prEN 13749
(Main)Railway applications – Wheelsets and bogies – Running gear structural requirements
Railway applications – Wheelsets and bogies – Running gear structural requirements
This document specifies the requirements for the validation of the structural integrity for the following running gear structural components:
- Components in the load path between the track and the car body (e.g. bogie frame, axlebox, or other equivalent components) and
- Components that are in the traction and braking load paths without secondary retention.
The following components are excluded from the scope of this document:
- Structural components that are rigidly attached to the car body (e.g. bolsters directly attached to the car body or connected via slewing rings, centre pivots, etc.);
- Equipment structures (e.g. traction motor housings, gearbox housings, and brake units), including components that are rigidly attached to them, that are not in the load path between the track and the car body;
- Components for which the structural integrity validation requirements are regulated by other specific EN standards (e.g. wheels, axles, brake discs, bearings, coil springs etc.);
- Suspension components including springs, dampers, elastic elements and their connecting elements;
- Revolving components (e.g. drive train components etc.).
Bahnanwendungen - Radsätze und Drehgestelle - Festigkeitsanforderungen an Drehgestellrahmen
Applications ferroviaires - Essieux montés et bogies - Méthode pour spécifier les exigences en matière de résistance des structures de châssis de bogie
Le présent document spécifie les exigences pour la validation de l’intégrité de la structure des composants structurels suivants des organes de roulement :
— les composants dans le chemin de charge entre la voie et la caisse du véhicule (par exemple, châssis de bogie, boîte d'essieu ou autres composants équivalents) et
— les composants sans chemins de charge secondaires qui sont dans les chemins de charge de traction et de freinage.
Les composants suivants ont été exclus du domaine d'application du présent document :
— composants structurels fixés de manière rigide à la caisse du véhicule (par exemple, des traverses de charge directement fixées à la caisse ou attachées à l’aide de bagues de rotation, des pivots centraux, etc.) ;
— structures d'équipement (par exemple, carters de moteur de traction, carters de boîte de vitesses et unités de frein), y compris les composants qui y sont fixés de manière rigide et qui ne se trouvent pas dans le chemin de charge entre la voie et la caisse du véhicule ;
— composants pour lesquels les exigences de validation de l’intégrité structurelle sont réglementées par d'autres normes européennes spécifiques (par exemple, roues, essieux, disques de frein, roulements, ressorts hélicoïdaux, etc.);
— composants de suspension, y compris les ressorts, les amortisseurs, les éléments élastiques et leurs éléments de connexion ;
— composants rotatifs (par exemple, composants de la transmission, etc.).
Železniške naprave - Kolesni pari in podstavni vozički - Konstrukcijske zahteve za tekalne sestave
Ta dokument določa zahteve za validacijo strukturne celovitosti za naslednje strukturne komponente tekalnih naprav:
- Komponente v obremenitveni poti med tirnicami in karoserijo vozila (npr. ogrodje podvozja, ležajna ohišja osi ali druge enakovredne komponente) in
- Komponente, ki so v obremenitvenih poteh vleke in zaviranja brez sekundarne zadržanosti.
Naslednje komponente so izključene iz obsega tega dokumenta:
- Strukturne komponente, ki so togo pritrjene na karoserijo vozila (npr. prečniki, ki so neposredno pritrjeni na karoserijo vozila ali povezani preko vrtljivih obročev, sredinskih zatičev itd.);
- Strukture opreme (npr. ohišja vlečnih motorjev, ohišja menjalnikov in zavorne enote), vključno s komponentami, ki so nanje togo pritrjene, ki niso v obremenitveni poti med tirnicami in karoserijo vozila;
- Komponente, za katere so zahteve za validacijo strukturne celovitosti regulirane z drugimi specifičnimi EN standardi (npr. kolesa, osi, zavorni diski, ležaji, vijačne vzmeti itd.);
- Komponente vzmetenja, vključno z vzmetmi, dušilci, elastičnimi elementi in njihovimi povezovalnimi elementi;
- Vrteče se komponente (npr. komponente pogonskega sklopa itd.).
