SIST-TP CEN/TR 17320:2019

Railway applications - Infrastructure - Determination of laboratory test parameters for assessing the mechanical durability of rail fastening systems - Complementary element

This European Technical Report has been prepared to provide a technical basis for determining the laboratory test parameters (load, angle and position of load application) to be used when carrying out repeated load tests according to the method of EN 13146-4, taking into account evidence from both track testing and theoretical analysis and also considering experience in using the past versions of the EN 13481 series of standards. Statistical variations in applied loads and their influence on safety factors are also considered.
This report may be used to determine and justify loading parameters which will be required by future versions of the EN 13481 standards, including cases outside the current Scope of those standards e.g. track with wider support spacing, higher axle loads, sharper curves, etc.

Bahnanwendungen - Infrastruktur - Bestimmung von Laborprüfparametern zur Beurteilung der mechanischen Dauerhaftigkeit von Schienenbefestigungssystemen

Applications ferroviaires - Infrastructure - Détermination des paramètres d’essai en laboratoire pour l’évaluation de la durabilité mécanique des systèmes d’attache de rails – Elément complémentaire

Železniške naprave - Infrastruktura - Določitev laboratorijskih preskusnih parametrov za ocenjevanje mehanske vzdržljivosti sistemov za pritrjevanje tirnic - Komplementarni element

To evropsko tehnično poročilo je pripravljeno, da podaja tehnično podlago za določanje laboratorijskih preskusnih parametrov (breme, kot in položaj obremenitve), ki se uporabljajo pri izvajanju ponavljajočih se preskusov obremenitve skladno z metodo standarda EN 13146-4, pri čemer se upoštevajo podatki iz preskušanja tirnic in teoretične analize, poleg tega pa se upoštevajo tudi izkušnje pri uporabi starejših različic serije standardov EN 13481. Upoštevajo se tudi statistične variacije uporabljenih bremen in njihov vpliv na varnostne dejavnike.
To poročilo se lahko uporablja za določanje in utemeljitev parametrov nalaganja, ki bodo zahtevani v prihodnjih različicah standardov EN 13481, vključno s primeri, ki so zunaj trenutnega obsega teh standardov, npr. proga s širšim razmikom podpore, večje osne obremenitve, ostrejši ovinki itd.

General Information

• Status: Published
• Public Enquiry End Date: 14-Nov-2018
• Publication Date: 19-Feb-2019
• ICS: 93.100 - Construction of railways
• Technical Committee: IŽNP - Reilway applications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 15-Feb-2019
• Due Date: 22-Apr-2019
• Completion Date: 20-Feb-2019
• Directive: 2008/57/EC - Directive 2008/57/EC of the European Parliament and of the Council of 17 June 2008 on the interoperability of the rail system within the Community (Recast)
• Ref Project: CEN/TR 17320:2019 - Railway applications - Infrastructure - Determination of laboratory test parameters for assessing the mechanical durability of rail fastening systems - Complementary element

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TP CEN/TR 17320:2019
01-april-2019
äHOH]QLãNHQDSUDYH,QIUDVWUXNWXUD'RORþLWHYODERUDWRULMVNLKSUHVNXVQLK
SDUDPHWURY]DRFHQMHYDQMHPHKDQVNHY]GUåOMLYRVWLVLVWHPRY]DSULWUMHYDQMHWLUQLF
.RPSOHPHQWDUQLHOHPHQW
Railway applications - Infrastructure - Determination of laboratory test parameters for
assessing the mechanical durability of rail fastening systems - Complementary element
Bahnanwendungen - Infrastruktur - Bestimmung von Laborprüfparametern zur
Beurteilung der mechanischen Dauerhaftigkeit von Schienenbefestigungssystemen
Ta slovenski standard je istoveten z: CEN/TR 17320:2019
ICS:
93.100 Gradnja železnic Construction of railways
SIST-TP CEN/TR 17320:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST-TP CEN/TR 17320:2019

