prEN 13452-1

Railway applications - Braking - Urban rail brake systems - Part 1: Requirements and definitions

This document specifies basic requirements and definitions for a brake system for use in urban rail vehicles.
Note: Urban rail vehicles are defined in EN17343.
This document is applicable to:
- tram vehicles and light rail vehicles;
- metro vehicles with steel wheels;
- metro vehicles with rubber tyred wheels;
- other urban rail vehicles.
This document does not apply to special transport systems, e.g. suspended monorail, rack and pinion lines, isolated operations such as scenic railways, special duty vehicles, etc.Compliance with the functional and performance requirements defined in this document is verified by testing in accordance with EN 13452-2.

Bahnanwendungen - Bremsen - Bremssysteme städtischer Schienenbahnen - Teil 1: Anforderungen und Definitionen

Applications ferroviaires - Freinage - Systèmes de freinage des transports publics urbains et suburbains - Partie 1: Exigences de performances

Železniške naprave - Zavore - Zavorni sistemi za mestno železnico - 1. del: Zahteve in definicije

General Information

• Status: Not Published
• Publication Date: 23-Mar-2025
• ICS: 45.140 - Metro, tram and light rail equipment
• Technical Committee: CEN/TC 256 - Railway applications
• Drafting Committee: CEN/TC 256/SC 3/WG 47 - Braking
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Start Date: 11-May-2023
• Due Date: 28-Jul-2022
• Completion Date: 11-May-2023
• Mandate: M/486 - Mandate for programming and standardisation addressed to the European standardisation bodies in the field of urban rail
• Ref Project: oSIST prEN 13452-1:2023 - Railway applications - Braking - Urban rail brake systems - Part 1: Requirements and definitions

Relations

• Revises: EN 13452-1:2003 - Railway applications - Braking - Mass transit brake systems - Part 1: Performance requirements
• Effective Date: 18-Jan-2023

Overview

prEN 13452-1:2023 (CEN) - Railway applications - Braking - Urban rail brake systems - Part 1: Requirements and definitions - defines the baseline functional and performance requirements for brake systems used on urban rail vehicles. This draft European standard updates and will supersede EN 13452-1:2003. It applies to trams, light rail vehicles, metro vehicles with steel or rubber-tyred wheels and other urban rail vehicles (urban rail vehicles are defined in EN 17343). It excludes special transport systems such as suspended monorails, rack-and-pinion lines, scenic/isolated railway operations and special-duty vehicles. Compliance with the functional and performance requirements in this Part 1 is verified by testing in accordance with EN 13452-2.

Key topics and technical requirements

This standard provides structured requirements and definitions covering:

• Brake system design principles: architecture, train brake control, brake application systems and components.
• Brake function types: service braking, emergency braking, safety braking, holding and parking brakes.
• Braking fundamentals: available adhesion, stopping distances, payload and power supply considerations.
• Operational requirements: passenger emergency alarm interface, driver vigilance, train protection and coupling/decoupling impacts.
• Performance requirements: equivalent response time, operational stopping distance, comfort and guaranteed performance metrics.
• Reliability and safety: failure consequence management, auxiliary/monitoring facilities, loss of dynamic braking.
• Wheel slide protection and sanding: recommendations and requirements for wheelslide protection systems and sanding systems (Annex A).
• Environmental and loading criteria: environmental condition treatment and defined load levels for different vehicle types.
• Vehicle-specific requirements: separate clauses with tailored characteristics and performance values for trams/light rail, metro (steel wheels), metro (rubber-tyred) and other urban rail vehicles.

Applications and users

This standard is practical for:

• Rolling stock designers and OEMs specifying or designing braking systems for urban rail vehicles.
• Brake system manufacturers developing components and systems to meet CEN performance criteria.
• Vehicle manufacturers and integrators ensuring system-level compliance and interoperability.
• Certification bodies and test laboratories verifying brake performance per EN 13452-2.
• Infrastructure managers and procurers defining minimum braking performance in tenders and technical specifications (e.g., tram-train operations where multiple system rules apply).