General Information
- Status
- Not Published
- Publication Date
- 28-Jun-2027
- Technical Committee
- CEN/TC 256 - Railway applications
- Drafting Committee
- CEN/TC 256/SC 2/WG 13 - Bogie frames
- Current Stage
- 4020 - Submission to enquiry - Enquiry
- Start Date
- 09-Apr-2026
- Due Date
- 11-May-2025
- Completion Date
- 09-Apr-2026
Relations
- Effective Date
- 06-Dec-2023
- Effective Date
- 18-Jan-2023
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Frequently Asked Questions
prEN 13749 is a draft published by the European Committee for Standardization (CEN). Its full title is "Railway applications – Wheelsets and bogies – Running gear structural requirements". This standard covers: This document specifies the requirements for the validation of the structural integrity for the following running gear structural components: - Components in the load path between the track and the car body (e.g. bogie frame, axlebox, or other equivalent components) and - Components that are in the traction and braking load paths without secondary retention. The following components are excluded from the scope of this document: - Structural components that are rigidly attached to the car body (e.g. bolsters directly attached to the car body or connected via slewing rings, centre pivots, etc.); - Equipment structures (e.g. traction motor housings, gearbox housings, and brake units), including components that are rigidly attached to them, that are not in the load path between the track and the car body; - Components for which the structural integrity validation requirements are regulated by other specific EN standards (e.g. wheels, axles, brake discs, bearings, coil springs etc.); - Suspension components including springs, dampers, elastic elements and their connecting elements; - Revolving components (e.g. drive train components etc.).
This document specifies the requirements for the validation of the structural integrity for the following running gear structural components: - Components in the load path between the track and the car body (e.g. bogie frame, axlebox, or other equivalent components) and - Components that are in the traction and braking load paths without secondary retention. The following components are excluded from the scope of this document: - Structural components that are rigidly attached to the car body (e.g. bolsters directly attached to the car body or connected via slewing rings, centre pivots, etc.); - Equipment structures (e.g. traction motor housings, gearbox housings, and brake units), including components that are rigidly attached to them, that are not in the load path between the track and the car body; - Components for which the structural integrity validation requirements are regulated by other specific EN standards (e.g. wheels, axles, brake discs, bearings, coil springs etc.); - Suspension components including springs, dampers, elastic elements and their connecting elements; - Revolving components (e.g. drive train components etc.).
prEN 13749 is classified under the following ICS (International Classification for Standards) categories: 45.040 - Materials and components for railway engineering. The ICS classification helps identify the subject area and facilitates finding related standards.
prEN 13749 has the following relationships with other standards: It is inter standard links to EN 13749:2021+A1:2023, EN 13749:2021. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
prEN 13749 is associated with the following European legislation: EU Directives/Regulations: 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU, 2016/797/EU; Standardization Mandates: M/483, M/591. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
prEN 13749 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
01-junij-2026
Železniške naprave - Kolesni pari in podstavni vozički - Konstrukcijske zahteve za
tekalne sestave
Railway applications - Wheelsets and bogies - Running gear structural requirements
Bahnanwendungen - Radsätze und Drehgestelle - Festigkeitsanforderungen an
Drehgestellrahmen
Applications ferroviaires - Essieux montés et bogies - Méthode pour spécifier les
exigences en matière de résistance des structures de châssis de bogie
Ta slovenski standard je istoveten z: prEN 13749
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2026
ICS 45.040 Will supersede EN 13749:2021+A1:2023
English Version
Railway applications - Wheelsets and bogies - Running
gear structural requirements
