SIST EN 12082-1:2026

Railway applications - Axleboxes - Part 1: Test procedures

This document is a part of a package of standards: EN 12080, EN 12081, EN 12082-1 and EN 12082-2.
This document specifies the principles and methods for a rig performance test of the system of axlebox rolling bearing(s), housing, seal(s) and grease, required for reliable operation of trains on European networks. The necessary type and extent of testing are specified by the deployment procedure specified in EN 12082-2, with respect to design requirements on the axlebox and its components.
This document covers a rig performance test, principles for a field test and a possible example for a water tightness test. Test parameters and minimum performance requirements for vehicles in operation on main lines are specified. Different test parameters and performance requirements may be selected for vehicles in operation on other networks (e.g. urban rail).
This document is historically developed for outboard applications with rotating inner rings, but can be used for vehicles with inboard bearing arrangements with rotating inner rings.
It gives some possible examples where a sequenced rig performance test addresses the broad range of different service conditions within a specific application or vehicle platform.

Bahnanwendungen - Radsatzlager - Teil 1: Prüfverfahren

Dieses Dokument ist Teil eines Normenpakets: EN 12080, EN 12081, EN 12082-1 und EN 12082-2.
Dieses Dokument legt die Grundlagen und Verfahren für die Prüfung des Leistungsvermögens auf dem Prüfstand der Baugruppe Radsatzlager, bestehend aus Wälzlager(n), Lagergehäuse, Dichtung(en) und Schmierfett, fest, die für den zuverlässigen Betrieb von Zügen auf den europäischen Schienennetzen erforderlich sind. Die erforderliche Art und der Umfang der Prüfungen werden durch das in EN 12082-2 festgelegte Inverkehrbringungsprozess bestimmt, unter Berücksichtigung der Gestaltungsanforderungen an das Radsatzlager und seine Bauteile.
Es behandelt eine Leistungsprüfung auf dem Prüfstand, grundlegende Prinzipien für einen Betriebserprobung und ein mögliches Beispiel für eine Wasserdichtheitsprüfung.. Für Fahrzeuge im Betrieb auf Vollbahnen sind die Prüfbedingungen und Mindestleistungsanforderungen spezifiziert. Für Fahrzeuge im Betrieb auf anderen Schienennetzen dürfen davon abweichende Prüfbedingungen und Leistungsanforderungen gewählt werden (z. B. städtische Schienenbahnen).
Dieses Dokument wurde ursprünglich für Außenlagerungen mit rotierenden Innenringen entwickelt, kann jedoch auch für Fahrzeuge mit Innenlageranordnungen mit rotierenden Innenringen verwendet werden.
Es enthält mögliche Beispiele, in denen eine sequentielle Leistungsprüfung auf dem Prüfstand die breite Vielfalt von verschiedenen Betriebsbedingungen innerhalb einer spezifischen Anwendung oder einer Fahrzeugplattform berücksichtigt.

Applications ferroviaires - Boîtes d'essieux - Partie 1: Méthodes d’essai

Le présent document fait partie d'un ensemble de normes : EN 12080, EN 12081, EN 12082-1 et EN 12082-2.
Le présent document spécifie les principes et les méthodes d'un essai de performance au banc, du système composé du (des) roulement(s), du corps de boîte, de la (des) étanchéité(s) et de la graisse, pour assurer la fiabilité de la circulation des trains sur les réseaux européens. Le type et le contenu des essais nécessaires sont spécifiés par la procédure de déploiement définie dans l’EN 12082-2, conformément aux exigences de conception relatives à la boîte d'essieu et à ses composants.
Le présent document inclut l’essai de performance au banc, les principes fondamentaux de l’essai en service et un exemple possible pour un essai d'étanchéité à l'eau. Les paramètres d'essai et les exigences minimales de performance pour les véhicules en service sur les lignes principales sont spécifiés. D'autres paramètres d'essai et exigences de performance peuvent être choisis pour les véhicules en service sur d'autres réseaux (par exemple, réseau ferroviaire urbain).
Le présent document a été initialement élaboré pour les applications à boîtes d'essieux extérieures avec des bagues intérieures tournantes, mais il peut également s’appliquer aux véhicules avec une configuration à boîtes d'essieux intérieures avec des bagues intérieures tournantes.
Il décrit quelques exemples possibles dans lesquels un essai de performance à plusieurs séquences tient compte de la vaste gamme de conditions de service différentes au sein d'une application spécifique ou de configuration particulière de véhicule.