---------------------- Page: 2 ----------------------

SIST-TP CEN/TR 17320:2019


CEN/TR 17320
TECHNICAL REPORT

RAPPORT TECHNIQUE

February 2019
TECHNISCHER BERICHT
ICS 93.100
English Version

Railway applications - Infrastructure - Determination of
laboratory test parameters for assessing the mechanical
durability of rail fastening systems - Complementary
element
Applications ferroviaires - Infrastructure - Bahnanwendungen - Infrastruktur - Bestimmung von
Détermination des paramètres d'essai en laboratoire Laborprüfparametern zur Beurteilung der
pour l'évaluation de la durabilité mécanique des mechanischen Dauerhaftigkeit von
systèmes d'attache de rails - Elément complémentaire Schienenbefestigungssystemen


This Technical Report was approved by CEN on 14 December 2018. It has been drawn up by the Technical Committee CEN/TC
256.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey 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
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 17320:2019 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST-TP CEN/TR 17320:2019
CEN/TR 17320:2019 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Symbols and abbreviations . 4
5 Purpose . 4
6 History and background . 5
6.1 ERRI D170 Reports; Evolution of the EN 13481 series . 5
6.2 System testing v. component testing . 6
6.3 Design v. actual loads . 6
6.4 Selection of the appropriate hypothetical load case . 7
6.4.1 General principles . 7
6.4.2 Effect of rail inclination . 7
6.4.3 Sleeper type . 7
6.5 Safety and dynamic factors . 7
6.6 Duration of test (3 million cycles) and loading frequency . 7
6.7 Pass/fail criteria . 8
6.8 Ballasted v. ballastless track . 8
7 Assumptions about track construction and maintenance conditions . 8
8 Input loading at wheel-rail contact point . 9
8.1 Vertical Loads . 9
8.2 Lateral loads - Relationship between lateral force and curve geometry . 9
9 Distribution of loads . 10
9.1 Vertical loads . 10
9.2 Lateral loads. 10
10 Experience in applying the EN 13481:2002 series and EN 13481:2012 series . 11
11 Recommendations for future development of the EN 13481 series . 11
Bibliography . 13

2

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SIST-TP CEN/TR 17320:2019
CEN/TR 17320:2019 (E)
European foreword
This document (CEN/TR 17320:2019) has been prepared by Technical Committee CEN/TC 256
“Railway applications”, the secretariat of which is held by DIN.
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.
3

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SIST-TP CEN/TR 17320:2019
CEN/TR 17320:2019 (E)
1 Scope
This document presents the technical basis for the loading conditions (the load magnitude, the load
angle and the position of load application) to be used when performing the repeated load tests
described by EN 13146-4. This basis consists of measurements made in-track, theoretical analysis and
experience of using the previous versions of the EN 13481 series. Statistical variations in the applied
loads and their influence on safety factors are also considered.
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 13481-1:2012, Railway applications – Track - Performance requirements for fastening systems –
Part 1: Definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13481-1:2012 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
rail seat
single discrete rail fastening point e.g. a sleeper end or location of a single baseplate
4 Symbols and abbreviations
E Young's Modulus of the rail steel
F vertical component of load at a single rail seat
F load carried by the rail seat directly below the wheel
max
I second moment of area of the rail for vertical bending
k stiffness of the (“Winkler”) foundation
V maximum train speed [km/hr]
W vertical wheel load
a sleeper or support spacing
5 Purpose
This document has been prepared to provide a reference document that will inform future revisions of
the EN 13481 series and other standards that define Performance Requirements for rail fastening
systems. Specifically, it provides a basis for calculating the loads that should be applied in the repeated
load tests that are performed in laboratories in order to confirm the durability of rail fastening systems
according to the method given by EN 13146-4.
4