Applications ferroviaires - Essieux montés et bogies - Bahnanwendungen - Radsätze und Drehgestelle -
Méthode pour spécifier les exigences en matière de Festigkeitsanforderungen an Drehgestellrahmen
résistance des structures de châssis de bogie
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 256.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
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 STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13749:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Requirement and interface management . 13
4.1 General . 13
4.2 Input to the running gear structural design and validation process . 14
4.3 Primary load paths . 14
4.4 Requirements for design loads . 14
4.5 Requirements for design load cases . 15
4.6 Scenarios for the determination of design loads . 17
4.6.1 Events for exceptional design loads . 17
4.6.2 Events for fatigue design loads . 22
4.7 Derivation of loads from operation . 25
5 Verification of the design data . 25
6 Structural integrity validation . 26
6.1 General . 26
6.2 The structural integrity validation plan . 26
6.2.1 General . 26
6.2.2 FEA model validation . 26
6.3 Validation by satisfactory service experience . 26
6.4 Static structural integrity validation . 27
6.4.1 General . 27
6.4.2 Static structural integrity simulation . 28
6.4.3 Static structural integrity validation by testing (3.27) . 29
6.5 Fatigue life validation . 29
6.5.1 General . 29
6.5.2 Fatigue utilization . 30
6.5.3 Fatigue life simulation . 31
6.5.4 Stress determination by testing . 32
6.5.5 Fatigue testing in the laboratory . 32
6.5.6 Track testing . 41
7 Quality requirements . 41
Annex A (informative) Symbols and units used in the informative annexes . 42
A.1 General . 42
A.2 Forces . 42
A.3 Accelerations . 42
A.4 Masses . 43
A.5 Other symbols and units . 43
A.6 Coordinate system . 43
A.7 Running gear classification . 44
Annex B (informative) Examples of loads due to running . 46
B.1 General . 46
B.2 Examples of loads for bogies of passenger rolling stock -categories B-I and B-II . 46
B.2.1 Exceptional loads . 46
B.2.2 Fatigue loads . 47
B.3 Examples of loads for bogies of metro, rapid transit, light rail vehicles and trams -
categories B-III and B-IV . 48
B.3.1 Application . 48
B.3.2 Load cases . 48
B.3.3 General expressions for the basic load cases . 49
B.4 Examples of loads for freight bogies with a central pivot and two sidebearers -
category B-V . 50
B.4.1 Bogie types . 50
B.4.2 Relationship of vertical forces . 50
B.4.3 Exceptional loads . 50
B.4.4 Fatigue loads . 51
B.5 Examples of loads for bogies of locomotives (with two bogies) - category B-VII . 52
B.5.1 Exceptional loads . 52
B.5.2 Fatigue loads . 53
Annex C (informative) Examples of loads due to components attached to the running
gear structure . 54
C.1 General . 54
C.2 Component inertia loads . 54
C.2.1 Derivation . 54
C.2.2 Design accelerations for equipment attached to the running gear structure . 55
C.2.3 Design accelerations for equipment attached to the axlebox (3.2) . 55
C.3 Loads resulting from viscous dampers . 55
C.4 Loads resulting from braking . 56
C.5 Loads resulting from traction motors . 56
C.6 Forces applied on anti-roll systems . 56
Annex D (informative) Examples of running gear load cases . 58
D.1 General . 58
D.2 Exceptional load cases . 58
D.3 Fatigue load cases . 58
D.3.1 General . 58
D.3.2 Load cases for passenger rolling stock (categories B-I, B-II) and locomotives
(category B-VII) . 59
D.3.3 Load cases for running gear with central pivot and two sidebearers (category B-V) . 60
D.3.4 Load cases for light rail vehicles and trams (Categories B-III and B-IV) . 62
Annex E (informative) Examples of fatigue test programmes . 66
E.1 Fatigue test programme for bogies with the body supported directly on the
sideframes (categories B-I and B-II) . 66
E.2 Fatigue test programme for a freight bogie with a central pivot and two sidebearers
(category B-V) . 69
E.2.1 General . 69
E.2.2 Vertical loads . 69
E.2.3 Transverse loads . 69
E.3 Fatigue test programme for locomotive bogies (category B-VII) . 72
E.4 Fatigue test programme for bogies of light rail vehicles and trams (category B-IV) . 72
Annex F (informative) Track testing . 73
F.1 General . 73
F.2 Test parameters . 73
F.2.1 Selection of test tracks . 73
F.2.2 Mass allocation . 74
F.2.3 Consideration of vehicle weight . 74
F.2.4 Measurement Sensors or Instrumentation . 75
F.2.5 Conditions for track measurements with powered vehicles . 76
