EN 15328:2020

Railway applications - Braking - Brake pads

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.

Bahnanwendungen - Bremsen - Bremsbeläge

Dieses Dokument legt Anforderungen für Bremsbeläge für Scheibenbremsen von Schienenfahrzeugen fest.
Dieses Dokument legt die Anforderungen und allgemeinen Prüfprogramme für Bremsbeläge am Reibungsprüfstand fest. Dieses Dokument deckt nicht die vorgeschriebene Verifizierung von Anhaltewegen fest, die zusätzlich zu Laboruntersuchungen, Prüfstandsversuchen und Betriebserprobungen durchgeführt werden. 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.
Dieses Dokument ist nicht für städtische Schienenbahnen anzuwenden.

Applications ferroviaires - Freinage - Garniture 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 définit les exigences, ainsi que les programmes d'essai génériques pour les garni-tures de frein sur des dynamomètres. Le présent document ne couvre pas les essais obligatoires destinés à vérifier les distances d'arrêt en plus des essais en laboratoire, des essais sur banc et des essais en ser-vice. Dans le but de qualifier les performances des garnitures de frein selon la classe choisie, la présente norme fournit des paramètres fixes sous forme de catégories définies dans le paragraphe Système de classification.
Le présent document n'est pas applicable aux applications ferroviaires pour le rail urbain.

Železniške naprave - Zavore - Zavorne obloge

General Information

• Status: Published
• Publication Date: 28-Jul-2020
• Withdrawal Date: 30-Jan-2021
• ICS: 45.040 - Materials and components for railway engineering
• Technical Committee: CEN/TC 256 - Railway applications
• Drafting Committee: CEN/TC 256/SC 3/WG 47 - Braking
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 29-Jul-2020
• Due Date: 07-Aug-2020
• Completion Date: 29-Jul-2020
• 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)
• 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/483 - Mandate for programming and standardisation addressed to the European standardisation bodies under directive 2008/57/EC in the field of the interoperability of the rail system within the European Union
• Ref Project: SIST EN 15328:2020 - Railway applications - Braking - Brake pads

Relations

• Amended By: EN 15328:2020/FprA1 - Railway applications - Braking - Brake pads
• Effective Date: 16-Jun-2021

Standards Content (Sample)

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

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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

F.2 Preferred space envelope for SBP 200 cm ......................................................................................... 78

F.3 Preferred space envelope for SBP 175 cm ......................................................................................... 79

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F.4 Space envelope for SBP 200 cm ............................................................................................................. 80

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

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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.
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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.
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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
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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.
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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
Nominal application force per brake disc kN
Instantaneous application force per brake disc kN
m Mass to be braked per brake disc (inclusive of the rotational masses) t
Q Water flow rate l/h
Refer to EN ISO 4287 μm
Refer to EN ISO 4287 μm
s Stopping distance from the moment on when F = 0,95 F to rest
2 b B
Theoretical initial speed at the brake application initiation km/h
v Instantaneous speed km/h
Maximum service speed km/h
max
Friction coefficient (brake pad):
a The instantaneous friction coefficient specified at every instant of the
braking time
Mean friction coefficient:
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
distance s
Nominal friction coefficient (brake pad) —
m,nom
Mean initial temperature at the beginning of the brake application °C
CI Cast iron
MU Multiple unit (EMU/DMU)
SBP Standard brake pad
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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.

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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,
normal conditions

Wet brake applications and hot brake applications with highest nominal application

force, for each mass

Brake applications with highest nominal application force used for cleaning, drying,

regenerating, or after continuous brake applications, for each mass

All other brake applications, with the exception of continuous brake applications and

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.
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— 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.

During the bedding-in phase, the mean coefficients of friction shall not exceed the following variations

from the nominal value of the bedded state:

— ± 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
...