ISO/TR 22131:2023

TECHNICAL ISO/TR
REPORT 22131
Second edition
2023-02
Railway applications — Railway
braking — Country specific
applications for ISO 20138-1
Applications ferroviaires — Freinage ferroviaire — Applications
nationales spécifiques de l'ISO 20138-1
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Slowing or stopping distance calculation using a method implemented in France .1
4.1 General . 1
4.2 Symbols and abbreviations . 1
4.3 Slowing or stopping distance calculation . 2
4.3.1 French model for “G” position . 2
4.3.2 Calculation using ISO 20138-1:2018, 5.7.5.1 step model . 4
4.4 Example of calculation. 4
4.4.1 Test results . 4
4.4.2 Comparison of calculation models with test results . 5
5 Calculation of braking performance implemented in Japan . 5
5.1 General . 5
5.2 Brake ratio for a single vehicle . 5
5.3 Example for brake ratio calculation . 6
5.4 Equivalent response time . 7
5.4.1 General . 7
5.4.2 Case 1: Determination based on train speed . 8
5.4.3 Case 2: Determination based on BC pressure response . 8
6 Stopping or slowing distance calculation methods for some particular rolling stock
in China . 9
6.1 General . 9
6.2 Symbols and abbreviations . 9
6.3 Train resistance retarding forces . 10
6.3.1 Basic running resistance . 10
6.3.2 Curve resistance .12
6.4 Train braking force .13
6.4.1 Total braking force of train . 13
6.4.2 Real friction coefficient . 14
6.4.3 Conversion friction coefficient. 14
6.4.4 Real brake block force .15
6.4.5 Nominal values of rigging efficiency . 16
6.4.6 Emergency brake cylinder pressure . 16
6.4.7 Conversion brake block force . 17
6.4.8 Conversion braking ratio . 18
6.4.9 Train unit brake ratio .20
6.4.10 Dynamic brake force . 20
6.4.11 Coefficient of adhesion . 21
6.5 Brake calculation . 21
6.5.1 Braking time . 21
6.5.2 Free running time . 22
6.5.3 Stopping/slowing distance . 22
Bibliography .24
iii
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 has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely 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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
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on the ISO list of patent declarations received (see www.iso.org/patents).
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expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 269, Railway applications, Subcommittee
SC 2, Rolling stock.
This second edition cancels and replaces the first edition (ISO/TR 22131:2018), which has been
technically revised.
The main change is: the symbols and terms in Clause 6 have been revised.
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.
iv
TECHNICAL REPORT ISO/TR 22131:2023(E)
Railway applications — Railway braking — Country
specific applications for ISO 20138-1
1 Scope
This document provides additional information to assist the understanding and the use of ISO 20138-1.
The calculations in this document follow the same principles but they are slightly different.
This document contains country specific calculation approaches currently in use and represents the
state of knowledge including for calculating:
— stopping and slowing distances;
— equivalent response time;
— brake performance;
— brake ratio.
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.
ISO 20138-1:2018, Railway applications — Calculation of braking performance (stopping, slowing and
stationary braking) — Part 1: General algorithms utilizing mean value calculation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 20138-1 apply.
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/
4 Slowing or stopping distance calculation using a method implemented in
France
4.1 General
This calculation is based on the alternative method of equivalent response time calculation, as used in
the French railway requirements, in particular, for trains operating in “G” position.
4.2 Symbols and abbreviations
For the purpose of Clause 4, the terms, symbols and abbreviations defined in Table 1 apply.
Table 1 — Symbols and abbreviations
Symbol or
Description Unit
abbreviation
Point when the brake force, deceleration or pressure has been substantially —
achieved, typically 95 %
a Equivalent deceleration (on level track, without considering gradient effect) m/s
e
g Standard acceleration of gravity m/s
[9]
“G” position Distributor valve and distributor isolating devices (as defined in EN 15355 ) —
i Gradient of the track (positive rising/negative falling) —
s Stopping/slowing distance on a gradient m
grad
s Stopping distances measured during the tests m
tests
t Delay time s
a
t Build-up time s
ab
t Equivalent response time s
e
2·t Equivalent response time multiplied by 2 s
e
v Initial speed m/s
v Final speed (= 0 in the case of a stopping distance) m/s
fin
X Time s
Y Factor of nominal braking force, deceleration or pressure —
4.3 Slowing or stopping distance calculation
4.3.1 French model for “G” position
This model provides a high level of accuracy for the calculation of stopping distances of trains with long
build up time (e.g. “G” position). It is currently used by the infrastructure managers in order to evaluate
the conformance of a train with the train control system and the length of the signalling secti
...