ISO 24221:2024/Amd 1:2026
(Amendment)Railway applications — Brake system — General requirements — Amendment 1
General Information
- Abstract
- Status
- Published
- Publication Date
- 21-Sep-2026
- Technical Committee
- ISO/TC 269/SC 2 - Rolling stock
- Drafting Committee
- ISO/TC 269/SC 2/WG 1 - Railway braking
- Current Stage
- 6060 - International Standard published
- Start Date
- 22-Sep-2026
- Due Date
- 03-Sep-2026
- Completion Date
- 22-Sep-2026
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ISO 24221:2024/Amd 1:2026 - Railway applications — Brake system — General requirements — Amendment 1
ISO 24221:2024/Amd 1:2026 - Applications ferroviaires — Système de freinage — Exigences générales — Amendement 1
Overview
ISO 24221:2024/Amd 1:2026 is an amendment to the ISO standard for railway applications - brake system - general requirements. Published by ISO, this document updates terminology, braking performance conditions, payload definitions, and safety-related wording for railway brake system design and assessment.
For organizations working in railway rolling stock, train braking systems, and rail vehicle safety, this amendment supports clearer implementation of the base standard and helps align brake system requirements with modern operational and safety practices.
Key Topics
This amendment focuses on several important updates for railway brake system requirements:
Title clarification
- Updates the title wording from “Braking system” to “Brake system”.
Terminology update
- Removes one terminological entry in Clause 3.9.
Emergency braking and safety analysis
- Adds requirements stating that:
- a dynamic brake subsystem involved in emergency braking shall be subject to a safety analysis
- brake management or brake blending used in emergency braking shall also be subject to a safety analysis
- Adds requirements stating that:
Brake blending guidance
- Clarifies that brake blending may occur at the local level, train level, or both
- Notes that blending can involve multiple brake systems acting together or one braking source being replaced by another
- Reaffirms that brake blending shall respect the maximum adhesion demand
- References applicable blending modes in ISO 24478
Load and payload conditions
- Revises the description of relevant load conditions for braking design
- Introduces updated wording around design mass in working order, normal payload, and maximum braking payload
- Supports braking performance across the full range of expected operating conditions
Testing and duty cycles
- Updates references for emergency brake applications and duty cycle evaluation at maximum design speed and design mass under maximum braking payload
Applications
ISO 24221:2024/Amd 1:2026 is relevant for professionals involved in:
- Railway vehicle design
- Brake system engineering
- Rolling stock integration
- Safety assessment and conformity work
- Passenger train and metro braking performance
- Brake blending implementation
- Emergency braking analysis
It is especially useful for manufacturers, system integrators, operators, and testing organizations that need consistent ISO railway standards compliance for brake systems.
Related Standards
This amendment is connected to several related standards and references, including:
- ISO 24221:2024 - the base standard for railway brake system general requirements
- ISO 24478 - for applicable brake blending modes
- ISO 10516 - for load and mass definitions used in braking design
- EN 14198 - referenced for certain maximum braking payload conditions in Europe
- EN 16185-1 - referenced for long-distance and high-speed train payload conditions
For stakeholders in railway applications standards, this amendment helps maintain alignment between brake system terminology, safety analysis, and operational braking performance requirements.
Relations
- Effective Date
- 07-Sep-2024
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ISO 24221:2024/Amd 1:2026 - Railway applications — Brake system — General requirements — Amendment 1
ISO 24221:2024/Amd 1:2026 - Applications ferroviaires — Système de freinage — Exigences générales — Amendement 1
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Frequently Asked Questions
ISO 24221:2024/Amd 1:2026 is a standard published by the International Organization for Standardization (ISO). Its full title is "Railway applications — Brake system — General requirements — Amendment 1". This standard covers: Railway applications — Brake system — General requirements — Amendment 1
Railway applications — Brake system — General requirements — Amendment 1
ISO 24221:2024/Amd 1:2026 is classified under the following ICS (International Classification for Standards) categories: 45.060.01 - Railway rolling stock in general. The ICS classification helps identify the subject area and facilitates finding related standards.