Using prEN 13452-1 helps ensure consistent braking safety, interoperable performance and comparable verification for urban rail fleets across Europe.

Related standards

• EN 13452-2 - Test methods (verification of Part 1 requirements)
• EN 17343 - Definition of urban rail vehicles
• EN 13452-1:2003 - Superseded edition
• EN 16185-1 - Possible overlap for certain borderline vehicle types (see Clause 9)

Keywords: urban rail brake systems, railway braking, CEN standard, tram braking, metro brakes, wheel slide protection, EN 13452-2, prEN 13452-1:2023.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2023
Železniške naprave - Zavore - Zavorni sistemi za mestno železnico - 1. del: Zahteve
in definicije
Railway applications - Braking - Urban rail brake systems - Part 1: Requirements and
definitions
Bahnanwendungen - Bremsen - Bremssysteme städtischer Schienenbahnen - Teil 1:
Anforderungen und Definitionen
Applications ferroviaires - Freinage - Systèmes de freinage des transports publics
urbains et suburbains - Partie 1: Exigences de performances
Ta slovenski standard je istoveten z: prEN 13452-1
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
45.140 Oprema za podzemne vlake, Metro, tram and light rail
tramvaje in lahka tirna vozila equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2023
ICS Will supersede EN 13452-1:2003
English Version
Railway applications - Braking - Urban rail brake systems -
Part 1: Requirements and definitions
Applications ferroviaires - Freinage - Systèmes de Bahnanwendungen - Bremsen - Bremssysteme des
freinage des transports publics urbains et suburbains - öffentlichen Nahverkehrs - Teil 1: Anforderungen an
Partie 1: Exigences de performances das Leistungsvermögen
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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13452-1:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Symbols . 8
5 Design principles . 8
5.1 Brake system . 8
5.1.1 General. 8
5.1.2 Service braking . 9
5.1.3 Emergency braking . 9
5.1.4 Safety braking . 9
5.1.5 Holding brake . 9
5.1.6 Parking brake . 10
5.1.7 Wheelslide protection systems . 10
5.1.8 Sanding systems . 10
5.2 Environmental condition . 10
5.3 Loading criteria . 10
5.4 Braking fundamentals . 11
5.4.1 Available adhesion . 11
5.4.2 Stopping distances . 11
5.4.3 Pay load . 11
5.4.4 Power supply . 11
5.5 Operational requirements . 11
5.5.1 Passenger emergency alarm . 11
5.5.2 Driver vigilance system . 12
5.5.3 Train protection . 12
5.5.4 Coupling/decoupling . 12
5.6 Performance requirements . 12
5.6.1 Equivalent response time . 12
5.6.2 Stopping distance . 12
5.6.3 Operational performance requirements . 13
5.6.4 Comfort performances . 14
5.6.5 Guaranteed performances . 14
5.7 Brake system failure consequences . 14
5.7.1 General. 14
5.7.2 Design principles . 14
5.7.3 Auxiliary and monitoring facilities . 15
5.7.4 Loss of dynamic brake . 15
5.8 Automatic train control . 15
5.9 Brake system structure . 15
5.9.1 General. 15
5.9.2 Train brake control system . 16
5.9.3 Brake application system . 16
5.9.4 Brake components . 16
5.9.5 Monitoring. 16
5.9.6 Brake test. 16
5.9.7 Isolation facilities . 17
6 Requirements for trams and light rail vehicles . 17
6.1 Characteristics for trams and light rail vehicles . 17
6.2 Brake system architecture . 17
6.3 Brake performance values . 18
6.3.1 General . 18
6.3.2 Operational performances . 18
6.4 Comfort performances . 18
6.5 Static performances . 19
6.5.1 Holding brake . 19
6.5.2 Parking brake . 19
6.6 Load levels . 19
6.7 Implementation . 19
7 Requirements for metro vehicles with steel wheels . 20
7.1 Characteristics for metro vehicles with steel wheels . 20
7.2 Brake system architecture . 20
7.3 Brake performance values . 21
7.3.1 General . 21
7.3.2 Operational performances . 21
7.3.3 Comfort performances . 21
7.3.4 Static performances . 22
7.4 Load levels . 22
7.5 Implementation . 23
8 Requirements for metro vehicles with rubber tyred wheels . 23
8.1 Characteristics for metro vehicles with rubber tyred wheels . 23
8.1.1 General . 23
8.1.2 Typical parameters . 23
8.2 Brake system architecture . 24
8.3 Brake performance values . 24
8.3.1 General . 24
8.3.2 Operational performances . 24
8.3.3 Comfort performances . 24
8.3.4 Static performances . 25
8.4 Load levels . 25
8.5 Implementation . 26
9 Requirements for other urban rail vehicles . 26
9.1 General . 26
9.2 Characteristics for other urban trains . 26
9.3 Brake system architecture . 27
9.4 Brake performance values . 27
9.4.1 General . 27
9.4.2 Operational performances . 27
9.4.3 Comfort performances . 27
9.4.4 Static performances . 28
9.5 Load levels . 28
9.6 Implementation . 29
Annex A (informative) Wheel slide protection recommendations . 30
Bibliography . 33
European foreword
This document (prEN 13452-1:2023) 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.
