EN IEC 63341-2:2026/A11:2026
(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
- Publication Date
- 19-Nov-2026
- Technical Committee
- CLC/TC 9X - Electrical and electronic applications for railways
- Drafting Committee
- WG 40 - Survey Group on the parallel vote of IEC 63341-2 ED1
- Current Stage
- 5060 - Voting results sent to TC, SR - Formal Approval
- Start Date
- 11-Sep-2026
- Due Date
- 06-Jul-2026
- Completion Date
- 11-Sep-2026
Published by CLC, EN IEC 63341-2:2026/A11:2026 is an amendment to EN IEC 63341-2 for onboard hydrogen fuel systems on rolling stock. It sets European requirements for how the hydrogen fuel system is fixed, protected against fire, connected for refuelling, maintained, and checked for leakage. The amendment is aimed at rolling stock designers, integrators, operators, maintainers, and test and validation teams.
What does EN IEC 63341-2:2026/A11:2026 specify?
EN IEC 63341-2:2026/A11:2026 amends the hydrogen fuel system standard for rolling stock. EN IEC 63341-2 applies to onboard hydrogen fuel systems that supply fuel cells for traction power and auxiliary power on rolling stock vehicles, and it also allows informative use for hydrogen internal combustion engine applications.
The scope is limited to gaseous hydrogen storage. It applies to any rolling stock type, including light rail vehicles, tramways, streetcars, metros, commuter trains, regional trains, high speed trains, and locomotives. The standard addresses the mechanical, fluidic, and electrical interfaces between the onboard hydrogen fuel system and the fuelling station, while the fuelling station, fuelling protocol, and protocol communication are outside the scope.
The amendment is organized as a short foreword, nine numbered modifications, and Annex ZA.
| Annex | What it covers |
|---|---|
| Annex D | Standards applicable in specific countries |
| Annex E | Fire protection requirements for integration of the HFS |
| Annex F | Requirements for minimum maintenance checks and tasks |
| Annex ZA | Normative references to international publications with corresponding European publications |
What are the key requirements of EN IEC 63341-2:2026/A11:2026?
EN IEC 63341-2:2026/A11:2026 adds specific European references for structure, welding, fire behaviour, leak testing, and fire resistance, and it tightens the maintenance text from recommendations into requirements. In practice, it tells manufacturers and maintainers what standards to use when validating the HFS and how to inspect it in service.
Structural, fire and refuelling requirements
- Clause 2 adds EN 12663-1, EN 15085-4, EN 45545-2, EN 1779, EN 1363-1:2020, EN 1364-1, and EN 1364-2. This gives designers the railway structural, welding, fire, and leak-testing documents to apply instead of leaving those choices open.
- Clause 8.8.3 requires HFS fixation to the car-bodyshell to be designed and validated to EN 12663-1, and welded joints for structural parts to be designed and validated to EN 15085-4. This matters because the mounting and welded structure must withstand railway loads and be controlled as railway welding work.
- Clause 8.9 requires EN 45545-2 for fire protection on materials and components. This means fire performance must be checked using the railway fire behaviour rules, not just general material selection.
- Clause 9.6.1 adds a note that the preferred refuelling receptacle is the H35VFH specified in ISO 17268-4. This supports connector compatibility at the vehicle refuelling point.
Maintenance, inspection and annex updates
- Clause 11.3.1 changes maintenance wording from recommendations to requirements. That makes maintenance planning part of compliance, not optional guidance.
- Clause 11.3.4.2 requires selection of a leakage test method with suitable sensitivity according to EN 1779. This means the leak check method must be technically matched to the inspection task.
- Annex E becomes normative and sets the fire barrier performance and test route for HFS integration. Annex F becomes normative and sets minimum maintenance checks, inspection records, event-triggered additional inspections, and the rule that maintenance stays non-destructive unless inspection evidence justifies removal.
What terms does EN IEC 63341-2:2026/A11:2026 define?
- Hydrogen fuel system (HFS) - the onboard system that stores and supplies hydrogen to the fuel cells on the rolling stock vehicle.
- Car-bodyshell - the vehicle body structure where the HFS fixation is validated.
- On-board hydrogen receptacle - the vehicle-side refuelling connection point.
- Fire barrier - the separating element in Annex E that must meet the stated fire resistance performance.
- Regular leakage inspection - the periodic leak check required for the HFS, using a suitable sensitive method.