Železniške naprave - Ohišja ležajev kolesnih dvojic - 1. del: Preskusni postopki

General Information

• Status: Published
• Public Enquiry End Date: 30-Nov-2024
• Publication Date: 22-Dec-2025
• ICS: 45.040 - Materials and components for railway engineering
• Technical Committee: IŽNP - Reilway applications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 17-Dec-2025
• Due Date: 21-Feb-2026
• Completion Date: 23-Dec-2025
• Directive: 2016/797/EU - Directive (EU) 2016/797 of the European Parliament and of the Council of 11 May 2016 on the interoperability of the rail system within the European Union (Text with EEA relevance)
• Mandate: M/591 - Standardisation request to the European Committee for Standardisation and the European Committee for Electrotechnical Standardisation as regards railway products in support of Directive (EU) 2016/797
• Ref Project: EN 12082-1:2025 - Railway applications - Axleboxes - Part 1: Test procedures

Relations

• Replaces: SIST EN 12082:2017+A1:2021 - Railway applications - Axleboxes - Performance testing
• Effective Date: 01-Feb-2026

Overview

EN 12082-1:2025 (CEN) - "Railway applications - Axleboxes - Part 1: Test procedures" defines the principles and methods for testing axlebox assemblies used on European rail networks. It specifies rig performance tests for the system of rolling bearings, box housing, seals and grease, gives principles for field testing and provides an example water tightness test. EN 12082-1:2025 is part of a standards package (EN 12080, EN 12081, EN 12082-2) and supports the deployment procedure described in EN 12082-2.

Key Topics

• Scope of testing: Rig performance test of axlebox rolling bearing(s), housing, seal(s) and grease; principles for field tests; example water tightness test.
• Test specification and execution: Requirements for test preparation, test rig setup, test parameters and carrying out the test, including pre-test, performance test and post-test actions.
• Performance and acceptance: Definition of acceptance criteria, results to be obtained during and after tests, and required content for a performance test report.
• Test instrumentation and measurements: Temperature measurement guidance, grease sampling zones and definition of forces relevant to axlebox tests (detailed examples provided in annexes).
• Sequenced testing: Guidance on sequenced rig performance tests to emulate a range of service conditions for specific vehicle platforms (examples for different train types are included).
• Water tightness: Modified requirements for water tightness testing (procedure, test conditions and pass/fail criteria) with informative sketches.
• Annexes and informative material: Schematic test rigs, temperature evaluation examples, mechanical and physico-chemical acceptance criteria and test cycle presentations.

Applications

• Who uses it: Testing institutes, axlebox and bearing designers, component manufacturers (bearings, seals, grease), railway vehicle manufacturers, certification bodies and railway operators.
• Practical value: Provides a standardized framework for verifying axlebox reliability and compatibility with European mainline service conditions. Useful for type-testing axlebox assemblies before deployment and for establishing consistent test reports required by EN 12082-2 deployment procedures.
• Network applicability: Test parameters and minimum performance requirements are specified for main-line vehicles; alternative parameters may be selected for urban/other networks. Historically focused on outboard applications with rotating inner rings but applicable to inboard arrangements with rotating inner rings.

Related Standards

• EN 12082-2:2025 - Axlebox Deployment Procedure
• EN 12081:2025 - Axleboxes - Lubricating greases
• EN 12080 - (axlebox package reference)
• Other normative references cited: EN 15663, ISO 15243, ASTM D7303, EN ISO 11885

Keywords: EN 12082-1:2025, axlebox test procedures, rig performance test, water tightness test, rolling bearing, axlebox seals, grease sampling, railway axlebox standards.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2026
Nadomešča:
SIST EN 12082:2017+A1:2021
Železniške naprave - Ohišja ležajev kolesnih dvojic - 1. del: Preskusni postopki
Railway applications - Axleboxes - Part 1: Test procedures
Bahnanwendungen - Radsatzlager - Teil 1: Prüfverfahren
Applications ferroviaires - Boîtes d'essieux - Partie 1: Méthodes d’essai
Ta slovenski standard je istoveten z: EN 12082-1:2025
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.