This document will supersede EN 13452-1:2003.
EN 13452-1:2003:
— normative references have been updated;
— requirements on design and specific vehicle type requirements have been revised;
— wheel slide protection recommendations have been added.
This series EN 13452, Railway applications — Braking – Urban rail brake systems consists of two parts:
— Part 1: Requirements and definitions
— Part 2: Test methods
Introduction
Regarding the Europe-wide competition required, this European Standard will allow all prospective
bidders to propose or offer rolling stock meeting specified minimum requirements for braking
performances.
In case of railway vehicles operating on more than one system (e.g. tram-trains), the technical
specification (technical agreement between stakeholders) defines which requirements are valid in the
different portions of the systems.
If mentioned in this document, the technical specification defines particular parameters and specifies any
additional braking requirements.
Regarding Clause 9, which mainly concerns other urban rail vehicles, there might be borderline cases
which can also fall within the scope of EN 16185-1.
1 Scope
This document specifies basic requirements and definitions for a brake system for use in urban rail
vehicles.
NOTE Urban rail vehicles are defined in EN 17343.
This document is applicable to:
— tram vehicles and light rail vehicles;
— metro vehicles with steel wheels;
— metro vehicles with rubber tyred wheels;
— other urban rail vehicles.
This document does not apply to special transport systems, e.g. suspended monorail, rack and pinion
lines, isolated operations such as scenic railways, special duty vehicles, etc.
Compliance with the functional and performance requirements defined in this document is verified by
testing in accordance with prEN 13452-2:2023.
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 14531-1:2015+A1:2018, Railway applications - Methods for calculation of stopping and slowing
distances and immobilization braking - Part 1: General algorithms utilizing mean value calculation for train
sets or single vehicles
EN 14531-2, Railway applications - Methods for calculation of stopping and slowing distances and
immobilization braking - Part 2: Step by step calculations for train sets or single vehicles
EN 15663, Railway applications — Vehicle reference masses
EN 17343, Railway applications - General terms and definitions
EN 50125-1, Railway applications - Environmental conditions for equipment - Part 1: Rolling stock and on-
board equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14478, EN 14531-1,
EN 14531-2, EN 17343 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
driver
human being in manual control of train motion, or automatic train control system
3.2
technical specification
project related document describing specific parameter and/or brake system requirements between a
customer and a supplier, as an addition to requirements of this standard
3.3
design specification
supplier’s project related document describing in detail the different functions of the brake system in
accordance with the requirements from the technical specification
Note 1 to entry: The design specification can be used as base for the test procedure document.
3.4
load compensation
adjustment of the braking force on a brake system in accordance with the load, with the objective of
maintaining the deceleration constant irrespective of load
3.5
maximum (average) jerk
change of deceleration measured and averaged within the time period t (build-up time) in accordance
ab
with EN 14531-1
3.6
maximum braking load
maximum load required for the specific braking function for which the brake is designed
Note 1 to entry: The technical specification can specify different value for the maximum braking load.
Note 2 to entry: Load condition can be lower than or equal to “design mass under exceptional payload” (MXD) as
defined in EN 15663.
3.7
brake equipment type
brake contributors with different characteristics (e.g. response time, way of operation…)
4 Symbols
For the purposes of this document, the following symbols apply:
a deceleration, expressed in m/s
s stopping distance, expressed in m, as defined in EN 14531
t time, expressed in s, as defined in EN 14531
t build-up time, from achieving a % to achieving b % of the established deceleration, expressed
ab
in s, as defined in EN 14478
v speed, expressed in m/s, as defined in EN 14531
5 Design principles
5.1 Brake system
5.1.1 General
If not specified otherwise in this document, the brake system is understood with all brake functions
active.
A brake system shall achieve the following objectives:
— to decelerate or stop a moving train;
— to maintain a train stationary;
— to control a train's speed on a downhill gradient.
The brake system shall be designed and built so that
