SIST EN ISO 24478:2024

SLOVENSKI STANDARD
01-oktober-2024
Železniške naprave - Zavore - Slovar (ISO 24478:2023, vključuje popravek 2024-04)
Railway applications - Braking - General vocabulary (ISO 24478:2023, including
corrected version 2024-04)
Bahnanwendungen - Bremsen - Fachbegriffe (ISO 24478:2023, korrigierte Fassung
2024-04)
Applications ferroviaires - Freinage - Vocabulaire général (ISO 24478:2023, y compris
version corrigée 2024-04)
Ta slovenski standard je istoveten z: EN ISO 24478:2024
ICS:
01.040.45 Železniška tehnika (Slovarji) Railway engineering
(Vocabularies)
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 24478
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2024
EUROPÄISCHE NORM
ICS 45.020; 01.040.45 Supersedes EN 14478:2017
English Version
Railway applications - Braking - General vocabulary (ISO
24478:2023, including corrected version 2024-04)
Applications ferroviaires - Freinage - Vocabulaire Bahnanwendungen - Bremsen - Fachbegriffe (ISO
général (ISO 24478:2023, y compris version corrigée 24478:2023, einschließlich korrigierte fassung 2024-
2024-05) 04)
This European Standard was approved by CEN on 1 August 2024.

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, Türkiye 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
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 24478:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 24478:2023, including corrected version 2024-04 has been prepared by Technical
Committee ISO/TC 269 "Railway applications” of the International Organization for Standardization
(ISO) and has been taken over as EN ISO 24478:2024 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 February 2025, and conflicting national standards
shall be withdrawn at the latest by February 2025.
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 supersedes EN 14478:2017.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations 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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 24478:2023, including corrected version 2024-04 has been approved by CEN as
International
Standard
ISO 24478
First edition
Railway applications — Braking —
2023-08
General vocabulary
Corrected version
Applications ferroviaires — Freinage — Vocabulaire général
2024-04
Reference number
ISO 24478:2023(en) © ISO 2023
ISO 24478:2023(en)
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 24478:2023(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Basic definitions .1
3.2 Brake system compatibility .1
3.3 Performance .2
3.4 Purposes of braking .2
3.5 Mechanics of braking .2
3.6 Kinematics and dynamics of braking .4
3.7 Types and characteristics of brakes .9
3.8 Brake application and release .11
3.9 Brake control. 12
3.9.1 General definitions . 12
3.9.2 Types of control . 13
3.9.3 Types of combined control .14
3.10 Brake system components .14
3.10.1 Components used for the command and control of braking .14
3.10.2 Sensors/indicators .16
3.10.3 Control assemblies .16
3.10.4 Brake control and/or system energy lines .17
3.10.5 Friction brake system components .18
3.10.6 Brake system energy storage . 20
3.10.7 Compressed air supply .21
3.10.8 Ancillary air system equipment .21
3.10.9 Hydraulic pressure supply . .21
3.10.10 Hand brake equipment. 22
3.10.11 Parking brake equipment . 22
3.11 Wheel slide protection (WSP). 22
3.12 Types of brake test . 23
4 Symbols and abbreviated terms.23
Annex A (informative) Delay time and build-up time for brake application .24
Annex B (informative) Delay time and release time for brake release .25
Annex C (informative) Brake chart .26
Annex D (informative) Overview of relationship between brake devices and signals .29
Annex E (informative) System set up and components .30
Bibliography .33

iii
ISO 24478:2023(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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this may not represent the latest information, which may be obtained from the patent database available at
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This document was prepared by Technical Committee ISO/TC 269, Railway applications, Subcommittee SC 2,
Rolling stock.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
This corrected version of ISO 24478:2023 incorporates the following correction: footnotes "a" and "b" have
been replaced with the symbols "c" and "d", respectively, in Figure B.1.

iv
ISO 24478:2023(en)
Introduction
This document provides unambiguous definitions of generic terminology used in the field of railway braking.
The terms and definitions reflect those used in numerous published International Standards.
The braking includes all factors that have a bearing on the stopping, slowing or immobilization performance
of the train (e.g. train resistance, gradient) and may involve the conversion and dissipation of braking energy.

