SIST FprEN IEC 63341-2:2025/FprAA:2026
(Amendment)Railway applications - Hydrogen and fuel cell systems for rolling stock - Part 2: Hydrogen fuel system
- 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
- 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
SIST FprEN IEC 63341-2:2025/FprAA:2026 is a CENELEC draft amendment to EN IEC 63341-2 for railway applications. It updates the requirements for onboard hydrogen fuel systems on rolling stock, including gaseous hydrogen storage, vehicle interfaces, fire protection, maintenance and validation. It is aimed at manufacturers, integrators, maintainers and railway operators working with hydrogen-powered or hybrid vehicles.
What does SIST FprEN IEC 63341-2:2025/FprAA:2026 specify?
SIST FprEN IEC 63341-2:2025/FprAA:2026 amends EN IEC 63341-2, which applies to onboard hydrogen fuel systems (HFS) used to supply fuel cells for traction power and auxiliary supply on rolling stock. It applies to gaseous hydrogen storage, any rolling stock type, and the mechanical, fluidic and electrical interfaces between the vehicle system and the fuelling station, while the fuelling station, fuelling protocol and protocol communication are outside scope. The document may also be used as informative recommendations for hydrogen internal combustion engines.
| Annex | What it covers |
|---|---|
| D | Standards applicable in specific countries |
| E | Fire protection requirements for integration of the HFS |
| F | Requirements for minimum maintenance checks and tasks |
| ZA | Normative references to international publications with corresponding European publications |
The amendment also revises Clause 2, 8.8.3, 8.9, 9.6.1, 11.3.1 and 11.3.4.2.
What are the key requirements of SIST FprEN IEC 63341-2:2025/FprAA:2026?
The main changes tighten structural, fire safety and maintenance requirements for the HFS.
Structural design
- Clause 8.8.3 requires fixation of the HFS to the car-bodyshell to be designed and validated according to EN 12663-1. In practice, the mounting and load path have to be treated as railway vehicle body design.
- The design, calculations and validation of welded joints for structural parts, such as the CHSS module structural frame, shall follow EN 15085-4. This means welding production requirements are part of the HFS design evidence.
Fire protection and interfaces
- Clause 8.9 requires the manufacturer to apply EN 45545-2 for fire protection of materials and components. For the reader, this links HFS material selection to railway fire behaviour rules.
- Annex E becomes normative and sets fire protection requirements for integration of the HFS. The fire barrier performance shall meet at least E15, I15 and shall be tested to EN 1363-1:2020, EN 1364-1 for vertical barriers and EN 1364-2 for horizontal barriers.
- Clause 9.6.1 adds a note that the preferred refuelling receptacle is the H35VFH specified in ISO 17268-4. That gives a preferred vehicle-side refuelling interface.
Maintenance and leakage inspection
- Clause 11.3.1 changes maintenance from recommendations to requirements, and Annex F turns the minimum maintenance list into a normative requirement set. The required scope includes visual inspections, external leak tests, functional verifications, review of failure logs, and checks of filling cycles and remaining service life.
- Clause 11.3.4.2 requires a leak test method with an appropriate level of sensitivity, selected according to EN 1779. In practice, the chosen method has to match the risk and be defensible in the maintenance record.
- Annex F also allows optional structural integrity tests, low-impedance tests, filter cleaning or exchange, and periodic HRS interface inspection and tests in accordance with ISO 19880-1. Additional inspections are required after defined events such as a potentially damaging incident or unusual behaviour.
What terms does SIST FprEN IEC 63341-2:2025/FprAA:2026 define?
SIST FprEN IEC 63341-2:2025/FprAA:2026 uses these key terms throughout the document:
- Hydrogen fuel system (HFS) - the onboard system that stores and supplies hydrogen for the fuel cells.
- Fuel cell power system - the system that uses hydrogen from the HFS to provide traction power and auxiliary supply.
- On-board hydrogen receptacle - the vehicle-side refuelling connection point.
- Fire barrier - the barrier whose fire performance is specified in Annex E for HFS integration.
- Leakage inspection - the regular check used to detect hydrogen leakage with a suitable test method.
- Maintenance checks and tasks - the minimum inspection and servicing actions required for safe operation and service records.
Who uses SIST FprEN IEC 63341-2:2025/FprAA:2026?