— it is continuous, automatic and inexhaustible,
— it comprises an energize-to-release brake command line, as a minimum for the emergency braking
or the safety braking,
— the man machine interface shall provide at least two separate means for demanding an emergency
braking or safety braking application,
NOTE 1 If safety braking is implemented on the train, it is acceptable to have only one emergency braking
control mean and only one safety braking control mean.
— trains or train sets can be stopped without risk to passengers and third parties and with acceptable
levels of jerk at service braking,
— traction effort shall be cut off on the whole train while braking is requested,
NOTE 2 Some operating conditions can require to superpose traction and service braking, e.g. roll-back.
— the adhesion limit specified in 5.4.1 is only to be considered as a design criteria for the brake
calculation according to EN 14531-1, in order to ensure that the brake system can fulfil the
requirements of Clause 6 to Clause 9,
— thermal load conditions shall not exceed the thermal capacity of the involved brake equipment types.
In achieving the above objectives, a number of functions shall be required, which are described below.
The means of achieving these functions shall be in accordance with the requirements defined in the
appropriate clause for the type of rolling stock.
5.1.2 Service braking
Service braking shall be provided and shall consistently achieve specified levels of performance. It shall
be designed for permanent use by the driver in controlling the train. Braking parameters shall be set to
take account of passenger’s comfort.
During blending the instantaneous deceleration shall not vary by more than ± 10 % from that demanded.
Service braking shall be overridden by both any emergency braking mode and a safety braking.
5.1.3 Emergency braking
The traction function (not the ED brake function) shall be cut off automatically and the process to achieve
this shall be initiated immediately. It cannot be reactivated before the brake demand is released
completely and without a deliberate action by the driver as defined in 3.1.
Emergency braking shall be provided and shall achieve a specified level of performance. Whenever the
term “emergency” is used, the type of emergency brake required shall be defined in the technical
specification.
The various emergency braking modes are defined with regard to initiation, see Table 1. The braking
performance achieved for each of these emergency braking modes does not necessarily need to be
different. It is acceptable to group two or more modes together when specifying the emergency brake
system for a particular train:
Table 1 — Emergency braking modes
Mode Usual means of initiation
Emergency braking 1 Driver vigilance, or ATO, or ATP system
Emergency braking 2 Passenger alarm
Emergency braking 3 Driver, via dedicated position on brake controller, or ATP system
Emergency braking 4 Authorized person via control separate from brake controller
When an ATP system is applied, the respective involved braking function shall be specified by the
technical specification.
NOTE It is possible for the different levels of emergency braking to be initiated by means other than those
indicated above, e.g. driver assistance systems.
5.1.4 Safety braking
Safety braking may be specified as a particular form of braking. It provides not necessarily a high level of
performance.
5.1.5 Holding brake
Holding brake may be provided as a separate function if this is specified by the technical specification.
The load (see Table 3), gradient and time for which it shall be effective, should be defined by the technical
specification.
As an option, a rollback function can be implemented with the aim, when the traction is required, to
automatically apply the brake in case of displacement of the train in a direction opposite to the travel
direction selected by the driver. The maximum rollback distance until the train is stopped may be given
in the technical specification.
5.1.6 Parking brake
The purpose of a parking brake is to be applied automatically when all driver controls are deactivated or
by loss of all energy. Manual control of the parking brake may be provided in addition, to keep the train
stationary in shut down configuration permanently without energy supply. It can be validated by an
analysis of the design.
5.1.7 Wheelslide protection systems
The objectives of fitting WSP systems to trains are to assist in achieving the following:
— optimize braking performance in degraded adhesion conditions to achieve the minimum practical
stopping distance;
— minimum level of wheel damage due to wheel slide or wheel lock;
— minimum level of track damage;
— minimize the consumption of the stored energy for brake actuation during operation.