F.3 Analysis of test data . 77
F.3.1 Signal handling . 77
F.3.2 Rainflow counting . 78
F.3.3 Procedures when measuring channels fail during measurement . 78
F.3.4 Technical validation . 79
F.4 Fatigue life evaluation . 79
F.5 Documentation . 80
F.6 Force measurements . 80
F.7 Rainflow counting . 81
F.7.1 General . 81
F.7.2 Parameters . 81
F.7.3 Possible approach . 81
F.7.4 Annotation . 82
F.8 Reference tracks . 82
F.8.1 Reference tracks for Germany . 82
F.8.2 Reference tracks for the Swiss railway system . 88
F.8.3 Reference tracks for the Austrian railway system . 88
Bibliography . 90
European foreword
This document (prEN 13749:2026) has been prepared by Technical Committee CEN/TC 256 "Railway
applications", the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 13749:2021+A1:2023.
In comparison with the previous edition, the following technical modifications have been made:
— non-structural requirements have been moved to EN 15827, including most of the description of
the technical spécification;
— the scope has been generalised to running gear structural components;
— new Clause 4 on requirements and interface management, outlining the structural design and
validation process, primary load paths and the process of deriving loads and load cases;
— addition of scenarios for determining design loads, and the process for deriving loads from
operation;
— Clause 5, vérification of design data, rewritten;
— Clause 6, validation and acceptance of the design, renamed "structural integrity validation" and
rewritten with reference to the EN 17149 series of standards;
— new Annex F added - code of practice for track testing.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
1 Scope
This document spécifiés the requirements for the validation of the structural integrity for the following
running gear structural components:
— components in the load path between the track and the car body (e.g. bogie frame, axlebox, or other
equivalent components) and
— components without secondary load paths that are in the traction and braking load paths.
The following components are excluded from the scope of this document:
— structural components that are rigidly attached to the car body (e.g. bolsters directly attached to
the car body or connected via slewing rings, centre pivots, etc.);
— equipment structures (e.g. traction motor housings, gearbox housings, and brake units), including
components that are rigidly attached to them, that are not in the load path between the track and
the car body;
— components for which the structural integrity validation requirements are regulated by other
spécific European standards (e.g. wheels, axles, brake discs, bearings, coil springs etc.);
— suspension components including springs, dampers, elastic elements and their connecting
elements;
— revolving components (e.g. drive train components etc.).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 14033-1:2017, Railway applications - Track - Railbound construction and maintenance machines -
Part 1: Technical requirements for running
EN 15085-1:2023, Railway applications - Welding of railway vehicles and components - Part 1: General
EN 15085-2:2020+A2:2025, Railway applications - Welding of railway vehicles and components - Part 2:
Requirements for welding manufacturer
EN 15085-3:2022+A1:2023, Railway applications - Welding of railway vehicles and components - Part 3:
Design requirements
EN 15085-4:2023, Railway applications - Welding of railway vehicles and components - Part 4: Production
requirements
EN 15085-5:2023, Railway applications - Welding of railway vehicles and components - Part 5: Inspection,
testing and documentation
EN 15227:2020, Railway applications - Crashworthiness requirements for rail vehicles
EN 15663:2017+A2:2024, Railway applications - Vehicle reference masses
EN 15827:2025, Railway applications - System Engineering requirements for bogies and running gear
EN 17149-2:2024, Railway applications - Strength assessment of rail vehicle structures - Part 2: Static
strength assessment
EN 17343:2023, Railway applications - General terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and définitions in EN 17343:2023 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
secondary load path
load path that is engaged in case the function of a component is infringed or fully lost
EXAMPLE Safety retention for a torque reaction link, or where the centre pivot contacts the frame on both
sides in case of missing traction links.
