CEN/TR 14067-7:2021

SLOVENSKI STANDARD
01-julij-2021
Železniške naprave - Aerodinamika - 7. del: Osnove preskusnih postopkov za
zaščito pred letečim drobirjem, ki ga sproža vlak
Railway applications - Aerodynamics - Part 7: Fundamentals for test procedures for train-
induced ballast projection
Bahnanwendungen - Aerodynamik - Grundlagen für Prüfverfahren für zuginduzierten
Schotterflug
Applications ferroviaires - Aérodynamique - Principes généraux pour des procédures
d'essais vis-à-vis des projection de ballast causés par la circulation des trains
Ta slovenski standard je istoveten z: CEN/TR 14067-7:2021
ICS:
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TR 14067-7
TECHNICAL REPORT
RAPPORT TECHNIQUE
April 2021
TECHNISCHER BERICHT
ICS 45.060.01
English Version
Railway applications - Aerodynamics - Part 7:
Fundamentals for test procedures for train-induced ballast
projection
Applications ferroviaires - Aérodynamique - Principes Bahnanwendungen - Aerodynamik - Grundlagen für
généraux pour des procédures d'essais vis-à-vis des Prüfverfahren für zuginduzierten Schotterflug
projections de ballast générées par la circulation des
trains
This Technical Report was approved by CEN on 19 April 2021. It has been drawn up by the Technical Committee CEN/TC 256.

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, Turkey 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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 14067-7:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Symbols and abbreviations . 4
5 General aspects of ballast projection and state of the art . 4
5.1 Introduction . 4
5.2 Summary of studies and incidents (by countries, manufacturers) . 5
5.3 Overview of ballasted track systems in Europe . 9
5.4 Ice accumulation induced ballast projection . 15
6 Economic judgement of damage . 18
6.1 Cost of reported damage . 18
6.2 Cost of homologation, measures to rolling stock and infrastructure . 22
6.3 Cost benefit analysis . 26
7 Homologation concepts . 27
7.1 General. 27
7.2 Existing technical approaches . 27
7.3 Responsibilities, interests and intended interface definitions . 28
7.4 Conceptual approaches. 29
8 Comparison of existing methods . 32
8.1 France . 32
8.2 Spain . 36
8.3 Italy . 46
8.4 Belgium . 47
8.5 Other countries . 47
8.6 Comparison of existing methods . 48
8.7 Conclusion drawn from French and Spanish assessments . 48
9 Available background . 48
10 Conclusion and next steps . 49
Annex A (informative) Summary comparison of existing methods addressing ballast
projection . 51
Annex B (informative)  Review of ballast projection papers . 56
Bibliography .103

European foreword
This document (CEN/TR 14067-7:2021) has been prepared by Technical Committee CEN/TC 256
“Railway Applications”, the secretariat of which is held by DIN.