If the accordance with EN 15595 is not specified in the technical specification or is not applicable for the
concerned vehicle, Annex A can be used as recommendation reference list.
5.1.8 Sanding systems
Sanding systems should be used to optimize braking performance by increasing the adhesion in degraded
adhesion conditions. Application of sand shall not disturb signalling systems and should not interrupt
power supply.
5.2 Environmental condition
The rolling stock and the equipment on board shall perform under the conditions as specified in the
technical specification in accordance with EN 50125-1. They shall work properly in those climatic zones,
for which they have been designed and where they will be operated.
For certain applications, further requirements may be required, e.g. for the Nordic countries. Especially
using hydraulic brakes, the response time is directly influenced by the temperature-dependency of the
hydraulic fluid viscosity. This shall be taken into consideration and shall be part of the technical
specification.
5.3 Loading criteria
In specifying the performance of the brake system, one of the key parameters is the payload at which the
performance is to be attained. The particular levels shall be defined by the technical specification, based
upon the characteristics of its particular system.
When not defined otherwise, the load definitions of EN 15663 for vehicle category M-II shall apply,
e.g. MVD, MND, MXD.
The maximum braking load is given as the maximum mentioned in 6.6, 7.4, 8.4 and 9.5.
5.4 Braking fundamentals
5.4.1 Available adhesion
One of the key factors involved in achieving a satisfactory braking performance is the available adhesion
between the wheel and the rail/track. This parameter varies not only between different types of transport
systems, but also with actual track conditions.
The infrastructure manager shall provide information about the level of available adhesion to be
considered on the concerned network and may take specific preventive or corrective measures to
minimize the effects of degraded adhesion during braking to achieve a satisfactory level of performance,
e.g. rail cleaning.
The maximum adhesion limit value for vehicle according to Clause 6 is 0,33 in emergency braking 3 and 4.
The maximum adhesion limit value for vehicle according to Clause 7 and Clause 9 (steel wheel) is 0,17 in
emergency braking 3 and 4.
The maximum required adhesion calculated according EN 14531-1:2015+A1:2018, 5.9 for parking brake
shall be lower than or equal to
— 0,15 for vehicle type in accordance with Clause 6,
— 0,12 for vehicle type in accordance with Clause 7 and Clause 9.
5.4.2 Stopping distances
This document defines acceptable performance levels by stating ranges of decelerations which typically
result in a satisfactory performance. However, for many applications, additional performance criteria,
often based on either the legislative requirements of a particular country or on the requirements of the
associated signalling system, can be specified by the technical specification. Frequently, these will be in
the form of maximum stopping distance against speed data. It is important to appreciate, when designing
brake systems to comply with such requirements, that the stopping distances quoted include the distance
covered during the brake response time.
5.4.3 Pay load
For the types of trains covered by this document, the pay loads carried are a high percentage of the empty
train mass. The design of the brake system shall address this issue in order to achieve effective use of the
adhesion. In consequence, when a fixed brake force is required (i.e. no load compensation), the stopping
distance will differ according to the load carried.
5.4.4 Power supply
Except for hydraulic active brake actuator without accumulator, the minimum brake energy to be stored
locally shall correspond to 2 emergency brake applications in the braking mode and load case consuming
the highest energy in static condition or on dry track if static tests are not possible.
For passive actuators, this requirement does not apply (because intrinsically fulfilled).
5.5 Operational requirements
5.5.1 Passenger emergency alarm
Trains carrying passengers shall be provided with equipment which allows passengers to initiate either
an emergency 2 brake application or an alarm. For further details, see EN 16334-2. Special customer
requirements should be specified by the technical specification.
5.5.2 Driver vigilance system
Manually driven trains shall be equipped with a dead person’s device or vigilance system which, in the
event of driver collapse, results in an emergency brake 1 application. Special customer requirements
should be specified by the technical specification.
5.5.3 Train protection
Safety devices may be fitted to provide self-acting train protection. These may initiate a brake application