EN 12082-1
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2025
EUROPÄISCHE NORM
ICS 45.040 Supersedes EN 12082:2017+A1:2021
English Version
Railway applications - Axleboxes - Part 1: Test procedures
Applications ferroviaires - Boîtes d'essieux - Partie 1: Bahnanwendungen - Radsatzlager - Teil 1:
Méthodes d'essai Prüfverfahren
This European Standard was approved by CEN on 17 November 2025.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12082-1:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Symbols and abbreviations . 8
5 Water tightness test . 9
5.1 General. 9
5.2 Test specification . 9
6 Rig performance test . 9
6.1 General. 9
6.2 Test specification . 10
6.3 Test execution . 11
6.3.1 Test rig . 11
6.3.2 Test parameters . 11
6.4 Carrying out the test . 13
6.4.1 Pre-test . 13
6.4.2 Performance test . 13
6.5 Acceptance criteria. 14
6.5.1 Results obtained during the test . 14
6.5.2 Results obtained after the test . 14
6.6 Performance test report . 14
7 Field test . 15
7.1 General. 15
7.2 Test specification . 16
7.3 Carrying out the test . 16
7.4 Test parameters . 17
7.5 Results to be obtained during and after field test and field test report . 17
Annex A (normative) Rig performance test . 18
A.1 Schematic examples of test rigs . 18
A.2 Temperature measurements . 20
A.3 Grease sampling zones . 21
A.4 Definition of forces . 21
A.5 Definition of test cycles . 22
A.5.1 Speed Classes and cumulative distances for testing . 22
A.5.2 Conditions for sequenced tests . 22
A.5.3 Rig performance tests with limited distance . 23
A.6 Graphical presentation of test cycles . 24
A.7 Temperature criteria. 25
A.8 Mechanical and physico-chemical acceptance criteria . 27
A.8.1 Mechanical criteria . 27
A.8.2 Physico-chemical criteria . 27
Annex B (informative) Sequenced performance tests . 30
B.1 General . 30
B.2 High Speed Train example . 30
B.3 Passenger train example. 31
B.4 Freight train example. 33
B.5 Peri-urban train example . 34
Annex C (informative) Water tightness test . 36
C.1 General . 36
C.2 Test conditions . 36
C.3 Test procedure . 37
C.4 Pass/fail criterion . 37
C.5 Test report . 37
C.6 Sketches . 38
C.6.1 Classic application . 38
C.6.2 Application with dynamic seals on both sides of the axlebox . 39
Annex D (informative) Temperature evaluation examples . 40
D.1 General . 40
D.2 Nomenclature. 40
D.3 Criterion A . 40
D.4 Criterion B . 41
D.5 Criterion C . 41
D.6 Criterion D . 42
D.7 Criterion E1 . 42
D.8 Criterion E2 . 42
Bibliography . 43