3.2
axlebox
assembly comprising the box housing, rolling bearings, sealing and grease
3.3
bogie frame
load-bearing structure generally located between primary and secondary suspension (3.23)
3.4
bolster
transverse load-bearing structure between vehicle body and bogie frame (3.3)
3.5
static force
force which is constant with time
Note 1 to entry: Force due to gravity is an example of static force.
3.6
quasi-static force
force which changes with time at a rate which does not cause dynamic excitation
Note 1 to entry: A quasi-static force might remain constant for limited periods
3.7
dynamic force
transient, impulsive or continuous force, uniform or random, that changes with time at a rate that causes
dynamic excitation
3.8
load case
set of loads or combinations of loads that represents a loading condition to which the structure or
component is subjected
3.9
exceptional load case
extreme load case (3.8) representing the maximum load at which full serviceability is to be maintained
and used for assessment against static material properties
3.10
fatigue assessment
assessment of the fatigue behaviour based on stress data determined by simulation or measurement
subjected to a theoretical fatigue life model (3.13) and resulting in a fatigue utilization
Key
1 fatigue assessment approach (3.11)
2 fatigue assessment method (3.12)
3 fatigue life model (3.13)
Figure 1 — Illustration of term hierarchy in fatigue assessment
Note 1 to entry: Laboratory fatigue testing is not addressed by the term fatigue assessment.
Note 2 to entry: Simulation includes finité element analysis, multi-body simulation, analytical models, hand
calculations.
3.11
fatigue assessment approach
fundamental principle of the fatigue life model (3.13) describing the nature of the stress data being
assessed (e.g. maximum stress cycle, damage equivalent stress or stress spectrum) and the assessment
strategy being applied (e.g. comparison of a maximum value to a threshold or damage cumulation); see
Figure 1
Note 1 to entry: For each fatigue assessment approach various fatigue assessment methods can be applied.
3.12
fatigue assessment method
detailed spécification of the fatigue assessment algorithm, see Figure 1
Note 1 to entry: A fatigue assessment method is typically formulated in a standard (e.g. EN 17149-3:2025 [1]).
3.13
fatigue life model
spécific application of a fatigue assessment method (3.12), including the applied parameter values for a
spécific assessment location; see Figure 1
3.14
fatigue resistance
material's or component's ability to withstand cyclic loading
Note 1 to entry: fatigue resistance is a property of a material or component. This term is not intended to address
the actual fatigue life. The actual fatigue life results from the actual loads being applied.
Note 2 to entry: In the context of fatigue assessment (3.10) the theoretical fatigue resistance is quantifiéd by the
fatigue life model (3.13)
Note 3 to entry: In the context of fatigue testing the fatigue resistance is the result or validation objective.
3.15
fatigue crack
indication that grows under the influéncé of fatigue load
3.16
maximum stress cycle approach
fatigue assessment based on the maximum stress cycle
fatigue assessment approach (3.11) evaluating the maximum fatigue stress cycle against a fatigue
strength limit
Note 1 to entry: If this fatigue strength limit is associated with N = ∞, then the fatigue assessment (3.10) results in
a theoretical proof of an infinité life. In some technical literature this is also referred to as endurance limit approach.
3.17
fatigue assessment based on equivalent loads
damage-equivalent loads approach
fatigue assessment approach (3.11) evaluating a constant amplitude stress spectrum determined by
damage equivalent loads against a corresponding fatigue strength limit
Note 1 to entry: The term damage equivalent stress is not used in the name of this approach to avoid
misunderstanding with damage equivalent stress spectra which are determined with a cumulative damage
approach (3.18) by processing variable amplitude stress spectra, e.g. by the application of counting methods and
Miner summation.
Note 2 to entry: A key characteristic of the damage-equivalent load approach is that damage calculations are not
performed by processing a variable amplitude stress spectrum, such as through the use of cycle counting methods
and Miner’s rule.
