Railway applications - Braking - Brake pads

This document specifies requirements for pads for disc brakes of railway rolling stock.
This document is applicable to pads designed to be fitted to disc braked rail vehicles. The brake pad may be manufactured from any material.
The document defines requirements and generic test programs for brake pads. In order to qualify the brake pad performance in accordance with the classification the standard provides fixed parameter figures as categories defined in paragraph classification scheme.

Bahnanwendungen - Bremsen - Bremsbeläge

Dieses Dokument legt Anforderungen für Bremsbeläge für Scheibenbremsen von Schienenfahrzeugen fest.
Dieses Dokument gilt für Bremsbeläge, die zum Einbau an Schienenfahrzeugen mit Scheibenbremsen konstruiert sind. Der Bremsbelag darf aus jedem Werkstoff hergestellt sein.
Dieses Dokument legt die Anforderungen und allgemeinen Prüfprogramme für Bremsbeläge fest. Zur Bestimmung der Leistung des Bremsbelags in Übereinstimmung mit der Klassifizierung, enthält die Norm feste Parameterwerte als Kategorien, die im Absatz über das Klassifizierungsschema definiert sind.

Applications ferroviaires - Freinage - Garnitures de frein

Le présent document spécifie les exigences relatives aux garnitures destinées aux freins à disque qui équipent le matériel roulant ferroviaire.
Le présent document s'applique aux garnitures destinées à être montées sur les véhicules ferroviaires équipés de freins à disque. Le choix du matériau des garnitures est libre.
Le présent document définit les exigences, ainsi que les programmes d'essai génériques pour les garnitures de frein. Dans le but de qualifier les performances des garnitures de frein par rapport au système de classification établi, la présente norme fournit des paramètres fixes sous forme de catégories définies dans le paragraphe Schéma de classification.

Železniške naprave - Zavore - Zavorne obloge

General Information

Status
Published
Public Enquiry End Date
31-Mar-2019
Publication Date
13-Aug-2020
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
12-Aug-2020
Due Date
17-Oct-2020
Completion Date
14-Aug-2020

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SLOVENSKI STANDARD
SIST EN 15328:2020
01-oktober-2020
Železniške naprave - Zavore - Zavorne obloge
Railway applications - Braking - Brake pads
Bahnanwendungen - Bremsen - Bremsbeläge
Applications ferroviaires - Freinage - Garnitures de frein
Ta slovenski standard je istoveten z: EN 15328:2020
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
SIST EN 15328:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 15328:2020

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SIST EN 15328:2020


EN 15328
EUROPEAN STANDARD

NORME EUROPÉENNE

July 2020
EUROPÄISCHE NORM
ICS 45.040
English Version

Railway applications - Braking - Brake pads
Applications ferroviaires - Freinage - Garniture de frein Bahnanwendungen - Bremsen - Bremsbeläge
This European Standard was approved by CEN on 15 June 2020.

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 15328:2020 E
worldwide for CEN national Members.

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SIST EN 15328:2020
EN 15328:2020 (E)
Contents Page
European foreword . 5
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Symbols and abbreviations . 9
5 Characteristics and test method of the brake pads . 10
5.1 Classification of brake pads . 10
5.2 Coefficient of friction . 10
5.3 Environmental impact, health and safety . 10
5.4 Usage requirements . 10
5.5 Frictional requirements for brake pads . 10
5.6 Requirements and optional test programs for brake pads for coaches . 12
5.7 Geometrical features of the brake pads . 13
5.8 Mechanical, physical and chemical characteristics . 14
5.9 Thermal and mechanical requirements . 15
5.10 In-service assessment. 15
5.11 Marking of brake pads. 15
5.12 Dynamometer tests . 15
5.13 Conditions for classification tests . 16
5.14 Interchangeability of brake pads . 18
Annex A (normative) Generic conditions for the execution of test programs . 19
A.1 General . 19
A.2 Response time . 19
A.3 Weighing . 19
A.4 Interruption of test sequence . 19
A.5 Temperatures . 19
A.6 Brake applications under wet conditions . 19
A.7 Conditioning of brake discs . 20
A.7.1 General . 20
A.7.2 Conditioning program . 21
A.7.3 Roughness measurement . 21
A.8 Bedding-in of brake pads . 21
A.9 Methods of temperature measurements . 21
A.10 Mean friction radius . 22
A.11 Rotation and ventilation conditions . 22
Annex B (normative) Test programs for classes A1 to G1 . 23
B.1 Test program: brake pads of class A1 . 23
2