European foreword
This document (EN 12082-1:2025) has been prepared by Technical Committee CEN/TC 256 “Railway
Applications”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2026, and conflicting national standards shall be
withdrawn at the latest by May 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12082:2017+A1:2021.
EN 12082:2017+A1:2021:
— document split into EN 12082-1 on Test procedures and EN 12082-2 on Deployment procedure;
— EN 12082-1 contains requirements for tests which are referred to in EN 12082-2 as part of the
axlebox deployment procedure. These test requirements focus on test preparation, test execution
and post-test actions including the test report. Main addressees of EN 12082-1 are testing institutes
which carry out the tests;
— requirements on test specifications and test reports are revised and separated for each test;
— tightness tests are now mentioned with water tightness test as one example;
— modified requirements on water tightness test with respect to test procedure and test conditions;
— modifications to rig performance test with respect to results obtained after the test, definition of
grease sampling areas, test report and test procedure;
— modifications to field test requirements with respect to acceptance criteria.
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).
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: 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 the United
Kingdom.
1 Scope
This document is a part of a package of standards: EN 12080, EN 12081, EN 12082-1 and EN 12082-2.
This document specifies the principles and methods for a rig performance test of the system of axlebox
rolling bearing(s), housing, seal(s) and grease, required for reliable operation of trains on European
networks. The necessary type and extent of testing are specified by the deployment procedure specified
in EN 12082-2, with respect to design requirements on the axlebox and its components.
This document covers a rig performance test, principles for a field test and a possible example for a water
tightness test. Test parameters and minimum performance requirements for vehicles in operation on
main lines are specified. Different test parameters and performance requirements may be selected for
vehicles in operation on other networks (e.g. urban rail).
This document is historically developed for outboard applications with rotating inner rings, but can be
used for vehicles with inboard bearing arrangements with rotating inner rings.
It gives some possible examples where a sequenced rig performance test addresses the broad range of
different service conditions within a specific application or vehicle platform.
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.
ASTM D7303:2023, Standard Test Method for Determination of Metals in Lubricating Greases by
Inductively Coupled Plasma Atomic Emission Spectrometry
DIN 51460-1:2007, Testing of petroleum products — Method for sample preparation — Part 1: Microwave
incineration
DIN 51829:2013, Petroleum products — Determination of additive and wear elements in greases —
Analysis by wavelength dispersive X-ray fluorescence spectrometry
EN 12081:2025, Railway applications — Axleboxes — Lubricating greases
EN 12082-2:2025, Railway applications — Axleboxes — Part 2: Deployment Procedure
EN 15663, Railway applications — Definition of vehicle reference masses
EN ISO 11885:2009, Water quality - Determination of selected elements by inductively coupled plasma
optical emission spectrometry (ICP-OES) (ISO 11885:2007)
ISO 15243:2017, Rolling bearings — Damage and failures — Terms, characteristics and causes
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
axlebox
assembly consisting of the following major components: rolling bearing(s), grease, seal(s) and box
housing
Note 1 to entry: Further components such as axle end cap components, bearing sleeve, box cover(s), distance rings,
fasteners may also be part of the assembly but their presence depends on the axlebox type design and they are not
considered major components.
3.2
box housing
structural component which contains rolling bearing(s), seal(s) and grease
3.3
ovality
change (permanent deformation) in the bore's shape of a box housing becoming slightly oval
3.4
rolling bearing
bearing operating with rolling motion between the parts, supporting load and moving in relation to each
other
3.5
cartridge bearing
rolling bearing with two or more rows of rolling elements within a self-contained unit, greased and
equipped with integral seals
3.6
grease
semi-solid lubricant, which consists of a thickener and additives dispersed in lubricating oil
3.7
seal
component that protects the rolling bearing(s) against ingress of water and dust and retains grease in the
rolling bearing(s)
3.8
roller set
assembly of cage and rollers
3.9
inboard bearing
designates the bearing row closer to the middle of the
wheelset or the test rig
3.10
inboard application
configuration with rolling bearings that are positioned on a wheelset axle
between the wheels of a wheelset
3.11
outboard bearing
bearing row that is next to the inboard bearing row to the
outside direction
3.12
outboard application
configuration with rolling bearings that are positioned on wheelset axle ends,
outside of the space between the wheels of a wheelset
3.13
maximum operational test speed
v
max
maximum operational speed for normal service (in km/h) for which the vehicle is homologated
3.14
nominal maximum rotational test speed
ntest
rotational speed (using the average wheel diameter) corresponding to v increased by 10 % (in rpm)
max
3.15
target zone
defined area on the underside of an axlebox that is designed to have its temperature monitored by a hot
