Overview
EN ISO 24478:2024 (adoption of ISO 24478:2023, corrected 2024-04) is a CEN standard that provides a unified, authoritative vocabulary for braking in railway rolling stock. Its scope is concise: it defines terms for brakes and braking in rolling stock, supporting clear communication across design, operation, maintenance and regulatory activities. This edition supersedes EN 14478:2017 and incorporates the ISO corrected version.
Key topics
The standard organizes braking terminology into precise areas to cover the full braking domain:
- Basic definitions: braking, brake, brake unit, etc.
- Brake system compatibility: compatibility between coupled vehicles and systems.
- Performance: braking performance parameters and deceleration definitions.
- Purposes of braking: stopping, slowing, drag braking, holding and parking.
- Mechanics, kinematics and dynamics: fundamental motion and force concepts related to braking.
- Types and characteristics of brakes: disc, tread, magnetic track brakes and other brake unit types.
- Brake application and release: delay/build-up and release characteristics (see informative Annexes A & B).
- Brake control: control types, combined control strategies and control assemblies.
- Brake system components: command/control components, sensors, energy storage, pneumatic/hydraulic supplies, hand/parking brakes.
- Wheel slide protection (WSP) and types of brake tests.
- Symbols and abbreviations, plus informative annexes (brake charts, device-signal relationships, system setup).
Practical applications
EN ISO 24478:2024 is a vocabulary standard - it does not prescribe performance values but delivers a consistent terminology foundation that enables:
- Clear technical specifications in procurement and contracts.
- Consistent design documentation and interface definitions for rolling stock braking systems.
- Unambiguous test descriptions, maintenance procedures and safety cases.
- Interoperability assessments and brake system compatibility checks across multi-vendor trains.
- Training materials and regulatory reports using standardised braking terms.
Who should use this standard
- Rolling stock designers and brake system engineers
- Systems integrators and component manufacturers
- Railway operators and maintenance organisations
- Safety assessors, certification bodies and conformity assessors
- Standards writers and technical authors preparing specifications or contracts
Related standards
EN ISO 24478:2024 aligns with ISO/TC 269 activities and complements other railway standards addressing braking performance, testing and safety. It acts as the authoritative railway braking vocabulary reference to be used alongside performance and test standards when specifying or assessing brake systems.
Keywords: EN ISO 24478:2024, railway braking vocabulary, braking terms, rolling stock brakes, brake system compatibility, wheel slide protection, brake components.
