Noise Assessment Method for High-Speed Railway Applications in Sweden
Xuetao Zhang
SP Technical Research Institute of Sweden of Institute Research Technical SP
Energy Technology
SP Report 2014:34 2
Noise Assessment Method for High- Speed Railway Applications in Sweden
Xuetao Zhang
Summary
A new noise assessment method was proposed, which is for evaluating noise impact along high-speed railway lines and for estimating noise mitigation measures where required. The method was prepared in a way that it can easily be further expanded to cover conventional trains as well as low speed or idling situations.
As the Nord2000 model has already been chosen as the propagation module of the new method, in this report only the source module and the calculation module are described. In fact these two modules have impact on each other: calculating maximum noise level of train passages requires a classification based on train types, while a dB-value description of noise mitigation measures benefits the desired noise calculation. In the report the most typical issue addressed is classification. It is found that a classification based on vehicle types is noise mitigation measure oriented, which is neither convenient for noise calculation nor proper for high-speed applications. Thus, “a classification of noise calculation oriented” was considered. Based on this understanding, a train classification based on noise emission strength was proposed. Moreover, noise mitigation measures are integrated and described by a single parameter, additional noise reduction, which shall be given either in total level or in spectrum.
For a source model an important part is source data. At this time (and in Sweden) there are no real source data available for high-speed railway noise. A set of default source data was then worked out based on the source data of X2 trains together with the TSI requirement on noise. This set of default source data is thought enough good for estimating noise impact along high-speed lines, based on two reasons: (1) As for X2 trains the rolling noise and the aerodynamic noise become comparable at about 370 km/h which is the same as for typical TGV trains; this suggests that the ratio between the two noise components is the same or comparable for the two train types. (2) Many TGV trains just fulfil the TSI requirement on noise. Therefore, although X2 trains are found too noisy, by adding on proper noise reduction (6 dB) useful default source data have been obtained.
Not only the mathematical equations for calculating desired acoustic quantities have been formulated, the necessary numerical formulations have also been provided that aims at benefiting a quick IT-implementation of the new method.
Key words: Noise assessment method, high-speed railway noise, source model, classification
SP Sveriges Tekniska Forskningsinstitut SP Technical Research Institute of Sweden
SP Report 2014:34 ISBN 978-91-86622-18-3 ISSN 0284-5172 Borås 2014
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Content
Summary 3
Content 4
Preface 6
1 Introduction 7 1.1 List of symbols 8
2 Basic source model 11 2.1 General 11 2.2 Source line and source position 11 2.2.1 Lateral source position 12 2.2.2 Source height 12 2.3 Classifications of trains/vehicles, tracks and driving conditions 17 2.4 Directional sound power levels 23 2.4.1 Directivity 23 2.4.2 Sound power levels 26 2.4.2.1 Rolling noise and the indirect roughness method 26 2.4.2.2 Aerodynamic noise 30 2.4.2.3 Other noise types 31 2.4.2.4 Default source data for high-speed railway noise 31 2.5 Tunnel openings 32 2.5.1 General 34 2.5.2 Values of a 35 2.5.3 Calculation procedure 36 2.6 Noise mitigation measures 37 2.6.1 Acoustic grinding 37 2.6.2 Reduction of the wheel component of noise 37 2.6.3 Reduction of the track component of noise 38 2.6.4 Shielding measures 38 2.6.4.1 Trackside barriers 38 2.6.5 Reduction of aerodynamic noise 39 2.7 Source data 39
3 Determination of railway noise impact 41 3.1 Propagation attenuation 41 3.2 Source line description 42 3.3 Instantaneous sound pressure level Lp 43 3.4 Leq,T and SEL of a single train passage 44 3.5 Leq,T of railway traffic noise 47 3.6 Standard noise indicators Lden and Lnight 47 3.7 Consideration of vertical directivity 48 3.8 The maximum level LAFmax 48
3.8.1 An empirical approach for estimating LAF max 49 3.9 Indoor noise impact levels 49 3.10 Steps of calculation process 52 3.11 Uncertainty 53
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4 Future work 55 4.1 Further improvement of the noise assessment method 55 4.2 Data collection 55 4.2.1 Collection of the representative source data 55 4.2.2 Specifying noise mitigation measures and the representative noise reductions 56
Reference 57
Annex A The transfer function between LW and Leq,Tp 59
Annex B Source data for X2 rolling noise 63
Annex C Default noise source data for high-speed railway systems 65
Annex D Default noise source data for high-speed railway systems under 200 km/h 69
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Preface
This project is funded by the Swedish Transport Administration (Trafikverket), with the framework contract number (ramavtal kontraktsnummer) TRV 2011/51717A and the order number (avropsavtal beställningsnummer) 2541.
The Nord2000 source model and the CNOSSOS-Harmonoise source model for railway noise have been referred to.
Kjell Strömmer (Trafikverket) provides his constructive comments on façade noise reduction.
All the above direct or indirect supports are gratefully acknowledged.
Borås 2014-08-10
Xuetao Zhang
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1 Introduction
The Swedish Transport Administration (Trafikverket) is now requiring a new noise assessment method for evaluating noise impact from high-speed railway lines (up to 320 km/h) and for estimating noise mitigation measures where required, because the current method used in Sweden is not applicable for the purpose [1]. SP Acoustics was consulted and a three-month long project was launched for preparing the new method. The project is divided into two parts. In the first part (Etapp A) three typical noise assessment methods in EU (Nord2000, CNOSSOS-Harmonoise, NMPB2008) have been reviewed [2]; this review provides a solid basis for the Swedish Transport Administration to choose the most suitable parts of these methods for building up a new Swedish noise assessment method. In the second part (Etapp B) the focus is put on preparing a new source module for high-speed railway noise, because the Nord2000 model has already been chosen as the propagation module of the new method. The calculations of desired acoustic quantities will also be formulated; and in fact they have an impact on building up a source module. For example, in order to calculate maximum noise level of train passages, a classification based on train types instead of on vehicle types is favoured.
In general, a noise assessment method consists of three parts: a propagation module which is for handling sound propagation under different conditions, a source module which is for specifying the noise sources and the source positions and determining the directional sound powers, and a calculation module which is for calculating desired acoustic quantities as well as estimating noise mitigation measures where required. As has been mentioned, in this report only the source module and the calculation module will be described.
Railway noise has multiple sub-sources, either localized ones such as locomotive traction noise or pantograph noise, or the ones distributed along the whole train such as rolling noise or aerodynamic noise around the bogies. Thus, railway noise will be described by source lines and/or point sources, with directional sound power levels specified. A source line consists of a line of incoherent point sources, differing from a line source which consists of a line of coherent point sources. And, source positions are specified by representative lateral positions and heights, referring to the physical origins.
For being able to accurately specify directional sound power levels for each noise source, trains, tracks and driving conditions are classified. A classification shall aim at helping with accurate noise calculations, while not increasing the burden in source data collection. Therefore, a classification of noise calculation oriented is favoured.
Desired calculation quantities are the European standard noise indicators Lden and Lnight, the common noise indicators for case studies Lp, Leq,T and SEL, the special Swedish noise indicator LAFmax, as well as the required indoor noise level of traffic noise, Leq,indoor. The frequency range is one-third octave bands of the centre frequencies between 25 Hz and 10 kHz.
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The new noise assessment method have been prepared in the way that it has a focus on high-speed railway applications (because of the short project time); however, it can be easily further expanded (in near future) to cover conventional speed (< 200 km/h) and low speed (< 50 km/h) as well as idling situations.
The source module will be described in Section 2 and the calculation module will be described in Section 3. And, in last section, possible future works will be discussed.
1.1 List of symbols
Aexcess excess attenuation
A1 f level difference between the average vibration at the measurement point and the railhead
A2 f level difference between the vibration displacement at the contact point on the railhead and the combined effective roughness
A4 f level difference between the vibration at the contact point and the vibration of the railhead averaged over the wheel passage interval
Atun the cross section of a tunnel portal c speed of sound in air
Caero v speed-dependent correction for façade sound reduction CF contact filter D(f) track decay rate f 1/ 3 octave band centre frequency
LAF max maximum sound pressure level using frequency weighting A and time weighting F
La,contact f equivalent vertical rail acceleration level at the contact point
La,head f equivalent vertical rail acceleration level at the railhead over the measurement position
La,meas f equivalent vertical rail acceleration level at the measurement position L yearly averaged day time L day eq
Lden yearly averaged day-evening-night weighted
Levening yearly averaged evening-weighted
( Leq,T ) equivalent continuous sound pressure level (over time interval T) f Leq,T under favourable weather condition h Leq,T under homogenous weather condition Lcvkm the contribution to from source type k of source height m of eq,T train type c at speed v Lkm the contribution to from source type k of source height m eq,T u Leq,T under unfavourable weather condition
Leq,indoor indoor , typically induced by traffic noise
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L L over the time interval defined in Figure A1 in Annex A. eq,Tp eq
LH ,tot the total transfer function of rolling noise
LH ,veh the vehicle transfer function of rolling noise, 1 axle per meter
LH ,tr the track transfer function of rolling noise, 1 axle per meter
Lnight yearly averaged night-weighed
LCE C-weighted sound exposure level of a train passing by a tunnel portal
Lp instantaneous sound pressure level L L , with T = 1/8 second pF eq,TF F L the contribution to from source type k of source height m p,km
Lp,tot instantaneous sound pressure level of total rolling noise
LRE sound exposure level for micro-pressure wave
Lr,r rail roughness level
Lr,w wheel roughness level
Lr,tot total roughness level
LW sound power level
LW , aero sound power level of aerodynamic noise i th LW sound power level of i unit of a train i th LW 1m sound power level per meter train emitted from i unit of a train i LW 1m,0 the omni-directional component of
Lwagon wagon length
Lx,contact f vibration displacement at the contact point M = v/c the Mach number
N axle number of axles per wagon
p f yearly averaged occurrence probability for favourable weather condition
ph yearly averaged occurrence probability for homogeneous weather condition
pu yearly averaged occurrence probability for unfavourable weather condition SEL sound exposure level Tx the time length for the measurement illustrated in Figure 2.8. t time v train speed W tunnel width
WT sound power radiated from a tunnel opening
La the propagation effect of air absorption,
Ld the propagation effect of spherical divergence of the sound energy
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Lfaçade v 30 Caero v, speed-dependent façade sound reduction for high- speed railway noise
Lr the propagation effect of obstacle dimensions and surface properties when calculating a contribution from sound reflected by an obstacle.
Ls the propagation effect of scattering zones,
Lt the propagation effect of the terrain (ground and barriers),
pMPW disturbance of micro-pressure wave i L ji the directional component of LW 1m
Lx () horizontal directivity for source x where x can be rail, track, wheel, bogie, pantograph y Lvertical ( ) vertical directivity for source or source component y where y can be R (which is for rolling noise), or, bogie/pantograph component of aerodynamic noise wavelength horizontal angle
j the horizontal angle of a train centre th ji the horizontal angle of i unit of a train vertical angle
C receptance of the contact stiffness
R rail receptance
W wheel receptance solid angle which depends on the geometry of the portal and the surroundings
tot total standard deviation function
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2 Basic source model
2.1 General
A source model for railway noise should specify the important noise types, the representative source positions, the directional sound power levels, and make classifications of vehicle/train types, track types and driving conditions as well as define the related calculation procedures.
Railway noise has multiple sources. The three main noise types are: traction noise (emitted from traction motors, cooling fans, gears and auxiliary equipment), rolling noise (through wheel-rail contact interaction) and aerodynamic noise (due to vortex shedding from wheels and pantographs, flow separations at train nose and tail, flow disturbances at edges and cavities). And, there are also other noise types like impact noise (at joints, points and switches, or due to out-of-round wheels), bridge noise, viaduct vibration noise, curve squeal noise, braking noise and braking squeal noise, noise from auxiliary equipment, etc. These noise sources are distributed over the height and length of the train, with directional sound powers of different strengths. A source model for railway noise should be capable to properly describe these features.
After more than 40 years research effort, railway noise has now been well understood and its most important component, rolling noise, can be properly predicted [3]. At high speed, the other noise type, aerodynamic noise, needs to be considered. For this noise type, theoretical modelling of it is still limited to a few simple configurations [3]; it will thus be handled in an empirical method [4-5]. Theoretical research on impact noise and curve squeal noise can be thought quite successful. However, for traction noise and other noise types the source descriptions of them are mainly based on measurements.