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SIST-TP CEN/TR 17320:2019
CEN/TR 17320:2019 (E)
6 History and background
6.1 ERRI D170 Reports; Evolution of the EN 13481 series
Committee D170 of the European Rail Research Institute (ERRI, formerly ORE) undertook the first work
toward the development of a European Standard for testing rail fastenings (and concrete sleepers)
between 1986 and 1994. This committee evaluated the test methods used by several major European
railways in order to establish “best practice”. The results of this work were published in a series of five
technical reports [1 – 5].
In 1992, the European Standards organization, CEN, established a new Technical Committee, TC 256, to
develop standards for Railway applications. These standards were necessary in order to support the
introduction of EC Utilities Directive 93/38/EEC. This Directive made it mandatory to use European
Specifications (including European Standards) as the technical basis of procurement for major public
utilities organizations, including railways (whether publicly or privately owned). The part of Technical
Committee TC 256 that was formed to develop European Standards for rail fastenings was Working
Group 17 (WG 17), which is part of Sub-Committee SC 1 “Infrastructure” of CEN/TC 256. This working
group included several experts who were also serving on ERRI Committee D170, so the work of the
ERRI committee was absorbed into the work of WG 17 from the outset.
NOTE The Utilities Directive has been progressively updated. The latest version of the Utilities / Procurement
Directive is 2004/17/EC.
The ERRI D170 reports [1-5] consider the case of conventional mainline track: concrete sleepers in
ballast, 60 kg/m rail and a maximum axle load of 22,5 t. Some reference was also made in these reports
to experience on the new high speed operations in France. In order to account for the conditions found
on other types of track, such as ballastless track (see 5.8), it was necessary to extrapolate from the
empirical data available for conventional mainline and high speed track [1-5].
The use of a reduced height of rail section in repeated load tests performed in the laboratory was
introduced in ERRI D170 Report 5 and it is explained by a paper published in the International Heavy
Haul Conference in 1989 [6]. A section of rail that has reduced height is used for the test so that the
over-turning moment on the rail is reduced, without reducing either the vertical or lateral components
of the load applied to the rail. It is appropriate to do this because the test is normally performed for a
short piece of rail that is fastened to the support at only a single rail seat. This means that in the
laboratory test, a single fastening system shall provide all of the resistance to the over-turning moment
applied by the actuator to the rail. In track, a long rail is fastened to the support at numerous rail seats
and numerous fastening systems along the length of the rail provide resistance to the applied over-
turning moment.
In the current standards, the modified rail height is defined in terms of a distance measured downward
from the gauge corner. It is accepted that, for future standards development, defining a distance
measured from a different reference point or plane could make the method applicable to a wider range
of rail sections.
The original EN 13481 series, published in 2002, distinguished between two basic 'categories' of
fastening systems – those suitable for “Main Line” application and those suitable for “Light Rail”
application. The “Main Line” category was further subdivided into fastening systems with “soft” rail
pads and those with “hard” rail pads. Maximum axle load and minimum curve radius assumptions were
made for each category. For the “Main Line” case the minimum curve radius was assumed to be 150 m
with hard pads and 400 m with soft pads. This led to a requirement to test assemblies with hard pads
for a load inclined at angle of 33° and those with soft pads at an angle of 26°.
The standard was extended to include heavy haul applications, by extrapolating from the empirical data
available for mainline tracks using methods published at an International Heavy Haul Conference [7].
This extension to the standard was published as a new part standard, EN 13481-8.
5

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SIST-TP CEN/TR 17320:2019
CEN/TR 17320:2019 (E)
The EN 13481 series was revised and re-issued in 2012. The most important change was in the
definition of fastening 'categories'. The “Light Rail” category was renamed “Category A”, with no
technical changes. A new category, “Category B”, was introduced to cover applications on heavy metro
systems and on secondary lines with lighter axle loads, but tighter curves, than the “Main Line” case.
The case of mainline track with soft pads and also curves with a radius of less than 400 m (but greater
than 150 m) was described by “Category C”. This represented a departure from the approach taken to
the standards published prior to 2012, where it had been assumed that soft pads would not be used on
tight curves. The angle of the inclined load was increased from 26° to 33° to account for this. The case of
mainline track with a minimum curve radius of 400 m was described by “Category D”. The “Heavy Haul’
category became “Category E”.
The various fastening categories may be described in terms of a minimum curve radius and a maximum
axle load. These are summarized in Table 1 below.
Table 1 — Minimum curve radius and maximum axle load for Categories A to E
Category Minimum Curve Radius Maximum axle load
m kN
A 40 130
B 80 180
C 150 260
D 400 260
E 150 350

