SIST FprEN IEC 63341-2:2025/FprAA:2026

• Abstract:

  This document amends EN IEC 63341-2 which applies to onboard hydrogen fuel systems used to supply the fuel cells for the traction power and the auxiliaries supply of rolling stock vehicles (such as hybrid vehicles as defined in EN IEC 62864-1).; NOTE 1 This document may also be used as informative recommendations for applications with hydrogen internal combustion engines.; EN IEC 63341-2 applies to hydrogen storage in gaseous form. Other means of storage (such as liquid, liquid cryo-compressed, metal hydrides) are not covered in this document. ; EN IEC 63341-2 applies to any rolling stock type (e.g. light rail vehicles, tramways, streetcars, metros, commuter trains, regional trains, high speed trains, locomotives).; EN IEC 63341-2 addresses the mechanical, fluidic and electrical interfaces between the on-board hydrogen fuel system and fuelling station. The fuelling station, fuelling protocol and communication for the fuelling protocol are not in the scope of this document. ; EN IEC 63341-2 defines:; – the scope of supply of hydrogen fuel system (HFS) and the description of the interfaces with sub-systems internal and external to the rolling stock such as fuel cell power system, fuelling station systems;; – the environmental constraints;; – the design requirements to support HFS compliance with railway applications;; – the safety and reliability requirements to design and install the HFS for railway applications;; – the marking and labelling requirements;; – the requirements related to storage, transportation, installation and maintenance;; – the validation (type, routine and investigation tests) requirements

• Status: Not Published
• Public Enquiry End Date: 25-Jan-2026
• ICS: 27.070 - Fuel cells
• ICS: 45.060.01 - Railway rolling stock in general
• Technical Committee: ŽEN - Electrical applications for railways
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 27-Jul-2026
• Due Date: 14-Sep-2026
• Completion Date: 02-Sep-2026
• Ref Project: FprEN IEC 63341-2:2025/FprAA:2026 - Railway applications - Hydrogen and fuel cell systems for rolling stock - Part 2: Hydrogen fuel system

• Amends: kSIST FprEN IEC 63341-2:2025 - Railway applications - Hydrogen and fuel cell systems for rolling stock - Part 2: Hydrogen fuel system
• Effective Date: 14-Jan-2025

Overview

SIST FprEN IEC 63341-2:2025/FprAA:2026 is a draft European amendment developed by SIST for hydrogen and fuel cell systems in railway rolling stock. Specifically, this document addresses the requirements for onboard hydrogen fuel systems (HFS) that supply fuel cells used for traction power and auxiliary systems in various types of rolling stock, including hybrid vehicles. Hydrogen storage considered by this standard is strictly in gaseous form, and the document provides essential requirements for interfaces, safety, reliability, design, installation, maintenance, and validation processes.

The standard offers practical guidelines for manufacturers and operators and can be referenced for hydrogen internal combustion engine applications as informative recommendations.

Key Topics

• Scope of Hydrogen Fuel System (HFS) Supply
  • Defines interfaces of the HFS with internal and external subsystems, including fuel cell power and fuelling stations.
• Design and Structural Requirements
  • Adopts EN 12663-1 for structural design validation and EN 15085-4 for welding quality.
• Fire Protection
  • Requires material and component fire protection per EN 45545-2.
  • Sets benchmark fire resistance tests for integration barriers (based on EN 1363-1, EN 1364-1, EN 1364-2).
• Hydrogen Storage & Interfaces
  • Focuses exclusively on gaseous hydrogen storage solutions.
  • Addresses the mechanical, fluidic, and electrical interfaces between rolling stock and fuelling stations, excluding protocols and station design.
• Safety and Reliability
  • Details containment integrity, regular leakage inspections (referencing EN 1779), and system marking and labelling.
• Maintenance and Inspection
  • Outlines minimum HFS maintenance checks, functional verifications, and leak testing.
  • Specifies requirements for non-destructive in-service container inspections, referencing ISO 19078 as a guideline.
  • Requires comprehensive record-keeping for maintenance activities.

Applications

Implementing SIST FprEN IEC 63341-2:2025/FprAA:2026 ensures safer, more reliable, and compliant deployment of hydrogen fuel systems in railway vehicles, including but not limited to:

• Light Rail Vehicles and Trams: Guidance for integrating safe hydrogen storage modules and fire protection measures.
• Metros, Commuter, and Regional Trains: Provides a framework for regular inspection and maintenance, boosting long-term system safety and performance.
• High-Speed Trains and Locomotives: Ensures robust structural design and leakage prevention suited to demanding operating environments.
• Hybrid Rolling Stock: Reference for hydrogen fuel system requirements aligned with evolving rail propulsion technologies.
• Hydrogen Internal Combustion Engine Applications: Serves as an informative foundation for applying hydrogen storage and safety best practices even where fuel cells are not utilized.

Related Standards

To ensure full compliance and robust system design, the following standards are referenced within SIST FprEN IEC 63341-2:2025/FprAA:2026:

• EN 12663-1: Structural requirements for railway vehicle bodies.
• EN 15085-4: Welding production requirements for railway vehicles.
• EN 45545-2: Fire protection requirements for railway vehicles.
• EN 1779: Leak testing criteria and method selection.
• EN 1363-1, EN 1364-1, EN 1364-2: Fire resistance testing for walls and ceilings.
• ISO 17268: Refuelling interfaces for gaseous hydrogen.
• ISO 19078: Inspection guidelines for in-service fuel containers.
• EN IEC 63341-1: Fuel cell power system requirements for railway applications.
• EN ISO 9223: Corrosivity of atmospheres for metal components.
• ISO 19880-1: Hydrogen refuelling station interface inspections.

