SIST EN 14531-1:2016

Railway applications - Methods for calculation of stopping and slowing distances and immobilisation braking - Part 1: General algorithms utilizing mean value calculation for train sets or single vehicles

This European Standard describes general algorithms which may be used for all types of train sets, units or single vehicles, including high speed, locomotive and passenger coaches, conventional vehicles and wagons.
This standard does not specify the performance requirements. It enables the estimation and,/or comparison by calculation of the various aspects of the performance: stopping or slowing distances, dissipated energy, power, force calculations and immobilization braking.
If it is required to validate, verify or assess braking performance it is recommended that a more detailed calculation is performed in accordance with prEN 14531-2, i. e. a step by step calculation.
This European Standard contains generic examples of the calculation of brake forces for individual brake equipment types and calculation of stopping distance and immobilisation braking relevant to a train (see Annex C and D).

Bahnanwendungen - Verfahren zur Berechnung der Anhalte- und Verzögerungsbremswege und der Feststellbremsung - Teil 1: Grundlagen

Diese Europäische Norm beschreibt allgemeine Berechnungsverfahren, die für alle Arten von Zugverbänden, Einheiten oder Einzelfahrzeugen, einschließlich Hochgeschwindigkeitsfahrzeugen, Lokomotiven, Reisezug-wagen, konventionellen Fahrzeugen und Güterwagen empfohlen werden.
Diese Norm legt keine Leistungsanforderungen fest. Sie ermöglicht die Ermittlung und/oder den Vergleich der verschiedenen Leistungsmerkmale mittels Berechnung: Anhalte- oder Verzögerungsbremswege, umgewandelte Energie, Berechnungen von Kräften und Feststellbremsungen.
Falls es erforderlich ist, die Bremsleistung zu bewerten, zu überprüfen oder zu beurteilen, wird empfohlen, dass eine genauere Berechnung in Übereinstimmung mit EN 14531-2, d. h. eine schrittweise Berechnung, durchgeführt wird.
Diese Europäische Norm enthält allgemeine Beispiele für die Berechnung von Bremskräften von individuellen Bremseinrichtungsarten und die für einen Zug relevante Berechnung von Anhalte- und Verzögerungs-bremswegen und der Feststellbremsung (siehe Anhang C und Anhang D).

Applications ferroviaires - Méthodes de calcul des distances d'arrêt, de ralentissement et d'immobilisation - Partie 1: Algorithmes généraux utilisant des valeurs moyennes pour des compositions de trains ou véhicules isolés

La présente Norme européenne décrit les algorithmes généraux qui peuvent être utilisés pour tous les types d'ensembles de trains, d'unités ou de véhicules isolés, ce qui inclut la grande vitesse, les locomotives et les voitures de passagers, les véhicules conventionnels et les wagons.
La présente Norme ne spécifie pas les exigences de performances. Elle permet l'estimation et/ou la comparaison par le calcul des différents aspects des performances : distances d'arrêt ou de ralentissement, énergie dissipée, puissance, calculs des efforts et freinage d'immobilisation.
Si elle est requise pour valider, vérifier ou évaluer les performances de freinage, il est recommandé d’effectuer un calcul plus détaillé, conformément au prEN 14531-2, c'est à dire un calcul pas à pas.
La présente Norme européenne contient des exemples génériques du calcul des efforts de freinage pour les types d'équipements de freinage individuels, du calcul de la distance d’arrêt et du freinage d’immobilisation propres à un train (voir les Annexes C et D).

Železniške naprave - Metode za izračun zavornih poti pri ustavljanju in upočasnjevanju ter zavarovanje stoječih vozil - 1. del: Splošni algoritmi, ki temeljijo na izračunu srednje vrednosti za vlakovne kompozicije ali posamezna vozila

Ta evropski standard opisuje splošne algoritme, ki se lahko uporabljajo za vse vrste vlakovnih kompozicij, enot ali posameznih vozil, vključno s hitrimi vlaki, lokomotivami in potniškimi vagoni, konvencionalnimi ter tovornimi vagoni.
Ta standard ne določa zahtev za delovanje. Omogoča oceno in/ali primerjavo na podlagi izračuna različnih vidikov delovanja: zavorne poti pri ustavljanju in upočasnjevanju, sproščena energija, moč, izračuni sil in zavarovanje stoječih vozil.
Če je zahtevano vrednotenje, preverjanje ali ocenjevanje zavorne zmogljivosti, je priporočeno izvesti podrobnejši izračun v skladu s standardom prEN 14531-2, tj. izračun po korakih.
Ta evropski standard vključuje splošne primere izračuna zavornih sil za posamezne vrste zavorne opreme ter izračun zavorne poti pri ustavljanju in zavarovanje stoječih vozil za ustrezen vlak (glej dodatka C in D).