Within this project, the focus is put on making a source model for high-speed railway noise. At high speed traction noise is negligible (while cooling fan noise may have some effect on the total noise level [18]); and, on a high-speed line, other noise types such as curve squeal noise or impact noise are as believed irrelevant. For some high- speed lines noise emission from viaduct vibration may be relevant; while the most important noise types are always rolling noise and aerodynamic noise.
The source model prepared in this project follows the main line of the Harmonoise source model for railway noise, while revised where necessary. The frequency range is one-third octave bands of the centre frequencies between 25 Hz and 10 kHz.
2.2 Source line and source position
A source line, differing from a line source which is modelled as a line of coherent point sources, is defined as a line of incoherent point sources. For rolling noise, roughness on two wheels’ running surfaces are incoherent; for aerodynamic noise, flow disturbances at two cavities as well as vortex shedding from two bogies are incoherent. Thus, the concept of source line removes possible confusions in source modelling.
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2.2.1 Lateral source position
For strategic noise mapping, it is acceptable to put all source lines at the centre of the track. However, for detailed case studies exact source locations may be required, e.g. to study the shielding effect of near-track low noise barriers. Therefore, the nearest rail was chosen as the lateral position for all the source lines/point sources, although for pantograph noise this position may be slightly worse than the centre of the track.
2.2.2 Source height
In the Nord2000 model, the default source heights for railway rolling noise are 0.01 m, 0.35 m and 0.7 m (above the railhead; the same hereafter), which are comparable to the somehow simplified choice made in the Harmonoise model: 0 and 0.5 m. (Note: In the Nord2000 calculation software, a source or receiver height less than 0.01 m will be treated as 0.01 m to avoid possible numerical difficulty.) However, in CNOSSOS-EU, only one source height of 0.5 m was specified for rolling noise; this choice is thought questionable as discussed in the following.
The source height around the railhead is for rail/track contribution and the source height of 0.5 m is for wheels’ contribution. In the Nord2000 model the two default source heights, 0.35 m and 0.7 m, are for wheels’ contribution. According to the measurement study showed in [6], see Figure 2.1, it seems that one height (0.5 m) or the two heights (0.35 m and 0.7 m) are the same good for describing wheels’ contribution. Considering that by reducing one source height will save quite a lot calculation time, the simplification made in the Harmonoise model is favoured.
Figure 2.1. Vibration distribution across the wheel (Figure 6 in [6]).
A balance between accuracy and calculation time is important; calculation errors should be controlled following the required accuracy. Accordingly, one is limited to make simplifications in a source model; each simplification should be evaluated, through benchmark calculations or measurements.
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3.5 hs: 0.01 m hs: 0.5 m 3 hr: 1.2 m hr: 3.5 m 2.5 hr: 2 m terrain 2
1.5
1
0.5 height w.r.t. railway(m) bed w.r.t. height 0
-0.5
-1 0 10 20 30 40 50 60 70 80 90 100 distance to track (m)
(a)
10 dr/hr = 7.5m/1.2m 8 dr/hr = 25m/3.5m 6 dr/hr = 100m/2m
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2
0 dB
-2
-4
-6
-8
-10 1 2 3 4 10 10 10 10 excess(hs = 0.01 m) - excess(hs = 0.5 m) (b)
Figure 2.2. (a) The representative terrain profile (2D) for a railway track and the surrounding, the two source heights (0.01 m and 0.5 m above the railhead), and the three typical receiving positions (7.5m/1.2m, 25m/3.5m, 100m/2m). (b) Difference in excess attenuations for the two source heights 0.01 m and 0.5 m.
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hs: 0.01 m hs: 0.5 m 4 hr: 1.2 m hr: 3.5 m terrain 3
2
1 height w.r.t. railway(m) bed w.r.t. height 0
-1 0 5 10 15 20 25 distance to track (m) (a)
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8
6
4
2 dB 0 dr/hr = 7.5m/1.2m dr/hr = 25m/3.5m -2
-4
-6
-8 1 2 3 4 10 10 10 10 excess(hs = 0.01 m) - excess(hs = 0.5 m) (b)
Figure 2.3. (a) The terrain profile is similar as that in Figure 2.2 while a near-track low noise barrier (1 m to the rail and 0.7 m over the railhead) is added; the two standard receiving positions (7.5m/1.2m, 25m/3.5m). (b) Difference in excess attenuations for the two source heights 0.01 m and 0.5 m.
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6 hs: 0.01 m hs: 0.5 m hr: 2 m 5 terrain
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3
2
1 height w.r.t. railway(m) bed w.r.t. height
0
-1 0 10 20 30 40 50 60 70 80 90 100 distance to track (m) (a)
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2
0
-2 dB
-4
dr/hr = 100m/2m
-6
-8 1 2 3 4 10 10 10 10 excess(hs = 0.01 m) - excess(hs = 0.5 m) (b)
Figure 2.4. (a) The terrain profile is similar as that in Figure 2.2 while a noise barrier (6 m from the rail and 4 m over the railhead) is added; one receiving position 100m/2m. (b) Difference in excess attenuations for the two source heights 0.01 m and 0.5 m.
In Figures 2.2 - 2.4, the difference in excess attenuations in sound propagation from each of the two source heights, 0.01 m and 0.5 m, to typical receiving positions was
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shown, for several representative situations. Based on these calculation results, we conclude that it is NOT proper to use 0.5 m source height for rail/track noise. In other words, two representative source heights are necessary and enough for describing rolling noise: 0.01 m for rail/track contribution and 0.5 m for wheels’ contribution.
Detailed source distribution along the whole train is usually not considered (in noise mappings), although the pantograph and the train head/locomotive are often point- source like. As for pantograph, its source data can be given as per meter train if only equivalent noise impact or total noise exposure is concerned. However, for some case studies, detailed source distribution needs to be considered. This issue will be discussed in detail when formulating how to calculate LAFmax.
For aerodynamic noise, 0.5 m source height is for the noise components around bogie areas including cooling fan noise, 4 m height for the roof component and 5 m for the pantograph. In the CNOSSOS source model for railway noise, only two source heights of 0.5 m and 4 m were chosen. Considering that pantograph noise is often more important than other roof components of the aerodynamic noise [18, 22], in this new source model 5 m instead of 4 m is chosen as the second source height for aerodynamic noise.
For traction noise, engine exhausts for diesel powered vehicles are often located at a roof height of 4 m above the railhead; louvers and cooling outlets can be at various heights about 2 ~ 3 m; gear transmission and electric motors are usually at the axle height of 0.5 m.
The positions of railway noise sources have been specified in Table 2.1.
Table 2.1 Source positions Lateral position: the rail nearest to the receiver Vertical position (above the railhead): Noise type Source height (m) Explanation Aerodynamic 0.5 for the components around bogie areas 5 for pantograph or other roof components Rolling 0.01 for rail/track component 0.5 for wheel component Traction 0.5 for electric motors, gear transmission 3 for louvers and cooling outlets 4 for engine exhaust
Impact noise has its source heights the same as those for rolling noise. Curve squeal, braking squeal and braking noise have a source height of 0.5 m. For bridge noise, the source heights are those for rolling noise plus the vertical expansion of the bridge. For viaducts, the representative source height(s) is currently not clear; the centre of the noise emission area could be an option.
For high-speed railway noise, three source heights of 0.01 m, 0.5 m and 5 m have been proposed for noise calculations. And, an extra source height will be considered if viaduct vibration noise contributes.
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2.3 Classifications of trains/vehicles, tracks and driving conditions
A vehicle is defined as any single railway subunit of a train that can be moved independently and can be detached from the rest of the train. Typically, a vehicle can be a locomotive, a self-propelled coach, a hauled coach or a freight wagon. Some units of a train, that are a part of a non-detachable set e.g. share one bogie between them, are grouped into a single vehicle according to the definition.
A train consists of a series of coupled vehicles.
A classification of train/vehicle types in a noise source model is mainly based on those important parameters which have significant effects on the noise emission. Some parameters are related to roughness level (e.g. brake type or normally maintained rail) while the others will affect the response of a vehicle or a track to a roughness-induced excitation (this response is described by respective transfer function). For aerodynamic noise, there are currently no any parameters specified. (Note: By “high speed vehicle” it indicates that aerodynamic noise needs to be considered; however, not all types of high-speed trains have the same aerodynamic and acoustic characteristics.) Within this project, it was considered that a classification should help with noise calculation while not increase the burden in source data collection. Accordingly, a classification of noise calculation oriented is expected.
Let us take the CNOSSOS-Harmonoise classification for railway vehicles [7], shown in Figure 2.5, as the starting point for this discussion. If choosing vehicle type “high speed vehicle”, we will find that other three descriptors become not necessary or less relevant: modern high-speed vehicles all have disc brakes, all have the same number of axles (?) and all do not need (or, are not practical to have) extra wheel measure (?). (The question mark “?” indicates that the author believes so while not 100% sure.) In fact, it is not proper for high speed trains to make a classification based on vehicle types because the design of the train nose and train tail, as well as the design of inter-coach spacing is important for good streamline behaviour of the train. Moreover, aerodynamic noise around a bogie depends not directly on the train speed but the mean flow velocity at the bogie which in turn depends on the train speed and the distance between the bogie and the train nose. A measurement of flow velocity made in Japan showed that at the middle of fifth car (118.9 m from the train nose) the mean flow velocity decreases to 42% of the train speed [8]. Thus, it is understood as that aerodynamic noise around pantograph, train nose and train tail can be considered as local noise sources while aerodynamic noise around bogies depends also on the train length and the bogies’ positions relative to the train nose. Therefore, for high- speed trains, a classification based on train types is favoured because if a train has been disassembled into individual vehicles the aerodynamic noise could not be properly defined.
A classification based on vehicle types can distinguish a locomotive from coaches, concerned with traction noise and possible difference in rolling noise. However, for specifying traction noise it has no problem to merge locomotive types into train types, such as a train with “diesel loco” or “electric loco” or “self-propelled”. What left in a vehicle classification is to distinguish a locomotive from a coach based on
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their rolling noise emission. In general, a locomotive may have larger wheels and traction wheels may be rougher than trailer wheels. In other words, a locomotive may emit rolling noise a few dB more than a coach vehicle does. However, this is not always true even for passenger trains: some coach vehicles can emit rolling noise more than the locomotive does. Considering a noise mapping, it is usually the mean roughness level of a train that will be specified. Accordingly, if difference in roughness levels between coach wheels is not specified, then it does not always make a sense to distinguish locomotive rolling noise from the coaches’. Moreover, when necessary (e.g. for detailed case studies) one can specify a roughness distribution along a train. Thus, it has no problem, for a classification based on train types, to distinguish locomotive rolling noise from the coaches’.
In Sweden, maximum value of AF-weighted sound pressure level of train pass-by noise, LAFmax, is an important noise indicator. Obviously, for calculating LAFmax, a classification based on train types is favored. It seems that a classification based on vehicle types is noise mitigation oriented, which is neither convenient for noise calculation nor proper for high-speed applications.
Thus, put all these discussions together, we like to conclude that a classification based on train types is better than based on vehicle types, not only for handling high- speed railway noise but also for detailed case studies.
Moreover, passenger trains can have different wheel types (with a straight or curved web) and different wheel sizes. These two parameters should be considered in classification because they are important in determining the vehicle transfer function. These two parameters may be merged into some other parameter. And, if considering noise emission strength, not all high-speed train types are necessary to be distinguished; those train types which behave acoustically the same or comparable shall be put into the same category. For example, some TGV train types and some ICE train types may be put into one category if they behave acoustically the same. This is to say, a train classification may not intend to point out the differences between train types but focus on their acoustic characteristics, or simply, their noise emission strengths. Of course the relevant noise source data shall be obtained from validated field measurements, or based on manufacturer’s product specification (the acoustical part) if the relevant information is provided.
Being noise calculation oriented, for high-speed applications, a train classification based on noise emission strength becomes very simple, as shown in Table 2.2-1.
The descriptor “wheel measure” (see Figure 2.5) is more relevant for noise reduction than for noise prediction, because a train with some kind of wheel measure may not be quieter than another train which has no wheel measures. The vehicle/train transfer function depends mainly on the wheel type and wheel size; wheel skirts and wheel dampers will provide a few dB effect. Therefore, a train type, e.g. passenger trains, may need to be further divided into several categories based on their vehicle transfer functions and/or wheel roughness levels. Under a train type, to apply some wheel measure(s) may change the train from one category to another quieter one.