- Minimum maintenance checks and tasks - the required in-service inspection and maintenance actions listed in Annex F.
Who uses EN IEC 63341-2:2026/A11:2026?
EN IEC 63341-2:2026/A11:2026 is used by rolling stock manufacturers, hydrogen system suppliers, railway operators, maintenance organizations, test laboratories, and conformity assessment teams. It supports design work, installation, validation, routine inspection, and service maintenance for hydrogen fuel cell rolling stock.
What changed in EN IEC 63341-2:2026/A11:2026 from the previous edition?
| Area | Change stated in the amendment |
|---|---|
| Clause 2 | Adds EN 12663-1, EN 15085-4, EN 45545-2, EN 1779, EN 1363-1:2020, EN 1364-1, and EN 1364-2 |
| 8.8.3 | Replaces the structural design text with references to EN 12663-1 and EN 15085-4 |
| 8.9 | Replaces the fire protection text with EN 45545-2 |
| 9.6.1 | Adds the preferred H35VFH receptacle note |
| 11.3.1 | Changes maintenance wording from recommendations to requirements |
| 11.3.4.2 | Adds leak-test method selection according to EN 1779 |
| Annex D | Retitles and narrows the annex to standards applicable in specific countries |
| Annex E | Makes the annex normative and replaces it with fire protection requirements for integration of the HFS |
| Annex F | Makes the annex normative and replaces it with minimum maintenance checks and tasks |
Which standards are used with EN IEC 63341-2:2026/A11:2026?
| Reference | What it contributes |
|---|---|
| EN 12663-1 | Structural requirements for vehicle bodies, used for HFS fixation to the car-bodyshell |
| EN 15085-4 | Welding production requirements for railway vehicles and components |
| EN 45545-2 | Fire behaviour requirements for railway vehicle materials and components |
| EN 1779 | Criteria for selecting a leak-testing method and technique |
| EN 1363-1:2020 | General fire resistance test requirements |
| EN 1364-1 / EN 1364-2 | Fire resistance tests for vertical and horizontal non-loadbearing barriers |
| ISO 17268-4 | Preferred hydrogen refuelling receptacle note |
| IEC 63341-1 | Companion part for the fuel cell power system |
| EN IEC 62864-1 | Defines hybrid vehicles mentioned in the scope |
| ISO 19880-1 | Used for minimum periodic HRS interface inspection and tests |
| ISO 19078 | Temporary inspection guideline noted for hydrogen systems |
| IEC 60529 / EN 60529 | Degrees of protection provided by enclosures |
| IEC 60571 / EN 50155 | Railway electronic equipment used on rolling stock |
| IEC 61373 / EN 61373 | Shock and vibration test |
| IEC 61991 / EN 50153 | Protective provisions against electrical hazards |
| IEC 62236-3-2 / EN 50121-3-2 | EMC for rolling stock apparatus |
| IEC 61709 / EN 61709 | Reliability reference conditions and stress models |
| IEC 62497 series / EN 50124 series | Insulation coordination |
| IEC 62498-1 / EN 50125-1:2014 | Environmental conditions for onboard equipment |
| ISO 9223 / EN ISO 9223 | Corrosivity classification of atmospheres |
| ISO 17268 / EN ISO 17268 | Gaseous hydrogen land vehicle refuelling connection devices |
| ECE/TRANS/180 Add.13 / Amend.1 | UN GTR No. 13 for hydrogen and fuel cell vehicles |
What does the EN IEC 63341-2:2026/A11:2026 document contain?
EN IEC 63341-2:2026/A11:2026 contains clause-by-clause amendments rather than a full rewrite. The document revises normative references, structural and fire protection text, the refuelling receptacle note, maintenance wording, leakage inspection guidance, and the annexes for national standards, fire protection, and maintenance tasks.
Annex E gives the fire barrier requirement and the associated test methods, while Annex F gives the maintenance scope, example inspection methods, recordkeeping expectations, and event-based additional checks. Annex ZA provides the correspondence between international publications and the European publications used in the amendment.
Relations
- Effective Date
- 14-Jan-2025
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Frequently Asked Questions
EN IEC 63341-2:2026/A11:2026 is a draft published by CLC. 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
EN IEC 63341-2:2026/A11:2026 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.
EN IEC 63341-2:2026/A11:2026 has the following relationships with other standards: It is inter standard links to EN IEC 63341-2:2026. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN IEC 63341-2:2026/A11:2026 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
...