axlebox detector (HABD)
3.16
main line
railway network open to different types of rolling stock
3.17
urban rail
public transport systems permanently guided at least by one rail, intended for the operation of local,
urban and suburban passenger services with self-propelled vehicles and operated either segregated or
not from general road and pedestrian traffic
[SOURCE: CEN-CENELEC Guide 26:2013, Clause 1]
3.18
network
infrastructure, on which any railway undertaking can operate rolling stock
3.19
deployment process
methodical procedure of introducing an axlebox or a change to an axlebox into vehicle service
4 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in Table 1 and Table 2 apply.
Table 1 — Symbols
Symbol Unit Description
d m average wheel diameter between new and fully worn condition
average
d m wheel diameter in new condition
max
d m wheel diameter at limit of wear condition
min
F N force
F N reference vertical force applied per wheelset on the track
F N axial test force
a
Fan N nominal axial test force
F N radial test force
r
F N nominal radial test force
rn
2 2
g m/s acceleration due to gravity (9,81 m/s )
j - number of wheelsets per vehicle
wheelset mass and masses on the wheelset between rolling circles,
m kg
like brake disc, etc.
m kg vehicle design mass according to EN 15663
max
n rpm rotational test speed corresponding to v
n rpm nominal maximum rotational test speed (see 3.14)
test
estimated number of elementary trips needed to achieve the
N -
trips
performance test (based on nominal speed)”
N - adjusted value of N to account for variations in speed”
trips_adj trips
t s time of one test cycle (see A.6)
t s time of one elementary trip
ramp up or ramp down time from n = 0 → n = n or n = n → n = 0
test test
t s
during one elementary trip
t s time at rotational speed n during one elementary trip
4 test
t s stop time (n = 0)
t s time of one half load cycle of the alternating axial test force
time during which axial test force is applied (including ramp up and
t s
ramp down) within the period t
ramp up or ramp down time from F = 0 → F = F or F = F →
a a an a an
t s
F = 0 during one half load cycle of the alternating axial test force
a
t s axial test force recovery time
Symbol Unit Description
ambient temperature (A running average can be used for this value.
T °C If a running average is used, the duration for the running average
a
shall be justified and documented)
measured temperature at a position z and then re-calculated to a
T °C
z20
temperature corresponding to an ambient temperature of 20 °C
measured temperature at a position z (measured positions are
T °C
zm
loading zones and target zones)
v km/h maximum operational test speed (see 3.13)
max
Table 2 — Abbreviations
Abbreviation Description
HABD hot axlebox detector
ICP inductively coupled plasma (spectrometry)
MEP mounted end play
XRF X-ray fluorescence (spectrometry)
5 Water tightness test
5.1 General
The necessity for a tightness test is subject to the specification of the deployment process. An example
for a water tightness test is given in Annex C.
5.2 Test specification
The test specification shall consist of all the information describing test parameters and acceptance
criteria.
The following requirements shall at least be fully documented and included in the test specification:
a) report recipients list
b) quality management system accreditation and its scope;
c) interface drawing showing mounting conditions of all components as in-service;
d) conditions of production of the bearings (serial production, prototype);
e) specification of the test parameters.
6 Rig performance test
6.1 General
The purpose of the rig performance test is to check the satisfactory design and safe function of the axlebox
major components during a sequence of simulated journeys.
Rig performance test and mandatory grease analyses shall be performed by a competent test facility.
NOTE Competence of a test facility is usually proven by accreditation to EN ISO/IEC 17025.
The test consists of putting a pair of axleboxes, assembled as for operating conditions, on the test rig
journals and subjecting them to one or more sequence(s) of repeated loading cycles determined from the
test specification (based on the operating conditions of the vehicles to be equipped with these axleboxes,
if available).
The bearings shall be mounted in such a way that the maximum difference in mounted clearance is
achieved with the selected bearings and available equipment. The mounted end plays (MEP) according
to the bearing specification shall be calculated by the laboratory customer taking into account: measured
bearing un-mounted clearance, measured journal diameters, measured bearing bore diameters, inner
and outer raceways angles (at the rolling element contact points), inner and outer raceways mean
diameter.
The MEP shall be measured before and after the performance test (axial play for tapered bearings and
radial play for cylindrical or spherical bearings).
During rig operation (during a sequence), the axleboxes are subjected to constant radial force and
alternated axial force.
Before the performance test, a pre-test shall be carried out. This does not constitute part of the evaluated
performance test. It is intended to observe the thermal behaviour of the axleboxes during the grease
migration at the beginning of the rig test.
The performance test consists of repeating identical cycles up to an agreed cumulative distance. The
number of cycles and the required test distance reflect the service conditions of the intended application.
Throughout the test, the performance of the axleboxes shall be monitored by measurement of