v
International Standard ISO 24478:2023(en)
Railway applications — Braking — General vocabulary
1 Scope
This document defines terms for brakes and braking in rolling stock.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Basic definitions
3.1.1
braking
process generating controlled forces which result in the deceleration of the train, or maintaining a constant
speed on a falling gradient, or preventing a stationary train from moving
3.1.2
brake
brake system
combination of brake unit(s) (3.1.3) with their trainwide/local control device(s) ensuring one or more
braking function(s)
Note 1 to entry: Brakes and brake systems can also be used for other functions e.g. shunting, de-icing of friction brake units.
3.1.3
brake unit
device or assembly of components, that generates a braking force
Note 1 to entry: See Annex E.
Note 2 to entry: For tread brake and disc brake, it consists of the brake actuator, the friction material (pads or block)
and the disc (for disc brake units).
Note 3 to entry: The magnetic track brake (3.7.3.3) unit includes two magnet assemblies (one per rail).
Note 4 to entry: The primary purpose of the brake unit might not be to generate a braking force, for example elements
of the traction system can also function as a brake unit.
3.2 Brake system compatibility
3.2.1
brake system compatibility
ability of the brake systems of coupled rail vehicles/trains to achieve the specified levels of braking
performance, functionality and safety

ISO 24478:2023(en)
3.3 Performance
3.3.1
braking performance
parameters and their values used to quantify braking as described in applicable braking standards
3.3.2
deceleration
result of a force acting contrary to the direction of movement
3.4 Purposes of braking
3.4.1
stopping
braking from an initial speed to a standstill
3.4.2
slowing
braking from an initial speed to a final speed, but not standstill
3.4.3
drag braking
continuous brake application
braking on a falling gradient to maintain a substantially constant speed value
3.4.4
stationary braking
braking used to prevent a stationary train from moving, using the holding, immobilizing (3.4.6) or parking
(3.4.7) functions
3.4.5
holding
braking which is used to prevent a stationary train from moving, under the specified conditions and for a
specified time, when the brake system energy used is being replenished
Note 1 to entry: Holding is usually achieved by the application of the service brake.
3.4.6
immobilizing
braking which is used to prevent a stationary train from moving, under the specified conditions and for a
specified time, using just the brake system energy stored on the train
Note 1 to entry: Immobilizing is usually achieved by the application of the service brake or parking brake equipment.
3.4.7
parking
braking which is used to prevent a stationary train from moving, under the specified conditions and for an
indefinite period of time, without the need for any brake system energy replenishment following application
Note 1 to entry: Parking is usually achieved by the application of the parking brake equipment.
3.5 Mechanics of braking
3.5.1
braking force
force generated by the brake system to stop, slow or hold the rail vehicle/unit/train stationary, or when drag
braking the train
Note 1 to entry: It does not include external forces which contribute to the overall deceleration of the rail vehicle, unit
or train (e.g. train resistance, gradient).

ISO 24478:2023(en)
3.5.2
retarding force
force transmitted between the rail vehicle/unit/train and the external environment in reaction to an applied
braking force
Note 1 to entry: For wheel/rail adhesion dependent brakes, the retarding force can be lower than or equal to the
braking force depending on the available wheel/rail adhesion.
Note 2 to entry: The retarding force can be calculated for a single brake equipment type.
3.5.3
decelerating force
sum of longitudinal forces acting on a moving train during braking (combination of retarding forces with all
other external and internal forces acting on a moving train)
Note 1 to entry: External forces can be caused by, for example, aerodynamic resistance, rising gradient or head wind.
Note 2 to entry: Internal forces can be caused by, for example, rolling resistance.
Note 3 to entry: External forces can also provide an accelerating effect (negative deceleration) in certain circumstances
(e.g. falling gradient, tail wind).
Note 4 to entry: The general assessment is usually done on straight and level track to reduce the number of variables.
3.5.4
retention force
force transmitted between the rail vehicle/unit/train and the external environment in reaction to an
applied braking force, used to hold the rail vehicle/unit/train stationary against the external forces (e.g. due
to gradient or wind loads)
Note 1 to entry: For wheel/rail adhesion dependent brakes, the retention force can be lower than or equal to the
braking force depending on the available wheel/rail adhesion.
3.5.5
static mass
mass of the rail vehicle/unit/train in a stationary condition
Note 1 to entry: Static mass is usually determined at the wheel-rail interface.
3.5.6
equivalent rotating mass
equivalent mass resulting from the moment of inertia of the wheels including coupled rotating parts
3.5.7
dynamic mass
sum of the static mass and the equivalent rotating mass
3.5.8
wheel/rail adhesion
physical phenomenon at the wheel-rail interface used to generate a retarding force
3.5.9
coefficient of wheel/rail adhesion
ratio of the tangential force at the wheel-rail interface and the force at this interface acting perpendicular to
the surface of the rail
Note 1 to entry: Usually the term “required adhesion” or “demanded adhesion” defines the minimum level of adhesion
to transmit the applied braking force (retarding force equal to braking force).
Note 2 to entry: Usually the term “available adhesion” defines the level of adhesion for which the effort that can be
transmitted from the wheel to the rail according to the actual conditions is maximum.