For conventional trains, a train classification shall be made based on train types including the traction manner and the wheel size(s). Passenger trains may need being further divided into three categories according to the noise emission strength (taking
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the TSI requirement on noise as the reference): normal, low and high. For freight trains, there will also be three groups: normal, high and very high. The train classification of conventional systems was presented in Table 2.2-2.
Driving conditions are used for specifying traction noise, for specifying curve squeal noise when a sharp curve is relevant, and for specifying brake squeal noise when braking to (nearly) stop. Except cooling fan noise which may at high speed still have some influence on the total noise level [18], traction noise is only relevant at low speed including idling. And, for high-speed lines, a sharp curve is irrelevant. Thus, driving conditions are classified following these considerations, as shown in Table 2.4.
For freight trains, wagons with different brake types shall be distinguished because the wheels’ roughness levels can differ much. However, without pre-provided information, what a brake type a freight wagon has is not predicable. For a strategic noise mapping which is based on statistics the information on the ratio of a brake type in use is useful. However, for predicting pass-by noise of a specified freight train, one needs to know which wagons are equipped with what brake type - in general such information is not available. Accordingly, this descriptor, brake type, is applicable when considering noise measure while not fully practical when making noise prediction.
A general classification of railway track types [7], see Figure 2.6, looks complicated. It can be divided into two categories, conventional railway tracks and high-speed railway tracks. For the latter track classification is likely to be very simple: for high- speed railways descriptors 3-6 are not or less relevant; only two descriptors are relevant: track base and railhead roughness. And, options for descriptor 2 reduces to two: normally maintained and other situations. (Note: Some French experience [18] may suggest that for high-speed lines a very smooth rail running surface shall not be expected.) The classification of tracks was presented in Table 2.3, which includes track classification for conventional systems.
Table 2.2-1. Classification of high-speed train types Digit 1 Note
Descriptor Train category * Type N trains just fulfils the
TSI noise requirement: 92 Explanation of the descriptor Based on noise dB(A) at the standard receiving emission level * position 25 m/3.5 m, with 1 dB N tolerance. Codes allowed Normal Q** ** Type Q trains shall be at least Quiet 3 dB(A) quieter than type N O trains. Other
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Table 2.2-2. Classification of conventional-speed (< 200 km/h) train types Digit 1 2 3 4
Descriptor Train type Train category Brake type Wheel measure
Explanation of A letter that according to the A letter that A letter that the descriptor describe the noise emission describe the describe the train type level LW brake type noise reduction measure type pm N c n passenger trains fulfil the TSI cast-iron block no measure Possible codes with self- noise propelled requirement (for coaches coaches*) with 1 dB tolerance pe L k d passenger trains at least 3 dB composite or dampers with electric quieter than sinter metal loco category N block pd** H n o passenger trains 2~5 dB more non-tread brake, other with diesel loco noisy than like disc, drum, category N magnetic c VH city tram or >= 6 dB more light metro noisy than category N a any generic freight train o other (e.g. maintenance train etc.) * A correction for train length is expected. ** To separate passenger train types by pm, pe and pd is for general engineering applications. As traction noise is often negligible above certain speed e.g. 80 km/h, these three train types may be merged into one type “p”.
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Table 2.3. Classification of railway track types Conventional railway tracks: shown in Figure 2.6 while may suffer revisions when necessary High-speed railway tracks:
Digit 1 2
Descriptor Track base Railhead roughness
Explanation of the descriptor Type of track base Indicator for roughness B N Codes allowed Ballast Normally maintained S* O Slab Others V Viaduct T Tunnel O Other (bridge …) *: A slab track is 5 dB+ more noisy than a conventional ballasted track [28].
Table 2.4. Classification of driving conditions Descriptor Speed range Category Specification
High speed (> 200 km/h) - irrelevant Possible codes Conventional speed 1 on a sharp curve 2 the others Low speed (< 50 km/h) 1 on a sharp curve including idling 2 accelerating 3 cruising or decelerating 4 braking to (nearly) stop 5 idling
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Figure 2.5. The CNOSSOS-Harmonoise classification for railway vehicles [7]. (Note: According to the definition of a vehicle, for descriptor 2 parameter value 1 is not proper.)
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Figure 2.6. The CNOSSOS-Harmonoise classification for railway track types [7].
2.4 Directional sound power levels
2.4.1 Directivity
Based on the work presented in [10], in general, directivity of railway noise has two components: the directional effect originated in source emission and the directional effect due to the motion of the source (the Doppler Effect). In ref. [10] the former directional effect was named “source term” in the formulation and the latter named “motion term”.
The angles are defined in Figure 2.7. As two source heights have been specified for each noise type (of rolling noise and aerodynamic noise), the respective horizontal and vertical directivity functions are specified as given by Eqs. (2-1) – (2-7).
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Receiver 2
Source
Receiver 1
Figure 2.7. Definition of angles: is a horizontal angle in the x-y plane and relative to the y-z plane; is a vertical angle in the y-z plane; ' is a vertical angle in a vertical plane containing the receiver and the source (or the centre of the source line); both and are relative to the x-y plane.
The horizontal directivities for rolling noise are:
Lwheel () 10lg[0.4 0.6*cos()] 20lg[1 M *sin()] (2-1)
2 Lrail () 10lg[0.001 0.999*cos ()] 20lg[1 M *sin()], f 400 Hz
Ltrack () 20lg[1 M *sin()], f 400 Hz (2-2) where M = v/c is the Mach number, v is the train speed and lg denotes for log10.
The horizontal directivities for aerodynamic noise are:
A 2 Lpantograph 10*lg0.006 1 0.006*cos 40*lg1 M *sin (2-3)
A 2 Lbogie() 10*lg0.03 0.97 *cos / 2 40*lg1 M *sin (2-4)
However, for low frequency components (estimated f 250 Hz), there is
A Lbogie(, f 250Hz) 40*lg1 M *sin (2-4’)
The vertical directivities for aerodynamic noise are:
pantograph Lvertical ( ) 10lg[0.4 0.6*cos( / 2)] (2-5)
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bogie Lvertical ( ) 0 (2-6)
As has been discussed in [10], the vertical directivities of wheel and rail noise can be described as L 10lg[0.4 0.6*cos( )] . However, the vertical directivity of total rolling noise depends also on the shielding effect of the train body and/or wheel skirts, as well as the near track noise barriers where they present. As these shielding effect varies with train type (and even with track section where near-track noise barriers present), a general vertical directivity function for total rolling noise was not specified because of lack of such data.
In ref. [7], a vertical directivity function was proposed for total rolling noise
R 40 2 f 600 Lvertical ( ) * sin2 sin *lg (2-7) 3 3 200
Note: In equations from (2-1) to (2-6) there is not a normalisation constant, considering the non-directional part of the sound power level data is determined at (equivalently) 0 angular position.
Remarks: In the CNOSSOS source model for railway noise [7] the directivity functions proposed therein differ from the directivity functions given by Eqs. (2-1) - (2-6), in two aspects,
The CNOSSOS directivity proposal considers only the source term, not the directional part of the Doppler Effect which is important at high speed for aerodynamic noise sources; The CNOSSOS directivity proposal (source term only) differs from the source term proposed in [10].
For other noise types, the directivities have been proposed as [10]:
Traction noise: neglected Impact noise: the same as that for rolling noise Braking noise: the same as that for wheel noise Curve squeal noise, braking squeal noise: the same as that for wheel noise (while a further study of the issue is required) Bridge noise: neglected Super structure vibration: neglected Cooling fan noise: L 10lg[0.25 0.75*cos()]
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2.4.2 Sound power levels
2.4.2.1 Rolling noise and the indirect roughness method
An engineering method to collect raw source data of railway rolling noise was proposed in [11-12]. The method is named the indirect roughness method, which was developed during the European project MetaRail (Methodologies and Actions for Rail Noise and Vibration Control) [11] and validated during the European project STAIRRS (Strategies and Tools to Assess and Implement noise Reducing measures for Railway Systems) [12]. Briefly, the indirect roughness method separates pass-by sound pressure spectra (not power spectra) into total effective roughness of the wheels and the rail and total transfer function of the vehicle and the track. (Note: By “effective roughness” means the rail roughness plus the wheel roughness plus the effect of the contact filter.) The total effective roughness (in wave-length domain) and total transfer function (in frequency domain) are given as 1/ 3 octave band spectra. The separation is accurate within 3 dB per octave band. Combination of the total effective roughness, the total transfer function and the axles per meter gives an estimation of the pass-by sound pressure spectra, which is accurate within 1 dB(A).
The total effective roughness is derived from the vertical rail vibration measured during a pass-by. The total vibro-acoustic transfer function is determined using the derived total effective roughness and the measured sound pressure from the pass-by.
The accuracy of the indirect roughness method has been analysed theoretically and by verification measurements, which showed a maximum systematic error of 3 dB per octave band in a frequency range from 100 to 3150 Hz. This frequency range directly restricts the wavelength range in which roughness levels can be obtained at a certain speed. For example, at a train speed of 100 km/h, the wavelength range is limited between 0.278 m and 0.009 m ( v f ).
Rolling noise consists of wheel vibration noise and track/rail vibration noise. When rolling noise dominates in railway noise (usually true for train speed range between
50 km/h and 200 km/h)，the total equivalent sound pressure level Lp,tot during a train pass-by can be determined by
N v L f 10lg axle L f L (2-8) p,tot H ,tot r,tot Lwagon f where
Lp,tot f the equivalent total sound pressure level (for a specified pass-by time period) that is due to rolling noise and in 1/3 octave band
LH ,tot f LH ,tot f LH ,veh f LH ,tr f , the total transfer function in 1/3 octave band
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Lr,tot v / f Lr,tot v / f Lr,w v / f Lr,r v / f CF , the total roughness level in 1/3 octave band
LH ,veh f vehicle transfer function, 1 axle per meter
LH ,tr f track transfer function, 1 axle per meter
Lr,w v / f wheel roughness level
Lr,r v / f rail roughness level
CF the contact filter
N axle number of axles per wagon
Lwagon wagon length
f 1/ 3 octave band centre frequencies
v train speed (m/s)
The key part of the method is to determine the total effective roughness. This quantity is to be determined as
Lr,tot f La,meas f A1 f A2 f A4 f 40lg2f (2-9) where
La,meas f 1/3 octave band level of equivalent vertical rail acceleration
A1 f the level difference between the average vibration at the measurement point and the railhead:
A1 f La,meas f La,head f (2-10)
Often one can take A1 f 0 .
A2 f the level difference between the vibration displacement at the contact point on the railhead and the combined effective roughness:
A2 f Lx,contact f Lr,tot f (2-11)
It describes to which extent roughness induces rail vibration. According to [13],
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A 20lg R (2-12) 2 R W C where
R rail receptance
W wheel receptance
C receptance of the contact stiffness
The spectrum A2 is determined for a range of parameter values using the TWINS software [14]. The pad stiffness is shown to be the most influential parameter. In the frequency range from 100 to 3150 Hz inclusive, the spectrum can be determined to an accuracy of 3 dB for application to conventional wheels (given in Table 2.5), provided that the rail pad stiffness can be allocated to one of the three categories, as listed in Table 2.6.
A4 f the level difference between the vibration at the contact point and the vibration of the railhead averaged over the wheel passage interval
A4 f La,head f La,contact f (2-13)
40lg2f = La,contact f Lx,contact f , to convert from acceleration to displacement
The conversion spectrum A4 depends on the spatial vibration decay D of the track [11]:
vDT x 8,686 8,686 A4 f La,head f La,contact f 10lg 1 e (2-14) vDT x where v is the train speed and Tx the time length for the measurement illustrated in Figure 2.8. The frequency dependent decay per meter, D(f), depends on the track characteristics (mainly the rail pads). As the stiffness and damping of the rubber rail pad depends on lifetime, temperature, pre-load and the loading history, this quantity varies during the track lifetime, and even can vary during a train passage.
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Figure 2.8. Vertical acceleration measurement during four wheel passages (Figure 3.1 in [12]).
The spatial vibration decay of the track, D(f), which is used in determining the conversion spectra of A2 and A4 , can be measured according to the standard method shown in [15], or using a simplified method proposed in [16].