1 Scope
This document discusses:
— economic aspects of ballast projection;
— comparison of methods in France and Spain for rolling stock;
— infrastructure assessment methods;
— review of available literature;
— next steps and recommendations regarding standardization and research.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 14067-4:2013+A1:2018, Railway applications - Aerodynamics - Part 4: Requirements and test
procedures for aerodynamics on open track
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14067-4 apply.
ISO and IEC maintain terminological 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 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in EN 14067-4 apply.
5 General aspects of ballast projection and state of the art
5.1 Introduction
The phenomenon of ballast projection has been caused in the past by lumps of ice or accreted snow falling
from the train structure during extreme winter conditions, which then strike the ballast bed causing
ballast to be ejected upwards, impacting the train underside or passing trains and leading to damage.
Typically, this damage includes breakage of train underbody equipment, failures of train systems or
reduced efficiencies, breakages of station or train windows, and impact damage to train or trackside
structures. This type of ballast projection occurs to regional trains as well as to high speed trains and has
been well-known for a long period in railways world-wide.
However, in the early 2000s there were a number of significant incidents of ballast projection involving
high speed trains which were not caused by ice fall, but seemed to arise from aerodynamic causes.
Substantial damage was caused to the underside of an ICE 3 train in one particular incident in Belgium in
2003. This phenomenon seems to be solely a high speed train phenomenon. The relevant contributory
factors involve:
— the aerodynamic design of the train, particularly the train underbody;
— the air speeds generated under the train, due to the Couette-type flow created by the high speed
train passing over the static track bed;
— train-induced pressures acting on the ballast;
— track vibrations caused by the traction engines and wheel passing over the rails.
The types of damage from this sort of incident principally includes: ballast stone impacts to the
underbody structure and damage to the underbody equipment, pipes and cables of high speed trains, and
damage to wheels and rails when ballast stones are trapped between them. Although possible, there
seems to be little evidence of collateral damage to other trains or of injury to trackside workers.
It should be noted that although the aerodynamically-induced ballast projection incidents have resulted
in some spectacular damage to trains, there is evidence of minor impact damage to train underbodies at
lower train speeds that appears to be deemed tolerable by train maintainers. Furthermore, since the first
upsurge in these incidents, there has been a complete cessation with no further incidents since 2004. This
reduction in incidents coincides with measures introduced by many European Infrastructure Managers
to reduce ballast levels relative to the top of sleepers.
Nevertheless, there is a widespread concern that this is still a valid train/infrastructure issue needing
certain controls, which is supported by its inclusion in the LOC&PAS and INF TSIs as an issue, (albeit
currently as an open point). Consequently, various national rules regarding the issue have been
developed, mainly focused on rolling stock, leading to a burden on train manufacturers trying to
introduce trains into different countries, as they are required to apply different methods to confirm their
trains’ performance with regard to ballast projection.
Within the revision published in June 2019, ballast projection is addressed in TSI LOC PAS and TSI INF as
an interface issue relevant for operation with train speeds >250 km/h. The issue is connected to the
essential requirements of safety and technical compatibility.
5.2 Summary of studies and incidents (by countries, manufacturers)
5.2.1 General
Table 1, reproduced from Claus [1], summarizes some of the major incidents up to 2006 of both types of
ballast projection in this century (those due to winter weather are not exhaustive).
Table 1— Reported past ballast projection incidents
Date Train Location Speed Track Weather Remarks
Type Type Conditions
2001 ICE 3 Fulda- 230 km/h Mono-block Winter
Göttingen, sleepers, conditions,
Germany lowered snow
ballast
2003 KTX South Korea 300 km/h Mono-block No snow See [Kw03] for
sleepers details
2003 ICE 3 Lille-Calais, 320 km/h Bi-block Winter
France sleepers conditions,
snow
2003 ICE 3 Belgium 300 km/h Mono-block No snow Speeds up to
sleepers, 275 km/h did
ballast not not cause
lowered problems in
double
traction
2004 ICE 3 France 320 km/h Bi-block No snow During
sleepers homologation
test runs
2004 ICE 3 Mannheim- 250 km/h Mono-block Winter Foreign parts
Stuttgart, sleepers, conditions, in the track
Germany lowered snow have been
ballast found
2004 ETR 500 Rome- 300 km/h Mono-block No snow New track
Naples, Italy sleepers, with ballast
ballast not above the
lowered sleepers, see
Fig 1
2006 ICE-T Hamburg- 230 km/h Mono-block Winter
Berlin, sleepers, conditions,
Germany lowered snow
ballast
The following sections give additional details of incidents and the current status of ballast projection
measures in different European countries.
5.2.2 Italy
During initial runs of the ETR 500 on the then newly constructed Rome-Naples high speed line in 2004 a
ballast projection incident occurred. The sleepers were of the mono-block type, as shown in the
photograph in Figure 1 taken at the time of the incident. It can be seen that the ballast was not specially
lowered between the sleepers, and significant amounts lay on top of the sleepers themselves.
On the first high speed line, the 25 kV Turin-Milan route, problems arose for 300 km/h running of the
ETR 500. Three levels of ballast height reductions were investigated with ballast impacts being
monitored using microphones. The b
...