ISO 24221:2024/Amd 1:2026 has the following relationships with other standards: It is inter standard links to ISO 24221:2024. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ISO 24221:2024/Amd 1:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
International
Standard
ISO 24221
First edition
Railway applications — Brake
2024-03
system — General requirements
AMENDMENT 1
AMENDMENT 1
2026-09
Applications ferroviaires — Système de freinage — Exigences
générales
AMENDEMENT 1
Reference number
ISO 24221:2024/Amd.1:2026(en) © ISO 2026
ISO 24221:2024/Amd.1:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 24221:2024/Amd.1:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 269, Railway applications, Subcommittee SC 2,
Rolling stock.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iii
ISO 24221:2024/Amd.1:2026(en)
Railway applications — Brake system — General
requirements
AMENDMENT 1
Title
In the title, replace “Braking system” with “Brake system”.
3.9
Delete the entire terminological entry.
4.2, fifth paragraph
At the end of the first sentence, replace “up to the maximum braking load.” with “up to the design mass
under maximum braking payload.”
4.2, eight paragraph
At the end of 4.2, add the following two paragraphs:
If a dynamic brake subsystem is involved in emergency braking it shall be subject to a safety analysis.
If brake management or brake blending is used in emergency braking it shall be subject to a safety analysis.
4.4
Replace the text wit
...
Norme
internationale
ISO 24221
Première édition
Applications ferroviaires — Système
2024-03
de freinage — Exigences générales
AMENDEMENT 1
AMENDEMENT 1
2026-09
Railway applications — Brake system — General requirements
AMENDMENT 1
Numéro de référence
ISO 24221:2024/Amd.1:2026(fr) © ISO 2026
ISO 24221:2024/Amd.1:2026(fr)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2026
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Genève
Tél.: +41 22 749 01 11
E-mail: copyright@iso.org
Web: www.iso.org
Publié en Suisse
ii
ISO 24221:2024/Amd.1:2026(fr)
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes nationaux
de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est en général
confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude a le droit de faire
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la Commission électrotechnique internationale (IEC) en ce qui concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient en particulier de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document
a été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2
(voir www.iso.org/directives).
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d’un ou de plusieurs brevets. L’ISO ne prend pas position quant à la preuve, à la validité et à l’applicabilité de
tout droit de brevet revendiqué à cet égard. À la date de publication du présent document, l’ISO n’avait pas
reçu notification qu’un ou plusieurs brevets pouvaient être nécessaires à sa mise en application. Toutefois,
il y a lieu d’avertir les responsables de la mise en application du présent document que des informations
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www.iso.org/patents. L’ISO ne saurait être tenue pour responsable de ne pas avoir identifié de tels droits de
brevets et de ne pas avoir signalé leur existence.
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commerce (OTC), voir le lien suivant: www.iso.org/iso/foreword.html.
Le comité chargé de l’élaboration du présent document est l’ISO/TC 269, Applications ferroviaires, Sous-
comité SC 2, Matériel roulant.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes se
trouve à l’adresse www.iso.org/members.html.
iii
ISO 24221:2024/Amd.1:2026(fr)
Applications ferroviaires — Système de freinage — Exigences
générales
AMENDEMENT 1
Titre
Dans le titre, replacer «Braking system» par «Brake system» (valable uniquement pour la version anglaise).
3.9
Supprimer l’entrée terminologique entière.
ème
4.2, 5 alinéa
À la fin de la première phrase, remplacer «jusqu’à la charge maximale de freinage.» par «jusqu’à la masse de
conception en charge maximale de freinage.»
ème
4.2, 8 alinéa
À la fin de 4.2, ajouter les deux alinéas suivants:
Si un sous-système de freinage dynamique est impliqué dans le freinage d’urgence, il doit être soumis à une
analyse de sécurité.
Si la gestion du freinage ou la conjugaison des freins est utilisée lors d’un freinage d’urgence, elle doit être
soumise à une analyse de sécurité.
4.4
Remplacer le texte par ce qui suit:
La conjugaison des freins peut se faire soit au niveau loca
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