SIST EN ISO 22074-4:2024/oprA1:2025

Overview

SIST EN ISO 22074-4:2024/oprA1:2025 is an important forthcoming amendment to the international standard governing railway infrastructure – rail fastening systems, specifically focusing on test methods for resistance to repeated loading. Developed under the aegis of ISO/TC 269/SC 1 and coordinated with the CEN, this amendment (Amendment 1) updates test procedures to enhance the reliability and performance evaluation of rail fastening assemblies under cyclic stresses.

The standard applies to rail fastening system components used extensively in rail tracks, ensuring safety, durability, and operational efficiency. It introduces clarifications and modifications to the critical aspect of clamping force measurement within these systems, which directly impacts the fastening system's ability to withstand dynamic loading from passing trains.

Key Topics

• Rail Fastening Systems: Components that secure rails to sleepers, essential for track stability and safe train operations.
• Repeated Loading Resistance: Methods for testing how rail fastening systems perform under repeated dynamic stresses equivalent to real-world operation.
• Clamping Force Measurement: Updated procedures to measure the clamping force that holds rail assemblies firmly, crucial for maintaining rail integrity.
• Test Methods Update: Modification of Subclause 5.4.3 with reference to ISO 22074-7 to define accurate clamping force determination techniques.
• Direct and Indirect Offset Fastening Systems: Differentiated approaches for test procedures depending on the type of fastening layout.

This amendment stipulates particular clarifications:

• For assemblies tested on two rail seats, specific guidelines define how to apply and interpret clamping forces.
• For direct offset fastening systems, vertical force is applied midway between two rail seats, and clamping force is halved to represent load distribution.
• Indirect offset fastening systems refer explicitly to the procedures in ISO 22074-7:2021.

Applications

This standard and its amendment serve multiple practical uses across the rail industry:

• Railway Track Design and Maintenance: Provides engineers and maintenance teams with standardized methods to validate fastening system durability under cyclic loading.
• Quality Assurance in Manufacturing: Assists manufacturers in certifying that rail fastening systems meet rigorous performance requirements before market release.
• Safety Compliance: Supports regulatory bodies and infrastructure managers in enforcing proper safety margins for railway components subjected to dynamic load.
• Research and Development: Enables R&D professionals to benchmark and improve fastening system designs with validated, repeatable test methods.
• International Trade Facilitation: Harmonizes testing standards globally, allowing for compatibility and ease of acceptance in international rail projects.

Related Standards

• ISO 22074-7: Specifies detailed procedures for determining clamping force in rail fastening systems, referenced within this amendment.
• ISO 22074 series: Covers various aspects of testing and requirements for railway rail fastening components.
• EN ISO 22074-4:2022: The base standard prior to this amendment, detailing initial test methods for resistance to repeated loading.
• ISO/TC 269: The technical committee responsible for railway applications standards, including infrastructure and components.

Summary

SIST EN ISO 22074-4:2024/oprA1:2025 Amendment 1 is a critical update enhancing the methodology of testing rail fastening systems against repeated loading stresses. By refining clamping force measurement techniques and addressing different fastening system layouts, it ensures high reliability, safety, and performance in railway infrastructure components. Industry stakeholders including manufacturers, designers, and regulatory bodies will benefit from adopting these harmonized and technically sound standards. For further information and official adoption, consult the ISO Central Secretariat or national standards bodies.

Keywords: railway infrastructure, rail fastening systems, repeated loading, clamping force, test methods, ISO 22074, rail track safety, railway standards, rail fasteners, infrastructure maintenance