under conditions defined by the technical specification (e.g. exceeding permitted speed limit(s),
overrunning signals, doors opening).
5.5.4 Coupling/decoupling
During coupling, brakes applied to secure the standstill of the train shall not be released.
The command “uncoupling“
— requires a deliberate action of the driver so that it cannot be the result of an unintentional or faulty
action (e.g. from inactive driver’s cab),
— shall only be accepted when the inexhaustible brakes (parking brake) are applied in advance,
— shall not be possible when the train is moving.
In the case of an unintentional train separation, all vehicles of the train shall be braked automatically to
standstill with a performance not less than the minimum given by Table 4, Table 8, Table 12 and Table 16
for safety braking.
5.6 Performance requirements
5.6.1 Equivalent response time
According to the definition of the equivalent response time in EN 14478 a % is chosen to be 10 % and
b % to be 90 %.
5.6.2 Stopping distance
For any train, and any initial speed the nominal stopping distance criteria shall be calculated as defined
below.
a) The reference conditions are
1) level track,
2) straight line,
3) coefficient of adhesion on dry clean rails,
4) ambient temperature within the designed temperature range of the commercial operation duty
cycle (see 5.2).
b) During a time called equivalent response time (t ), no deceleration is transmitted to the train.
e
c) After this time t , the deceleration is constant (a ), until the train is stopped.
e e
With this theoretical braking, for every initial speed v , the stopping distance s shall be calculated by the
following formula:
v
sv= ×+t (1)
0e
2a
e
For a given stopping distance s and equivalent response time t , the equivalent deceleration a shall be
e e
calculated by the following formula:
v
a = (2)
e
2 × sv−× t
( )
0e
where
v is the initial speed, expressed in m/s, as defined in EN 14531;
t is the equivalent response time, expressed in s, as defined in EN 14478;
e
a is the equivalent deceleration, expressed in m/s , as defined in EN 14531.
e
5.6.3 Operational performance requirements
The technical specification shall specify if the operational performance requirements are linked to
— stopping distances s: CASE A,
or
— equivalent response time t and equivalent deceleration a : CASE B.
e e
CASE A and CASE B shall not be required together.
CASE A: The maximum required stopping distances shall be calculated with t and a for any initial speed
e e
using Formula (1). t and a are defined in the following tables:
e e
— Table 2 — Theoretical operational performances
— Table 6— Theoretical operational performances
— Table 10 — Theoretical operational performances
— Table 14 — Theoretical operational performances
The acceptance criteria are only the stopping distances and not t and a .
e e
CASE B: the values in the following tables shall be taken as maximum values for the t and minimum
e
values for a :
e
— Table 2 — Theoretical operational performances
— Table 6 — Theoretical operational performances
— Table 10 — Theoretical operational performances
— Table 14 — Theoretical operational performances
and a .
The acceptance criteria are te e
The performances under failure conditions shall be in accordance with 5.7.
To be noted that CASE A and CASE B shall fulfil the comfort performances according to 5.6.4.
NOTE Performances mentioned in these tables are nominal performances, not guaranteed performances.
5.6.4 Comfort performances
For each type of rolling stock, comfort performances shall be associated to the operational performances.
These comfort performances are expressed with maximum values for deceleration and jerk in the
following tables:
— Table 3 — Deceleration and jerk levels
— Table 7 — Deceleration and jerk levels
— Table 11 — Deceleration and jerk levels
— Table 15 — Deceleration and jerk levels
The specified jerk limits in Clause 6 to Clause 9 only apply at braking initiation.
5.6.5 Guaranteed performances
If guaranteed performances are required, the associated confidence level assigned to the rolling stock
shall be defined in common agreement with the operator and the infrastructure manager.
5.7 Brake system failure consequences
5.7.1 General
The technical specification should specify the consequences of the worst single failure of the brake
system, i.e. the operating conditions that should be observed and the performances that should be
obtained for emergency braking (or safety braking, where relevant), holding brake and parking brake.
If not specified in the technical specification, the consequences on the emergency braking (or safety
braking, where relevant), holding brake and parking brake performances and operating conditions (e.g.
reduced speed) of the worst single failure of the brake system shall be considered, according to the results