SIST FprEN IEC 63341-2:2025/FprAA:2026 is used by rolling stock manufacturers, hydrogen system integrators, railway operators and maintenance organizations. Design and validation engineers use it for mounting, welding, fire protection and interface definition. Quality, safety and maintenance teams use it to plan inspections, choose leak tests, define records and set service actions for hydrogen-equipped vehicles.
What changed in SIST FprEN IEC 63341-2:2025/FprAA:2026 from the previous edition?
SIST FprEN IEC 63341-2:2025/FprAA:2026 modifies EN IEC 63341-2:2025 by:
- adding new normative references in Clause 2
- replacing the structural design text in 8.8.3 with explicit references to EN 12663-1 and EN 15085-4
- requiring EN 45545-2 for fire protection in 8.9
- adding the preferred H35VFH receptacle note in 9.6.1
- changing maintenance language in 11.3.1 from recommendations to requirements
- adding an EN 1779-based sensitivity requirement for regular leakage inspection in 11.3.4.2
- retitling and converting Annex E and Annex F to normative requirements
- revising Annex D and its title
Which standards are used with SIST FprEN IEC 63341-2:2025/FprAA:2026?
| Reference | What it contributes |
|---|---|
| EN 12663-1 | Structural requirements for railway vehicle bodies |
| EN 15085-4 | Welding production requirements for railway vehicles |
| EN 45545-2 | Fire behaviour requirements for materials and components |
| EN 1779 | Criteria for selecting leak testing methods and techniques |
| EN 1363-1:2020 | General fire resistance test requirements |
| EN 1364-1 | Fire resistance test for vertical non-loadbearing walls |
| EN 1364-2 | Fire resistance test for horizontal non-loadbearing ceilings |
| EN 60529 / IEC 60529 | Degrees of protection provided by enclosures |
| EN 50155 / IEC 60571 | Electronic equipment used on rolling stock |
| EN 61373 / IEC 61373 | Shock and vibration testing for rolling stock equipment |
| EN 50153 / IEC 61991 | Protective provisions against electrical hazards |
| EN 50121-3-2 / IEC 62236-3-2 | EMC for rolling stock apparatus |
| EN 61709 / IEC 61709 | Reliability reference conditions and failure-rate models |
| EN 50124 series / IEC 62497 series | Insulation coordination |
| EN 50125-1 / IEC 62498-1 | Environmental conditions for equipment on board rolling stock |
| IEC 63341-1 | Fuel cell power system companion part |
| EN ISO 9223 / ISO 9223 | Corrosivity classification of atmospheres |
| EN ISO 17268 / ISO 17268 | Gaseous hydrogen refuelling connection devices |
| UN GTR No. 13 | Global technical regulation for hydrogen and fuel cell vehicles |
What does the SIST FprEN IEC 63341-2:2025/FprAA:2026 document contain?
The document is a set of targeted amendments rather than a full rewrite. It updates structural design, fire protection, receptacle selection, maintenance, leakage inspection and country-specific references, then adds normative fire protection and maintenance annexes. It also includes a reference mapping in Annex ZA for the international publications used in the text.
The detailed annexes support design, testing, maintenance planning and compliance evidence. Annex E gives the fire-barrier performance and test framework, Annex F gives the minimum maintenance checklist and recordkeeping expectations, and Annex ZA links the cited international publications to their European equivalents.
Relations
- Effective Date
- 14-Jan-2025
Get Certified
Connect with accredited certification bodies for this standard
DNV
DNV is an independent assurance and risk management provider.
Lloyd's Register
Lloyd's Register is a global professional services organisation specialising in engineering and technology.
DNV Energy Systems
Energy and renewable energy certification.
Sponsored listings
Frequently Asked Questions
SIST FprEN IEC 63341-2:2025/FprAA:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Railway applications - Hydrogen and fuel cell systems for rolling stock - Part 2: Hydrogen fuel system". This standard covers: 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
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
SIST FprEN IEC 63341-2:2025/FprAA:2026 is classified under the following ICS (International Classification for Standards) categories: 27.070 - Fuel cells; 45.060.01 - Railway rolling stock in general. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST FprEN IEC 63341-2:2025/FprAA:2026 has the following relationships with other standards: It is inter standard links to kSIST FprEN IEC 63341-2:2025. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST FprEN IEC 63341-2:2025/FprAA: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)
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
...