These are the extreme values beyond which the EN 13481 series is not applicable. The definitions in
EN 13481-1:2012 give “typical” values of curve radius and axle load which are less severe than these
limiting values. Train speed is not a factor in selecting the relevant category.
6.2 System testing v. component testing
CEN/TC 256/SC 1 adopted a policy of writing standards to be used for the type approval of systems and
sub-systems within the track structure, rather than standards to be used for the approval of individual
components. This is in accordance with the requirements of the EC Utilities Directive 93/38/EEC. All
standards developed by WG 17 to date have followed this philosophy.
UIC or individual railway administrations were left to control standards for components of the fastening
system.
6.3 Design v. actual loads
To meet the requirements of the EC Utilities Directive and later the EC Interoperability Directives, it
shall be possible to demonstrate that a rail fastening system complies with the standard before the
details of a particular application are known. This allows a fastening system to be “placed on the
market” with a Declaration of Conformity. It is therefore necessary to assess the compliance of the
fastening system against a hypothetical or “design” loading case, rather than an estimate made for the
loading case appropriate for a particular application.
6

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SIST-TP CEN/TR 17320:2019
CEN/TR 17320:2019 (E)
6.4 Selection of the appropriate hypothetical load case
6.4.1 General principles
The empirical data collected by Committee D170 of ERRI indicates that the most severe loading
experienced by rail fastenings in normal use is found on the low rail, for the case of a train travelling
slowly around a tight curve (i.e. a condition of severe cant excess).
This same empirical data also indicates that the durability of a conventional rail fastening system is
determined by its ability to withstand repeated application of a lateral force to the head of the rail,
rather than its ability to withstand repeated vertical forces.
6.4.2 Effect of rail inclination
An increase in the rail inclination, from 1:40 to a 1:20 for example, makes the repeated load test less
severe. It can therefore be assumed that a fastening system that has passed the test at one inclination
does not need to be tested again for a case in which the rail inclination is greater. For example, a
fastening system that passes a given test at an inclination of 1:40 can be assumed to pass the test at an
inclination of 1:20.
6.4.3 Sleeper type
The 2012 (and earlier) standard states that testing shall be carried out on the “type” of sleeper which
will be used in the track. This was intended to mean that if a pre-stressed monobloc sleeper will be used
with the fastening system under consideration in the track then the test should be performed on a pre-
stressed monobloc sleeper (or part of such a sleeper). For the repeated load test, the detailed
differences between specific designs of pre-stressed monobloc sleepers for example do not normally
have a significant effect. This may not be the case for some of the other tests, such as the electrical test
or insert pull-out resistance test. A basic engineering assessment may be used to decide whether or not
it is not necessary to repeat tests if the fastening has been shown to comply with standards when tested
on a different sleeper. Some laboratories carry out repeated load tests on fastenings on reinforced
concrete blocks on the basis that this is another “worst case” condition. If the fastening complies with
the standard on such a block, it can be assumed that it will pass the test when it is run on a real sleeper.
6.5 Safety and dynamic factors
Standards developed by WG 17 to date have not explicitly separated the concepts of “Safety factors”
from “Dynamic factors”. It is possible to infer factors from the vertical components of the test loads in
the standard using a simple (e.g. Beam on Elastic Foundation – see Clause 9 of this document) model
with the given axle loads, sleeper spacings and speeds combined wit
...