By measuring two quantities,
1. the pass-by time history of Lp,tot f at 7.5m from the centre of the track and 1.2m above the railhead and 2. the pass-by time history of the vertical rail acceleration in 1/3 octave bands,
La,meas f (measured at the centre of and under the rail), the total roughness can be determined using Eq. (2-9), and then the total transfer function can be determined using Eq. (2-8).
With the total roughness and total transfer function determined, at a given train speed can be determined. However, the source data shall be the sound power level, not a sound pressure level at a given receiving position. This issue was addressed during the Harmonoise project and was solved during the Imagine project. In ref. [17] a practical method was proposed to transfer a measured Leq,Tp to the corresponding sound power level LW, as shown in Annex A. With this proposal the engineering method for source data collection of rolling noise is completed.
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Table 2.5. Spectra A2 for three categories of rail pad stiffness [12]
Table 2.6. Proposed ranges of pad stiffness Soft pad Medium pad Stiff pad Biblock sleepers 400 MN/m 400 – 800 MN/m 800 MN/m Monoblock sleepers 800 MN/m 800 MN/m - Wooden sleepers all - -
In ref. [4] the source data for the rolling noise component of X2 trains had been worked out using the indirect roughness method. These source data, with a certain adjustment by referring to the ratio of the CNOSSOS-Harmonoise default track and vehicle transfer functions [7], are presented in Annex B.
2.4.2.2 Aerodynamic noise
As theoretical modelling of railway aerodynamic noise is still limited to a few simple configurations [3], this noise type will be handled using an empirical method proposed in [4-5]. Briefly, one should measure train pass-by noise at a typical high speed ( v0 250 km/h). As the rolling noise component of the pass-by noise can be accurately predicted using the theoretical model TWINS [14], or the engineering method “the indirect roughness method” which was described in 2.4.2.1, the
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contribution of the aerodynamic noise at this typical speed can be obtained by subtracting the rolling noise contribution from the measured total. With the pantograph noise measured independently, or, estimated by referring to a typical known data, the source data of the aerodynamic noise for this speed, LW , aero f ,v0 , can be obtained by applying the respective tabular values given in Annex A.
The source data of aerodynamic noise at other speeds can then be obtained by applying the spectrum shift, f f0 *v / v0 , and the speed dependence of the noise sound level, in the way [5]
v v 0 , Hz (2-15) LW , aero f ,v LW , aero f * , v0 60log10 f 250 v v0
v v 0 , Hz (2-16) LW , aero f ,v LW , aero f * , v0 40log10 f 250 v v0
Note: Equations (2-15) and (2-16) could be revised to have a smooth transition from the speed index 6 to 4.
2.4.2.3 Other noise types
Source data for cooling fan noise is currently not available.
Source data for other non-high-speed noise types have not been handled within this project because of the short of time.
2.4.2.4 Default source data for high-speed railway noise
There are currently no high speed trains in Sweden, neither high speed lines. For evaluating noise impact from high-speed lines, a set of default source data was then worked out.
As many TGV trains fulfil the TSI requirement on noise [18], it would be good to take the source data for TGV trains as the default one. However, unfortunately, such TGV source data are currently not available. Thus, the source data for X2 trains are considered. It was found that X2 trains have a transition speed around 370 km/h [4- 5], which is nearly the same as for TGV trains [3]. This feature implies that a set of default source data based on X2 train type can be made the same good as the TGV source data. (Note: At the transition speed, the sound power of the aerodynamic noise becomes the same as that of the rolling noise.)
The noise level of X2 trains are about 6 dB(A) over the TSI noise limits. Thus, by reducing 6 dB, a set of default source data for high speed railway noise was obtained as shown in Annex C.
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2.5 Tunnel openings
Among the existing European noise assessment methods only the Nord2000 method provides a description on handling tunnel opening noise [19]. However, the method described in [19] is based on the Japanese work [24] and is for road vehicle noise. For high-speed railway applications, strong micro-pressure waves (MPW) emitted from the portal of a long tunnel (sonic boom incidents which are clearly audible up to about 1 km distance) are the most serious problem [30-32], which differ much from the tunnel opening noise for road vehicles.
Figure 2.9. Measured C-weighted sound pressure level as a function of time for an ICE 3 –type train with 300 km/h at Euerwang southern portal at a distance of 65 m (next public road) in front of the tunnel (Fig. 5 in [31]). The first high peak is caused by the sonic boom.
A clearly audible MPW was reported before only for the Shinkansan-lines in Japan [31,33]. At regular traffic of European high-speed lines this phenomenon did not show up in the past due to the use of ballasted track (its absorption effect mitigates the impact) and the specifications for length and cross section of the tunnels. In December 2005 prior to the opening of the new high-speed line Nuremberg- Ingolstadt in Germany, sonic boom occurred at the tunnels Euerwang and Irlahüll (which both are more than 7 km long and have a double slab track) when the test trains ICE S or ICE 3 entered the tunnels at the opposite entrance with speeds up to 330 km/h [31].
To compare micro-pressure sound and train pass-by noise, the adjusted sound exposure level LRE is defined as
LRE 2LCE 93, for LCE 100 dB (2-17)
LRE 1.18LCE 11, for LCE 100 dB
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where C-weighting takes the contribution at low frequencies of micro-pressure wave effects into account. LRE for the MPW at public places in the immediate vicinity of the tunnel entrances (Note: a better wording seems portals/exits, not entrances) can be compared to LCE of the train pass-by measured at the same locations. (Note: The train pass-by noise is delayed by more than one minute with respect to the occurrence of the sonic boom for a 7 km long tunnel and a train running at a speed of 300 km/h [31], as shown in Figure 2.9.)
One example of recorded sonic booms is presented in Figure 2.10. The third-octave spectra are characterised by strong contributions below 125 Hz including infra-sound below 20 Hz. For the original tunnel without using absorbers the pronounced sound pressure levels above 250 Hz were recorded, which corresponds to a hearing impression as sharp and bright bang [31].
Only the whole tunnel equipped with track absorbers reduction up to 9 dB in the low frequency range were obtained, which leads to a clear reduction of the micro-wave sound effect: only weakly audible and experienced as a dull dump. And, after this successful countermeasure, the effect of the MPW including a correction level of 8 dB(A) for impulsive noise contributes only 0.4 dB(A) at day time and 0.1 dB(A) at night time [31].
Figure 2.10. Third octave band spectra of the sound pressure level for an ICE 3-type train with 300 km/h at a distance of 50 m to Euerwang southern portal. without absorbers; partly equipped with absorbers; fully equipped with absorbers (Fig. 6 in [31]).
In ref. [30] a prediction formula for MPW disturbance pMPW in the far field is proposed as
s 2A 1 t 2 t 2 p t tun p't k exp p' t d k exp p't d MPW 1 2 2 2 c cs s0 2 0 4T1 0 T2 4T2 (2-18)
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where t is for time, s for the axial distance from the portal, c for the speed of sound in air, Atun for the cross section of the tunnel portal, for the solid angle which ' depends on the geometry of the portal and the surroundings, p p / t , T1 1.4r / c with r the (hydraulic) tunnel radius, T2 r / c , k1 1/4 T1 and k2 11/50 T2 .
For the case shown in [30] it was found that s0 8 (the origin where the axial distance s is measured) together with a solid angle of 5 / 4 . This formula has been evaluated and concluded as that it is satisfactory [30].
In the rest of this sub-section the method proposed in [19] to handle tunnel noise is presented. The method is based on Japanese work on road vehicle noise [24]. It is not clear at this time if the method can properly handle the railway tunnel noise directly after the micro-pressure wave (see Figure 2.9), because the ratio between the cross sections of the vehicles and the tunnel opening can be different for road and for railway applications. Thus, the method will probably suffer revision in near future.
2.5.1 General
Tunnel openings are regarded as special sound sources. Each train passing through a tunnel yields a certain sound energy level, LJ, through the tunnel opening. This energy depends on the total sound power level of the train and its speed, but it also depends on the sound propagation properties inside the tunnel.
At a certain moment a single train car is positioned inside the tunnel at the distance x from the tunnel mouth. For a stationary car, consider its sound power radiating through the tunnel opening to be WT. In a short time interval t the corresponding energy E through the opening will be WTt. The time interval can be estimated by x/v, x and v being the driving distance and the speed respectively during the time t. Positioning it at subsequent equidistant positions can simulate the pass through of the car through the tunnel and thus the total radiated energy through the tunnel opening can be calculated. By summing over all cars and the engine the corresponding level for the train is obtained.
It can be shown [24] that the sound power WT radiating through the tunnel opening due to a stationary sound source in the tunnel, is:
W ax (2-19) WT (a, x) (1 ) 2 r2 (ax)2
W is the total sound power, in watts, of the source, x is the distance, in m, of the sound source from the tunnel mouth, r is the radius, in m, of the tunnel (in case of a semi-circular cross section), a is a parameter regarding the sound absorption inside the tunnel (0 a 1).
For a tunnel with a rectangular cross section, the sound power is [24]:
W 1 wT h WT (a, x) tan (2-20) 4 2 2 2 x (wT h )(ax)
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wT is half the width, in m, of the tunnel mouth, h is the height, in m.
For a tunnel with a semi-circular cross section, the total energy radiating through the tunnel opening during a source passage through the tunnel is:
W x i max ax E (a) (1 i (2-21) T 2 v 2 2 i0 r (axi )
xi = xi, imax = INTEGER(Lt/x) (after rounding), Lt = tunnel length, in m, v is the driving speed, in m/s.
For a tunnel with rectangular cross section, the corresponding total energy radiating through the tunnel opening is :
i max W x 1 wT h ET (a) tan (2-22) 4 2 2 2 v i0 x (w h )(ax ) i T i
To obtain the total sound energy of a whole train we have to sum eq. (2-21) and (2- 22) over all cars. The result becomes the same as if we exchanged the sound power of the individual car, W, with that of the whole train.
2.5.2 Values of a
For a tunnel with a specified average sound absorption coefficient, , the value of a is given by, [24]:
a 1 (1) (2-23)
Table 2.7 gives some guidance to the value of in case no other information is available. The sound energy radiated in case 1 is denoted ETr. This case is the reference case to determine the directivity of the sound emission from the tunnel mouth, see clause 2.4.3 in [19]. The sound energy radiated in the other cases is denoted ET.
Table 2.7. Sound absorption coefficient, Frequency range, Hz f < 160 160-400 500-1250 f>1600
1. Reference, ETr 0,08 0,08 0,08 0,08 Smooth concrete surfaces, reflecting rail bed 2. Rough concrete surfaces, 0,08 0,11 0,14 0,14 reflecting rail bed 3. Concrete surfaces, ballast rail bed 0,1 0,2 0,3 0,3 4. Typical sound absorbing treatment 0,15 0,5 0,8 0,65
The effective value of a in case of tunnel sections with different a-values, is calculated by Eq. (2-24) :
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1 j max a a l (2-24) j j j1 Lt
where j and lj are the -value and length of the various sections respectively L't is the smaller of the total tunnel length Lt and 400 m. The sum includes the sections as seen from the tunnel mouth limited to the greater of the tunnel length Lt and 400 m (corresponding to jmax), whichever is applicable.
2.5.3 Calculation procedure
0,75 h
0,24 h
-w -0,5 w 0 0,5 w w
0,68 R
0,21 R
-0,5 R 0 0,5 R
Figure 2.11. Point source distribution in tunnel openings
The calculation of the sound energy level caused by a single train's passage through the tunnel, is carried out according to the following steps :
1 Choose a value of x. 10 m is an appropriate default choice.
2 Determine sub-source distribution. The sound energy level is distributed between 4 different sub-sources located according to Table 2.8 and Figure 2.11, for a semi-circular- and rectangular
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cross section respectively. The positions are expressed in terms of the cross section radius r, or the height h and half width w. The source positions are associated with approximately equal sub- areas of the tunnel opening. The positions are given relative to the track centre line, on the rail head.
Table 2.8. Point source distribution in the tunnel opening. Source Semi-circular Rectangular Horizontal Vertical Horizontal Vertical Source 1 0,5R 0,21R 0,5w 0,24h Source 2 0,5R 0,68R 0,5w 0,75h Source 3 -0,5R 0,21R -0,5w 0,24h Source 4 -0,5R 0,68R -0,5w 0,75h
2.6 Noise mitigation measures
Applicable noise mitigation measures will be considered where required. Noise mitigation measures can be divided into three groups: roughness related (brake types and acoustic grinding), transfer function related (dampers, rail pads, sleeper mats, wheel skirts) and propagation path related (noise barriers).