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EN 15328:2020 (E)
B.2 Test program: brake pads of classes B1 and C1 . 25
B.3 Test Program: brake pads of classes B2 and C2 . 30
B.4 Test program: brake pads of class C0 . 35
B.5 Test program: brake pads of class C3 . 37
B.6 Test program: brake pads of class D1 . 39
B.7 Test program: brake pads of class D2 . 43
B.8 Test program: brake pads of class E1 . 46
B.9 Test program: brake pads of class F1 . 48
B.10 Test program: brake pads of classes F2 and G1 . 51
B.11 Test program: brake pads of class F3 . 54
B.12 Assessment of static friction coefficient . 57
Annex C (normative) Test programs for coaches . 58
C.1 Test program S1.1 (v = 200 km/h – organic brake pads) . 58
max
C.2 Test program S2.1 (wet test) . 61
C.3 Instantaneous coefficient of friction for test program S1.1, S2.1, T1 and T2 . 61
C.4 Mean coefficient of friction for test programs S1.1, S2.1, T1 and T2 . 62
C.5 Test program T1 (v = 200 km/h – sintered brake pads). 63
max
C.6 Test program T2 wet test (sintered brake pads) . 66
Annex D (normative) Documentation of brake tests . 67
Annex E (normative) Generic test programs for locomotives, MUs and high speed trains . 69
E.1 Use of the generic test programs . 69
E.2 Locomotives and MUs . 69
E.2.1 Test parameters . 69
E.2.2 Brake steps . 72
E.2.3 Masses . 72
E.2.4 Continuous brake applications . 73
E.3 High speed trains . 73
E.3.1 Test parameters . 73
E.3.2 Brake steps . 75
E.3.3 Masses . 76
E.3.4 Brake forces for high-speed brake applications . 76
E.3.5 Power for continuous brake applications . 77
Annex F (normative) Brake pads shapes and envelopes . 78
F.1 General . 78
2
F.2 Preferred space envelope for SBP 200 cm . 78
2
F.3 Preferred space envelope for SBP 175 cm . 79
3

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EN 15328:2020 (E)
2
F.4 Space envelope for SBP 200 cm . 80
2
F.5 Maximum Space envelope for SBP 175 cm . 80
Annex G (normative) Drawings for dove tails . 81
Annex H (informative) In-service test . 83
H.1 Test requirements . 83
H.2 Mechanical requirements . 83
H.3 Thermal requirements . 84
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2016/797/EU aimed to be covered . 85
Bibliography . 87

4

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SIST EN 15328:2020
EN 15328:2020 (E)
European foreword
This document (EN 15328:2020) 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 January 2021, and conflicting national standards shall
be withdrawn at the latest by January 2021.
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 has been prepared under a standardization request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of
EU Directive 2016/797/EU.
For relationship with EU Directive 2016/797/EU, see informative Annex ZA, which is an integral part of
this document.
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.
5

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SIST EN 15328:2020
EN 15328:2020 (E)
Introduction
This document gives the requirements for the design, dimensions, performance and testing of a brake
pad which, as part of a disc brake system, acts on one friction face of a brake disc in accordance with
EN 14535-1 and EN 14535-2.
The generic test program can also be used with different program parameter figures for specific project
applications. The use of project adapted programs is subject to agreement between the parties involved.
This document contains the requirements for interfacing the brake pads with the rail vehicle, the testing
procedures in order to confirm that it satisfies the basic safety and technical requirements, the material
control procedures to ensure product quality, reliability and conformity, as well health and
environmental requirements are fulfilled.
Each manufacturer is responsible for ensuring that the quality of design, workmanship and construction
is in accordance with good engineering practice.
6