ISO 24478:2023(en)
3.6 Kinematics and dynamics of braking
3.6.1
fully-established brake
state in which all relevant brake units are assumed to be generating their braking force corresponding to
the brake demand
Note 1 to entry: The brake demand will be determined by the driver or the train control system.
Note 2 to entry: The term “fully-established brake” is not to be confused with the term “ full service brake application”
(3.8.3).
3.6.2
free running distance
s
a
distance travelled during the delay time (3.6.12)
3.6.3
build-up distance
s
ab
distance travelled during the build-up time (3.6.14)
3.6.4
braking distance with a fully-established brake
s
f
distance travelled with a fully-established brake to a point when achieving standstill or the final speed
3.6.5
braking distance
s
g
distance travelled from the commencement of the brake application until achieving standstill or the final speed
3.6.6
distance during release time
s
cd
distance travelled during the release time (3.6.15)
3.6.7
slowing distance
s
sl
distance travelled from the initiation of brake demand until achieving the final speed
3.6.8
stopping distance
s
distance travelled from the initiation of brake demand until standstill
3.6.9
equivalent free running distance
s
a,e
distance travelled during equivalent response time (3.6.22)
Note 1 to entry: During the equivalent response time, it is assumed that there is no braking force applied.
3.6.10
equivalent braking distance
s
f,e
distance travelled during the equivalent braking time (3.6.23)
Note 1 to entry: During the equivalent braking time it is assumed that the fully established braking force is applied.

ISO 24478:2023(en)
3.6.11
reaction time
t
r
time taken by the driver, or any train control system able to trigger a brake demand (e.g. automatic signalling
equipment, passenger alarm system, driver vigilance system), to receive the information that a brake
demand is required and to initiate that demand
3.6.12
delay time
t
a
period of time commencing when a change in brake demand is initiated and ending when achieving a % of
the fully-established braking parameter
Note 1 to entry: See Annex A.
Note 2 to entry: Braking parameter can be taken as braking force, deceleration or brake cylinder pressure.
Note 3 to entry: The delay time includes the propagation time of the trainwide brake control signal to the local brake
control device (3.10.1.12).
3.6.13
release delay time
t
c
period of time commencing when a change in brake demand is initiated and ending with reduction to c % of
the previously fully-established braking parameter
Note 1 to entry: See Annex B.
Note 2 to entry: Braking parameter can be taken as braking force, deceleration or brake cylinder pressure on train or
vehicle level.
Note 3 to entry: The release delay time includes the propagation time of the trainwide brake control signal to the local
brake control device (3.10.1.12).
3.6.14
build-up time
t
ab
period of time commencing at the end of the delay time and ending when achieving an increase from a % to
b % of the established braking parameter
Note 1 to entry: See Annex A.
Note 2 to entry: Braking parameter can be taken as braking force, deceleration or brake cylinder pressure.
3.6.15
release time
t
cd
period of time commencing at the end of the delay time and ending when achieving a decrease from c % to
d % of the established braking parameter
Note 1 to entry: See Annex B.
Note 2 to entry: Braking parameter can be taken as braking force, deceleration or brake cylinder pressure.
3.6.16
response time (build-up)
t
b
sum of the delay time and the build-up time
Note 1 to entry: See Annex A.
ISO 24478:2023(en)
3.6.17
response time (release)
t
d
sum of the delay time and the release time
Note 1 to entry: See Annex B.
3.6.18
braking time with a fully-established brake
t
f
time elapsed from achieving a fully-established brake (3.6.1) until standstill or commencing brake release
3.6.19
braking time
t
g
elapsed time from the commencement of brake application until standstill (stopping) or completion of brake
release and achieving the final speed (slowing)
3.6.20
slowing time
t
sl
total time from initiation of the brake demand until achieving the final speed being the sum of brake system
delay time and braking time
Note 1 to entry: This excludes the reaction time (3.6.11).
3.6.21
stopping time
t
total time from initiation of the brake demand until standstill, being the sum of brake system delay time and
braking time
Note 1 to entry: This excludes the reaction time (3.6.11).
3.6.22
equivalent response time
t
a,e
sum of delay time and half of the build-up time
Note 1 to entry: See Annex A and Annex C.
Note 2 to entry: During the equivalent response time period, it is assumed that there is no braking force applied.
3.6.23
equivalent braking time
t
f,e
sum of the braking time with fully-established brake (3.6.1) and half of the build-up time (3.6.14)
Note 1 to entry: During the whole of this period it is assumed the fully established braking force is applied.
3.6.24
nominal deceleration
result of a decelerating force acting on a train determined without safety margin or a confidence level on a
set of given conditions (e.g. dry rail, straight and level track)
Note 1 to entry: In Europe, typical test conditions and a method to determine the nominal deceleration are defined in
[5] [1]
EN 16834 or alternatively in EN 13452-1 for urban rail brake systems.