2.6.1 Acoustic grinding
Acoustic grinding may be carried out when serious corrugations presented on rail running surfaces. In ref. [3] it stated that “However, mostly wheel and rail running surfaces are actually very smooth. Once cast-iron brake blocks have been eliminated, further reduction in the excitation will be difficult …” This statement suggests that roughness related noise mitigation measure is irrelevant for high-speed lines. For conventional lines, in future when cast-iron brake blocks have been eliminated, this type of noise mitigation measures may disappear.
2.6.2 Reduction of the wheel component of noise
For reducing the wheel component of rolling noise, the most important aspects are the shape of the web and the wheel diameter. In principle, an acoustically optimized wheel has a smaller diameter and a thicker straight web and larger radius transitions between web and tyre and between web and hub; such a wheel radiates less noise [3]. However in practice, only a small change in wheel diameter can be tolerated within an existing bogie. And, weight and geometric constraints limit the wheel thickness.
The wheel component of rolling noise can be reduced by increasing wheel damping. The damping ratio for a free wheel is around 104 ; however, when coupling with the rail it increases considerably to greater than 103 . Accordingly, additional damping should exceed this “rolling damping”. The calculations using the TWINS software showed that for a damping ratio 3*102 the reduction of the wheel component of rolling noise is about 6 dB (although the mobility is reduced by nearly 20 dB) [3]. In general, adding wheel damping is very effective in reducing or eliminating curve
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squeal noise while much more modest in reducing the wheel component of rolling noise.
To mount a shield on a wheel will obstruct sound radiation from the web then reduce noise radiation from the wheel, provided that the shield is mounted in such a way that it does not vibrate significantly. Such wheel screens can reduce the wheel component of noise by 6 dB [3].
2.6.3 Reduction of the track component of noise
The noise radiated by the track is strongly related to the stiffness of the rail fastening, in particular the rail pad between the rail and the sleeper. In general, stiffer rail pads result in larger damping loss factor. However, to reduce track forces and damage to sleepers and track components, it has become common practice to use relatively soft rail pads with dynamic stiffness in the range 80-400 MN/m [3].
Added rail damping can increase the track decay rates without introducing stiff rail pads. Overall noise reduction of rail absorbers is about 3-4 dB for the track with soft pads [3].
2.6.4 Shielding measures
The other area of noise control that is close to the source is to reduce the sound transmission to the receiver. This type of noise measure can be made by introducing shielding in the form of vehicle-mounted “shrouds”, rail shielding and track-mounted low barriers. Rail shielding can reduce rail radiation by 2~3 dB(A) [29]. For tracks with a high decay rate, a combination of low barriers mounted close to the rail and bogie-mounted shrouds can lead to 8-10 dB(A) noise reduction [3].
2.6.4.1 Trackside barriers
About 1000 km of trackside barriers have already been constructed along European railway lines. Trackside barriers are seen as a secondary noise measure (although the simplest to be implemented) because this noise mitigation measure is less cost effective than noise controls at source [3].
Noise Barrier
Receiver
Source
the line of sight
Figure 2.12. The geometry in estimating barrier’s insertion loss.
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Table 2.9. Relationship between barrier insertion loss and design feasibility. Barrier insertion Design feasibility Reduction in sound Relative reduction loss (dBA) energy in loudness 5 Simple 68.4% Readily perceptible 10 Obtainable 90.0% Half as loud 15 Difficult 96.8% One-third as loud 20 Nearly impossible 99.0% One-fourth as loud
Barrier’s insertion loss (IL) can be estimated using an empirical formula
IL 51.5x (dB) (2-25) where x (in m) is the distance from the barrier’s top to the line of sight (between the sound source and the receiver), as shown in Figure 2.12. (Note: When using Eq. (2- 25) to estimate barrier’s insertion loss, it has been assumed that the barrier is enough long, usually not less than 8 times the distance between the source and the receiver.)
It is worth being aware of the relationship between barrier IL and design feasibility, as shown in Table 2.9. With this information, it is clear that, if not specially demanded, barrier IL higher than 15 dB should NOT be considered.
The empirical formula (2-25) is based on road traffic noise. For high-speed trains rolling noise together with aerodynamic noise is of a high level also at low and medium frequencies (see Figure 3.2). Thus, equation (2-25) may overestimate the barrier IL in some extent. Thus, for high-speed railway applications, a validated propagation model such as the Nord2000 can be used, together with a representative spectrum for high-speed train noise, to determine the barrier IL.
2.6.5 Reduction of aerodynamic noise
Morden high-speed trains should have been properly designed to have a streamline behavior. What can be further improved are in three aspects:
To have a low-noise pantograph [20-21] To reduce noise from bogie areas [3] To reduce noise from inter-coach gaps [3]
2.7 Source data
For rolling noise, representative source data for each train type shall be collected using the indirect roughness method described in 2.4.2.1. It is not necessary to separate total effective roughness into rail and wheel roughness, while it is necessary to separate the total transfer function into the track and vehicle transfer functions. As there are no standard methods for making such a separation, one has to refer to the TWINS calculations, existing examples, or the Harmonoise default transfer functions to work it out.
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(Note: To collect representative source data of rolling noise using the indirect roughness method is much more expensive than using the old method – only noise measurement. Without question, to collect such source data for all train types needs a lot of time and it is very costly. Therefore, for saving the cost, one may consider that only for new train types their source data will be collected in this way; for train types with the source data of the old type ready the current source model can be used.)
Only for high-speed trains one needs to work out the representative source data for aerodynamic noise, using the method described in 2.4.2.2.
Traction noise can be measured in idling condition, or, in a driving condition of accelerating at full traction power from standstill as described in ISO 3095 [9].
Source data for other noise types, such as impact noise, curve squeal noise, bridge noise, braking squeal noise, etc. will be measured when required; however, no standard methods for these measurements have been made ready.
Representative values of noise reduction for each mitigation measure shall also be determined. By “representative values” it does not mean the highest values reported in respective product development for which ideal conditions are often used to find the best result; they should be, for respective noise mitigation measures, the mean values found in the engineering applications.
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3 Determination of railway noise impact
3.1 Propagation attenuation
According to the Nord2000/2006 propagation model [23], at a specified receiving position (with distance R to the point sound source) the sound pressure level is predicted in the way
LR LW Ld La Lt Ls Lr L 10*log 4 R 2 L L L L W 10 a t s r (3-1) 2 LW 10*log104 R Aexcess
LW propagation attenuatio n where
LW is the sound power level within the considered frequency band,
Ld is the propagation effect of spherical divergence of the sound energy,
La is the propagation effect of air absorption,
Lt is the propagation effect of the terrain (ground and barriers),
Ls is the propagation effect of scattering zones,
Lr is the propagation effect of obstacle dimensions and surface properties when calculating a contribution from sound reflected by an obstacle.
Aexcess excess attenuation
As defined in Eq. (3-1), propagation attenuation consists of the spherical divergence 2 of the sound energy, 10*log104 R , and the other propagation effects which are integrated and named as the excess attenuation, , wherein weather effect on sound propagation path (wind gradient and temperature gradient) is included. Excess attenuation depends on propagation conditions, terrain and screen effects, as well as the source height and the receiver height. It will be handled by the Nord2000/2006 propagation model, which is comprehensive and the currently best for engineering applications [2]. Hereafter excess attenuation will be treated as a known quantity.
For case studies a real terrain and weather conditions will be specified. However, for strategic noise mappings a representative terrain(s) and typical weather conditions (neutral and favourable) will be used based on the statistics. Here favourable weather condition means the slightly downwind condition or other equivalent ones (e.g. a positive temperature gradient with height will lead to such a favourable weather condition). And, the statistics means yearly averaged occurrence probability (; or, based on other long time intervals, e.g. monthly averaged occurrence probability).
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3.2 Source line description
Some railway noise sources can be treated as point sources such as pantograph noise and locomotive traction noise, while rolling noise and aerodynamic noise around bogie areas have to be modelled by a source line. Even for the former their horizontal locations have to be specified e.g. relative to the train head. Therefore, a source line description is necessary for calculating railway noise.
In general, a railway consists of straight sections (of a large ratio) and curved sections. For a curved section there is a corresponding centre of the circle and the curvature. It is possible a receiving position is coincidentally located at such a centre of the circle, then calculation for this curved section becomes simple. However, this lucky situation does not help much because noise from other railway sections also need to be handled. As any curved section can be simulated by section-wise straight sections, calculation formulations based on a straight section is thought enough for handling railway noise.
......
Receiver 2
Receiver 1
Figure 3.1. Angle positions of a source line and its elements to receivers
In Figure 3.1 a train is divided into N units with mth unit located at the middle. The distance between Receiver 1 and the railway denotes as d; the horizontal angle j is defined as the angle between the normal of the railway and the straight line which connects the middle of the train and Receiver 1. In practice, it has no problem to determine the location of the middle of a train if the train length and the location of the train head have been specified.
th For i unit its horizontal angle is ji . It can be seen that differs for different receiving distances, that has to be so because the open angle of a train to a receiver depends on the distance. This is also related to the fact that both propagation attenuations and the directional effects differ at different measurement distances.
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j is for specifying the horizontal position of the train. Therefore, in principle, any part of a train, e.g. the train head, can be used as the reference to define .
3.3 Instantaneous sound pressure level Lp
Directivity can well be defined only for point sources. By applying the concept “source line”, railway noise will in general be modelled as a line of incoherent directional point sources. Without losing generality, one can divide the whole train into N ( 1 ) sections of equal-length of l0 1 m , and treat each section as an incoherent point sub-source. Thus, each sub-source will contribute to the total sound power level by
i i i LW LW 1m10lgl0 LW 1m,010lgl0 L ji , (3-2)
i where LW 1m is the sound power level produced by 1 meter long source element, i LW 1m,0 is for its omni-directional component and L ji is for its directional component. And, to have a good angle resolution, l0 / d should be enough small, e.g. 0.2 (which has a maximum open angle 11.3o).
Let us begin with a sound source type k of the source height m. Assuming that the 1 2 two ends of a source line are located at y and y , respectively, the contribution of this sound source to the instantaneous sound pressure level at the receiver is given by
2 m m y (L 1mAexcess ) /10 jN L 1m, A /10 10 W ,km 10 W ,km excess L 10lg dy 10lg d p,km j 2 1 4 r 4 d y j1 (3-3) where lg is a short form for log10 and in the second equation the transformation, dy / d (d 2 y2 ) / d r2 / d , has been applied. (Note: In Eq. (3-3), the sound i i power level for each point source is LW LW 1m10lgdy.)
Firstly, the horizontal angles for each section of a length l0 can be determined according to their horizontal positions:
1 ym j j tan , (3-4) d
y ji ym j i m*l0 d *tan j i m*l0 . (3-5)
Next, the open angle of the ith unit to the receiver is given by
44
1 y ji 0.5l0 1 y ji 0.5l0 ji tan tan d d . (3-6)
1 l0 1 l0 tan tan j i m 0.5* tan tan j i m 0.5* d d
Thirdly, the corresponding angle position of the ith unit is chosen to be
1 y ji 0.5l0 ji 1 d * tan j i m 0.5*l0 ji ji tan tan d 2 d 2 (3-7)
Thus, we obtain the calculation formula for source type k of a source height m
N m 1 LW ,km 1m, ji Aexcess ji /10 Lp,km j 10lg 10 ji (3-8) 4 d i1
i In the case all the units are acoustically equivalent, i.e. LW ,km 1m,0 LW ,km 1m,0, there will be
N m 1 L ji Aexcess ji /10 Lp,km j LW ,km 1m,010lg 10 ji (3-8’) 4 d i1
Eq. (3-8’) is used for noise mapping where simplifications are often taken for cutting down the calculation time; Eq. (3-8) is used for case studies where detailed sound power distribution can be important.
