oSIST prEN 17936:2023
(Main)Railway applications - Acoustics - Measurement of source terms for environmental noise calculations
Railway applications - Acoustics - Measurement of source terms for environmental noise calculations
The standard addresses the measurement of source terms for environmental noise calculation for rail traffic (including light rail). It is applicable to the measurement of in-service trains on operational tracks.
It is not applicable to type acceptance testing of rolling-stock or tracks.
The following rail traffic noise sources are in the scope:
- Rolling noise ;
- Traction noise ;
- Aerodynamic noise ;
- Impact noise (e.g. rail joints, switch & crossings, wheel flats) ;
- Bridge noise ;
- Squeal noise.
Noise from rail vehicles at standstill is included e.g.: engine idling and auxiliary equipment.
Noise from fixed installations (e.g.: stations, depots, electricity sub-stations) are not in the scope of this standard. Each source shall individually be characterized in terms of its frequency spectrum (up to one-third octave band details), source height and directivity. Rolling noise will then be described in terms of its generating wheel and rail roughness along with the vehicle and track transfer functions. Source terms will be specific to a vehicle and track type. The scope includes measurement procedures and conditions and sampling requirements.
Bahnanwendungen - Akustik - Messung der Quellterme für Umgebungslärmberechnungen
Applications ferroviaires - Acoustique - Mesurage des termes sources pour le calcul du bruit en environnement
Železniške naprave - Akustika - Merjenje osnovnih pogojev za izračun okoljskega hrupa
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 17936:2023
01-februar-2023
Železniške naprave - Akustika - Merjenje osnovnih pogojev za izračun okoljskega
hrupa
Railway applications - Acoustics - Measurement of source terms for environmental noise
calculations
Bahnanwendungen - Akustik - Messung der Quellterme für
Umgebungslärmberechnungen
Applications ferroviaires - Acoustique - Mesurage des termes sources pour le calcul du
bruit en environnement
Ta slovenski standard je istoveten z: prEN 17936
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.100 Gradnja železnic Construction of railways
oSIST prEN 17936:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 17936:2023
DRAFT
EUROPEAN STANDARD
prEN 17936
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2022
ICS
English Version
Railway applications - Acoustics - Measurement of source
terms for environmental noise calculations
Applications ferroviaires -¿ Acoustique -¿ Mesurage des Bahnanwendungen - Akustik - Messung der
termes sources pour le calcul du bruit en Eingangsparameter für Umgebungslärmberechnungen
environnement
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 256.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17936:2022 E
worldwide for CEN national Members.
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Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Acoustic basics for this standard . 10
4.1 Accuracy / uncertainties . 10
4.2 Frequency range and spectral bands . 10
4.3 Type of measurements . 10
5 Instrumentation and calibration . 10
5.1 General. 10
5.2 Acoustic instrumentation . 11
5.3 Calibration of the acoustic instrumentation . 11
5.3.1 Temporary setup . 11
5.3.2 Automated calibration . 11
5.4 Non-acoustic instrumentation . 12
5.4.1 Time and duration . 12
5.4.2 Speed, track and direction . 12
5.4.3 Meteorological parameters . 12
5.4.4 Wheel and track parameters . 12
5.4.5 Combined roughness . 12
6 How to derive source terms . 12
6.1 General. 12
6.2 Procedure . 13
6.3 Directivity . 14
6.4 Distribution over source heights . 14
7 Measurement procedures . 14
7.1 General. 14
7.2 Rolling noise . 15
7.2.1 General. 15
7.2.2 Measurement steps . 16
7.2.3 Network and fleet roughness . 17
7.3 Traction and equipment noise . 18
7.3.1 General. 18
7.3.2 Source level for traction/equipment noise following EN ISO 3095 . 18
7.3.3 Source level for traction/equipment noise using statistical data collection . 18
7.3.4 Source separation . 18
7.4 Impact noise . 19
7.5 Curve squeal . 19
7.6 Bridge noise . 20
7.7 Braking noise. 21
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7.7.1 General . 21
7.7.2 Source level for braking noise following EN ISO 3095 . 21
7.7.3 Source level for braking noise at arbitrary sites . 21
7.7.4 Source level for braking noise at speed . 21