ISO 24478:2023(en)
3.6.25
safe deceleration
guaranteed emergency brake rate
GEBR
result of a decelerating force acting on a train determined with a specified confidence level on a set of given
conditions (e.g. variation of braking force, equipment failures and/or degraded environmental and operating
conditions)
Note 1 to entry: In general, it is the result of nominal deceleration multiplied by one or more correction factors.
Note 2 to entry: For ETCS application, the safe deceleration is calculated using the nominal deceleration and the train-
side correction factors (e.g. Kdry_rst and Kwet_rst), the confidence level (EBCL) and the weighting factor for reduced
adhesion.
3.6.26
instantaneous deceleration
absolute value of the first derivative of speed with respect to time at some instant during speed reduction
3.6.27
free running acceleration
a
a
mean value of acceleration throughout the delay time (3.6.12) when there is no braking force applied and no
deceleration due to the brake system
3.6.28
increasing brake deceleration
a
ab
variation in deceleration while the braking force is increasing from zero up to that associated with a fully-
established brake demand
3.6.29
deceleration with a fully-established brake
a
f
deceleration equal to a mean value with respect to the braking distance and based on fully established
braking forces for all functioning brake equipment types within specific speed range(s)
3.6.30
braking deceleration
a
g
deceleration throughout the braking distance (3.6.5)
3.6.31
equivalent free running acceleration
a
a,e
assumed zero brake deceleration throughout the equivalent response time (3.6.22)
Note 1 to entry: During the equivalent response time it is assumed there is no braking force applied.
3.6.32
equivalent brake deceleration
a
f,e
assumed constant brake deceleration throughout the equivalent braking time (3.6.23)
3.6.33
decreasing brake deceleration
a
cd
variation in deceleration while the braking force is reducing from fully-established to zero

ISO 24478:2023(en)
3.6.34
mean deceleration
a
deceleration which is equal to a mean value with respect to the stopping or slowing distance in a specific
speed range
3.6.35
jerk
first derivative of the deceleration with respect to time associated with a change in deceleration
Note 1 to entry: Determined in the direction of travel.
3.6.36
braking jerk limit
maximum allowed value of jerk during braking in order to comply with passenger comfort requirements
3.6.37
braking energy
energy which is dissipated or transferred during the braking process
Note 1 to entry: It corresponds to the reduction in rail vehicle or train kinetic and potential energy.
3.6.38
brake system energy
energy that is used to fulfil the brake application and release
3.6.39
braking power
power (braking energy per unit of time) which is dissipated during the braking process
3.6.40
braked weight percentage
lambda
λ
way of assessing the brake performance of a rail vehicle or train, expressed as a percentage
[5]
Note 1 to entry: Braked weight percentage is determined using EN 16834 .
3.6.41
braked weight
way of expressing the brake performance of a rail vehicle or train
Note 1 to entry: Braked weight is expressed in tonnes.
[5]
Note 2 to entry: Braked weight is determined using EN 16834 .
3.6.42
braking torque
resultant torque generated by the brake pad force (3.7.3.2.1) and coefficient of friction operating at the mean
swept radius of the brake pad on the disc face
Note 1 to entry: This is typically used when assessing the performance of disc brakes during dynamometer testing.
3.6.43
standstill
condition in which the rail vehicle/unit/train is stationary and all vehicle movement relative to the rail
has stopped
ISO 24478:2023(en)
3.7 Types and characteristics of brakes
3.7.1
wheel/rail adhesion dependent brake
brake system which transmits a braking force via the wheel/rail contact area
3.7.2
wheel/rail adhesion independent brake
brake system which does not transmit a braking force via the wheel/rail contact area
3.7.3
friction brake
brake system which generates a braking force by friction between two or more surfaces
3.7.3.1
tread brake
type of friction brake system which generates a braking force between the running surface of a wheel
(tread) and one or more brake blocks
3.7.3.1.1
brake block force
force applied by the brake block to the running surface of a wheel (tread)
Note 1 to entry: The brake block force is an example of a brake application force (3.7.6).
3.7.3.1.2
braking force at the wheel tread
tangential force generated by the coefficient of friction between the brake block and the wheel tread
3.7.3.2
disc brake
type of friction brake system which generates a braking force by applying one or more brake pads against a
brake disc
3.7.3.2.1
brake pad force
force applied by a brake pad to the brake disc
Note 1 to entry: The brake pad force is an example of a brake application force (3.7.6).
3.7.3.2.2
braking force at the brake disc
tangential force generated by the coefficient of friction between the brake pads and the brake disc
3.7.3.2.3
disc braking force at the wheel tread
braking force at the brake disc multiplied by the ratio of the mean swept radius of the brake pad on the disc
face and the wheel radius
3.7.3.3
magnetic track brake
MTB
type of friction brake system which generates a braking force between the rail surface(s) and pole shoe(s)
attracted magnetically into contact
Note 1 to entry: The pole shoe attraction can be generated by an electro-magnet or a permanent magnet.

