EN 16729-2:2020

SLOVENSKI STANDARD
01-maj-2020
Železniške naprave - Infrastruktura - Neporušitveno preskušanje na progi - 2. del:
Preskušanje z vrtinčnimi tokovi na progi
Railway applications - Infrastructure - Non-destructive testing on rails in track - Part 2:
Eddy current testing of rails in track
Bahnanwendungen - Infrastruktur - Zerstörungsfreie Prüfung an Schienen im Gleis - Teil
2: Wirbelstromprüfung an Schienen im Gleis
Applications ferroviaires - Infrastructure - Essais non destructifs sur les rails de voie -
Partie 2 : Contrôle par courant de Foucault des rails en voie
Ta slovenski standard je istoveten z: EN 16729-2:2020
ICS:
19.100 Neporušitveno preskušanje Non-destructive testing
93.100 Gradnja železnic Construction of railways
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16729-2
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2020
EUROPÄISCHE NORM
ICS 93.100
English Version
Railway applications - Infrastructure - Non-destructive
testing on rails in track - Part 2: Eddy current testing of
rails in track
Applications ferroviaires - Infrastructure - Test non- Bahnanwendungen - Infrastruktur - Zerstörungsfreie
destructive sur des rails Prüfung an Schienen im Gleis - Teil 2:
Wirbelstromprüfung an Schienen im Gleis
This European Standard was approved by CEN on 15 December 2019.

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, 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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16729-2:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 9
5 Basic principles . 9
5.1 General . 9
5.2 Purpose of testing . 9
6 Requirements for the eddy current testing system on rails . 10
7 Requirements for testing procedure . 10
8 Requirements for documentation . 11
Annex A (normative) System acceptance of eddy current systems for detecting head checks . 12
A.1 General . 12
A.2 Requirements for detecting and sizing head checks . 12
Bibliography . 32

European foreword
This document (EN 16729-2:2020) 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 September 2020, and conflicting national standards
shall be withdrawn at the latest by September 2020.
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 EN 16729 series, Railway applications – Infrastructure – Non-destructive testing on rails in track,
consists of:
— Part 1: Requirements for ultrasonic inspection and evaluation principles;
— Part 2: Eddy current testing of rails in track;
— Part 3: Requirements for identifying internal and surface rail defects;
— Part 4: Qualification of personnel for non-destructive testing on rails.
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, Turkey and the
United Kingdom.
Introduction
This document represents the actual state of the art of eddy current testing for surface cracks on rails in
track applied by European railway companies.
1 Scope
This document is applicable to testing of rails installed in track for detecting rail surface cracks. This
document applies to testing equipment in inspection-trains or reprofiling machines and manual
systems. This document specifies the requirement for testing principles and systems in order to
produce comparable results in respect to the location and the characteristic of surface cracks. This
document is not aiming to give any guidelines for managing the result of eddy current rail testing. This
document does not define the requirements for vehicle acceptance. This document is not concerned
with production testing of rails in a production plant. This document applies only to rail profiles
meeting the requirements of EN 13674-1.
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 13231-5, Railway applications — Track — Acceptance of works — Part 5: Procedures for rail
reprofiling in plain line, switches, crossings and expansion devices
EN 16729-1:2016, Railway applications — Infrastructure — Non-destructive testing on rails in track —
Part 1: Requirements for ultrasonic inspection and evaluation principles
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 16729-1:2016 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
real crack
crack caused by traffic loads or production induced
Note 1 to entry: Cracks may also be simulated. They then constitute an artificial feature designed to represent a
real defect of a known size, orientation and position.
3.2
testing area for gauge corner cracks
see Figure 1
Dimensions in mm
Key
x horizontal coordinate
z vertical coordinate
SO top of rail
a distance between contact point of wheelset and centre of rail
1-2 minimum gauge inspection area
Figure 1 — Testing area for gauge corner cracks
3.3
testing area for running surface cracks
see Figure 2
Dimensions in mm
Key
x horizontal coordinate
z vertical coordinate
SO top of rail
a distance between contact point of wheelset and centre of rail
3-4 minimum running surface inspection area
Figure 2 — Testing area for running surface cracks
3.4
depth to be machined
depth to be machined to remove cracks
Note 1 to entry: see Figure 3
Key
d' depth to be machined (depth of the crack rectangular to the surface including
to a safety distance to ensure the removal of the crack)
α' penetrating angle
1 gauge side
A sectional plane
Pocket length
Figure 3 — Depth to be machined depending on the head checks position
3.5
detectability
capability to recognize, discover and register surface cracks with the help of a testing system
3.6
reproducibility
conformity of several results from the verified test system
4 Symbols and abbreviations
Symbol Definition Unit
d' Depth to be machined (from each probe) mm
α' penetrating angle °
d' Maximum depth to be machined (maximum of all mm
max
probes)
d Depth of the cluster (median value) mm
median
IM Infrastructure manager
ET Eddy Current Testing
LH Left Rail
RH Right Rail
5 Basic principles
5.1 General
With the help of eddy current testing, surface cracks can be detected in electrically conducting materials
(ferromagnetic or non-ferromagnetic materials).
Eddy current testing is based on the induction of electric current in electrically conducting material. The
measured and analysed size refers to the distribution of the induced currents (eddy currents).
The distribution of the eddy currents in the material is governed by physical laws; the density of these
eddy currents drastically decreases with the distance to the surface.
To determine the depth of a head check crack, the pocket length of the crack and the penetrating angle
are used. The penetrating angle can vary depending on steel grade, traffic, tonnage and support
conditions of the rail. The penetrating angle α' (see Figure 3) commonly used for testing head checks in
rail is 25 °.
Parameters influencing the testing results are:
— conductivity of the material;
— permeability of the material;
— dimension and geometry of the defect;
— geometry between the eddy current probe and the material surface;
— design and size of the probe;
— setting of the excitation frequency.
More detailed information on the eddy current method can be found in EN ISO 15549.
5.2 Purpose of testing
The purpose of eddy current testing on rails is to detect, quantify or classify rail defects in the material
surface mainly due to rolling contact fatigue which can affect the structural integrity of the rails in track
and which are defined in EN 13231-5. This is not limited to, but generally covers the following defects:
— head checks;
— squats;
— flaking;
— spalling.
6 Requirements for the eddy current testing system on rails
Inspection of the rail surface can be carried out manually or by using mechanized devices.
When testing with an eddy current probe, it is placed above the rail head. The impedance of the probe is
influenced by the interaction of the electromagnetic field generated by the probe and the rail head. This
influence recorded by the complex voltage of the probe can be calculated to the severity of cracking on
rail surface.
The minimum requirements for a test system are:
— suitable for the test task;
— capable of dealing with various material characteristics (e.g. welds, steel grades);
— probes optimized to the position, direction, depth and distance between cracks;
— probes optimized to test non-planar rail surfaces;
— capable of testing rough and rusty surfaces;
— capable of recording the correct location of the defect;
— capable of testing forwards and backwards in track independent of the direction of the traffic (if
mounted on vehicle, independent of the orientation of the vehicle).
NOTE The list does not include the requirements for operational use of the test system in track.
7 Requirements for testing procedure
The IM shall define:
— inspection area;
— defect type;
— minimum and maximum defect size;
— frequency and requirements of system verification;
— testing speed;
— rail profiles and wear limits to be inspected;
— rail grades to be inspected;
— penetrating angle.
8 Requirements for documentati
...