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EN 15328:2020 (E)
1 Scope
This document specifies requirements for pads for disc brakes of railway rolling stock.
The document defines requirements and generic test programs for brake pads on dynamometer. This
document does not cover mandatory tests to verify stopping distances in addition to laboratory, bench
test and in-service tests. In order to qualify the brake pad performance in accordance with the
classification the standard provides fixed parameter figures as categories defined in paragraph
classification scheme.
This document is not applicable for urban rail applications.
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 14478:2017, Railway applications - Braking - Generic vocabulary
EN 14535-1:2019, Railway applications - Brake discs for railway rolling stock - Part 1: Brake discs pressed
or shrunk onto the axle or drive shaft, dimensions and quality requirements
EN 14535-2:2019, Railway applications - Brake discs for railway rolling stock - Part 2: Brake discs mounted
onto the wheel, dimensions and quality requirements
EN 14535-3:2015, Railway applications - Brake discs for railway rolling stock - Part 3: Brake discs,
performance of the disc and the friction couple, classification
EN 16451:2015, Railway applications - Braking - Brake pad holder
EN ISO 4287:1998, Geometrical product specifications (GPS) - Surface texture: Profile method - Terms,
definitions and surface texture parameters (ISO 4287:1997)
UIC 548:2016, Brakes - Requirements of friction test benches for the international certification of brake
pads and brake blocks
7

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SIST EN 15328:2020
EN 15328:2020 (E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14478:2017, EN 14535-1:2019,
EN 14535-2:2019 and EN 14535-3:2015 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 https://www.iso.org/obp/ui
3.1
instantaneous coefficient of friction
instantaneous value of coefficient of friction of the friction couple brake pad/brake disc at any instant
during braking
3.2
static coefficient of friction
coefficient of friction achieved by the friction couple at the point where relative movement between the
brake pad friction face and brake disc friction face begins
3.3
brake disc temperature
arithmetic average value of the temperature measurements on the brake disc friction faces
3.4
contact surface area
static contact surface of the brake pad available for frictional engagement with the brake disc friction face
3.5
friction material
consumable portion of the brake pad that acts on the friction face of the brake disc in order to provide
the specified brake performance
3.6
brake pad
assembly of friction material and an associated fixing element acting on one friction face of a brake disc
Note 1 to entry: A brake pad can be manufactured in one piece or comprise two separate parts. Where
manufactured in two separate halves, the brake pad comprises one left-hand and one right-hand half. For a brake
disc four brake pad halves or two brake pads can be used.
8

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SIST EN 15328:2020
EN 15328:2020 (E)
4 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in Table 1 apply.
Table 1 — Symbols and abbreviations
Symbol Designation Unit
F
Nominal application force per brake disc kN
B
F
Instantaneous application force per brake disc kN
b
m Mass to be braked per brake disc (inclusive of the rotational masses) t
Q Water flow rate l/h
R
Refer to EN ISO 4287 μm
a
R
Refer to EN ISO 4287 μm
z
s Stopping distance from the moment on when F = 0,95 F to rest
m
2 b B
v
Theoretical initial speed at the brake application initiation km/h
0
v Instantaneous speed km/h
v
Maximum service speed km/h
max
Friction coefficient (brake pad):
µ

a The instantaneous friction coefficient specified at every instant of the
braking time
Mean friction coefficient:
s
2
The mean friction coefficient μ integrated over the time from where
1 m

µµ=⋅ ⋅ d —
m ∫ as
95 % of the nominal application force F is reached over the stopping
s
B
2
0
distance s
2
µ
Nominal friction coefficient (brake pad) —
m,nom
θ
Mean initial temperature at the beginning of the brake application °C
0
CI Cast iron
MU Multiple unit (EMU/DMU)
SBP Standard brake pad
9