ISO 24478:2023(en)
3.7.4
dynamic brake
brake system which generates a braking force using the motion of the rail vehicle or its functional elements,
using an energy transfer system not using consumable friction materials
Note 1 to entry: Energy transfer systems include electro-dynamic, aerodynamic and hydro-dynamic brake systems.
3.7.4.1
hydro-dynamic brake
type of dynamic brake system which generates a braking force using a hydraulic transfer system
Note 1 to entry: Hydraulic transfer systems include viscous shear transmission retarders and accumulator storage
systems.
3.7.4.2
aerodynamic brake
type of dynamic brake system which generates a braking force by aerodynamic resistance
3.7.4.3
eddy current brake
type of dynamic brake system which generates a braking force using electro-magnetic induction in the
reaction part
Note 1 to entry: The reaction part of the system can be the running rail (linear eddy current brake) or a brake disc
(rotary eddy current brake).
3.7.4.4
electro-dynamic brake
type of dynamic brake system which generates a braking force by using the energy recovery capability of
the electric traction system
Note 1 to entry: The energy can be stored and used on board, or transferred into the traction energy supply system, or
dissipated by resistors.
3.7.4.5
rheostatic brake
type of electro-dynamic brake which dissipates the braking energy recovered by heating resistors
3.7.4.6
regenerative brake
type of electro-dynamic brake which transfers the braking energy recovered into the traction energy supply
system and/or onboard storage systems
3.7.5
parking brake
brake system dedicated to perform the parking function (3.4.7)
3.7.6
brake application force
force applied directly on the friction elements (e.g. brake block/wheel, brake pads/disc)
Note 1 to entry: For the magnetic track brake, the brake application force is generated by the magnetic attraction of
the pole shoes on the head of the rail.
Note 2 to entry: For brake disc calipers, the term “clamping force” is also used to refer to the brake application force.
Note 3 to entry: For the tread brake, the term “single brake block force” is also used to refer to the brake application force.

ISO 24478:2023(en)
3.8 Brake application and release
3.8.1
emergency brake application
pre-defined brake application that achieves the specified emergency braking performance and level of safety
Note 1 to entry: The braking performance of the emergency brake application is typically equal to or higher than the
maximum service brake application.
Note 2 to entry: The safety level needs to take into account the usable brake equipment types.
3.8.2
service brake application
application of a graduable braking force in order to control the speed of a train, including slowing or stopping
and temporary immobilization
Note 1 to entry: Service brake application is the most commonly used method of brake operation.
3.8.3
full service brake application
maximum available service brake application
3.8.4
safety brake application
brake application specific to urban rail vehicles/units/trains intended to achieve a higher level of system
integrity than that achieved with a service brake application or an emergency brake application
Note 1 to entry: The performance of the safety brake application can be lower than achieved by a full service brake or
emergency brake application.
3.8.5
irreversible brake application
irretrievable brake application
brake application which cannot be released by the driver before specific conditions are reached
Note 1 to entry: Examples of specific conditions include either
a) the train achieves a defined speed, or
b) the expiry of the time limit of the brake application.
3.8.6
graduable brake application and release
function to increase or reduce the braking force either in steps or continuously
3.8.7
brake mode
setting, in brake systems with pneumatic trainwide indirect brake (3.9.1.8) architecture, that defines the
distributor valve build-up and release timings
Note 1 to entry: In Europe in the “EN-UIC” design, the brake modes “G” for goods timings and “P” for passenger timings
[2]
are defined in EN 14198 .
3.8.8
brake position
setting that defines the behaviour of the local brake control device (3.10.1.12) (e.g. distributor valve) in
regard of brake application and release timings and braking forces that can include additional brake units
Note 1 to entry: Selecting the brake position does not necessarily need the operation of a lever, etc. on the rail vehicle.
[2]
Note 2 to entry: In Europe in the “EN-UIC” design, the brake position (e.g. “P”, “G”, “R”, “R+ Mg”) is defined in EN 14198 .