7.8 Aerodynamic noise . 21
8 Sampling requirements . 22
8.1 Practical validity . 22
8.2 Site requirements and selection . 22
8.3 Train selection . 22
8.4 Train speeds . 22
8.5 Numbers of pass-bys . 23
9 Processing . 23
10 Uncertainties . 29
11 Reporting . 29
Annex A (informative) Methods to determine combined effective roughness . 31
A.1 General . 31
A.2 Direct method requiring track and vehicle possession . 31
A.3 Indirect method using rail vibration – trackside method . 31
A.4 Survey methods . 31
Annex B (informative) Calculation of apparent sound power from sound pressure . 33
B.1 Definition . 33
B.2 Calculation Method . 33
B.3 Calculation procedure. 34
B.4 Tabulated transfer functions for CNOSSOS for given track geometries and source-
receiver combinations . 34
Annex C (informative) Separation methods for rolling noise of vehicle and track . 59
C.1 Principle of separation . 59
C.2 Separation based on calculation . 59
C.3 Separation based on measurement . 60
C.4 Separation based on external reference . 60
Annex D (informative) Specific environments . 61
Annex E (informative) Transposition between train and track types . 62
Bibliography . 63
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European foreword
This document (prEN 17936:2022) has been prepared by Technical Committee CEN/TC 256 “Railway
Applications”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
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Introduction
In Europe various prediction methods for environmental noise exist. For noise mapping and planning of
railway lines, the prediction methods are enshrined in national or European legislation such as Directive
2015/996/EU (CNOSSOS). An integral aspect to ensure realistic results is to use valid input data.
Environmental noise prediction models consist of traffic noise source terms and a propagation model.
This calculation of railway traffic sources is based on traffic data (e.g. train types, speeds, flow,
operational data) and the vehicle/track noise source terms.
In this document, measurement methods are specified for the acoustic input parameters for the
vehicle/track noise source terms. The collection of traffic flow data are outside the scope of this
document. The method may be used to collect data from different railway source types, within the
practical constraints of widely available measurement equipment and operational railways.
The document covers the measurement of separate physical source types which are listed in the scope.
Each source type is characterized in terms of its frequency spectrum (up to one-third octave band
details), source height and directivity. Rolling noise is described in terms of its generating wheel and rail
roughness along with the vehicle and track transfer functions.
Where it is required, the document details the derivation of transfer functions that allow rolling noise to
be calculated from wheel/rail acoustic roughness.
The complete process showing different types of inputs to an environmental prediction noise scheme is
illustrated in Figure 1.
Figure 1 — Elements of an environmental noise prediction scheme
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1 Scope
This document addresses the measurement of source terms for environmental noise calculation for rail
traffic (including light rail, such as trams, metros, etc). It is applicable to the measurement of in-service
trains on operational tracks.
It is not applicable to type acceptance testing of rolling-stock or tracks, or to derive source terms for time
domain models.
The following rail traffic noise source types are in the scope:
• Rolling noise ;
• Traction noise ;
• Aerodynamic noise ;
• Impact noise (e.g. rail joints, switch and crossings, wheel flats) ;
• Braking noise ;
• Bridge noise ;
• Squeal noise.
Noise from rail vehicles at standstill, such as stationary engine idling and auxiliary equipment at yards
and stations is covered by EN ISO 3095:2013 for measurement procedures and operating conditions, and
by ISO 3740:2019, and ISO 3744:2010 for the determination of sound power.
The calculation of the propagation of sound is part of generally standardized propagation models which
are not addressed in this document.
Noise from fixed installations (e.g.: stations, depots, electricity sub-stations) are not in the scope of this
document.
Source terms are specific to a vehicle and track type. The scope includes measurement procedures and
conditions and sampling requirements.