temperatures, the values of which, both absolute and relative, shall remain within limits. Finally, on
completion of the test, the bearings and the grease shall be inspected and shall not show any changes
beyond limits imposed.
6.2 Test specification
The test specification shall consist of all the information describing test parameters and acceptance
criteria.
The following requirements shall at least be fully documented and included in the test specification:
a) report recipients list;
b) quality management system accreditation and its scope;
c) interface drawing showing mounting conditions of all components as in-service;
d) boundary dimensions and interface tolerances of the rolling bearing(s);
e) MEP requirements;
f) conditions of production of the bearings (serial production, prototype);
g) grease (according to EN 12081:2025) designation, quantity and distribution, batch reference and
production date;
h) specification of the test parameters according to 6.3.2;
i) deviations to the test parameters in A.4 and A.6;
j) required test distance;
k) deviations to the performance test report according to 6.6;
l) possible extrapolation of the physico-chemical criteria according to A.8.2.
m) Type of vehicle (see Table A.1)
6.3 Test execution
6.3.1 Test rig
The test rig shall apply testing conditions which are derived from the service operating conditions and
ensure accurate monitoring of the axleboxes under test. The influence of the rig on the tested axleboxes
shall be minimized. Especially, the avoidance of the transfer of disturbances from one axlebox to the other
one.
The test rig shall at least include:
a) one axle or two synchronized axles, on which the axleboxes are mounted on the journals;
b) rotation mechanism to apply the nominal test speed ntest;
c) device for measuring the rotational speed of the axle n;
d) device arranged to subject each axlebox to a radial force F = F ;
r rn
e) measuring device to monitor this radial test force F ;
r
f) device arranged to subject each axlebox to an alternating axial force F ;
a
g) measuring device to monitor this alternating axial test force F ;
a
h) ventilation equipment to simulate the cooling in operation;
i) sensors permitting temperature measurement:
1. by one sensor in the loaded zone of each rolling bearing row, aligned centrally above the bearing
rows and in contact with the outer ring, with typical positions shown in Figure A.3 (for an
axlebox with two bearings);
2. in the target zone of the hot axlebox detectors (HABD), by one sensor in direct contact with the
surface of the axlebox housing as indicated in Figure A.3 (a non-contacting temperature sensor
–measuring in the same zone – shall be used only in case there are no suitable surfaces to attach
a sensor);
3. of the ambient air stream which is directed at each axlebox, measured at the outlet of the cooling
fans (see Figure A.1). For ducted air streams the sensors have to be positioned adequately in the
air flow upstream of each axlebox (see Figure A.2).
Examples of test rigs are shown in A.1.
6.3.2 Test parameters
6.3.2.1 General
The test parameters shall be specified on the basis of the operating conditions of the vehicles to be
equipped with the axleboxes and documented in accordance with the test specification in 6.2. The
following information is required, agreed and documented in the test specification before the test and
presented in the test report:
a) design mass according to EN 15663: m , (in kg) is:
max
1) the “design mass under normal payload” (see EN 15663) when considering passenger vehicles
(including High Speed Trains) or freight vehicles;
2) the “design mass in working order” when considering locomotives. Locomotives are treated as
passenger vehicles without payload.
b) mass not carried by the bearings: m (wheelset mass and masses on the wheelset between wheel
rolling circles, like brake disc, etc.), in kg;
c) axial test force recovery time: t , in s;
d) wheel diameter new: d and at the limit of wear: d , in m;
max min
e) maximum operational speed: v , in km/h;
max
f) pre-test procedure;
g) required test distance, in km.
If not calculated according to A.4, the test forces: F and F (in N) have to be specified in the test
an rn
specification according to 6.2.
Deviations from the test parameters in A.4 and A.6 (pre-test shall not be considered) are allowed, based
on test specifications 6.2. Those deviations shall be indicated in the test report.
6.3.2.2 Rotational test speed
The maximum rotational test speed n (in rpm), maintained most of the time during the test, is that of a
test
wheelset on which the wheels are half worn and where the rotational speed is equal to the maximum
operational vehicle speed v , increased with a safety margin of 10 %.
max
110 × v
max
n =  (1)
test
6 ×π× d
average
where
d dd+ /2
( )
average min max
The tolerances are specified in A.6.
Since the speed may vary within tolerances specified in A.6 the number of elementary trips N need to
trips
be adjusted to N _ to evaluate the acceptance criteria in A.7.
trips adj
Test carried out with a n rotation speed calculated from the worn wheel diameter d should be
test min
considered acceptable if this complies with the test specification 6.2.
6.3.2.3 Radial and axial forces
The test forces are applied to each axlebox inducing forces on the rolling bearings, simulating as closely
as possible the distribution of forces from the primary suspension. There shall be a constant radial force
and an alternating axial force. The axial force shall be aligned with the axis of the axle.
The methods to define the nominal radial test force F and the nominal axial test force Fan are specified
rn
in A.4 based on the load data specified in accordance with 6.2. The forces are calculated for one axlebox.