of the safety analyses.
It is recommended that the presence of unbedded components (e.g. brake blocks or pads) are considered
by the technical specification.
5.7.2 Design principles
In the course of the design the following risks shall be considered and mitigated. As a minimum, the
following hazards due to a failure shall be taken into account.
a) The brake performance is higher than the level of braking demanded:
1) impact on track shifting forces;
2) excessive jerk.
b) The brake performance is lower than the level of braking demanded:
1) keeping traction effort on the train while emergency or safety braking is requested;
2) required emergency braking performance not achieved;
3) required parking brake performance not achieved.
c) There is no brake force when demanded; this event shall not happen with a single failure:
1) no emergency or safety braking on the whole train when requested;
2) automatic (emergency or safety) braking not initiated in the case of an unintended train
separation (loss of train integrity);
3) parking brake: loss of performance over the time.
d) There is a brake force when a brake demand has not been made:
1) undue local brake application (incl. parking).
e) Brake component failures that could cause death or injury or damage to the train or infrastructure,
e.g. derailment.
The hazards in the previous list shall be assessed in accordance with the process specified in the technical
specification and/or in the applicable regulations.
If not specified otherwise in the technical specification, service braking shall not be subject to a safety
analysis, provided, the required integrity level of the vehicle is covered by emergency or, where relevant,
safety braking.
5.7.3 Auxiliary and monitoring facilities
Associated facilities may be provided to assist in the operation of the train by the provision of monitoring
and recovery systems. The details of such systems, if required, shall be defined by the technical
specification. For example, it is recommended that the application and release of brakes is monitored and
that a means of testing them regularly is provided.
5.7.4 Loss of dynamic brake
If a dynamic brake is provided (e.g. by using the propulsion equipment), in the event of its failure, a
second means of braking shall automatically be available to achieve at least a single stop. The details of
such systems shall be defined by the technical specification.
5.8 Automatic train control
These trains operate under the control of an automatic system instead of the trains being driven manually
(see EN 62290). The required braking performance values shall be defined by the technical specification
in conjunction with the control system. For a brake system being designed to operate on an existing
automatically controlled network, the required braking performance shall be defined by the technical
specification.
5.9 Brake system structure
5.9.1 General
Any brake system fitted shall achieve specific functions and shall attain the required level of integrity.
The following points are provided to assist in determining adequate systems.
When a train comprises a number of units, the brakes on all units in the train shall be controlled so that
the train achieves the specified performance.
For any brake system, there are two key functions:
— the generation and transmission of a brake demand to all vehicles (train brake control system);
— the conversion of that demand into a braking force on each vehicle (brake application system).
5.9.2 Train brake control system
The function of the train brake control system is the generation and transmission of a demand signal from
a control device in the train to all vehicles in that train.
The emergency/safety brake control shall be such, that the loss of the control signal(s) shall result in the
application of the emergency/safety braking on all vehicles, unless otherwise defined by the technical
specification.
5.9.3 Brake application system
The function of the brake application system is the conversion of the (train) demand signal into a brake
application demand, at every appropriate brake location, and the generation of the required braking
effort.
For one emergency/safety braking, each brake application system which needs application energy, shall
provide a reserve of energy. The capacity of this reserve shall be sufficient to ensure the application of
the brakes from max. operating speed, including wheel slide protection operation, where relevant, even
in the event of a train separation.
5.9.4 Brake components
Components provided for the emergency/safety brake may also be used for other braking functions as
long as it does not compromise the integrity of the emergency/safety brake.
5.9.5 Monitoring
In order to identify defects which can affect the saf
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