Thus, for a train found at horizontal angle position j , the instantaneous sound pressure level is determined by integrating the contributions from all the sources
L /10 p,km j . (3-9) Lp j 10lg10 k,m
3.4 Leq,T and SEL of a single train passage
Equivalent sound pressure level over a time period T is defined as
T T (LW t Aexcess t ) /10 1 L t /10 1 10 L 10lg 10 p dt 10lg dt (3-10) eq,T 2 T 0 T 0 4 rt
For handling Leq,T of a train pass by, we first re-write Eq. (3-3) in a different way
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Li 1m,t Ai t /10 N 10 W ,km exces L t 10lg l (3-3’) p,km j 4 r 2 t 0 i1 i
Thus, equivalent sound pressure level over a train pass-by time period T is given by
t T t T i i 0 0 N LW ,km 1m,t Aexces t /10 1 L t /10 l 10 Lkm 10lg 10 p,km j dt 10lg 0 dvt eq,T 2 T Tv i1 4 ri t t0 t0
2 i i yi L 1m,t A t /10 l N 10 W ,km exces 10lg 0 dy 2 i Tv i1 1 4 ri t yi (3-11)
th 1 2 w here i section is located at yi at time t0 and yi at t0 T ; v is the train speed. Applying the transformation, dy / d (d 2 y2 ) / d r2 / d , Eq. (3-11) becomes
i,max N i i km l L 1m, A t /10 L 10lg 0 10 W ,km i excess d eq,T i 4 dTv i1 i,min (3-12)
i,max N i l0 LW ,km 1m,0/10 L A /10 10lg 10 10 i excess i d i 4 dTv i1 i,min
where i corresponds to ji in Figure 3.1. And, there are
1 d * tan j t0 i m 0.5*l0 i t0 i t0 i,min tan (3-13) d 2
1 d * tan j t0 T i m 0.5*l0 i t0 T i t0 T i,max tan d 2 (3-14)
1 l0 1 l0 i t tan tan j t i m 0.5* tan tan j t i m 0.5* d d
(3-15)
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The corresponding contribution to the sound exposure level is
i,max N i km l0 LW ,km 1m,0/10 L A /10 SEL L 10lg T 10lg 10 10 i excess i d km eq,T i 4 dv i1 i,min (3-16)
i In the case all sections are acoustically equivalent, i.e. LW ,km 1m,0 LW ,km 1m,0, there will be
N i,max km l0 L A /10 L L 1m,0 10lg 10 i excess i d (3-12’) eq,T W ,km i 4 dTv i1 i,min
N i,max l0 L A /10 SEL L 1m,0 10lg 10 i excess i d (3-16’) km W ,km i 4 dv i1 i,min
For a complete train pass-by, there are and . i,min min 2 i,max max 2 Thus, one obtains
N / 2 l Li 1m,0/10 L A /10 SEL 10lg 0 10 W ,km 10 excess d ; (3-17) km 4 dv i1 / 2 and for the case all sections are acoustically equivalent
/ 2 Nl L A /10 SEL L 1m,0 10lg 0 10 excess d km W ,km 4 dv / 2 (3-17’)
/ 2 l L A /10 L 1m,0 10lg train 10 excess d W ,km 4 dv / 2 where subscript k is for source type such as rolling noise or aerodynamic noise, and subscript m is for source height. Eq. (3-17) is used for detailed case studies while Eq. (3-17’) is useful for noise mappings for which all train sections are often treated as equivalent ones.
km Leq ,T /10 Leq,T 10lg10 (3-18) km
SEL 10lg10 SELkm /10 (3-19) km
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3.5 Leq,T of railway traffic noise
Within a time period T train category c of a total length Lcv passed at a speed v contributes to the total equivalent sound pressure level as
cvkm Leq,T SELkm 10lgLcv /Tltrain (3-20)
/ 2 L L A /10 L 1m,0 10lg cv 10 excess d W ,km 4 dvT / 2
cvkm cv Leq ,T /10 Leq,T 10lg10 (3-21) km
The equivalent sound pressure level of the railway traffic noise, which contains the contributions from all train categories passed at different speeds, can be calculated as
cv cvkm Leq ,T /10 Leq ,T /10 Leq,T 10lg10 10lg 10 (3-22) cv cvkm
3.6 Standard noise indicators Lden and Lnight
The European standard noise indicator Lden is typically day-evening-night weighted, which is defined as
1 L /10 L 5/10 L 10/10 eq ,day eq ,evening eq ,night Lden 10lg 10lgTday10 Tevening10 Tnight10 T24hours (3-23)
According to this definition, traffic in evening or in night get a penalty 5 dB or 10 dB, respectively, which is equivalent to multiply the number of passed vehicles by 3.16 or by 10, respectively.
Each member state may define the time periods of day, evening and night slightly differently, provided the standard definitions of 07.00-19.00 (12 hours or 43200 s) for day, 19.00-23.00 (4 hours or 14400 s) for evening and 23.00-07.00 (8 hours or 28800 s) for night.
Lden, as well as Lday, Levening, and Lnight, is calculated based on yearly averaged daily traffic data (for defining corresponding LW) and under typical propagation conditions (for calculating corresponding Aexcess). Denoting yearly averaged occurrence probability ph for homogeneous (neutral) propagation condition, pf for favourable (downwind) condition, and pu for unfavourable (upwind) condition, there will be
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h f u yav Leq ,T Leq ,T Leq ,T Leq,T 10lgph10 p f 10 pu10 (3-24)
yav where Leq,T denotes yearly averaged equivalent sound pressure level for the time h f u period T which can be day, evening or night; Leq,T , Leq,T and Leq,T are the components of under respective propagation condition. With these quantities ready, Lden can be obtained using Eq. (3-23).
3.7 Consideration of vertical directivity
Vertical directivity of railway noise will be relevant when way-side high buildings are considered. In the cases the horizontal directivity L in all the equations in this section shall be replaced by the full directivity L L .
3.8 The maximum level LAFmax
The time weighting F is 1/8 second. Although this is a short time interval, a train at a speed of 320 km/h can move about 11 meters. To the standard measurement position 25 m from the track centre, this movement will have a largest open angle about 24.5o. And, double the distance, half the largest open angle.
Accordingly, L L with T = 1/8 second. Therefore, strictly, equations from pF eq,TF F
(3-12) to (3-15) and (3-18) shall be used for calculating L pF and LAF max .
There are two typical situations in which the maximum level shall occur when the train centre is (nearly) located in front of the receiver: (1) if assuming the sound power is horizontally uniformly-distributed, as well as the effect of horizontal directivity is negligible; (2) a freight train which is very long compared with the receiving distance. However, in general, the sound power distribution along the train and the horizontal directivity cannot be neglected. Therefore, LpFmax may be found when the train centre is not located in front of the receiver. Thus, one needs to calculate L pF at several angle positions in order to find LAF max :
At first taking the train centre located in front of the receiver as the starting point to calculate and its A-weighted total level; and then continue the calculation
by shifting the train centre’s angular position by 5o , 10o … (stopped when the A-weighted total level of is reduced; 30o should be enough.) Within these results will be found.
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3.8.1 An empirical approach for estimating LAF max
In practice, the horizontal distribution of the sound power of a train is usually unknown. For example, wheels’ roughness levels may differ not much for some trains while significantly for other trains. Therefore, for noise mapping purpose, a simplified calculation approach based on statistics is expected. In ref. [19] such an empirical approach for estimating has been proposed, stated in the following.
As the local effects(, such as the difference in wheel roughness levels of the train, or, the pantograph noise,) are more pronounced near the train they will be distance dependant. Until better information is available the following frequency independent correction, derived from train external noise data measured by SP, shall be applied
d LpFmax maxLp max , Lp max 3 2lg (3-25) 10
where d is the distance between the receiver and the track. Lp max is the calculated maximum train pass-by noise level assuming that the sound power is horizontally uniformly-distributed.
3.9 Indoor noise impact levels
Indoor noise impact level depends on the noise impact level at the façade(s) and the transmission loss of the façade(s), as well as the acoustic characteristics of the room.
A façade can be a quiet or the most exposed one. In ref. [7], it was summarised as
the most exposed façade will be the external wall of the dwelling exposed to the highest value of Lden/Lnight from the specific noise source under consideration (e.g. road traffic). a quiet façade, meaning the façade of a dwelling at which the value of Lden four metres above the ground and two metres in front of the façade, for the noise emitted from a specific source, is more than 20 dB lower than at the façade having the highest value of Lden.
For calculating façade noise impact, a reference receiving height is 4 m above the local ground (for noise mappings). However, for real situations, any applicable receiving height(s) can be specified.
As has been discussed in [2], sound insulation of a building façade is a topic of building acoustics, not an issue that a propagation model or a source model will handle. Once the sound level near or on the building façade has been determined, the indoor sound level will be calculated based on the theory of building acoustics.
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In [25], guideline values for limiting traffic noise impact on housing areas proposed by Swedish Government are
30 dBA Leq indoors 45 dBA LAFmax indoors and night time 55 dBA Leq outdoors at the façade 70 dBA LAFmax at the patio adjacent to the residential
These guideline values implicitly take 25 dB as the representative level difference between outdoor and indoor noise levels. However, what level differences should be in frequency range from 25 Hz to 200 Hz have not been specified.
The measurement study of façade sound reductions carried out by SP [36] showed that façade sound reduction can often be around 20 dB below 200 Hz and increases with frequency to 30~40 dB or more. Therefore, façade sound reduction depends also on the spectra of outdoor noise. In ref. [37], for road traffic noise, façade sound reduction increases with vehicle speed up to 5 dB raised (correction CF) because at a higher speed the sound power of road vehicle noise increases more in high frequency components. And, after noise barriers where high frequency components of the noise have been more reduced the façade sound reduction decreases with the barrier noise reduction level also up to 5 dB lowered (correction Cs).
According to ref. [34], for conventional trains (which usually run at a speed below 200 km/h) the Swedish Transport Administration (Trafikverket) takes 30 dB(A) as the difference between outdoor and indoor noise levels. However, for high-speed trains, because of the aerodynamic noise, the total railway noise has a high level also at low and medium frequencies (see Figure 3.2). Thus, façade sound reduction will become lower than that for conventional trains, for speeds above 200 km/h.
Figure 3.2. One-third octave band spectra of the power car and trailing coaches (Fig. 3 in [35]).
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Following what made in [37], a speed-dependent correction Caero is estimated as
Caerov 10*200 / v 1, v 200 km/ h (3-26)
Caerov 0, v 200 km/ h
Caero400 will give 5 dB(A) reduction in façade sound insulation. (Note: This preliminary estimation of the correction needs to be evaluated.)
Thus, the façade sound insulation for railway noise will be estimated as
Lfaçade v 30 Caerov (3-27)
Scientifically, if the noise sound power transmitted into a room through the façade is the only sound source, the indoor noise level will be determined based on (1) the noise level at/near the façade (outside); (2) the noise reduction of the façade; (3) the volume of the room; (4) the absorption area of the room; and (5) the distance to the façade (inside the room). The indoor sound pressure level can be determined, approximately, according to the theory of building acoustics [26-27]
D 4 Lp LW 10lg (3-28) 4 r 2 R
where LW is the sound power level transmitted into the room, r the distance to the façade, D the direction index, and R S the absorption area of the room.
An interesting empirical formulae proposed by Schultz (ASHRAE Transactions 1983, 91(1), pp 124-153) suggests, out of the near field, –3 dB/doubling of distance and independent of room absorption
Lp f LW f 10lgr 5lgV 3lg f 12 (3-29) where V is the room volume and f the frequency.
As can be seen, indoor sound pressure level varies with position and frequency, and depends on room volume and room absorption area. To find a representative level difference (of a function of frequency) between outdoor and indoor noise levels one needs to know (1) representative façade transmission reduction and (2) main parameters in determining the representative indoor noise level (if possible, not levels). A reliable while simplified method for calculating representative indoor noise level is still an issue to solve.
Accordingly, as a temporary solution, representative façade sound reduction is given by Eq. (3-27); and, the indoor noise impact level is then obtained by subtracting the value of façade sound insulation from the façade noise impact level.
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Note: In future these two questions need to be answered:
Representative façade sound reduction (in Sweden) and The reliable and accurate method to calculate representative indoor noise level.
3.10 Steps of calculation process
Specifying the important sources and determining the total source heights: (1) for train speed equal or above 200 km/h, both rolling noise and aerodynamic noise shall be considered; (2) for train speed below 200 km/h while above 50 km/h (for electric locomotive) or above 100 km/h (for diesel locomotive), only rolling noise shall be considered; (3) for the other low speeds, both rolling noise and traction noise shall be considered.