The axial force shall not be applied when the test speed n is less than 20 % of the nominal test speed n .
test
=
6.3.2.4 Air cooling
An air cooling system shall provide an average air speed of 8 m/s to 10 m/s with measurements taken
from several points across each axlebox in the area impinged by the air stream. The cooling shall be
stopped when the test speed is equal to zero.
6.4 Carrying out the test
6.4.1 Pre-test
Before running the performance test, a pre-test shall be run. This test is designed to observe the thermal
behaviour of the bearings and to redistribute the grease.
Methods to carry out a pre-test shall be stated in the test specification specified in 6.2.
If there is no proposal in the test specification, an example of pre-test is illustrated in A.6: It consists of
four cycles, each made up of two elementary trips, one in each rotational direction. The speeds are 25 %,
50 %, 75 % and 100 % of the nominal rotational test speed, respectively. The axial force is applied as
agreed, e.g. 25 %, 50 %, 75 % and 100 % of the nominal axial force F . The radial test force is maintained
an
at its nominal value F . Each elementary trip is made up of a speed increase, a constant speed, a slowing
rn
down and a stop.
It is recommended that the pre-test is considered complete when at 100 % of the nominal test speed, all
the bearings temperatures have been stabilized within a 5 °C range, for a minimum of 2 h, in each
rotational direction.
The total pre-test run time shall not exceed 250 h.
The elementary trips achieved during the pre-test are not submitted to any acceptance criteria specified
in 6.5.
6.4.2 Performance test
The test consists of repeating identical cycles. A cycle consists of two elementary trips, one for each
direction of rotation, separated by a stop and composed of a starting period, a period of nominal
rotational test speed n and a slowing down period to stop.
test
The required test distance (in kilometres), as well as the time at the nominal test speed n during each
test
cycle, depend on the operating in-service vehicles to be equipped with these axleboxes. The conditions
specified in A.5 and A.6 are intended for several operational speed classes and vehicle categories.
As an alternative method, the cumulative distance of the rig performance test may be separated into
sequences using various input parameters from operation in service. Exemplified sequenced testing is
presented in Annex B.
In case of an interruption of the performance test not related to the performance of the tested axleboxes,
the following procedure shall be applied:
— interruption time less than or equal to one hour: the unfinished trip or cycle (depending on the rig
setting) shall not be post-processed according to Table A.2. The cumulative distance of the test shall
be increased by this not post-processed trip or cycle;
— interruption time longer than one hour: the unfinished trip or cycle and the two trips following the
restart of the test rig shall not be post-processed. The cumulative distance of the test shall be
increased by these not post-processed trips.
These rules shall be applied after each single interruption. If the number of interruptions exceeds (5 +
0,03 × N ), the performance test shall be abandoned without a result.
trips_adj
6.5 Acceptance criteria
6.5.1 Results obtained during the test
Throughout the test, temperatures shall be measured, during each elementary trip, at loading zones and
target zones of both axleboxes. The measured temperatures shall be expressed relative to an ambient
temperature of 20 °C by calculation with the aid of the following formula:
TT= −×0,6 T− 20 (2)
( )
za20 zm
where
0,6 factor of dissipation by convection. It takes into account the amount of energy that is dissipated
by the axlebox by convection, excluding the conduction and radiation effects. This mean value
is empiric (based on the experience of laboratories).
This calculation shall be applied for the assessment of all criteria in Table A.2 except if an air-conditioned
wind flow with (20 ± 2) °C is used for cooling the axleboxes for the test period.
The rig test shall not be carried out if the ambient temperature is not comprised between 10 °C and 40 °C.
For each thermal sensor, the maximum temperature as well as the simultaneous differences between
axleboxes shall be registered. Sufficient temperature data points shall be registered in order that the
results may be interpreted according to the criteria of Table A.2 (a sampling period of 100 s or less is
recommended).
For the further evaluation according to the Criterion C in Table A.2, the maximum value of those
simultaneous differences shall be used.
For consecutive elementary trips, the difference of maximum temperatures for an identical load zone
sensor position shall be noted and shall be used in the further evaluation according to the Criterion E in
Table A.2.
The limits to be observed and the tolerable number of violations are given in Table A.2.
The first 4 elementary trips of the performance test (or of each sequence, in case of sequenced test) shall
not be evaluated according to Table A.2. They are however still counted as achieved test distance.
6.5.2 Results obtained after the test
On completion of the cumulative distance the bearings shall be dismounted for examination; similarly
grease samples from the zones indicated in A.3 shall be analysed. The mechanical criteria to be fulfilled
by the bearings and the physico-chemical criteria to be fulfilled by the grease are specified in A.8.
Cartridge bearings shall be weighed before and after the test for information. For the measurement after