ISO 24478:2023(en)
3.8.9
overcharge function
function, in brake systems with pneumatic trainwide indirect brake (3.9.1.8) architecture, to equalize the
control pressures of all the distributor valves in the train to the normal working pressure (3.10.4.2) in the
brake pipe
Note 1 to entry: This function can be achieved by a temporary increase of the pressure in the brake pipe above the
normal brake pipe pressure to release all the brakes in the train. This is followed by the assimilation process (3.8.10).
Note 2 to entry: This can be initiated by the driver or automatically after a brake application.
3.8.10
assimilation process
controlled pressure reduction, in brake systems with pneumatic trainwide indirect brake (3.9.1.8)
architecture, down to the normal working pressure (3.10.4.2) at a rate that does not initiate a brake
application, and that follows the temporary increase of the brake pipe pressure
3.8.11
quick release function
facility, in brake systems with pneumatic trainwide indirect brake (3.9.1.8) architecture, to accelerate the full
release of the brakes by filling the brake pipe with a higher air flow for a limited time
Note 1 to entry: It can be used in long trains with single pipe air brake architecture.
3.8.12
high pressure quick release function
release which is similar to the quick release function, where the air is supplied to the brake pipe at a higher
pressure than the normal working pressure
3.8.13
direct release function
systematic complete reduction of braking force in one step when any level of brake release is demanded
Note 1 to entry: This feature is associated with a brake application device known as a "triple valve" which is generally
used in long freight trains.
3.9 Brake control
3.9.1 General definitions
3.9.1.1
brake demand
signal sent to the brake system representing the braking requirement of the driver and/or any train control
system (e.g. automatic signalling equipment, passenger alarm system, driver vigilance system)
3.9.1.2
main brake system
trainwide continuous brake system which provides at least an automatic operation, inexhaustibility and the
specified safety level for emergency braking, service braking and to keep the train stationary
3.9.1.3
trainwide brake control
system architecture where the brake demand is converted into a signal which is transmitted along the train
3.9.1.4
local brake control
system architecture where the trainwide brake control signal and/or other locally generated brake control
signals are converted into an output signal to the brake equipment, resulting in a braking force being
generated on the rail vehicle concerned
Note 1 to entry: The action may be executed in a local brake control device (3.10.1.12).

ISO 24478:2023(en)
3.9.1.5
continuous train brake
system architecture where the trainwide brake control signals are transmitted to all rail vehicles along the train
3.9.1.6
automatic train brake system
continuous train brake system where the loss or interruption of the trainwide brake control signal causes
an automatic application of one or more devices of the brake system
Note 1 to entry: The initiation of an automatic brake application will take precedence over other local brake/release
commands.
Note 2 to entry: In case of an unintended train separation, the automatic function results in the brake application on
all parts of the train.
3.9.1.7
inexhaustible train brake
system architecture where sufficient energy is stored on-board the train for assuring the specified braking
performance and safety level, in all operating conditions
Note 1 to entry: The term “inexhaustibility” is often used when discussing the ability of a brake system to sustain a
specified braking performance and safety level.
3.9.1.8
trainwide indirect brake
system architecture where an increase of the brake demand corresponds to a reduction in the value of the
trainwide brake control signal
3.9.1.9
trainwide direct brake
system architecture where an increase of the brake demand corresponds to an increase in the value of the
trainwide brake control signal
3.9.2 Types of control
3.9.2.1
pneumatic control
system where the trainwide brake control or local brake control is achieved by the action of air pressure
differences and/or flow rates
3.9.2.2
hydraulic control
system where the trainwide brake control
...