Railway applications - Track - Track geometry quality - Part 5: Geometric quality levels - Plain line, switches and crossings

This European Standard defines the minimum requirements for the quality levels of track geometry, and specifies the safety related limits for each parameter as defined in EN 13848-1 and measured by any track geometry measurement system as defined in EN 13848-2, EN 13848-3 and EN 13848-4.
This standard covers the following topics:
-   immediate action limits;
-   recommendations on tolerance levels for isolated defects;
-   relative importance of parameters with respect to the vehicle behaviours;
The necessity to measure, the frequency of measurements and the selection of measured parameters are not covered by this standard.
This European Standard applies to high-speed and conventional lines, including switches and crossings, of 1 435 mm and wider gauge railways provided that the vehicles operated on those lines comply with EN 14363 and other vehicle safety standards.

Bahnanwendungen - Oberbau - Qualität der Gleisgeometrie - Teil 5: Geometrische Qualitätsstufen - Gleise, Weichen und Kreuzungen

Diese Europäische Norm legt die Mindestanforderungen für die Qualitätsstufen der Gleisgeometrie fest und definiert die Sicherheitsgrenzen für jeden Parameter nach EN 13848-1, der von jedem Messsystem für die Gleisgeometrie nach EN 13848-2, EN 13848-3 und EN 13848-4 gemessen wurde.
Diese Norm behandelt die folgenden Themen:
   Sicherheitsgrenzen;
   Empfehlungen von Toleranzwerten für Einzelfehler;
   verhältnismäßige Bedeutung der Parameter im Hinblick auf das Fahrzeugverhalten.
Die Notwendigkeit der Durchführung von Messungen, die Häufigkeit der Messungen und die Auswahl der gemessenen Parameter werden in dieser Norm nicht behandelt.
Diese Europäische Norm gilt für Hochgeschwindigkeits- und konventionelle Strecken einschließlich Weichen und Kreuzungen mit 1 435 mm und größeren Spurweiten, vorausgesetzt, dass die Fahrzeuge, die auf diesen Strecken in Betrieb sind, den Anforderungen nach EN 14363 und anderen Fahrzeugsicherheitsnormen entsprechen.

Applications ferroviaires - Voie - Qualité géométrique de la voie - Partie 5 : Niveaux de qualité géométrique de la voie - Voie courante et appareils de voie

La présente Norme définit les exigences minimales pour les niveaux de qualité géométrique de la voie et spécifie les limites en relation avec la sécurité pour chaque paramètre défini dans l'EN 13848-1 et mesuré à l’aide d’un système de mesure de géométrie de voie défini dans les EN 13848-2, EN 13848-3 et EN 13848-4.
La présente Norme couvre les sujets suivants :
   les limites d’action immédiate ;
   les recommandations relatives aux niveaux de tolérance pour les défauts isolés ;
   l’importance relative des paramètres par rapport au comportement des véhicules ;
La présente norme ne couvre pas la nécessité de mesure, la fréquence des mesures et le choix des paramètres de mesure.
La présente Norme européenne s'applique à la voie courante des lignes conventionnelles et à grande vitesse y compris les appareils de voie, ayant un écartement de voie de 1 435 mm et plus large permettant aux véhicules de circuler sur ces lignes en conformité avec l’EN 14363 et d’autres normes de sécurité de véhicule.

Železniške naprave - Zgornji ustroj - Kakovost tirne geometrije - 5. del: Ravni kakovosti tirne geometrije - Preproste linije, kretnice in križišča

Ta evropski standard opredeljuje minimalne zahteve za ravni kakovosti tirne geometrije in določa varnostne omejitve za vsak parameter, kot je opredeljen v standardu EN 13848-1 in izmerjen s katerim koli sistemom za merjenje tirne geometrije skladno s standardi EN 13848-2, EN 13848-3 in EN 13848-4.
Ta standard obravnava naslednje teme:
– omejitve takojšnjih ukrepov;
– priporočila glede ravni tolerance za posamezne defekte;
– relativni pomen parametrov glede na vedenje vozila;
Ta standard ne zajema potreb za merjenje, pogostosti meritev in izbire merjenih parametrov.
Ta standard se uporablja za visokohitrostne in običajne proge, vključno s kretnicami in križišči, s širino 1435 mm ali več, če so vozila, ki obratujejo na njih, skladna s standardom EN 14363 in drugimi standardi o varnosti vozil.