the test, the cartridge bearing shall be cleaned on all external surfaces.
6.6 Performance test report
Upon completion of the test, a report shall be established including at least the content such as follows:
a) designation and origin of each component of the tested axleboxes;
b) conditions of production of the bearings (serial production, prototype) and how they were selected
for the test (example: from a batch production, in presence of XXX Company representatives);
c) testing organization, site, personnel who edit and authorize the test report, description of the test rig
(measuring equipment, sensors and their positions, data acquisition period, etc.);
d) reference to a quality management system accreditation;
e) test parameters in accordance with the test specification;
f) reference, index and edition date of the test specification;
g) bearing mounting parameters in accordance with 6.1;
h) timing, distance and the finally observed stabilized temperature of the pre-test and timing and
distance of performance tests;
i) results obtained during and after the test, enabling evaluation of the products to the criteria in 6.5,
A.7 and A.8;
j) statement that the test was undertaken in accordance with EN 12082-1:2025, including the
information and conditions agreed in test specification according to 6.2 regarding the rig
performance test;
k) number and duration of each interruption of the performance test in accordance with 6.4.2 as well
as reasons for interruptions;
l) for each temperature sensor and considering all evaluated (see 6.4.2 and 6.5.1) elementary trips of
the performance test (or of each sequence, in case of sequenced test), the mean value and the
standard deviation of the maximum temperature values (of each elementary trip) shall be calculated.
Pre-test values shall not be taken into account;
m) designation, characteristics of the lubricating grease (including batch reference and production
date), quantity used in each axlebox and in case of cartridge bearings: the loss of grease;
n) axlebox sketch or drawing showing all test forces application areas and their directions;
o) installation sketch of the tested axlebox including modifications to allow its assembly on the test rig;
p) airflow directions; air speeds and cross-sectional area (in m ) of each axlebox cooling system;
q) output measurements uncertainties (temperatures and grease analysis results).
7 Field test
7.1 General
The field test shall be done in order to adjust, confirm and fix maintenance related instructions: i.e.
bearing re-greasing procedure (if applicable), overhaul distance, diagnostic parameters (i.e. temperature
and/or vibration and/or noise alarm levels, etc.).
The field test includes monitoring of a sufficiently large sample of axleboxes during a specified distance
and/or time and provides data for validation of the proposed maintenance regime.
The axlebox to be tested during the service test shall have passed the performance test in accordance
with this standard or deemed similar according to EN 12082-2:2025, Annex A.
The axlebox to be tested in the field shall have passed the performance test according to this standard.
Results of existing field tests can be referred to with respect to technical assessment, in accordance with
A.5.3 and EN 12082-2:2025, A.1.
7.2 Test specification
The test specification shall consist of all the information describing test parameters and acceptance
criteria.
The following requirements shall at least be fully documented and included in the test specification:
a) test report recipients list;
b) reference to the linked performance test report or proven design application;
c) specification of the test parameters according to 7.4;
d) required test distance;
e) annual specified distance travelled of the intended service;
f) minimum quantity of axleboxes to be monitored;
g) duration (in terms of time or distance travelled) of each intermediate inspection interval;
h) scope of monitoring and inspections activities;
i) values for iron content and copper content if a grease analysis is specified and if not, for information
only (determination methods according to Table A.4).
7.3 Carrying out the test
The axleboxes to be tested shall, as far as possible, be mounted on vehicles covering high annual distance
at the maximum operating speeds authorized for that category of vehicle, and with the highest possible
axle loads.
The extent of the field test (cumulative distance, possible intermediate inspections) shall be specified in
the test specification according to 7.2.
The number of axleboxes to be monitored depends on the amount of vehicles and is specified in the test
specification according to 7.2. For vehicles with powered and non-powered wheelsets both types of
wheelsets shall be comprised by this number of wheelsets to be monitored according to their share in the
vehicle.
The test shall take at least two times the annual specified distance travelled of the intended service or the
maximum maintenance interval for the bearings, whatever comes first. For speeds above 200 km/h,
minimum distance travelled can be limited to 1 000 000 km.
The axleboxes which have accumulated the greatest distance travelled during the field test shall be
chosen for the evaluation and validation.
For new types of applications or novel maintenance related instructions wheelsets shall be monitored
per intermediate inspection during the complete field test. A quantity of 20 wheelsets (i.e. 40 axleboxes)
is recommended.
The scope of the intermediate and final inspections shall be specified in the test specification based on
field data which are available (e.g. field sensor data). At t
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