SLOVENSKI STANDARD
kSIST-TP FprCEN/TR 17320:2018
01-november-2018
äHOH]QLãNHQDSUDYH,QIUDVWUXNWXUD'RORþLWHYODERUDWRULMVNLKSUHVNXVQLK
SDUDPHWURY]DRFHQMHYDQMHPHKDQVNHY]GUåOMLYRVWLVLVWHPRY]DSULWUMHYDQMHWLUQLF
.RPSOHPHQWDUQLHOHPHQW
Railway applications - Infrastructure - Determination of laboratory test parameters for
assessing the mechanical durability of rail fastening systems - Complementary element
Bahnanwendungen - Infrastruktur - Bestimmung von Laborprüfparametern zur
Beurteilung der mechanischen Dauerhaftigkeit von Schienenbefestigungssystemen
Ta slovenski standard je istoveten z: FprCEN/TR 17320
ICS:
93.100 Gradnja železnic Construction of railways
kSIST-TP FprCEN/TR 17320:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST-TP FprCEN/TR 17320:2018

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kSIST-TP FprCEN/TR 17320:2018


FINAL DRAFT
TECHNICAL REPORT
FprCEN/TR 17320
RAPPORT TECHNIQUE

TECHNISCHER BERICHT

August 2018
ICS 93.100
English Version

Railway applications - Infrastructure - Determination of
laboratory test parameters for assessing the mechanical
durability of rail fastening systems - Complementary
element



This draft Technical Report is submitted to CEN members for Vote. It has been drawn up by the Technical Committee CEN/TC
256.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey 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 Technical Report. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a Technical Report.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprCEN/TR 17320:2018 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------
kSIST-TP FprCEN/TR 17320:2018
FprCEN/TR 17320:2018 (E)
Contents
European foreword . 3
1 Scope . 4
2 Purpose . 4
3 Terms and definitions . 4
4 Symbols and abbreviations . 4
5 History and background . 5
5.1 ERRI D170 Reports; Evolution of EN 13481 . 5
5.2 System testing v. component testing . 6
5.3 Design v. actual loads . 6
5.4 Selection of the appropriate hypothetical load case . 7
5.4.1 General principles . 7
5.4.2 Effect of rail inclination . 7
5.4.3 Sleeper type . 7
5.5 Safety and dynamic factors . 7
5.6 Duration of test (3 million cycles) and loading frequency . 7
5.7 Pass/fail criteria . 8
5.8 Ballasted v. ballastless track . 8
6 Assumptions about track construction and maintenance conditions . 8
7 Input loading at wheel-rail contact point . 9
7.1 Vertical Loads . 9
7.2 Lateral loads - Relationship between lateral force and curve geometry . 9
8 Distribution of loads . 10
8.1 Vertical loads . 10
8.2 Lateral loads. 10
9 Experience in applying EN 13481:2002 and EN 13481:2012 . 11
10 Recommendations for future development of EN 13481 . 12
Bibliography . 13


2

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kSIST-TP FprCEN/TR 17320:2018
FprCEN/TR 17320:2018 (E)
European foreword
This document (FprCEN/TR 17320:2018) 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 Vote.
3

---------------------- Page: 5 ----------------------
kSIST-TP FprCEN/TR 17320:2018
FprCEN/TR 17320:2018 (E)
1 Scope
This document presents the technical basis for the loading conditions (the load magnitude, the load
angle and the position of load application) to be used when performing the repeated load tests
described by EN 13146-4. This basis consists of measurements made in-track, theoretical analysis and
experience of using the previous versions of the EN 13481 series of standards. Statistical variations in
the applied loads and their influence on safety factors are also considered.
2 Purpose
This document has been prepared to provide a reference document that will inform future revisions of
the EN 13481 series of standards and other standards that define Performance Requirements for rail
fastening systems. Specifically, it provides a basis for calculating the loads that should be applied in the
repeated load tests that are performed in laboratories in order to confirm the durability of rail fastening
systems according to the method given by EN 13146-4.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13481-1:2012 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
rail seat
single discrete rail fastening point e.g. a sleeper end or location of a single baseplate
4 Symbols and abbreviations
E Young's Modulus of the rail steel
F vertical component of load at a single rail seat
F load carried by the rail seat directly below the wheel
max
I second moment of area of the rail for vertical bending
k stiffness of the (“Winkler”) foundation
V maximum train speed [km/hr]
W vertical wheel load
a sleeper or support spacing
4