Calculating the excess attenuation Aexcess: for the concerned weather condition(s), for each of the receiving distances and receiving heights, each of the source heights, and at each of horizontal angle positions (e.g.) -88o : 2o : 88o. (Note: For a strategic noise mapping a rougher angular resolution such as -80o : 20o : 80o is acceptable.) Specifying directional sound power for each sub-source as well as relevant or required noise reduction(s): for each combination of train categories and track categories, together with each driving condition(s) and speed, as well as relevant noise mitigation measures.
For individual events (detailed case studies): Lp shall be calculated using
equations from (3-3) to (3-9); Leq,T and SEL shall be calculated using equations from (3-12) to (3-19).
For traffic noise: Leq,T shall be calculated using equations from (3-20) to (3-22), as well as equations from (3-12) to (3-17).
For strategic noise mappings: the European standard noise indicators Lden and
Lnight shall be determined using equations (3-23) and (3-24), as well as equations from (3-12) to (3-17) together with equations from (3-20) to (3-22). Calculating L of a train passage: L L (with T = 1/8 second), and AF max pF eq,TF F its A-weighted total level, shall be calculated using equations from (3-12) to (3- 15) and (3-18). Calculations shall begin with by taking the train centre located in front of the receiver; and then continue the calculations by shifting the train centre’s angular position by 5o , 10o … (stopped when the A-weighted total o level of L pF is reduced; 30 should be enough.). Within these results, the
LpF with the largest A-weighted total level is the . Calculating indoor noise level: Before a better method will be worked out, indoor noise level is obtained by simply subtracting the value of façade sound insulation given by Eq. (3-27) from the façade noise level.
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3.11 Uncertainty
In ref. [19] the uncertainty has been estimated. Before an extensive validation of the method will be carried out, it is recommended to assume the following approximate uncertainties for A-weighted values:
Table 3.1. The uncertainties for each component of the noise assessment method. Source of error Expected standard deviation Standard conditions* Other cases
Source data s = 1,5 s = 3
Description of terrain t = 1 t = 2 Favourable or f = 1 f = 2 homogeneous propagation, or (hs+hr) > 0.1 d
Unfavourable propagation, u = 3 u = 5 or (hs+hr) < 0.1 d
* Standard conditions are defined as in Table 3.2.
Table 3.2. Standard conditions. Source data Well defined standard track with large traffic of commonly occurring train categories Description of terrain Smooth ground surfaces with known impedances and not more than one well-defined barrier Favourable or Only one ground reflected ray homogeneous propagation, or (hs+hr) > 0.1 d Unfavourable propagation, Receiver not in the shadow zone or (hs+hr) < 0.1 d
As an example, the total prediction error (expressed as standard deviation) for the most favourable conditions is given by:
2 2 2 tot s t f 4.25 2.1 dB (3-30)
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4 Future work
4.1 Further improvement of the noise assessment method
This noise assessment method for (high-speed) railway noise will in future be further improved in the following directions:
The empirical method (for noise mappings) for calculating LAFmax. The method for calculating indoor noise impact. The method for handling railway tunnel openings. Train/track categorizations for conventional railway systems. Database for high-speed as well as for conventional speed railway systems, for rolling noise, aerodynamic noise, and traction noise (especially cooling fan noise). Database for other noise types. Database for noise mitigation measures. Methods for predicting noise impact in other situations than train passages, such as at stations, in shunting yards, etc.
4.2 Data collection
4.2.1 Collection of the representative source data
Representative source data of rolling noise shall be collected at typical speeds around 80 km/h and 160 km/h for each train type and each track type, using the indirect roughness method and referring to ISO 3095. Representative source data of aerodynamic noise shall be collected at typical speed not less than 250 km/h for each high-speed train type, by measuring the way-side total noise level at 25 m distance (to the track centre) and 3.5 m above the railhead. The source data is obtained by subtracting the rolling noise component from the measured total noise level. The source data for traction noise shall be collected for each locomotive type and/or traction type (e.g. EMU or DMU), using the methods described in ISO 3095. The source data for other noise types shall be collected using applicable methods; currently there are no standard methods made ready for such measurements.
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4.2.2 Specifying noise mitigation measures and the representative noise reductions
Each component of railway noise could be mitigated. However, those most important components should be handled first. Applicability, reliability, and the cost efficiency are the key parameters in choosing proper mitigation measures. Those applicable techniques, new innovations and successful engineering experiences shall be integrated and categorised. In this database of noise mitigation measures, for each important noise types and under typical situations probable mitigations measures shall be specified quantitatively. For example, when rail dampers have already been applied, or track decay rate is already very high, rail shield can further provide 2 dB reduction of the noise component.
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Reference
[1] Kjell Strömmer (Trafikverket), Uppdragsbeskrivning 2014-04-30: Definition av bullermodell för höghastighetståg. [2] Xuetao Zhang, Three Typical Noise Assessment Methods in EU, SP Report 2014:33, June 15, 2014. [3] David Thompson, Railway Noise and Vibration: Mechanisms, Modelling and Means of Control, Elsevier 2009. [4] Xuetao Zhang, Prediction of high-speed train noise on Swedish tracks, SP Report 2010:75. [5] Xuetao Zhang, Empirically modelling railway aerodynamic noise using one microphone pass-by recordings, (accepted to be published in) Notes on Numerical Fluid Mechanics and Multidisciplinary Design (2014). [6] B. Hemsworth, Vibration of a rolling wheel – preliminary results, Journal of Sound and Vibration (1983) 18 -194. [7] Common Noise Assessment Methods in Europe (CNOSSOS-EU), JRC72550, European Union, 2012. ISBN 978-92-79-25281-5 (pdf); ISSN 1831-9424 (online). [8] N. Yamazaki, A. Ido, T. Kurita and M. Matsumoto, Experimental Study on Flow Field under a High Speed Shinkansen Train, pp529, Proceedings of IWRN10 (the 10th International Workshop on Railway Noise), Nagahama, Japan, 18-22 October, 2010. [9] ISO 3095, Railway applications – Acoustics – Measurement of noise emitted by railbound vehicles. [10] Xuetao Zhang, The directivity of railway noise at different speeds, Journal of Sound and Vibration 329 (2010) 5273–5288. [11] F.G. de Beer, M.H.A. Janssens, and M.G. Dittrich, Indirect Roughness Measurement (MetaRail Task III.3, Deliverable 8), June 1998. [12] F.G. de Beer, H.W. Jansen, and M.G. Dittrich, STAIRRS Level 2 measurement methods: Indirect roughness and transfer function, 15 July 2002. [13] D.J. Thompson, C.J.C. Jones. Study on the sensitivity of the indirect roughness method to variations in track and wheel parameters (STAIRRS report) ISVR Contract Report 01/xx, April 2001. [14] D.J. Thompson, M.H.A. Janssens, F.G. de Beer. TWINS Track-Wheel Interaction Noise Software, Theoretical manual (version 3.0) (Silent Freight/Silent Track Report) TNO-report HAG-RPT-9900211, November 1999. [15] prEN 15461:2005 (E), Railway applications – Noise emission – Characterisation of the dynamic properties of track sections for pass by noise measurements. [16] Xuetao Zhang, Applying the TSI formulae together with the multiple-interpolations method to determine track decay rates using train pass-by measurements (in06_55), Inter- Noise 2006, 3-6 December 2006, Honolulu, Hawaii, USA. [17] Xuetao Zhang, A practical method to determine the sound power of railway rolling noise using one-microphone recordings, ForumAcusticum 2005, 29 Aug. – 2 Sept., Budapest, paper 579_0. [18] F. Poisson, P.E. Gautier, F. Letourneaux, Noise sources for high speed trains: a review of results in the TGV case, the 9th International Workshop on Railway Noise, Munich, Germany, September 4-8, 2007. [19] Hans G. Jonasson & Svein Storeheier, Nord2000. New Noise Prediction Method for Railway Traffic Noise, SP Report 2001:11, Borås 2001. [20] T. Takaishi, N. Yamazaki, T. Sueki and T. Uda, Recent studies on aerodynamic noise reduction at RTRI, Proceedings of IWRN10 (the 10th International Workshop on Railway Noise), Nagahama, Japan, 18-22 October, 2010. [21] M. Ikeda, T. Mitsumoji, T. Sueki and T. Takaishi, Aerodynamic noise reduction of a pantograph by shape-smoothing of panhead and its support and by the surface covering with porous material, Proceedings of IWRN10 (the 10th International Workshop on Railway Noise), Nagahama, Japan, 18-22 October, 2010.
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[22] Ulf Carlsson & Anders Frid, Gröna Tåget – trains for tomorrow’s travellers, Pass-by and internal acoustic noise, KTH Railway Group – Report 1107, 2011. [23] Birger Plovsing, Nord2000. Comprehensive Outdoor Sound Propagation Model. Part 1: Propagation in an Atmosphere without Significant Refraction, AV 1849/00, Noise & Vibration, DELTA, 31 March 2006. [24] K. Takagi et al., Prediction of road traffic noise around tunnel mouth, Proc. InterNoise 2000, pp. 3099-3104. [25] Regeringens proposition 1996/97:53, Infrastrukturinriktning för framtida transporter. [26] Tor Erik Vigran, Bygningsakustikk – et grunnlag, ISBN 82-519-1725-5, © Tapir Akademisk Forlag, Trondheim 2002. [27] SS-EN 12354-5:2009, Building acoustics – Estimation of acoustic performance of building from the performance of elements – Part 5: Sounds levels due to the service equipment. [28] Georgios Michas, Slab Track Systems for High-Speed Railways, Master Thesis, Division of Highway and Railway Engineering, Department of Transport Science, Royal Institute of Technology (Kungliga Tekniska Högskolan), Stockholm 2012. [29] G. Koller, T. Oguchi, Y. Matsuda, Noise reduction with rail shielding technology – Field tests on German railway track, Proceedings of IWRN11 (the 11th International Workshop on Railway Noise), Uddevalla, Sweden, 9-13 September, 2013. [30] Th. Tielkes, H.-J.Kaltenbach, M. Hieke, P. Deeg, M. Eisenlauer, Measures to counteract micro-pressure waves radiating from tunnel exits of DB’s new Nuremberg-Ingolstadt high- speed line, Proceedings of IWRN9 (the 9th International Workshop on Railway Noise), Munich, Germany, September 4-8, 2007. [31] K.G. Degen, Ch. Gerbig, J. Onnich, Acoustic assessment of micro-pressure waves radiating from tunnel exists of DB high-speed lines, Proceedings of IWRN9 (the 9th International Workshop on Railway Noise), Munich, Germany, September 4-8, 2007. [32] M. Hieke, Ch. Gerbig and Th. Tielkes, Mastering micro-pressure waves effects at the katzenbergtunnel – Design of measures, prediction of efficiency and full-scale test verufucation, Proceedings of IWRN11 (the 11th International Workshop on Railway Noise), Uddevalla, Sweden, 9-13 September, 2013. [33] S. Yamamoto, Micro-pressure wave issued from a tunnel exit, Abstract of the Spring Meeting of the Physical Society of Japan, April 1977. [34] Kjell Strömmer (Trafikverket), private communication, August 2014. [35] C. Mellet, F. Létourneaux, F. Poisson, C. Talotte, High speed train noise emission: Latest investigation of the aerodynamic/rolling noise contribution, Journal of Sound and Vibration 293 (2006) 535-546. [36] Clara Göransson & Geir Andresen, Fasaders ljudisolering i moderna svenska villor, SP RAPPORT 1995:39. [37] Naturvårdsverket, Vägtrafikbuller, Nordisk beräkningsmodell, reviderad 1996, RAPPORT 4653, mars 1999.
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Annex A The transfer function between LW and Leq,Tp
In general the sound power of train pass-by noise contains contributions from more than one noise sources with different representative source heights. For source j there will be [17]
Lj Lj 1m,0 A j , (A-1) eq,Tp W propagation(Tp )
N i,max j 1 L A j /10 A 10lg 10 i excess i d (A-2) propagation(Tp ) i 4dN i1 i,min
j where LW 1m,0 is the non-directional sound power level per meter train for source j j (of a source height hj), A the propagation attenuation for sound traveling propagation(Tp ) from the source j to a specified receiver, Lj the contribution from source j to the eq,Tp recorded L . The train is horizontally divided into N equal and small sections eq,Tp
(usually not less than 1 m). Moreover, the typical time, Tp, is defined in Figure A1 and the integration limit angles are defined in Figure A.2.