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 ISO 3095:2013, Acoustics - Railway applications - Measurement of noise emitted by railbound vehicles
(ISO 3095:2013)
EN 15610:2019, Railway applications - Acoustics - Rail and wheel roughness measurement related to noise
generation
EN 17343, Railway applications - General terms and definitions
CEN/TR 16891:2016, Railway applications - Acoustics - Measurement method for combined roughness,
track decay rates and transfer functions
EN 61672-1:2013, Electroacoustics - Sound level meters - Part 1: Specifications
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EN 61672-2:2013, Electroacoustics - Sound level meters - Part 2: Pattern evaluation tests
EN IEC 60942:2018, Electroacoustics - Sound calibrators
EN 61260-1:2014, Electroacoustics - Octave-band and fractional-octave-band filters - Part 1: Specifications
ISO 3740:2019, Acoustics — Determination of sound power levels of noise sources — Guidelines for the use
of basic standards
ISO 3744:2010, Acoustics — Determination of sound power levels and sound energy levels of noise sources
using sound pressure — Engineering methods for an essentially free field over a reflecting plane
ISO 5725-2:2019, Application of statistics – Accuracy (trueness and precision) of measurement methods
and results – Part 2: Basic method for the determination of repeatability and reproducibility of a standard
measurement method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 3095:2013, EN 17343 and
the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
number of axles
N
ax
number of axles in the selected train or part of train
3.2
third octave band frequency
f
centre frequency of a third octave frequency band in [Hz]
3.3
third octave wavelength
centre wavelength of a third octave wavelength band in [m]
3.4
acceleration signal
a(t)
2
time signal of the rail acceleration in [m/s ]
3.5
equivalent vertical rail vibration level spectrum
L (f)
aeq,Tp
third octave spectrum of the rail head acceleration energy averaged over pass-by time T , in dB re 1
p
2
[µm/s ]
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3.6
rolling noise transfer function
LHpR,tot,nl (f)
transfer function in third octave bands between the sound pressure at a fixed point, 7,5 m, and the
combined effective roughness frequency spectrum, normalised to the axle density Nax/l, in [dB re 20
Pa/√m]
[SOURCE: CEN/TR 16891:2016 definition 3.14]
3.7
combined effective roughness
roughness function that excites rolling noise
Note 1 to entry: The combined roughness is the RMS of the rail and wheel roughness spectra. It becomes the
combined effective roughness when the effect of the contact patch filter is included.
[SOURCE: EN 15610:2019, definition 3.4]
3.8
combined effective roughness wavelength spectrum
LRtot (λ)
wavelength spectrum in third octave bands of the combined effective wheel-rail roughness including the
contact filter, in dB re 1 [µm]
[SOURCE: CEN/TR 16891:2016, definition 3.12]
3.9
combined effective roughness frequency spectrum at speed v
LRtot (f,v)
frequency spectrum in third octave bands of the combined effective wheel-rail roughness at a given speed
v, including the contact filter, in dB re 1 [µm]
[SOURCE: CEN/TR 16891:2016, definition 3.13]
3.10
direct roughness measurement method
refers to an acoustic roughness measurement method for which the sensor measures the running surface
roughness so that either the rail or the wheel roughness is measured independently of any effect of wheel-
rail interaction
[SOURCE: EN 15610:2019, definition 3.5]
3.11
indirect roughness measurement method
refers to an acoustic roughness measurement method that measures a quantity that is the result of wheel-
rail interaction, such as noise, rail or axle box vibration, whereby the original excitation by the combined
effective wheel and rail roughness is inferred
[SOURCE: EN 15610:2019, definition 3.6]
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3.12
sound power level
LW (or apparent sound power level)
ten times the logarithm to the base 10 of the ratio of the sound power, P (3.2), of a source to a reference
value, P0, expressed in decibels, where the reference value, P0, is 1 pW
[SOURCE: ISO 3740:2019, definition 3.3]
Note 1 to entry The apparent sound power level is the sound power level as derived from a specific field
measurement point. In this context, it is the sound power level required to produce the sound pressure level in the
measurement point at the trackside in third octave or octave bands i.
3.13
sound power level per unit length
LW
(apparent) sound power level LW normalized to the train length in Watt/m
= 10 lg (W/W ) - 10 lg (l/l ) (1)
LW’ 0 0
where
l is 1m.
0
3.14
integration length
l
length of vehicle or track over which the sound pressure is integrated
3.15
sound power transfer function
LHWR,n
apparent sound power per unit (combined) effective roughness, per axle, in one third octave bands, in
analogy with [1], formulas 2.3.8 - 2.3.10
Note 1 to entry This depends also on vehicle length.
3.16
sound pressure transfer function
LHpR,nl
transfer function of combined effective roughness to sound pressure at the trackside, normalised to the
axle density Nax/l
Note 1 to entry In principle, this is independent of the train or vehicle length and speed if rolling noise is the main
source.
[SOURCE: CEN/TR 16891:2016, definition 3.14]
3.17
acoustic transfer function from sound pressure to sound power
LHpW
transfer function between the measured pass-by sound pressure level Lpeq,Tp and the apparent sound
power level per meter LW’, in one third octave bands or octave bands
Note 1 to entry This only includes geometric divergence and ground attenuation and results from integration over
the pass-by of single or multiple sound sources for a vehicle or group of vehicles.