This document is pivotal for railway operators, vehicle manufacturers, safety assessors, and maintenance providers invested in the safe implementation and operation of hydrogen technologies in rolling stock. Adhering to these harmonized standards helps advance the sustainable use of hydrogen rail propulsion across Europe and worldwide.

SLOVENSKI STANDARD
SIST FprEN IEC 63341-2:2025/oprAA:2026
01-januar-2026
Železniške naprave - Vozna sredstva - Sistemi gorivnih celic za vozna sredstva - 2.
del: Sistem za shranjevanje vodika - Dopolnilo AA
Railway applications - Hydrogen and fuel cell systems for rolling stock - Part 2: Hydrogen
fuel system
Applications ferroviaires - Systèmes à hydrogène et à pile à combustible pour le matériel
roulant - Partie 2: Système à hydrogène
Ta slovenski standard je istoveten z: FprEN IEC 63341-2:2025/prAA:2025
ICS:
27.070 Gorilne celice Fuel cells
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
SIST FprEN IEC 63341- en
2:2025/oprAA:2026
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST FprEN IEC 63341-2:2025/oprAA:2026

SIST FprEN IEC 63341-2:2025/oprAA:2026

EUROPEAN STANDARD DRAFT
FprEN IEC 63341-2:2025
NORME EUROPÉENNE
EUROPÄISCHE NORM
prAA
November 2025
ICS  -
English Version
Railway applications - Hydrogen and fuel cell systems for rolling
stock - Part 2: Hydrogen fuel system
Applications ferroviaires - Systèmes à hydrogène et à pile à To be completed
combustible pour le matériel roulant - Partie 2: Système à
hydrogène
This draft amendment prAA, if approved, will modify the European Standard FprEN IEC 63341-2:2025; it is submitted to CENELEC
members for enquiry.
Deadline for CENELEC: 2026-01-30.

It has been drawn up by CLC/TC 9X.

If this draft becomes an amendment, CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this amendment the status of a national standard without any alteration.

This draft amendment was established by CENELEC in three official versions (English, French, German).
A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to
the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 81192 Ref. No. FprEN IEC 63341-2:2025/prAA:2025 E

SIST FprEN IEC 63341-2:2025/oprAA:2026
FprEN IEC 63341-2:2025/prAA:2025 (E)

Contents Page
1 European foreword . 3
2 1 Modification to Clause 2, “Normative references” . 4
3 2 Modification to 8.8.3, “Structural design” . 4
4 3 Modification to 8.9, “Fire protection” . 4
5 4 Modification to 9.6.1, “On-board hydrogen receptacle” . 4
6 5 Modification to 11.3.1, “Maintenance requirements” . 4
7 6 Modification to 11.3.4.2, “Regular leakage inspection” . 4
8 7 Modifications to Annex D, “Standards, laws and regulations applicable in specific
9 countries or regions” . 4
10 8 Modifications to Annex E, “Recommendations for fire protection of the HFS” . 5
11 9 Modifications to Annex F, “Recommendations for minimum maintenance checks and
12 tasks” . 5
13 Annex ZA (normative) Normative references to international publications with their
14 corresponding European publications . 7
SIST FprEN IEC 63341-2:2025/oprAA:2026
FprEN IEC 63341-2:2025/prAA:2025 (E)
15 European foreword
16 This document (FprEN IEC 63341-2:2025/prAA:2025) has been prepared by CLC/TC 9X “Electrical and
17 electronic applications for railways”.
18 This document is currently submitted to the Enquiry.
19 The following dates are proposed:
• latest date by which the existence of this (doa) dav + 6 months
document has to be announced at national
level
• latest date by which this document has to be (dop) dav + 12 months
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) dav + 36 months
conflicting with this document have to be (to be confirmed or
withdrawn modified when voting)
SIST FprEN IEC 63341-2:2025/oprAA:2026
FprEN IEC 63341-2:2025/prAA:2025 (E)

20 1 Modification to Clause 2, “Normative references”
21 Add the following references:
22 EN 12663-1, Railway applications - Structural requirements of railway vehicle bodies - Part 1: Locomotives
23 and passenger rolling stock (and alternative method for freight wagons)
24 EN 15085-4, Railway applications - Welding of railway vehicles and components - Part 4: Production
25 requirements
26 EN 45545-2, Railway applications - Fire protection on railway vehicles - Part 2: Requirements for fire
27 behaviour of materials and components
28 EN 1779, Non-destructive testing - Leak testing - Criteria for method and technique selection
29 EN 1363-1:2020, Fire resistance tests - Part 1: General requirements
30 EN 1364-1, Fire resistance tests for non-loadbearing elements - Part 1: Walls
31 EN 1364-2, Fire resistance tests for non-loadbearing elements - Part 2: Ceilings
32 2 Modification to 8.8.3, “Structural design”
33 Replace the content of the subclause with the followi
...