---------------------- Page: 6 ----------------------
kSIST-TP FprCEN/TR 17320:2018
FprCEN/TR 17320:2018 (E)
5 History and background
5.1 ERRI D170 Reports; Evolution of EN 13481
Committee D170 of the European Rail Research Institute (ERRI, formerly ORE) undertook the first work
toward the development of a European standard for testing rail fastenings (and concrete sleepers)
between 1986 and 1994. This committee evaluated the test methods used by several major European
railways in order to establish “best practice”. The results of this work were published in a series of five
technical reports [1 – 5].
In 1992, the European Standards organization, CEN, established a new Technical Committee, TC 256, to
develop standards for Railway applications. These standards were necessary in order to support the
introduction of EC Utilities Directive 93/38/EEC. This directive made it mandatory to use European
Specifications (including European Standards) as the technical basis of procurement for major public
utilities organisations, including railways (whether publicly or privately owned). The part of Technical
Committee TC 256 that was formed to develop European Standards for rail fastenings was Working
Group 17 (WG 17), which is part of Sub-Committee SC 1 “Infrastructure” of CEN/TC 256. This working
group included several experts who were also serving on ERRI Committee D170, so the work of the
ERRI committee was absorbed into the work of WG 17 from the outset.
NOTE The Utilities Directive has been progressively updated. The latest version of the Utilities / Procurement
Directive is 2004/17/EC.
The ERRI D170 reports [1-5] consider the case of conventional mainline track: concrete sleepers in
ballast, 60 kg/m rail and a maximum axle load of 22,5 t. Some reference was also made in these reports
to experience on the new high speed operations in France. In order to account for the conditions found
on other types of track, such as ballastless track (see 5.8), it was necessary to extrapolate from the
empirical data available for conventional mainline and high speed track [1-5].
The use of a reduced height of rail section in repeated load tests performed in the laboratory was
introduced in ERRI D170 Report 5 and it is explained by a paper published in the International Heavy
Haul Conference in 1989 [6]. A section of rail that has reduced height is used for the test so that the
over-turning moment on the rail is reduced, without reducing either the vertical or lateral components
of the load applied to the rail. It is appropriate to do this because the test is normally performed for a
short piece of rail that is fastened to the support at only a single rail seat. This means that in the
laboratory test, a single fastening system shall provide all of the resistance to the over-turning moment
applied by the actuator to the rail. In track, a long rail is fastened to the support at numerous rail seats
and numerous fastening systems along the length of the rail provide resistance to the applied over-
turning moment.
In the current standards, the modified rail height is defined in terms of a distance measured downward
from the gauge corner. It is accepted that, for future standards development, defining a distance
measured from a different reference point or plane could make the method applicable to a wider range
of rail sections.
The original EN 13481 series of standards, published in 2002, distinguished between two basic
'categories' of fastening systems – those suitable for “Main Line” application and those suitable for
“Light Rail” application. The “Main Line” category was further subdivided into fastening systems with
“soft” rail pads and those with “hard” rail pads. Maximum axle load and minimum curve radius
assumptions were made for each category. For the “Main Line” case the minimum curve radius was
assumed to be 150 m with hard pads and 400 m with soft pads. This led to a requirement to test
assemblies with hard pads for a load inclined at angle of 33° and those with soft pads at an angle of 26°.
5