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SIST EN 15328:2020
EN 15328:2020 (E)
5 Characteristics and test method of the brake pads
5.1 Classification of brake pads
This document defines the characteristics required for the categories A1 to G1 of brake pads, listed in
Table 5. The characteristic requirements for the application in coaches used in general operation are
listed in Table 7.
5.2 Coefficient of friction
The coefficient of friction should be independent of the wear (full thickness of the brake pad), the specific
pressure, the temperature and the environmental conditions.
In wet conditions, or when there is snow, the instantaneous coefficient of friction should vary only slightly
compared to the coefficient of friction under dry conditions.
These frictional characteristics shall be assessed in accordance with 5.5 to 5.6.
5.3 Environmental impact, health and safety
All raw materials used in the manufacture of the brake pads shall comply with the relevant requirements
for environment, health and safety.
NOTE Relevant requirements are given in regulations of environment, health and safety, notably REACH
regulations.
In addition, a safety data sheet shall be presented.
5.4 Usage requirements
The composition of the material from which the brake pads are made should be chosen so that the best
compromise is obtained between:
— the frictional properties,
— the wear of the brake pads, and
— the aggressiveness against the brake disc.
5.5 Frictional requirements for brake pads
5.5.1 General
This subclause describes the requirements for brake pads used in locomotives, MUs, freight wagons and
coaches. Optional test programs and requirements for coaches are defined in 5.6.
5.5.2 Priority levels of brake applications
In the test programs A1 to G1, the brake applications are prioritized, in accordance with a decreasing
level of importance, as given in Table 2.
Brake applications with highest nominal application force (highest nominal deceleration) under normal
conditions representing emergency brake applications are rated with priority 1. All other brake
applications are rated according to their safety relevance with priorities 2 to 4. Continuous and parking
brake applications are not stopping brake applications and therefore assessed according to different
criteria and there is no priority level assigned with these brake applications. Bedding brake applications
which are carried out prior to the main stopping brake applications are assessed separately.
10

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EN 15328:2020 (E)
Table 2 — Priority levels of brake applications for test programs
Priority level Type of brake application
Dry brake applications with the highest nominal application force for each mass,
1
normal conditions
Wet brake applications and hot brake applications with highest nominal application
2
force, for each mass
Brake applications with highest nominal application force used for cleaning, drying,
3
regenerating, or after continuous brake applications, for each mass
All other brake applications, with the exception of continuous brake applications and
4
bedding brake applications and the examination of static coefficient of friction
Continuous brake applications, brake applications used for bedding-in, examination

of static coefficient of friction
Normal conditions refer to brake applications under dry conditions with low initial temperature and with
the brake disc and the brake pad unaffected by high thermal load or residual wetness.
Brake pads of categories A1 to G1 are characterized by their friction behaviour, expressed as the velocity-
dependent nominal line.
The nominal line for the coefficient of friction is calculated for each brake pad and each test program as
the linear regression line of the mean coefficients of friction (expressed in a rounding range of 0,001)
versus speed of all brake applications with priority 1, extending from the lowest to the highest test speed.
5.5.3 Criteria for the nominal line
The nominal line should lie between 0,300 and 0,450.
It shall lie between 0,280 and 0,470. The difference between the maximum value and the minimum value
of the nominal line shall be less or equal to 0,150.
5.5.4 Criteria for the mean coefficient of friction
Allowed deviations of coefficients of friction are expressed by means of tolerance bands centred around
the nominal line.
The tolerance bands for the mean coefficients of friction in accordance with their priority level are given
in Table 3.
Table 3 — Tolerance bands for the mean coefficients of friction vs. priority levels
Priority level of
1 2 3 4
brake application
Tolerance band 1 ±10 % ±15 % ±20 % ±25 %
Tolerance band 2 ±15 % ±20 % ±25 % ±30 %
The mean coefficient of friction for each brake application shall lie within the bounds of the tolerance
band 1 in accordance with its priority, while the following exceptions are tolerated.
— A total of 6 % of all brake applications (rounded to the closest integer) of priority 1 may deviate from
tolerance band 1 towards the negative side.
— A total of 12 % of all brake applications (rounded to the closest integer) of priority 1 may deviate
from tolerance band 1.
11

