leaf springs, still widely used in several railway applications thanks to their robustness, durability and proven reliability;
- Volute springs, designed for specific suspension configurations requiring high load-bearing and energy absorption capabilities.
Selecting the most suitable spring depends on several factors, including operating conditions, vehicle weight, load cycles, required spring stiffness and fatigue resistance.
Springs Group manufactures railway springs in compliance with the main international railway standards, including EN standards and UIC specifications for railway applications.
Inspection and preventive maintenance
Preventive maintenance is essential to preserve the efficiency of railway suspension systems and prevent failures that could compromise operational safety and vehicle performance.
Typical maintenance activities include:
- Visual inspections to identify permanent deformation, corrosion or surface cracks;
- Dimensional inspections to verify free height and geometric characteristics;
- Spring stiffness and load-deflection testing;
- Non-destructive testing (NDT), where required by maintenance programmes or manufacturer specifications.
During maintenance, it is important to verify that railway springs continue to meet their original elastic characteristics. Even small variations in free height or spring stiffness may affect suspension performance, alter wheel-to-rail load distribution and accelerate wear on other bogie components.
Early identification of any anomalies allows springs to be replaced before deterioration impacts suspension performance, reducing vehicle downtime and optimising maintenance costs.
When should a railway spring be replaced?
Railway springs are designed to withstand millions of operating cycles, yet they remain subject to wear and fatigue throughout their service life.
Replacement becomes necessary in the event of:
- Loss of elastic properties;
- Permanent deformation;
- Cracks or defects detected during inspections;
- Advanced corrosion;
- Wear exceeding the limits specified by the manufacturer or maintenance programme.
Railway springs are classified as safety-critical components. Any deterioration may compromise suspension performance, vehicle stability and ride quality. For this reason, damaged or defective springs are generally not repaired but replaced with components fully compliant with the original technical specifications.
Besides visible damage, fatigue caused by repeated loading and unloading cycles must also be considered. Consequently, many railway maintenance programmes include the preventive replacement of springs during scheduled overhauls, even when no obvious defects are visible.
EN 13298 and UIC 822 standards
Compliance with recognised technical standards is a fundamental requirement throughout the railway industry to ensure safety, reliability and long-term performance.
EN 13298 applies to steel helical springs used in railway vehicle suspension systems. The standard establishes design criteria, defines the technical and quality requirements for the components, specifies approved manufacturing processes and quality assurance procedures, and sets the requirements for dimensional inspections, mechanical testing and verification activities to ensure the reliability, safety and performance of railway springs.
UIC 822, issued by the International Union of Railways (UIC), is one of the principal technical references for railway suspension springs. The specification defines requirements for materials, manufacturing processes, heat and surface treatments, testing procedures and acceptance criteria, ensuring high levels of fatigue strength, reliability and long-term performance under service conditions. Compliance with UIC 822 helps ensure that railway springs installed on freight wagons, locomotives and other rolling stock meet the demanding quality and safety requirements of the railway industry.
Quality assurance and testing
The quality of railway springs depends not only on their design but also on the control of the entire manufacturing process.
Every stage, from steel selection and heat treatment to shot peening and final inspection, must be monitored through documented procedures and calibrated measuring equipment.
Laboratory testing typically includes dimensional inspections, compression testing, spring stiffness verification, load testing and geometric checks to ensure full compliance with railway technical specifications. Springs Group also operates dedicated testing equipment specifically designed to perform railway spring testing in accordance with the applicable industry standards, ensuring high measurement accuracy and repeatability.
For railway applications, complete material traceability is often required, from the steel melt through to the finished component. Manufacturing records, inspection reports and test certificates facilitate maintenance activities, customer audits and compliance verification within railway safety management systems.
Railway springs for maintenance and spare parts
In addition to supplying springs for new rolling stock, Springs Group manufactures railway springs for maintenance, overhaul and spare parts, supporting specialised workshops, railway fleet operators and rolling stock manufacturers.
The ability to manufacture components that match the original specifications, using technical drawings, OEM part numbers or physical samples, supports maintenance, overhaul, refurbishment and retrofit projects, even for railway vehicles whose original spare parts are no longer available.
Comprehensive technical documentation, full material traceability and certified testing simplify inspection procedures and help ensure compliance with railway industry requirements.
With extensive experience in the railway sector, Springs Group supplies a complete range of railway springs, including compression coil springs, leaf springs and other engineered spring solutions, designed to meet the requirements of the main international railway standards. The company supports customers with both new production and replacement springs for the maintenance of freight wagons, locomotives and other rolling stock.