General Information

Status
Published
Public Enquiry End Date
09-Apr-2015
Publication Date
10-Sep-2017
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
05-Sep-2017
Due Date
10-Nov-2017
Completion Date
11-Sep-2017

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.þDBahnanwendungen - Oberbau - Qualität der Gleisgeometrie - Teil 5: Geometrische Qualitätsstufen - Gleise, Weichen und KreuzungenApplications ferroviaires - Voie - Qualité géométrique de la voie - Partie 5 : Niveaux de qualité géométrique de la voie - Voie courante et appareils de voieRailway applications - Track - Track geometry quality - Part 5: Geometric quality levels - Plain line, switches and crossings93.100Gradnja železnicConstruction of railways45.080Rails and railway componentsICS:Ta slovenski standard je istoveten z:EN 13848-5:2017SIST EN 13848-5:2017en,fr,de01-oktober-2017SIST EN 13848-5:2017SLOVENSKI

STANDARDSIST EN 13848-5:2008+A1:20111DGRPHãþD
SIST EN 13848-5:2017
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 13848-5
August
t r s y ICS
{ uä s r r Supersedes EN
s u z v zæ wã t r r z ªA sã t r s rEnglish Version
Railway applications æ Track æ Track geometry quality æ Part

wã Geometric quality levels æ Plain lineá switches and crossings Applications ferroviaires æ Voie æ Qualité géométrique de la voie æ Partie

w ã Niveaux de la qualité géométrique de la voie æ Voie courante et appareils de voie

Bahnanwendungen æ Oberbau æ Qualität der Gleisgeometrie æ Teil

wã Geometrische Qualitätsstufen æGleiseá Weichen und Kreuzungen This European Standard was approved by CEN on

s u July
t r s yä

egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä

translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä

CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä

EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels

t r s y CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN

s u z v zæ wã t r s y ESIST EN 13848-5:2017

EN 13848-5:2017 (E) 2 Contents Page European foreword ....................................................................................................................................................... 3 1 Scope .................................................................................................................................................................... 4 2 Normative references .................................................................................................................................... 4 3 Terms and definitions ................................................................................................................................... 4 4 Symbols and abbreviations ......................................................................................................................... 5 5 General Considerations................................................................................................................................. 5 6 Assessment of track geometry quality .................................................................................................... 6 7 Immediate action limits ................................................................................................................................ 7 7.1 Introductory remarks .................................................................................................................................... 7 7.2 Track gauge ....................................................................................................................................................... 8 7.3 Longitudinal level ........................................................................................................................................... 9 7.4 Cross level ....................................................................................................................................................... 10 7.5 Alignment ........................................................................................................................................................ 10 7.6 Twist ................................................................................................................................................................. 11 8 Alert and intervention limit ..................................................................................................................... 12 8.1 Introduction ................................................................................................................................................... 12 8.2 Mean track gauge over 100 m .................................................................................................................. 12 Annex A (informative)

Relative importance of the various parameters ............................................... 14 A.1 Track-vehicle system .................................................................................................................................. 14 A.2 Influence of track geometry parameters on vehicle behaviour and safety ............................ 15 A.3 Other criteria ................................................................................................................................................. 15 Annex B (informative)

Alert and intervention limits ................................................................................... 17 B.1 Introduction ................................................................................................................................................... 17 B.2 Alert limit and intervention limit ........................................................................................................... 17 B.2.1 Track gauge .................................................................................................................................................... 17 B.2.2 Longitudinal level ........................................................................................................................................ 18 B.2.3 Cross level ....................................................................................................................................................... 18 B.2.4 Alignment ........................................................................................................................................................ 19 B.2.5 Twist ................................................................................................................................................................. 19 Annex C (normative)

Twist limits for nominal track gauge of 1668 mm .............................................. 21 Annex D (informative)

A-Deviations .................................................................................................................. 22 Annex ZA (informative)

Relationship between this European Standard and the essential requirements of EU Directive 2008/57/EC ........................................................................................ 23 Bibliography ................................................................................................................................................................. 25 SIST EN 13848-5:2017

EN 13848-5:2017 (E) 3 European foreword This document (EN 13848-5:2017) 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 February 2018, and conflicting national standards shall be withdrawn at the latest by February 2018. 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 13848-5:2008+A1:2010. 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 European Standard is one of the series EN 13848 Railway applications – Track – Track geometry quality as listed below: — Part 1: Characterization of track geometry — Part 2: Measuring systems – Track recording vehicles — Part 3: Measuring systems – Track construction and maintenance machines — Part 4: Measuring systems – Manual and light weight devices — Part 5: Geometric quality levels – Plain line, switches and crossings — Part 6: Characterization of track geometry quality 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 13848-5:2017