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EN 15328:2020 (E)
— A total of 5 % of all brake applications (rounded to the closest integer) of priorities 2 to 4 may deviate
from tolerance band 1 towards the negative side.
— A total of 10 % of all brake applications (rounded to the closest integer) of priorities 2 to 4 may
deviate from tolerance band 1.
No mean coefficient of friction shall lie outside of tolerance band 2.
5.5.5 Criteria for continuous brake applications
During continuous brake applications, after 10 s the instantaneous coefficient of friction shall stay inside
the band defined by µ = 0,250 and µ = 0,500.
min max
After 2 minutes the instantaneous coefficient of friction shall not vary more than 0,05 during any minute
and the coefficient of friction shall stay inside the band defined by µ = 0,250 and µ = 0,500.
min max
The brake pad wear during any continuous brake application, including the stop brake application
thereafter, shall not exceed 1 mm. The wear in mm can be calculated from the weight differences before
and after the continuous brake application.
5.5.6 Criteria for bedding brake applications
The nominal coefficient of friction of the bedded state shall be defined as the average of measured mean
coefficients of friction µ of the last 5 braking stops carried out during the bedding section.
m
During the bedding-in phase, the mean coefficients of friction shall not exceed the following variations
from the nominal value of the bedded state:
th
— ± 30 % from the 11 bedding-in brake application until 30 % of number of the bedding-in
applications are finished;
— ± 15 % during the rest of the bedding-in process.
5.6 Requirements and optional test programs for brake pads for coaches
5.6.1 General
The frictional requirements for brake pads in coaches used
...

SLOVENSKI STANDARD
oSIST prEN 15328:2019
01-marec-2019
Železniške naprave - Zavore - Zavorne obloge
Railway applications - Braking - Brake pads
Bahnanwendungen - Bremsen - Bremsbeläge
Applications ferroviaires - Freinage - Garnitures de frein
Ta slovenski standard je istoveten z: prEN 15328
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
oSIST prEN 15328:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 15328:2019

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oSIST prEN 15328:2019


DRAFT
EUROPEAN STANDARD
prEN 15328
NORME EUROPÉENNE

EUROPÄISCHE NORM

January 2019
ICS 45.040
English Version

Railway applications - Braking - Brake pads
Applications ferroviaires - Freinage - Garnitures de Bahnanwendungen - Bremsen - Bremsbeläge
frein
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, 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 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
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15328:2019 E
worldwide for CEN national Members.

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oSIST prEN 15328:2019
prEN 15328:2019 (E)
Contents Page
European foreword . 5
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Symbols and abbreviations . 8
5 Characteristics and test method of the brake pads . 9
5.1 Classification of brake pads . 9
5.2 Coefficient of friction . 9
5.3 Environmental impact, health and safety . 10
5.4 Usage requirements . 10
5.5 Frictional requirements for brake pads . 10
5.5.1 General . 10
5.5.2 Priority levels of brake applications . 10
5.5.3 Criteria for the nominal line . 11
5.5.4 Criteria for the mean coefficient of friction . 11
5.5.5 Criteria for continuous brake applications . 11
5.5.6 Criteria for bedding brake applications . 12
5.6 Requirements and optional test programs for brake pads for coaches . 12
5.6.1 General . 12
5.6.2 Tolerance ranges . 12
5.6.3 Criteria for continuous brake applications . 12
5.6.4 Criteria for bedding brake applications . 12
5.6.5 Coefficient of friction under high thermal load . 12
5.6.6 Coefficient of friction under wet conditions . 13
5.7 Geometrical features of the brake pads . 13
5.7.1 Brake pad shape . 13
5.7.2 Brake pad wear . 13
5.7.3 Brake pad fixing . 13
5.8 Mechanical, physical and chemical characteristics . 13
5.9 Thermal and mechanical requirements . 14
5.10 In-service assessment. 14
5.11 Marking of brake pads. 15
5.12 Dynamometer tests . 15
5.13 Conditions for classification tests . 15
5.13.1 Classification scheme for locomotives, motor units, high-speed trains, freight wagon
and coaches . 15
5.13.2 Optional classification scheme for coaches . 16
5.13.3 Validity of certification . 17
5.13.4 Scope of classification . 17
5.14 Interchangeability of brake pads . 17
Annex A (normative) Generic conditions for the execution of test programs . 18
A.1 General . 18
A.2 Brake application time . 18
2