The constant amplitude stress spectrum usually is determined by a set of design load cases that in general are
combinations of individual loads. The load amplitudes and combination factors are selected with the objective to
obtain a constant amplitude stress spectrum that envelopes the real damage equivalent stress in service. In this
approach the damage equivalence is implicitly or explicitly considered by the selection of the values for load
amplitudes and combination factors.
Note 3 to entry: This approach has historically been used with design loads from EN 12663-1 [2], EN 12663-2 [3]
and this document and fatigue assessment (3.10) methods according to e.g. RP60 [4], DVS 1612 [5] or DVS 1608
[6]. In some cases these design loads do not produce the maximum stress cycle. The admissible stress values in
some cases are not the actual physical endurance limits.
In the past, this approach has been referred to as endurance limit approach. It has been applied with satisfactory
results.
To avoid ambiguity with the maximum stress cycle approach (3.16) , the term endurance limit approach is not used
in this document.
Note 4 to entry: For fatigue assessments where two or more individual loads are used in combination with load
factors to create damage equivalent load case (3.8) combinations it may not be possible to prove that the resulting
stress from the considered load combinations represents a real constant amplitude damage equivalent stress
compared to the real stress spectrum. In such cases the load factors for the load case (3.8) combinations should
be selected based on experience or based on detailed evaluations to ensure that the resulting stress from the
considered load combinations are sufficiéntly conservative with respect to the real damage equivalent stress in
service.
3.18
cumulative damage approach
fatigue assessment based on cumulative damage
fatigue assessment approach (3.11) evaluating a variable amplitude stress spectrum against a
corresponding fatigue strength curve
Note 1 to entry: In many assessment methods of the cumulative damage approach (3.18) damage equivalent
stresses are determined.
3.19
fatigue load case
repetitive load case (3.8) used for assessment against fatigue strength
3.20
safety factor
factor applied during the strength assessment which makes an allowance for a combination of the
uncertainties and the safety criticality
3.21
sideframe
longitudinal structural member of the bogie frame (3.3)
3.22
primary suspension
suspension system consisting of the resilient elements (and associated connecting and locating parts)
generally located between the axlebox (3.2) and bogie frame (3.3)
3.23
secondary suspension
suspension system consisting of the resilient elements (and associated connecting and locating parts)
generally located between the bogie frame (3.3) and vehicle body or bolster (3.4)
3.24
track testing
performing of tests under expected service conditions, on railway infrastructure that represents the
actual operating environment, and monitoring and recording the responses
3.25
validation
confirmation, through the provision of objective evidence, that the requirements for a spécific intended
use or application have been fulfilléd
[SOURCE: EN ISO 9000:2015 [7], 3.8.13, modifiéd - Notes 1 to 3 to entry have been deleted.]
3.26
structural integrity
ability of a structure to maintain performance during operation with respect to structural safety,
robustness, serviceability, and durability
[SOURCE: EN ISO 19900:2019 [8], 3.50, modifiéd - removed cross references to other terms; removed
"structural component"; "throughout the total service life" changed to "during operation"]
3.27
structural integrity validation by testing
validation (3.25) actions based on physical testing with the focus on structural integrity (3.26),
performed in a laboratory or as track tests
Note 1 to entry: The typical tests required in the context of structural integrity validation are static and fatigue
tests in the laboratory and track testing (3.24) with the focus on stress / strain measurement and load related
qualities like accelerations or displacements.