EN 13848-5:2017 (E) 4 1 Scope This European Standard defines the minimum requirements for the quality levels of track geometry, and specifies the safety related limits for each parameter as defined in EN 13848-1 and measured by any track geometry measurement system as defined in EN 13848-2, EN 13848-3 and EN 13848-4. This European Standard covers the following topics: — immediate action limits (IAL); — recommendations on tolerance levels for isolated defects; — relative importance of parameters with respect to the vehicle behaviours. The necessity to measure, the frequency of measurements and the selection of measured parameters are not covered by this European Standard. This European Standard applies to high-speed and conventional lines, including switches and crossings, of 1 435 mm and wider gauge railways provided that the vehicles operated on those lines comply with EN 14363 and other vehicle safety standards. This European Standard does not apply to Urban Rail Systems. 2 Normative references The following 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 13848-1:2003+A1:2008, Railway applications - Track - Track geometry quality - Part 1: Characterisation of track geometry EN 14363:2016, Railway applications - Testing and Simulation for the acceptance of running characteristics of railway vehicles - Running Behaviour and stationary tests EN 13803:2017, Railway applications - Track - Track alignment design parameters - Track gauges 1 435 mm and wider 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 nominal track gauge reference value for track gauge used by individual networks 3.2 design track gauge design value of track gauge for a given track section, which might be different from the nominal track gauge 3.3 mean track gauge sliding arithmetic mean track gauge over a specified distance Note 1 to entry: In this European Standard a length of 100 m is applied. SIST EN 13848-5:2017

EN 13848-5:2017 (E) 5 3.4 QN3 level quality limit for discrete track defects in accordance with EN 14363 3.5 isolated defect part of the signal exceeding a given limit such as IAL, IL or AL with at least one sample for a sampling distance of 0,25 m Note 1 to entry: The length of the exceedance is given by the number of samples exceeding the limit. 4 Symbols and abbreviations For the purposes of this document, the symbols and abbreviations listed in Table 1 apply. Table 1 — Symbols and abbreviations Symbol or abbreviation Designation Unit AL Alert limit mm or mm/m IL Intervention limit mm or mm/m IAL Immediate action limit mm or mm/m D1 Wavelength range D1: 3 m <

¶ 25 m m D2 Wavelength range D2: 25 m <
¶ 70 m m D3 Wavelength range D3: 70 m <
¶ 150 m for longitudinal level Wavelength range D3: 70 m <
¶ 200 m for alignment m
Twist base-length m
Wavelength m N/A Not applicable

R Curve radius m D Cross level mm V Speed km/h 5 General Considerations The importance of assessing the track geometric quality arose in the middle of the 20th century. Therefore, European Infrastructure Managers developed their own track recording vehicles allowing a continuous measurement of track geometry and based on this experience, their own track geometry quality evaluation standards evolved. These independent developments resulted in different measuring and evaluation methods which are no longer adequate in the light of the requirements of European railway interoperability. This is because it is difficult to compare the track geometry conditions of various European infrastructures. Yet, at least for safety reasons, it is necessary to make such comparisons. The main purpose of the standard is to define minimum requirements for track geometry based on isolated defects to ensure safe operation of trains. It is based on both the experience of various European Infrastructure Managers and current track conditions. SIST EN 13848-5:2017

EN 13848-5:2017 (E) 6 This European Standard sets out quality levels, in particular immediate action limits (IAL), with the aim of harmonizing European track geometry quality standards. It can be significant in: — setting minimum requirements for the level of track geometry quality in order to manage safe operation; — optimization of track geometry maintenance works; — optimization of vehicle ride quality and dynamic loading of the track; — harmonizing vehicle acceptance procedures. Requirements given in this European Standard should be taken into account: — by Infrastructure Managers; — by track maintenance managers; — by vehicle manufacturers; — by track contractors; — by regulatory authorities; — for research purposes. The values stated in this European Standard are based on the values prescribed by various European networks. Furthermore, this standard takes into account, as far as possible, the studies made on this topic: — survey on isolated defects; — ORE Question B55 report No 8 [6]; — Technical Report CEN/TR 16978 [7]. 6 Assessment of track geometry quality All the parameters as defined in EN 13848-1 are encompassed in this European Standard; their respective importance and their influence on vehicle behaviour are described in Annex A. Three indicators can describe the track geometric quality: — extreme values of isolated defects; — standard deviation over a defined length, typically 200 m; — mean value. Consideration should be given to successions of isolated defects because they could generate resonance effects, and to combinations of defects in several parameters at the same location (see Annex A). Three main levels shall be considered: SIST EN 13848-5:2017