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prEN 15328:2019 (E)
A.3 Weighing . 18
A.4 Interruption of test sequence . 18
A.5 Temperatures . 18
A.6 Brake applications under wet conditions . 18
A.7 Conditioning of brake discs. 19
A.7.1 General . 19
A.7.2 Conditioning program . 20
A.7.3 Roughness measurement . 20
A.8 Bedding in of brake pads . 20
A.9 Methods of temperature measurements. 20
A.10 Mean friction radius . 20
A.11 Rotation and ventilation conditions . 21
Annex B (normative) Test programs A1 to G1 . 22
B.1 Test Program: Brake Pads on Discs of Energy Class A1 . 22
B.2 Test Program: Brake Pads on Discs of Energy Class B1 and C1 . 24
B.3 Test Program: Brake Pads on Discs of Energy Class B2 and C2 . 29
B.4 Test Program: Brake Pads on Discs of Energy Class C0 . 33
B.5 Test Program: Brake Pads on Discs of Energy Class C3 . 35
B.6 Test Program: Brake Pads on Discs of Energy Class D1 . 37
B.7 Test Program: Brake Pads on Discs of Energy Class D2 . 41
B.8 Test Program: Brake Pads on Discs of Energy Class E1 . 44
B.9 Test Program: Brake Pads on Discs of Energy Class F1 . 46
B.10 Test Program: Brake Pads on Discs of Energy Class F2 and G1 . 49
B.11 Test Program: Brake Pads on Discs of Energy Class F3 . 51
B.12 Test Program P — Draft — Definition of static friction coefficients . 54
Annex C (normative) Test programs for coaches . 55
C.1 Test Program S1.1 (v = 200 km/h – organic pads) . 55
max
C.2 Test Program S2.1 (wet test) . 57
C.3 Instantaneous coefficient of friction for test program S1.1, S2.1, T1 and T2 . 58
C.4 Mean coefficient of friction for test programs S1.1, S2.1, T1 and T2 . 59
C.5 Test program T1 (v = 200 km/h – sintered pads) . 60
max
C.6 Test program 6B wet test (sintered pads) . 61
Annex D (normative) Documentation of brake tests . 63
Annex E (normative) Generic test programs for locomotives, motor units and high speed
trains . 65
E.1 Use of the generic test programs . 65
E.2 Locomotives and motor units . 65
E.3 High speed trains . 69
Annex F (normative) Brake Pads shapes and envelopes . 74
F.1 General . 74
2
F.2 Preferred space envelope for standard brake pad 200 cm . 74
2
F.3 Preferred space envelope for standard brake pad 175 cm . 75
2
F.4 Space envelope for SBP 200 cm . 76
2
F.5 Maximum Space envelope for SBP 175 cm . 76
Annex G (normative) Drawings for dove tails . 77
Annex H (informative) In service test . 79
H.1 Test requirements . 79
H.2 Mechanical requirements . 79
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H.3 Thermal requirements . 80
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2008/57/EC aimed to be covered . 81
Bibliography . 83