3.28
structural integrity validation by simulation
validation (3.25) by analysis, including numerical methods such as finité element analysis, multi-body
simulation, analytical models, hand calculations
3.29
significant permanent deformation
plastic deformation of an amount that infringes on the functionality of the structure by exceeding the
component geometric tolerances
Note 1 to entry: local yielding, which does not exceed geometric tolerances or infringe on the structure's function
is excluded
3.30
verification
confirmation, through the provision of objective evidence, that spécifiéd requirements have been
fulfilléd
Note 1 to entry: Vérification is answering whether a spécific requirement is met, without questioning this
requirement
[SOURCE: EN ISO 9000:2015 [7], 3.8.12, modifiéd - Notes 1, 2 and 3 to entry removed, added new Note
1 to entry]
3.31
running gear
transmits forces between carbody and wheels, for example a bogie
3.32
load-transmitting equipment
component or assembly which transfers or generates inertia loads, equipment loads (such as traction,
braking, suspension component forces), including attachment brackets and housings
3.33
technical specification
document défining other or additional requirements not définéd in this standard
Note 1 to entry: Usually this is produced by and agreed between the customer and/or the manufacturer (sometimes
called the supplier), or a Railway Undertaking, and can be an accompaniment to contractual requirements.
3.34
ultimate load case
extreme load case (3.8) used for assessment against static material properties, under which ultimate
failure or rupture need to be prevented, but serviceability need not be maintained
3.35
reverse curve
two curves with alternating direction, with minimal distance between them in accordance with track
design conditions
Note 1 to entry: Includes S-curves as définéd in EN 14363:2016 [9]
3.36
validation plan
includes the validation (3.25) strategy and the documentation of the evidence of demonstrating that
the validation objectives (3.37) are mét/satisfiéd
3.37
validation objectives
spécific goals set to confirm that a system, product, or process performs as intended under définéd
conditions
Note 1 to entry: These guide the validation (3.25) activities and serve as criteria for determining whether the
requirements, functional performance, and safety standards have been successfully met.
3.38
design scenario
set of circumstances which leads to a combination of loads applied to the bogie frame (3.3)
Note 1 to entry: This can be the same as a design load case (3.8).
3.39
primary load path
fundamental route of force transmission between wheelset and carbody as well as for traction and
braking, excluding damper loads and secondary retention
3.40
fatigue assessment locations
set of locations which définé the scope of the fatigue life validation (3.25)
3.41
design limit
design limit value
threshold for the value of a parameter used as an acceptance criterion in the design release and
validation (3.25) process
EXAMPLE The design limit for the fatigue strength utilization as définéd in this document is 1,0 or 100 %; see
6.5.2.
3.42
load block
spécifiéd loads définéd for all actuators including amplitudes, number of cycles and phase relations
3.43
load stage
sequence of one or more load blocks that is repeated with a définéd repetition count
3.44
load stage factor
ratio of loads applied during a load stage (3.43) with respect to the design load stage (3.43)
3.45
test setup
mechanical system of load application and restraints including location, type of load and degree of
freedom
Note 1 to entry: The test setup comprises the mechanical system of the test rig including the test specimen,
actuators and restraints.
3.46
fatigue test programme
définition of loads being applied during the fatigue test définéd by a sequence of load stages
3.47
design documentation
version-controlled définition of manufacturing and quality requirements for a component or assembly
(including e.g. the geometry, material properties and acceptance criteria)
Note 1 to entry: Typically the design documentation consists of a combination of drawings, spécifications or
CAD models
Note 2 to entry: The design documentation should hold all data required to définé a manufacturing process and
allow predictions of reproducible properties and functionalities, e.g. strength properties, cast or welding quality
properties, surface conditions.
3.48
validation domain
collective term for the different validation (3.25) methods, in particular simulation, testing in the
laboratory and track testing (3.24)
4 Requirement and interface management
4.1 General
The structural design and validation (3.25) process shall be consistent with the general principles set
out in EN 15827:2025, 6.1.
4.2 Input to the running gear structural design and validation process
The input to the running gear (3.31) structural design and validation (3.25) process shall be determined
based on an operating envelope in accordance with EN 15827:2025, Annex I. The input shall comprise,
as a minimum, the subset of parameters in accordance with EN 15827:2025, 5.2 as relevant to the
structural design and validation.
NOTE To achieve consistency in the overall development process, it is usual to establish a common operating
envelope in accordance with EN 15827:2025 [10] for all different disciplines and areas of expertise.