EN 13848-5:2017 (E) 7 — Immediate Action Limit (IAL): refers to the value which, if exceeded, requires taking measures to reduce the risk of derailment to an acceptable level. This can be done either by closing the line, reducing speed or by correction of track geometry; — Intervention Limit (IL): refers to the value which, if exceeded, requires corrective maintenance in order that the immediate action limit shall not be reached before the next inspection; — Alert Limit (AL): refers to the value which, if exceeded, requires that the track geometry condition is analysed and considered in the regularly planned maintenance operations. These values are given as a function of speed, which is an important factor for the evaluation of track geometry quality. EN 13848-2, EN 13848-3 and EN 13848-4 give measuring methods for track geometry whereby track geometry quality can be assessed. The values in the tables are given for a loaded track as defined in EN 13848-1. When the measurements are made on unloaded track, the difference in the measured values that may result need to be taken into account. The normative part of the standard gives IALs for isolated defects and minimum mean track gauge and ILs for maximum mean track gauge. The informative part of this European Standard gives ILs and ALs for isolated defects and mean track gauge, and ALs for standard deviations. The track geometry limits AL, IL and IAL may differ from the levels defined for other purposes as for example vehicle acceptance. More particularly QN3 is quite different from IAL because, in accordance with EN 14363, it characterizes track sections which do not exhibit the usual track geometry quality. Quality level QN3 does not represent the most adverse condition; rather, it represents a still tolerable maintenance status which allows regular train operations. Further quality levels of track geometry may be used for track works acceptance (see EN 13231-1). NOTE The intervention limit depends on the corrective maintenance policy, the frequency of inspection and defect growth rate. 7 Immediate action limits 7.1 Introductory remarks The immediate action limit values given in this standard are derived from experience, from actual track condition and from theoretical considerations of the wheel-rail interaction as physical tests with different vehicles up to the point of derailment are not practicable. A survey made among European networks showed that the values set in the tables are consistent with the current conditions. Considering the lack of experience at speeds higher than 300 km/h, IALs for these speeds are set on the basis of extrapolation from values at lower speeds. Exceeding these immediate action limit values requires specific measures to be implemented to reduce the risk of derailment or other hazards to an acceptable level. It is permitted to consider only those exceedances with a minimum length of 1 m as an isolated defect. By applying this option the limit value is relaxed implicitly; therefore the limit of IAL shall be lowered accordingly. Typically for longitudinal level D1 reductions between 5 % and 10 % can be expected. The wavelength range D3 is not taken into account in the following, as it is not directly linked with safety, but more with vehicle ride quality. With the exception of track gauge, all limit values stated below shall be applied to the mathematical absolute value of the measured track geometry parameters. SIST EN 13848-5:2017

EN 13848-5:2017 (E) 8 7.2 Track gauge The values provided in the Tables 2 and 3 apply to nominal track gauges 1 435 mm and wider. In the latter case the limit values can be modified in accordance with the tolerances of the distance between the flange contact faces of the wheelset. The minimum and maximum values in Table 2 and Table 3 refer to the nominal track gauge and are independent from the design track gauge. This standard gives no IAL maximum values for mean track gauge because the risk associated with a wide mean track gauge is covered by the IAL values of isolated defects of track gauge. Minimum IAL values for mean track gauge are set in order to control one important parameter influencing equivalent conicity. Nevertheless normative intervention limit values are given for maximum mean track gauge in 8.2. Table 2 — Track gauge – IAL – Isolated defects – Nominal track gauge to peak value Speed (in km/h) Nominal track gauge to peak value [mm] IAL Minimum Maximum V

¶ 80
«11 +35 80 < V
¶ 120
«11 +35 120 < V
¶ 160
«10 +35 160 < V
¶ 230
«7 +28 230 < V
¶ 300
«5 +28 300 < V
¶ 360

«5 +28 NOTE 1 Except for speeds higher than 300 km/h, the immediate action limits are normative. NOTE 2 These limit values are superseded by the values defined in INF TSI where applicable. The values in Table 2 may be stricter in switches and crossings in order to respect specific safety parameters. SIST EN 13848-5:2017