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European foreword
This document (prEN 15328:2019) 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 has been prepared under a standardization request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of
EU Directive 2008/57/EC.
For relationship with EU Directive 2008/57/EC, see informative Annex ZA, which is an integral part of
this document.
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Introduction
This document gives the requirements for the design, dimensions, performance and testing of a brake
pad which, as part of a disc brake system, acts on one friction face of a brake disc in accordance with
EN 14535-1 and EN 14535-2.
The generic test program can also be used with different program parameter figures for specific project
applications. The use of project adapted programs is suspended to the involved parties agreement.
This document contains the requirements for interfacing the brake pads with the rail vehicle, the testing
procedures in order to confirm that it satisfies the basic safety and technical requirements, the material
control procedures to ensure product quality, reliability and conformity, as well health and
environmental requirements are fullfilled.
Each manufacturer is responsible for ensuring that the quality of design, workmanship and construction
is in accordance with good engineering practice.
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1 Scope
This document specifies requirements for pads for disc brakes of railway rolling stock.
This document is applicable to pads designed to be fitted to disc braked rail vehicles. The brake pad may
be manufactured from any material.
The document defines requirements and generic test programs for brake pads. In order to qualify the
brake pad performance in accordance with the classification the standard provides fixed parameter
figures as categories defined in paragraph classification scheme.
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 14478, Railway applications — Braking — Generic vocabulary
EN 14535-1, Railway applications — Brake discs for railway rolling stock — Part 1: Brake discs pressed or
shrunk onto the axle or drive shaft, dimensions and quality requirements
EN 14535-2, Railway applications — Brake discs for railway rolling stock — Part 2: Brake discs mounted
onto the wheel, dimensions and quality requirements
EN 14535-3, Railway applications — Brake discs for railway rolling stock — Part 3: Brake discs,
performance of the disc and the friction couple, classification
EN 16451, Railway applications — Braking — Brake pad holder
EN ISO 4287, Geometrical product specifications (GPS) — Surface texture: Profile method — Terms,
definitions and surface texture parameters (ISO 4287)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14478, EN 14535 (all parts) 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
instantaneous coefficient of friction
instantaneous value of coefficient of friction of the friction couple pad/disc at any one instant during
braking
3.2
static coefficient of friction
coefficient of friction achieved by the friction couple at the point where relative movement between the
pad friction surface and disc friction face begins
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3.3
brake disc temperature
arithmetic average value of the measured temperature of the disc friction
3.4
friction face
radially and circumferentially extending planar surface of the disc available for frictional engagement of
the brake pad
3.5
friction surface
radially and circumferentially extending planar surface of the pad available for frictional engagement
with the brake disc friction face
3.6
contact surface area
static contact surface of the pad available for frictional engagement with the brake disc friction face
3.7
friction material
consumable portion of the pad that acts on the friction face of the brake disc in order to provide the
specified brake performance
3.8
brake pad
assembly of friction material and an associated fixing element acting on one friction face of a brake disc
Note 1 to entry: A brake pad can be manufactured in one piece or comprise two separate parts. Where
manufactured in two separate halves, the pad comprises one left-hand and one right-hand half. For a brake disc four
brake pad halves or two brake pads can be used.
3.9
brake pad holder
component for the secure mounting and positioning of the brake pad and transmitting the brake pad
force
3.10
brake disc
rotor having one or more co-planar annular friction faces for the engagement of brake pads and means
of transmitting rotation between itself and the associated axle or drive shaft element
4 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in Table 1 apply.
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Table 1 — Symbols and abbreviations
Symbol Designation Unit
D Diameter of wheel mm
F
Nominal application force per disc kN
B
F
Instantaneous application force per wheel kN
b
m Mass to be braked per disc (inclusive of the rotational masses) t
R
Surface roughness (maximum height of profile) μm
z
s Stopping distance from the moment on when F = 0,95 F to rest
m
2 b B
v Theoretical initial speed at the brake application initiation km/h
v
Instantaneous speed km/h
i
v
Final speed at the end of braking km/h
3
v
Maximum service speed km/h
m
Friction coefficient (brake pad):
F The instantaneous friction coefficient μ specified at every instance of
a
tR
µ =

a
the braking time by the ratio between the total brake force F and the
F
tR
b
total application force F
b
Mean friction coefficient:
s
2
The mean friction coefficient μ integrated over the time from where
1 m
µµ=⋅ ⋅ d —
m as