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3.18
distribution function D(f)
set of two or more frequency spectra in third octave bands, used to quantify the contributions of
individual sources, such as vehicle and track, or rolling noise and other sources
Note 1 to entry The energy sum of these spectra is always zero dB in each third octave band. The contribution of
each source is obtained by subtraction of the distribution function from the total sound spectrum.
4 Acoustic basics for this standard
4.1 Accuracy / uncertainties
The following factors can affect the uncertainty in source terms results:
— sample selection of trains or rail vehicles, including roughness variation of wheels
— measurement sites, including rail roughness variation, geometry and propagation factors
— operating conditions of trains or rail vehicles including speed and active noise sources.
Further details on uncertainty are covered in Clause 10.
4.2 Frequency range and spectral bands
Source terms for prediction models are most commonly defined in octave bands from 63 to 8000 Hz. Data
are collected in third octave bands for 50-10000 Hz and converted into octave bands at the final
processing step.
4.3 Type of measurements
Sound pressure measurements are performed in situ with single microphones, from which a sound power
quantity is derived. The sound power is derived using the actual prediction model for which the source
terms are required, or a more detailed model. Methods for this calculation are described in Annex B.
NOTE Model requirements include a non-local reacting ballast reflection and diffraction over the ballast.
5 Instrumentation and calibration
5.1 General
Measurements can be taken with temporary, supervised setups as well as with stationary mounted,
automated, non-supervised setups. While most instrumentation and calibration requirements are
necessary for both types of setups, some extra requirements are necessary for stationary ones.
Furthermore, some tasks conducted by the supervisor for temporary setups also have to be executed by
instrumentation for stationary mounted setups.
Depending on the type of measurement, only a selection of the following instrumentation might be
needed.
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5.2 Acoustic instrumentation
Each component of the acoustic instrumentation system shall meet the requirements for a class 1
instrument specified in EN 61672-1:2013.
The sound calibrator shall meet the requirements of class 1 according to EN IEC 60942:2018.
Microphones with free field characteristics shall be used. A suitable microphone windscreen shall always
be used. Stationary mounted setups shall be suitable for permanent outdoor usage and shall include bird
spikes.
Where one-third octave frequency band analysis is required, the filters shall meet the requirements of
class 1, according to EN 61260-1:2014.
The compliance of the calibrator with the requirements of EN IEC 60942:2018 shall be verified at least
once a year. The compliance of the instrumentation system with the requirements of EN 61672-1:2013
and EN 61672-2:2013 shall be verified at least every 2 years. The date of the last verification of
compliance with the relevant standards shall be recorded.
5.3 Calibration of the acoustic instrumentation
5.3.1 Temporary setup
Before and after each series of measurements taken with a temporary setup, a sound calibrator shall be
applied to the microphone(s) to verify the calibration of the entire measuring system at one or more
frequencies over the frequency range of interest. If the difference between two consecutive calibrations
is more than 0,5 dB, or the difference between a measured value and the nominal value is more than 1,1
dB, all of the measurement results in between shall be rejected.
5.3.2 Automated calibration
For stationary-mounted setups, the manual test with a calibrator, as described above, shall be conducted
at least once a year. Additionally, automated daily tests shall be conducted by one of the two following
procedures.
1. Testing the instrumentation by supplying a known electric signal. The difference between the
measured value and the nominal value shall be not more than 1,1 dB. This can be done by built-in
acoustic sources in the microphone (signal at the microphone output has to be equal to a signal of at
least 80 dB), charge-injection-calibration, electrostatic calibration or any other equivalent
procedure.
2. Testing the instrumentation by additional measurements (other microphones or sources). For this,
a second microphone is installed. The difference between the measured values of both microphones
shall not exceed 1,5 dB.
If the daily test of the instrumentation fails, all of the measurements taken since the last successful daily
test shall be rejected.
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5.4 Non-acoustic instrumentation
5.4.1 Time and duration
The date and local time of each pass-by shall be recorded. The duration of the pass-by of the considered
train/unit (over buffers) shall be measured with a precision of better than +-0,05s.
The pass-by time T can be determined the front and rear axle peaks in the time signal of rail or sleeper
p
vibration or sound pressure, plus a time increment proportional to the distance of the first and last axle
to the front or rear of the train respectively. Alternatively, an optical presence detector c
...
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