EN 13848-5:2017 (E) 9 Table 3 — Track gauge – IAL – Nominal track gauge to mean track gauge over 100 m Speed (in km/h) Nominal track gauge to mean track gauge over 100 m [mm] Minimum V

¶ 40 N/A 40 < V
¶ 80
«8 80 < V
¶ 120
«7 120 < V
¶ 160
«5 160 < V
¶ 230
«5 230 < V
¶ 300
«3 300 < V
¶ 360

«2 NOTE Except for speeds higher than 300 km/h, the immediate action limits are normative. The slow deterioration of mean track gauge gives time to plan maintenance when the intervention limit (IL) is reached, and therefore IAL values should normally not be reached. The minimum values in Table 3 may be relaxed by 1 mm when the nominal rail inclination is 1:20. 7.3 Longitudinal level The IAL values for longitudinal level isolated defects are given in Table 4. Table 4 — Longitudinal level – IAL – Isolated defects – Zero to peak value

Zero to peak value [mm] Speed (in km/h) Wavelength range D1 D2 V
¶ 80 28 N/A 80 < V
¶ 120 26 N/A 120 < V
¶ 160 23 N/A 160 < V
¶ 230 20 24 230 < V
¶ 300 16 18 300 < V

¶ 360 14 16 NOTE Except for speeds higher than 300 km/h, the immediate action limits are normative. In Table 4, for speeds less than or equal to 40 km/h, the limit can be relaxed to 31 mm. Special attention should be paid to short wavelength defects which, although unlikely, can become dangerous when their amplitude is high. SIST EN 13848-5:2017

EN 13848-5:2017 (E) 10 7.4 Cross level This standard gives no IAL values for cross level because the risk associated with a cross level defect is tied to twist and cant deficiency. IAL values for twist are given in 7.6. Cant deficiency limits depend on track alignment design, construction rules, vehicle design and the kind of operation on each line. Attention should be paid to variations of cross level with wavelength of approximately 20 m which can cause higher risk of derailment for freight wagons due to wheel unloading related to dynamic behaviour. Each Infrastructure Manager may specify limits for his own network taking into account the above characteristics. 7.5 Alignment The IAL values for alignment isolated defects are given in Table 5. Table 5 — Alignment – IAL – Isolated defects – Zero to peak value

Zero to peak value [mm] Speed (in km/h) Wavelength range D1 D2 V
¶ 80 22 N/A 80 < V
¶ 120 17 N/A 120 < V
¶ 160 14 N/A 160 < V
¶ 230 12 18 230 < V
¶ 300 10 14 300 < V

¶ 360 8 12 NOTE Except for speeds higher than 300 km/h, the immediate action limits are normative. In Table 5, for speeds less than or equal to 40 km/h, the limit can be relaxed to 25 mm. Some types of track construction may have a greater risk of buckling when subject to high amplitude alignment defects. For specific considerations e.g. ride comfort, bridges, crossings, D2 domain may be applied to speeds up to or equal to 160 km/h The limit values for D1 may be increased in switches and crossings at the point of designed instantaneous change in curvature for a turnout route when the radius is less than 500 m. Special attention should be paid to short wavelength defects which, although unlikely, can become dangerous when their amplitude is high. SIST EN 13848-5:2017

EN 13848-5:2017 (E) 11 7.6 Twist The track twist limit is a function of the measurement base-length () applied in accordance with one of the equations (see Figure 1): 1) Twist limit = ((20/) + 3)

for
¶ (R
(curve A) with a maximum value of: 7 mm/m for lines designed for speed V

¶ 200 km/h; 5 mm/m for lines designed for speed V > 200 km/h; 2) Twist limit = ((20/) + 1,5)

for

< D < (R /1,5 (curve B) with a maximum value of 6 mm/m and a minimum value of 3 mm/m. For both equations:

is the twist base-length, with 1,3 m
¶ 20 m D is the cross level (in mm) R is the curve radius (in m)
Key

twist base-length (in m) – cf. Table 1 A curve A B curve B C IAL value for twist (in mm/m) Figure 1 — Twist – IAL – Isolated defects – Zero to peak value SIST EN 13848-5:2017