General Information

• Status: Withdrawn
• Public Enquiry End Date: 29-Jun-2015
• Publication Date: 20-Jan-2016
• Withdrawal Date: 13-Dec-2018
• ICS: 45.060.01 - Railway rolling stock in general
• Technical Committee: IŽNP - Reilway applications
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 14-Dec-2018
• Due Date: 06-Jan-2019
• Completion Date: 14-Dec-2018
• 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)
• Mandate: M/334 - Mandate for programming and standardisation addressed to CEN, CENELEC and ETSI in the field of the Interoperability of the trans-european conventional rail system
• 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: EN 14531-1:2015 - 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

Relations

• Consolidated By: SIST EN 14531-1:2016+A1:2019 - 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
• Effective Date: 18-Jan-2023
• Consolidated By: SIST EN 14531-1:2016+A1:2019 - 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
• Effective Date: 19-Jan-2023
• Consolidated By: SIST EN 14531-1:2016+A1:2019 - 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
• Effective Date: 12-Sep-2018
• Replaces: SIST EN 14531-1:2005 - Railway applications - Methods for calculation of stopping distances, slowing distances and immobilization braking - Part 1: General algorithms
• Effective Date: 01-Mar-2016
• Amended By: SIST EN 14531-1:2016/oprA1:2017 - 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
• Effective Date: 08-Jun-2016
• Replaces: SIST EN 14531-1:2005 - Railway applications - Methods for calculation of stopping distances, slowing distances and immobilization braking - Part 1: General algorithms
• Effective Date: 08-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 14531-1:2016
01-marec-2016
1DGRPHãþD
SIST EN 14531-1:2005
äHOH]QLãNHQDSUDYH0HWRGH]DL]UDþXQ]DYRUQLKSRWLSULXVWDYOMDQMXLQ
XSRþDVQMHYDQMXWHU]DYDURYDQMHVWRMHþLKYR]LOGHO6SORãQLDOJRULWPLNL
WHPHOMLMRQDL]UDþXQXVUHGQMHYUHGQRVWL]DYODNRYQHNRPSR]LFLMHDOLSRVDPH]QD
YR]LOD
Railway applications - Methods for calculation of stopping and slowing distances and
immobilisation braking - Part 1: General algorithms utilizing mean value calculation for
train sets or single vehicles
Bahnanwendungen - Verfahren zur Berechnung der Anhalte- und
Verzögerungsbremswege und der Feststellbremsung - Teil 1: Grundlagen
Applications ferroviaires - Méthodes de calcul des distances d'arrêt, de ralentissement et
d'immobilisation - Partie 1: Algorithmes généraux utilisant des valeurs moyennes pour
des compositions de trains ou véhicules isolés
Ta slovenski standard je istoveten z: EN 14531-1:2015
ICS:
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
SIST EN 14531-1:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 14531-1:2016

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SIST EN 14531-1:2016


EN 14531-1
EUROPEAN STANDARD

NORME EUROPÉENNE

December 2015
EUROPÄISCHE NORM
ICS 45.060.01 Supersedes EN 14531-1:2005
English Version

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
Applications ferroviaires - Méthodes de calcul des Bahnanwendungen - Verfahren zur Berechnung der
distances d'arrêt, de ralentissement et Anhalte- und Verzögerungsbremswege und der
d'immobilisation - Partie 1 : Algorithmes généraux Feststellbremsung - Teil 1: Allgemeine Algorithmen für
utilisant le calcul par la valeur moyenne pour des Einzelfahrzeuge und Fahrzeugverbände unter
rames ou des véhicules isolés Berücksichtigung von Durchschnittswerten
This European Standard was approved by CEN on 27 June 2015.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14531-1:2015 E
worldwide for CEN national Members.