The following sections set out requirements for design loads, the derivation of design load cases and
the events that are used to définé them.
4.3 Primary load paths
The primary load paths are définéd as those regions which carry the primary loads transmitted by the
structural members of the running gear (3.31). The primary load paths are relevant for the selection of
the static and fatigue assessment locations (3.40); see 6.5.3.2.
The following loads shall be considered as primary loads:
— vertical forces in the interface to the carbody;
— lateral forces in combination with rolling moment in the interface to the carbody;
— longitudinal forces in the interface to the carbody;
— longitudinal forces in the interface to the wheelset (or wheel in case of non-wheelset);
— lateral forces in the interface to the wheelset (or wheel in case of non-wheelset);
— vertical loads (forces or displacements) due to track twist;
— forces induced by traction equipment;
— forces induced by braking equipment;
— forces induced by inertia of mounted equipment.
The combinations of the primary loads with other relevant loads shall be determined under
consideration of the scenarios définéd in 4.6 to determine the design load cases; see section 4.5.
NOTE Design load cases usually will be a combination of loads and not be restricted to single primary loads.
4.4 Requirements for design loads
Design loads shall consider the input based on the définéd operating envelope in accordance with
EN 15827:2025, 5.2, in particular:
— the operating environment;
— functional performance;
— vehicle parameters, including the running gear configuration;
— design and validation requirements.
The design loads shall be determined as a set of design scenarios with the associated parameters. The
values of the parameters used to determine the design loads shall be sufficiént to cover the operating
envelope. The design load cases shall be derived from these scenarios under consideration of the
operating environment, the functional performance, and the vehicle and running gear configuration.
The list of scenarios is not exhaustive; spécific applications may require additional events to be
considered.
For some applications and fatigue assessment approaches (e.g. cumulative damage, damage equivalent
load or maximum stress cycle approach (3.16) ) it will be necessary to use additional vehicle loading
conditions (expressed as functions of the cases in EN 15663:2017+A2:2024) to obtain an accurate
description of the vehicle payload spectrum for design purposes.
The development of the design load cases is discussed in 4.5; examples of design load cases associated
with running and due to the attachment of equipment are given in Annex B and Annex C respectively.
NOTE If the maximum stress cycle approach for the fatigue strength assessment is to be used, the data on the
number of events is not used and only the extreme repetitive load conditions are spécifiéd.
In reality, the loads are combined in a complex manner and so it is difficult to represent them exactly
in analysis. Consequently, it is generally the practice, for ease of analysis, to represent the true loads by
a series of load cases which include the above effects in a simplifiéd form, either individually or in
combination. It is essential that the simplification ensures that the effects of the true loads are not
underestimated.
4.5 Requirements for design load cases
The load cases used for running gear structural component simulations, static tests and fatigue tests
shall be spécifiéd on the basis of the design loads in accordance with 4.4 and the vehicle reference
masses. EN 15663:2017+A2:2024 provides standard reference masses from which design payload
conditions may be derived for different types of vehicle if the technical spécification (3.33) is inadequate.
The load cases can comprise displacements as well as forces, e.g. track twist.
The load cases fall into two groups, namely external and internal.
External load cases can result from:
— running on the track (e.g. vertical forces due to the load carried by the vehicle, transverse forces
on curves or when going across points and crossings, twisting of the bogie frame (3.3) as a result
of the vehicle going over twisted track);
— starts/stops and associated vehicle accelerations;
— loading/unloading cycles of the vehicle;
— lifting and jacking.
Internal load cases are due to the presence and operation of running gear mounted components (e.g.
brakes, dampers, anti-roll bars, motors, inertia forces caused by masses attached to the bogie frame
(3.3)).
The définition of each load case can comprise three components:
— static;
— quasi static;
— dynamic.
The commonly adopted approach for the design and assessment of running gear structures is to divide
the load cases into two main types.
The first type comprises static load cases, which represent those extreme (exceptional) loads that
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