95 % of the nominal application force F is reached over the stopping
s
B
2
0
distance s
2
µ
Nominal friction coefficient (brake pad) —
m,nom
θ
Mean initial temperature at the beginning of the brake application °C
0
CI Cast iron
SBP Standard brake pad
Regolamento Internazionale delle Carrozze (en: International Coach
RIC
Regulations)
5 Characteristics and test method of the brake pads
5.1 Classification of brake pads
This standard defines the characteristics required of brake pads for the categories A1 to G1 of brake pads,
listed in Table 5. The characteristic requirements for the application in coaches used in general operation
are, listed in Table 6.
5.2 Coefficient of friction
The coefficient of friction should be independent of the extent to which the pads are bedded-in, the
specific pressure, the temperature and the environmental conditions.
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In wet conditions, or when there is snow, the coefficient of friction at any given moment should vary only
slightly compared to the coefficient of friction under dry conditions.
These prescriptions shall be achieved in accordance with 5.5 to 5.9.
5.3 Environmental impact, health and safety
All raw materials used in the manufacture of the brake pads shall comply with the relevant regulations
of environment, health and safety. In addition, a safety data sheet shall be presented.
5.4 Usage requirements
The composition of the material from which the brake pads are made should be chosen so that the best
compromise is obtained between:
— the frictional properties,
— the wear of the pads, and
— the aggressiveness against the brake disc.
5.5 Frictional requirements for brake pads
5.5.1 General
This chapter describes the requirements for brake pads used in locomotives, motor units, freight wagon
and coaches. Optional test programs and requirements for coaches are defined in 5.6.
5.5.2 Priority levels of brake applications
In the test programs A1 to G1, the brake applications are prioritized, in accordance with a decreasing
level of importance, as given in Table 2.
Table 2 — Priority levels of brake applications for test programs
Priority level Type of brake application
1 Dry brake applications with the highest clamp force for each mass, normal conditions
Wet brake applications and hot brake applications with highest clamp force, for each
2
mass
Brake applications with highest clamp force used for cleaning, drying, regenerating,
3
or after continuous brake applications, for each mass
All other brake applications, with the exception of continuous brake applications and
4
bedding brake applications and the examination of static coefficient of friction
Continuous brake applications, brake applications used for bedding in, examination of

static coefficient of friction
Normal conditions refer to brake applications under dry conditions with low initial temperature and with
the disc and the pad unaffected by high thermal load or residual wetness.
Brake pads of categories A1 to G1 are characterized by the velocity-dependent nominal line, µ .
m,nom
The nominal line for the coefficient of friction is calculated for each brake pad and each test program as
the linear regression line of the mean coefficients of friction (expressed in a rounding range of 0,001)
versus speed of all brake applications with priority 1, extending from the lowest to the highest test speed.
The nominal line takes the form
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µ = av⋅+ b
m,nom
where
a -1
shall be given in the unit (100 km/h) .
5.5.3 Criteria for the nominal line
The nominal line should lie between 0,300 and 0,450.
It shall lie between 0,280 and 0,470. The difference between the maximum value and the minimum value
of the nominal line shall be less or equal to 0,150.
5.5.4 Criteria for the mean coefficient of friction
Deviations of coefficients of friction are calculated by means of a tolerance band centred around the
nominal line.
The tolerance bands for the mean coefficients of friction in accordance with their priority are given in
Table 3.
Table 3 — Tolerance bands for the mean coefficients of friction vs. priorities
Priority level of
1 2 3 4
brake application
Tolerance band 1 ±10 % ±15 % ±20 % ±25 %
Tolerance band 2 ±15 % ±20 % ±25 % ±30 %
The mean coefficient of friction for each brake application shall lie within the bounds of the tolerance
band 1 in accordance with its priority, while the following exceptions are tolerated.
— A total of 6 % of all brake applications (rounded to the closest integer) of priority 1 may deviate from
tolerance band 1 towards the negative side.
— A total of 12 % of all brake applications (rounded to the closest integer) of priority 1 may deviate
from tolerance band 1.
— A total of 5 % of all brake applications (rounded to the closest integer) of priorities 2 to 4 may deviate
from tolerance band 1 towards the negative side.
— A total of 10 % of all brake applications (rounded to the closest integer) of priorities 2 to 4 may
deviate from tolerance band 1.
No mean coefficient of friction shall lie outside of tolerance band 2.
5.5.5 Criteria for continuous brake applications
During continuous brake applications, after 10 seconds the instantaneous coefficient of friction shall stay
inside the band defined by µ = 0,250 and µ = 0,500.
min max
After 2 minutes the instantaneous coefficient of friction shall not vary more than 0,05 during any minute
and the coefficient of friction shall stay inside the band defined by µ = 0,250 and µ = 0,500.
min max
The pad wear during any continuous brake application, including the stop brake application thereafter,
shall not exceed 1 mm. The wear in mm can be calculated from the weight differences before and after
the continuous brake application.
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