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
Contents Page

European foreword . 4
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Definitions, symbols and abbreviations . 6
3.1 Terms and definitions . 6
3.2 Symbols and indices . 8
4 Stopping and slowing distances calculation . 11
4.1 General . 11
4.2 Accuracy of input values . 11
4.3 General characteristics . 11
4.3.1 Train formation . 11
4.3.2 Characteristics of a train . 12
4.4 Brake equipment type characteristics . 14
4.4.1 General . 14
4.4.2 Tread braking . 15
4.4.3 Disc braking . 15
4.4.4 Forces of friction brake (tread brake) equipment . 16
4.4.5 Forces of friction brake (disc brake) equipment. 21
4.4.6 Mean dynamic coefficient of friction ( m ) tread and disc brakes . 25
m
4.4.7 Brake forces of other brake equipment types . 25
4.4.8 Time characteristics . 34
4.4.9 Blending concept . 37
4.4.10 Sharing, proportioning of the brake forces - achieved forces . 38
4.5 Initial and operating characteristics . 38
4.5.1 Gradient of the track . 38
4.5.2 Initial speed . 39
4.5.3 Coefficient of adhesion . 39
4.5.4 Level of the brake demand . 40
4.5.5 Quantity of each brake equipment type available . 40
4.5.6 Calculation in degraded conditions . 40
4.6 Total decelerating force at train level . 40
4.7 External forces . 41
4.7.1 Gradient . 41
4.7.2 Wind force on the train . 41
4.7.3 Train resistance . 41
4.8 Stopping and slowing distance calculation based on mean values . 42
4.8.1 General . 42
4.8.2 Mean braking force with respect to the distance . 42
4.8.3 Equivalent deceleration (a ) based on mean forces . 42
e
4.8.4 Mean decelerations supplied by each braking force ( a ) . 43
i
4.8.5 Equivalent free run distance (s ) . 43
0
4.8.6 Stopping and slowing distance on level track (s) . 44
4.8.7 Stopping and slowing distance on a gradient (s ) . 44
grad
2

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
4.8.8 Other specific formulae for the calculation of stopping distance . 45
4.9 Supplementary dynamic calculations . 45
4.9.1 General . 45
4.9.2 Mass to be braked (m ) . 46
B
4.9.3 Braking energy . 46
4.9.4 Maximum braking power of each brake equipment type . 48
4.9.5 Maximum specific power flux for each type of friction brake . 48
4.10 Specific expressions of braking performance . 49
4.10.1 General . 49
4.10.2 Braked weight percentage (λ) . 49
4.10.3 Braked weight . 49
4.10.4 Braking ratio . 49
4.10.5 Equivalent brake force . 49
5 Immobilization brake calculation . 49
5.1 General . 49
5.2 General characteristics . 49
5.3 Static coefficient of friction . 50
5.4 Train and operating characteristics . 50
5.5 Immobilization force provided by equipment type . 50
5.5.1 General . 50
5.5.2 Force of a screw hand brake (Tread brake) . 51
5.5.3 Force of a screw hand brake (Disc brake) . 51
5.5.4 Force of a tread brake unit . 51
5.5.5 Force of a disc brake unit arrangement . 52
5.5.6 Force of a permanent magnetic track brake . 52
5.6 Immobilization force for each axle. 53
5.7 Total immobilization force per train . 53
5.8 Immobilization safety factor . 54
5.9 Coefficient of adhesion required by each braked axle . 54
5.10 Maximum achievable gradient . 55
Annex A (informative) Workflow of stopping and slowing distance calculation method . 56
Annex B (informative) Workflow of immobilization calculations . 58
Annex C (informative) Brake equipment type example calculations . 59
Annex D (informative) Train stopping distance and immobilization brake calculation
example . 71
D.1 General . 71
D.2 Train stopping calculations . 72
D.3 Train stopping calculations on a gradient . 74
D.4 Train immobilization (parking) brake calculations . 74
Annex E (informative) Development of the formula for the mean brake force with respect to
the braking distance . 76
Annex F (informative) Slowing or stopping distance calculation using alternative method of
equivalent response time calculation as French Railway requirements in particular
for trains operating in 'G' position . 77
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2008/57/EC . 79
Bibliography . 82
3