EN 13848-5:2017 (E) 12 Twist values in accordance with Figure 1 shall only be applicable if the twist extends for at least 1 m. The minimum base-length considered herein is 1,3 m and the maximum is 20 m in accordance with ORE B55 RP8. For nominal track gauge wider than 1435 mm, Infrastructure Managers should define the limit values for their own network, for example based on rules for converting parameter values for track gauges wider than 1435 mm in accordance with EN 13803. For nominal track gauge of 1668 mm, the limit values for acceptable twist are given in Annex C. Exceeding the above limits of cross level D can be allowed provided that other measures are taken to ensure safety, e.g. installation of check rails or rail-lubrication systems. NOTE For long twist base-lengths, certain tight curves having a high design twist require special care in maintenance because of the small difference between the IAL values and the design twist values. 8 Alert and intervention limit 8.1 Introduction Unlike immediate action limits, which take into account the track/vehicle interaction, as well as the risk of unexpected events (see Annex A), the other quality levels are mainly linked with maintenance policy. Maintenance policy may be directed either at upholding safety alone or at achieving good ride quality, lower life cycle cost or more attractive (higher speed) services in addition to safety. The alert limits and intervention limits set by the European Infrastructure Managers will be set at least to ensure safety and can be tightened to achieve a given level of ride quality. The frequency of inspections should be chosen to take account of the intervention and alert levels set down in each European Infrastructure Manager standard and to ensure the geometric quality of the track. For these reasons, the values given in Annex B should be considered as purely indicative, reflecting the common practice of most European Infrastructure Managers. 8.2 Mean track gauge over 100 m The limit values provided in Table 6 are normative and apply to the nominal track gauges 1 435 mm and wider. They represent the differences to the nominal track gauge and are independent from the design track gauge. Table 6 — Track gauge – IL – Nominal track gauge to mean track gauge over 100 m Speed (in km/h) Nominal track gauge to mean track gauge over 100 m [mm] Maximum V

¶ 40 N/A 40 < V
¶ 80 N/A 80 < V
¶ 120 +20 120 < V
¶ 160 +20 160 < V
¶ 230 +20 230 < V
¶ 300 +20 300 < V
¶ 360 +20 SIST EN 13848-5:2017

EN 13848-5:2017 (E) 13 When values in Table 6 are reached, special attention should be paid to riding stability of freight wagons in small radius curves. SIST EN 13848-5:2017

EN 13848-5:2017 (E) 14 Annex A (informative)

Relative importance of the various parameters A.1 Track-vehicle system The railway track has three functions: carrying the train, guiding it and absorbing the traction and braking forces. These functions lead to vertical, lateral and longitudinal forces between train and track. The track-vehicle interaction cannot be defined precisely as a deterministic process, because it depends on a great number of external and internal factors of the system. Some external factors have not been taken into account in the determination of immediate action limits, such as wind or resonance effects due to the substructure. Considering only track-vehicle interaction, three types of criteria have to be taken into account: — Safety parameters 1) Sum of the guiding forces (Y) This parameter characterizes the risk of track shift under load due to high forces on the track. The lateral resistance of a track is mainly related to the friction of sleepers on the ballast. Then, it depends on the vertical force applied on the track. It is expressed with a very simple law, the so called Prud’Homme formula or limit, which is given by: k1 (10 + P0/3) where: P0 is the static axle load (in kN); k1 being equal to 1 for locomotives, traction units and passenger coaches and 0,85 for freight wagons. 2) Lateral (Y) and vertical (Q) forces combination The ratio Y/Q generated by a wheel characterizes the risk of derailment, corresponding to climbing of the wheel flange onto the rail. Y/Q ratio has to be lower than a critical value depending on the wheel flange angle, the contact condition, the speed and other factors. — Comfort parameters Comfort is evaluated by measuring vertical and lateral accelerations in the vehicle body (respectively *zand *y). — Parameters influencing component life SIST EN 13848-5:2017

EN 13848-5:2017 (E) 15 The life of track components and vehicle components is mainly linked to vertical and lateral forces, more particularly in small radius curves (R

¶ 600 m), where quasi-static lateral and vertical forces have to be considered. A.2 Influence of track geometry parameters on vehicle behaviour and safety To define track geometry quality, it is necessary to choose and to combine significant geometrical parameters of the track and determine thresholds for safety taking into account the above mentioned track/vehicle interactions aspects. Experience and theoretical considerations have shown that practically all track geometry parameters have an influence on the vehicle behaviour. Particular combinations of track geometry parameters could have a strong influence on t

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