---------------------- Page: 7 ----------------------
kSIST-TP FprCEN/TR 17320:2018
FprCEN/TR 17320:2018 (E)
The standard was extended to include heavy haul applications, by extrapolating from the empirical data
available for mainline tracks using methods published at an International Heavy Haul Conference [7].
This extension to the standard was published as a new part standard, EN 13481-8:2009.
The EN13481 series of standards was revised and re-issued in 2012. The most important change was in
the definition of fastening 'categories'. The “Light Rail” category was renamed “Category A”, with no
technical changes. A new category, “Category B”, was introduced to cover applications on heavy metro
systems and on secondary lines with lighter axle loads, but tighter curves, than the “Main Line” case.
The case of mainline track with soft pads and also curves with a radius of less than 400 m (but greater
than 150 m) was described by “Category C”. This represented a departure from the approach taken to
the standards published prior to 2012, where it had been assumed that soft pads would not be used on
tight curves. The angle of the inclined load was increased from 26° to 33° to account for this. The case
of mainline track with a minimum curve radius of 400 m was described by “Category D”. The “Heavy
Haul’ category became “Category E”.
The various fastening categories may be described in terms of a minimum curve radius and a maximum
axle load. These are summarized in Table 1 below.
Table 1 — Minimum curve radius and maximum axle load for Categories A to E
Category Minimum Curve Radius Maximum axle load
m kN
A 40 130
B 80 180
C 150 260
D 400 260
E 150 350
These are the extreme values beyond which the EN 13481 series of standards is not applicable. The
definitions in EN 13481-1:2012 give “typical” values of curve radius and axle load which are less severe
than these limiting values. Train speed is not a factor in selecting the relevant category.
5.2 System testing v. component testing
CEN/TC 256/SC 1 adopted a policy of writing standards to be used for the type approval of systems and
sub-systems within the track structure, rather than standards to be used for the approval of individual
components. This is in accordance with the requirements of the EC Utilities Directive 93/38/EEC. All
standards developed by WG 17 to date have followed this philosophy.
UIC or individual railway administrations were left to control standards for components of the fastening
system.
5.3 Design v. actual loads
To meet the requirements of the EC Utilities Directive and later the EC Interoperability Directives, it
shall be possible to demonstrate that a rail fastening system complies with the standard before the
details of a particular application are known. This allows a fastening system to be “placed on the
market” with a Declaration of Conformity. It is therefore necessary to assess the compliance of the
fastening system against a hypothetical or “design” loading case, rather than an estimate made for the
loading case appropriate for a particular application.
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kSIST-TP FprCEN/TR 17320:2018
FprCEN/TR 17320:2018 (E)
5.4 Selection of the appropriate hypothetical load case
5.4.1 General principles
The empirical data collected by Committee D170 of ERRI indicates that the most severe loading
experienced by rail fastenings in normal use is found on the low rail, for the case of a train travelling
slowly around a tight curve (i.e. a condition of severe cant excess).
This same empirical data also indicates that the durability of conventional rail fastening systems is
determined by its ability to withstand repeated application of a lateral force to the head of the rail,
rather than its ability to withstand repeated vertical forces.
5.4.2 Effect of rail inclination
An increase in the rail inclination, from 1:40 to a 1:20 for example, makes the repeated load test less
severe. It can therefore be assumed that a fastening system that has been tested successful at one
inclination does not need to be tested again for a case in which the rail inclination is greater. For
example, a fastening system that passes a given test at an inclination of 1:40 can be assumed to pass the
test at an inclination of 1:20.
5.4.3 Sleeper type
The 2012 (and earlier) standard states that testing shall be carried out on the “type” of sleeper which
will be used in the track. This was intended to mean that if a pre-stressed monobloc sleeper will be used
with the fastening system under consideration in the track then the test should be performed on a pre-
stressed monobloc sleeper (or part of such a sleeper). For the repeated load test, the detailed
differences between specific designs of pre-stressed monobloc sleepers for example do not normally
have a significant effect. This may not be the case for some of the other tests, such as the electrical test
or insert pull-out resistance test. A basic engineering assessment may be used to decide whether or not
it is not necessary to repeat tests if the fastening has been shown to comply with standards when tested
on a different sleeper. Some laboratories carry out repeated load tests on fastenings on reinforced
concrete blocks on the basis that this is another “worst case” condition. If the fastening complies with
the standard on such a block, it can be assumed that it will pass the test when it is run on a real sleeper.
5.5 Safety and dynamic factors
Standards developed by WG 17 to date have not explicitly separated the concepts of “Safety factors”
from “Dynamic factors”. It is possible to infer factors from the vertical components of the test loads in
the standard using a simple (e.g. Beam on Elastic Foundation – see Clause 8 of this report) model with
the given axle loads, sleeper spacings and speeds combined with a typical foundation
...