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
European foreword
This document (EN 14531-1:2015) 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 June 2016, and conflicting national standards shall be
withdrawn at the latest by June 2016.
This document supersedes EN 14531-1:2005.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive 2008/57/EC.
For relationship with EU Directive 2008/57/EC, see informative Annex ZA, which is an integral part of
this document.
This series of European standards EN 14531, Railway applications — Methods for calculation of stopping
and slowing distances and immobilization braking consists of:
— Part 1: General algorithms utilizing mean value calculation for train sets or single vehicles;
— Part 2: Step-by-step calculations for train sets or single vehicles.
The two parts are interrelated and should be considered together when conducting the step-by-step
calculation of stopping and slowing distances.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
4

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
Introduction
This European Standard describes a common calculation method for railway applications. It describes
the general algorithms utilizing mean value calculation for use in the design and validation of brake
equipment and braking performance for all types of train sets and single vehicles. In addition the
algorithms provide a means of comparing the results of other braking performance calculation
methods.
EN 14531 was originally planned to have six parts covering the calculation methodology to be used
when conducting calculations relating to the braking performance of various types of railway vehicles
under the heading EN 14531, Railway applications – Methods for calculation of stopping, slowing
distances and immobilization braking. The six parts were as follows:
— Part 1: General algorithms
— Part 2: Application to single freight wagon
— Part 3: Application to mass transit (LRV's and D- and E- MU's)
— Part 4: Application to single passengers coach
— Part 5: Application to locomotive
— Part 6: Application to high speed trains
EN 14531-1 was originally published in 2005 followed by EN 14531-6 which was published in 2009.
Following the above it was decided that a common methodology could be used for Parts 2 to 5 and this
should be contained under a revised version of Part 1 with a title of Railway applications — Methods for
calculation of stopping and slowing distances and immobilisation braking — Part 1: General algorithms
utilizing mean value calculation for train sets or single vehicles while revising Part 6 to be Part 2 with the
title of 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 14531-1:2005 and EN 14531-6:2009 are referenced in the current technical specifications for
interoperability (TSIs) (Freight wagons and locomotive and passenger rolling stock (RST)). The tables
of the Annex ZA give the equivalence of the TSI referenced clauses of the original EN 14531 series to the
clauses of this issue of EN 14531-1 and EN 14531-2.
5

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
1 Scope
This European Standard describes general algorithms for the brake performance calculations to be used
for all types of train sets, units or single vehicles, including high speed, locomotive and passenger
coaches, conventional vehicles and wagons.
This European Standard does not specify the performance requirements. It enables the estimation
and/or comparison by calculation of the various aspects of the performance: stopping or slowing
distances, dissipated energy, power, force calculations and immobilization braking.
If it is required to validate, verify or assess braking performance it is recommended that a more detailed
calculation is performed in accordance with EN 14531-2, i.e. a step by step calculation.
This European Standard contains generic examples of the calculation of brake forces for individual
brake equipment types and calculation of stopping distance and immobilization braking relevant to a
train (see Annexes C and D).
2 Normative references
The following referenced documents, in whole or in part, are normatively referenced in this document
and are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 14067-4, Railway applications - Aerodynamics - Part 4: Requirements and test procedures for
aerodynamics on open track
EN 14478, Railway applications - Braking - Generic vocabulary
EN 14531-2, Railway applications – Methods for calculation of stopping and slowing distances and
immobilisation braking – Part 2: Step by step calculations for trains or single vehicles
prEN 15328, Railway applications - Braking - Brake pads
EN 16452, Railway applications – Braking – Brake blocks
EN 15663, Railway applications - Definition of vehicle reference masses
3 Terms, definitions, symbols and indices
3.1 Terms and definitions
For the purpose of this document, the terms and definitions given in EN 14478 and EN 14531-2 and the
following apply.
3.1.1
static mass per axle
mass measured by weighing at the wheel-rail interface, or estimated from design evaluation, of each
axle in a stationary condition for each operating condition required
3.1.2
static mass of the train
summation of all the static mass values per entity
Note 1 to entry: E.g. per axle, for each operating condition.
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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
3.1.3
equivalent rotating mass
linear conversion of the moment of inertia due to rotating parts coupled to the wheelsets during
braking into an equivalent additional static mass
Note 1 to entry: This includes brake discs, gear wheels etc.
3.1.4
brake equipment type
group of equipment that provide braking force
Note 1 to entry: When brake equipment is used on one part of the train under certain conditions and used on
another part of the same train under other conditions, two different brake equipment types shall be considered.
3.1.5
tread brake unit/disc brake unit
functional unit from which brake force is delivered, typically consisting of a brake cylinder, slack
adjuster portion and all associated component parts
Note 1 to entry: Sometimes referred to as tread/disc brake actuator.
3.1.6
isolated brake equipment
equipment not considered in the calculation due to assumed isolation
Note 1 to entry: E.g. brake equipment of a bogie.
3.1.7
active brake equipment
equipment considered to be operational in the calculation of a specific brake equipment type
3.1.8
mean value calculation
calculation method in which the values used for each active brake equipment type are a mean value
based on speed, force or distance as applicable for a particular speed range
3.1.9
decelerating force
force resulting from summation of all forces acting contrary to the direction of movement when
considering a train
Note 1 to entry: Each operational brake equipment type produces its own decelerating force which when added
to the additional external forces opposing motion results in the total decelerating force of the train.
Note 2 to entry: For the purpose of this standard a decelerating force is considered as a positive value, therefore
accelerating force is considered as a negative value.
3.1.10
braking force
force produced by the active brake equipment types to brake the train
Note 1 to entry: It does not include external forces which contribute to the overall decelerating force of the
vehicle or train.
7

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
3.1.11
external forces
forces typically including rolling resistance, gradient, head wind etc
3.1.12
entity
group or item considered in a calculation
Note 1 to entry: E.g. train, vehicle, bogie, axle, wheel.
3.2 Symbols and indices
For the purposes of this document, the general symbols given in Table 1 and indices given in Table 2
apply.
NOTE Specific symbols and indices are defined in the relevant clauses.
Table 1 — Symbols
Symbol Definition Unit
2
area

m
A

2
a deceleration

m / s
2
area of a friction surface swept by the friction elements
m
A
s
braked weight
T
B


m
wheel diameter
D

force N
F

braking force related to the rail
N
F
B

downhill force on the train N
F
g

2
2
standard acceleration of free fall = 9,80665 m/s (see: ISO 80000-3)
g m / s
n

gradient (rising gradient is positive; e.g. for a gradient of 5 ‰, i = 0,005) -
i

cylinder ratio -
i
c

rigging ratio -
i
rig

transmission ratio -
i
tra

2
inertia due to rotation of masses

J kg ⋅ m

m
mass kg

n
quantity -

power W
P

p pressure Pa

m
r radius


m
s distance

8

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
safety factor -
S

s
time
t

τ
coefficient of adhesion -

v speed
m / s
J
energy
W

energy per unit area J

W
S
2

m
braked weight percentage -
λ
m
coefficient of friction -
η
efficiency -
9

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
Table 2 — General indices
Indices Term
AMG attraction force for a magnetic track

ap application point
ax axle
a available
B braking force
BEC braking force for an eddy current brake
BED electro-dynamic braking force
BFR fluid retarder braking force
BMG braking force for a magnetic track brake
b block or pad
bog bogie
C cylinder
act unit/actuator
cha characteristic
Bd braking force demanded
disc disc
dyn dynamic
e equivalent
ent entity
ext external
fin final state
H hand brake
i brake equipment type
j range or step
im immobilization, parking, holding
ind independent of adhesion
nt internal
inst instantaneous
max maximum
min minimum
mot motor
MG magnetic track brake
n normal direction
R response
Ra train resistance to motion
req required
rig rigging
rot rotating
R1 return spring
R2 regulator
S spring
st static
T tangential direction
tot total
tra transmission
10

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SIST EN 14531-1:2016
EN 14531-1:2015 (E)
wind wind
0 initial state
1, 2, 3, 4 –- etc. intermediate state


4 Stopping and slowing distances calculation

4.1 General
The principle of the algorithm flow is presented in Annex A, Figure A.1.
In general the formulae contained in this clause are used in the first instance when considering constant
brake forces with respect to speed.
In the second instance the formulae may be used as a mean value calculation when considering a non
constant speed dependent brake force which is transformed to a mean brake force value. This mean
value of brake force is considered as a fully developed force without considering the response time and
results in the same braking distance as if calculated using the speed dependent brake force. See
Annex E.
The algorithms in this standard use mean values, however if it is necessary to use instantaneous values
and algorithms using finite time steps then EN 14531-2 shall be used.
4.2 Accuracy of input values
The accuracy of the calculation d
...