For the two standard receiving positions, 7.5 m/1.2 m (7.5 m from the track centre and 1.2 m above the railhead) and 25 m/3.5 m, the values of propagation attenuation for each sources (of rolling noise and aerodynamic noise) have been pre-calculated and provided in Tables A.1 and A.2. With these tabular values, it is j convenient to determine one set of quantities ( , or, LW 1m,0) if the other set of quantities are known.
t0 Tp / 2 t0 t0 Tp / 2
v ltrain d
Receiver
Figure A1. The time interval of Tp .
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si
v
i,min i,max
Figure A2. The trace of a sub-source during the time interval Tp .
Table A.1. The propagation attenuation A j for the standard receiving propagation(Tp ) position 7.5 m/1.2 m (train speed has non-important effect). Source height (m) (above railhead) Freq. (Hz) 0 0,5 25 -11,1 -9,4 31,5 -11,1 -9,4 40 -11,1 -9,5 50 -11,2 -9,8 63 -11,8 -10,8 80 -14,0 -13,9 100 -16,5 -15,1 125 -15,0 -13,0 160 -13,6 -12,4 200 -13,3 -13,3 250 -14,8 -17,0 315 -18,5 -18,1 400 -16,2 -16,5 500 -17,7 -16,4 630 -16,3 -15,5 800 -17,8 -15,5 1000 -17,8 -14,7 1250 -17,8 -14,7 1600 -17,1 -14,9 2000 -17,8 -15,0 2500 -17,5 -15,1 3150 -17,5 -15,3 4000 -16,5 -15,5 5000 -16,5 -15,9 6300 -16,7 -16,3 8000 -17,5 -16,7 10000 -17,3 -17,5 Note: The normalisation factors of the directivity functions are set zero.
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Table A.2. The propagation attenuation A j for the standard receiving propagation(Tp ) position 25 m/3.5 m (at train speed 320 km/h). rolling noise aerodynamic noise Source height (m) (above railhead) Freq. (Hz) 0 0,5 0,5 5 25 -16,8 -15,2 -13,4 -17,3 31,5 -16,8 -15,2 -13,5 -17,8 40 -16,9 -15,4 -13,6 -18,4 50 -17,1 -15,7 -13,9 -19,5 63 -18,1 -16,6 -14,9 -21,2 80 -19,9 -18,3 -16,4 -24,3 100 -20,4 -18,1 -16,3 -27,5 125 -19,6 -17,6 -15,9 -23,4 160 -19,1 -17,8 -16,0 -19,6 200 -19,2 -18,7 -16,9 -17,9 250 -21,0 -21,2 -19,3 -20,3 315 -22,6 -23,2 -23,8 -20,8 400 -22,7 -26,2 -26,0 -19,1 500 -26,3 -25,0 -27,9 -20,2 630 -27,3 -20,6 -25,0 -20,2 800 -25,6 -18,6 -22,0 -20,0 1000 -22,9 -19,3 -20,5 -20,1 1250 -21,4 -20,9 -20,5 -20,3 1600 -21,7 -19,6 -20,8 -20,6 2000 -24,1 -20,9 -21,4 -20,8 2500 -21,7 -20,2 -22,3 -21,2 3150 -22,6 -21,0 -22,9 -21,6 4000 -21,7 -21,3 -23,4 -22,2 5000 -22,9 -22,3 -24,5 -22,9 6300 -24,3 -23,5 -26,1 -24,0 8000 -25,7 -25,0 -28,2 -25,4 10000 -26,8 -26,8 -30,8 -27,3 Note: The normalisation factors of the directivity functions are set zero.
62
63
Annex B Source data for X2 rolling noise
Table B.1. The transfer functions, based on [4] while with a certain adjustment by referring to the ratio of the CNOSSOS default values for track and vehicle transfer functions [7].
Freq. (Hz) LH,tr (BV50 rail) LH,veh 25 45.0 20.0 31,5 49.0 22.0 40 52.5 26.0 50 55.0 30.0 63 57.5 34.1 80 60.1 38.2 100 62.4 42.4 125 64.9 46.5 160 67.4 50.6 200 69.8 54.7 250 71.0 58.8 315 72.3 68.3 400 73.5 67.1 500 74.9 63.0 630 76.6 65.6 800 77.1 69.5 1000 81.2 70.5 1250 82.0 71.6 1600 85.8 78.1 2000 88.5 86.8 2500 86.3 94.1 3150 90.5 96.8 4000 90.9 94.4 5000 94.6 97.6 6300 92.6 99.3 8000 91.9 100.6 10000 94.1 101.5
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Table B.2. The total roughness Lr and the contact filter CF. (Note: the data for > 40 cm and < 1 cm were estimated by referring to the Harmonoise default.)
Wavelength (cm) Lr (X2+BV50 rail) (dB) CF920_25KN (dB) 400 23.7 0 315 22.7 0 250 21.7 0 200 20.7 0 160 19.7 0 125 18.7 0 100 17.7 0 80 16.7 0 63 15.7 0 50 14.7 0 40 13.7 0 31.5 11.1 0 25 9.4 0 20 8.0 0 16 8.2 0 12.5 8.5 0 10 7.1 0 8 8.3 0 6.3 11.4 0 5 12.0 -0.2 4 10.3 -0.5 3.15 7.4 -0.9 2.5 5.0 -1.6 2 2.3 -2.5 1.6 -3.3 -3.8 1.25 -6.9 -5.8 1 -9.4 -8.5 0.8 -10.4 -11.4 0.63 -11.4 -12.6 0.5 -12.4 -13.5 0.4 -13.4 -14.5 0.315 -14.4 -16.0 0.25 -15.4 -16.5 0.2 -16.4 -17.7 0.16 -17.4 -18.6 0.125 -18.4 -19.6 0.1 -19.4 -20.6 0.08 -20.4 -21.6 0.063 -21.4 -22.6 0.05 -22.4 -23.6 0.04 -23.4 -24.6
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Annex C Default noise source data for high-speed railway systems
This set of default noise source data for high-speed railway systems is based on the source data of X2 trains while reduced by 6 dB to fulfil the TSI requirement on noise (92 dB(A) at the standard receiving position 25 m from the track centre and 3.5 m above the railhead, with 1 dB(A) tolerance).
Table C.1. Sound power level per meter train of rail/track radiation (0,01 m above railhead) Speed (km/h) Freq. 200 210 220 230 240 250 260 270 280 290 300 310 320 (Hz) 25 63,8 64,0 64,2 64,4 64,6 64,8 64,9 65,1 65,3 65,4 65,6 65,7 65,9 31,5 66,8 67,0 67,2 67,4 67,6 67,8 67,9 68,1 68,3 68,4 68,6 68,7 68,9 40 69,3 69,4 69,6 69,8 70,0 70,2 70,4 70,5 70,7 70,8 71,0 71,2 71,3 50 70,9 71,1 71,3 71,5 71,7 71,9 71,9 72,1 72,3 72,4 72,6 72,8 72,9 63 73,0 73,2 73,4 73,6 73,8 74,0 74,1 74,3 74,5 74,6 74,8 74,9 75,1 80 76,8 76,9 77,1 77,3 77,5 77,7 77,9 78,0 78,2 78,4 78,5 78,7 78,8 100 80,6 80,7 81,0 81,2 81,4 81,6 81,6 81,8 82,0 82,1 82,3 82,4 82,6 125 80,6 80,8 81,0 81,2 81,4 81,6 81,7 81,9 82,0 82,2 82,4 82,5 82,6 160 79,8 80,1 80,6 81,2 81,4 81,6 81,7 81,9 82,1 82,2 82,4 82,5 82,7 200 79,9 80,2 80,6 81,0 81,5 82,0 82,2 82,6 83,1 83,4 83,6 83,8 83,9 250 81,1 81,4 81,7 82,0 82,4 82,7 82,9 83,2 83,5 83,8 84,3 84,6 85,0 315 85,3 85,3 85,2 85,3 85,6 85,8 86,0 86,3 86,5 86,8 87,0 87,3 87,5 400 84,6 84,6 84,5 84,5 84,4 84,4 84,4 84,3 84,3 84,3 84,5 84,8 85,0 500 86,9 87,2 87,5 87,6 87,5 87,5 87,5 87,4 87,4 87,3 87,3 87,3 87,2 630 87,1 86,9 86,6 86,6 86,8 87,1 87,3 87,5 87,8 87,8 87,8 87,7 87,7 800 91,1 90,8 90,1 89,5 89,2 89,0 88,8 88,6 88,4 88,3 88,5 88,7 88,9 1000 96,9 96,9 96,8 96,5 95,9 95,3 95,1 94,6 94,1 93,6 93,4 93,2 93,1 1250 96,9 97,3 97,7 97,9 97,8 97,7 97,7 97,6 97,5 97,2 96,7 96,2 95,8 1600 97,1 97,5 98,2 98,9 99,3 99,7 100,1 100,3 100,7 100,9 100,9 100,8 100,8 2000 96,8 97,3 97,9 98,6 99,2 99,9 100,1 100,7 101,2 101,7 102,1 102,4 102,6 2500 89,9 90,6 91,4 92,1 92,7 93,3 93,6 94,1 94,7 95,2 95,7 96,2 96,7 3150 88,8 90,1 91,6 92,8 93,5 94,2 94,7 95,3 95,9 96,5 97,0 97,4 97,9 4000 83,3 83,7 84,9 86,1 87,5 88,8 90,0 91,0 92,1 93,2 93,8 94,3 94,8 5000 81,8 82,8 83,9 85,1 86,2 87,2 87,4 88,4 89,3 90,3 91,4 92,4 93,4 6300 75,4 76,1 76,9 77,9 78,9 79,8 80,6 81,5 82,4 83,3 84,2 85,0 85,8 8000 72,2 72,5 72,9 73,4 74,2 74,9 75,6 76,1 76,8 77,5 78,3 79,1 79,8 10000 73,0 73,3 73,7 74,2 74,6 75,0 75,2 75,6 75,9 76,3 77,0 77,6 78,1 A- weighted 104,5 104,8 105,3 105,8 106,1 106,5 106,7 107,0 107,4 107,7 107,9 108,1 108,3
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Table C.2. Sound power level per meter train of wheel radiation (0,5 m above railhead) Speed (km/h) Freq. 200 210 220 230 240 250 260 270 280 290 300 310 320 (Hz) 25 38,8 39,0 39,2 39,4 39,6 39,8 39,9 40,1 40,3 40,4 40,6 40,7 40,9 31,5 39,8 40,0 40,2 40,4 40,6 40,8 40,9 41,1 41,3 41,4 41,6 41,7 41,9 40 42,8 42,9 43,1 43,3 43,5 43,7 43,9 44,0 44,2 44,3 44,5 44,7 44,8 50 45,9 46,1 46,3 46,5 46,7 46,9 46,9 47,1 47,3 47,4 47,6 47,8 47,9 63 49,6 49,8 50,0 50,2 50,4 50,6 50,7 50,9 51,1 51,2 51,4 51,5 51,7 80 54,9 55,0 55,2 55,4 55,6 55,8 56,0 56,1 56,3 56,5 56,6 56,8 56,9 100 60,6 60,7 61,0 61,2 61,4 61,6 61,6 61,8 62,0 62,1 62,3 62,4 62,6 125 62,2 62,4 62,6 62,8 63,0 63,2 63,3 63,5 63,6 63,8 64,0 64,1 64,2 160 63,0 63,3 63,8 64,4 64,6 64,8 64,9 65,1 65,3 65,4 65,6 65,7 65,9 200 64,8 65,1 65,5 65,9 66,4 66,9 67,1 67,5 68,0 68,3 68,5 68,7 68,8 250 68,9 69,2 69,5 69,8 70,2 70,5 70,7 71,0 71,3 71,6 72,1 72,4 72,8 315 81,3 81,3 81,2 81,3 81,6 81,8 82,0 82,3 82,5 82,8 83,0 83,3 83,5 400 78,2 78,2 78,1 78,1 78,0 78,0 78,0 77,9 77,9 77,9 78,1 78,4 78,6 500 75,0 75,3 75,6 75,7 75,6 75,6 75,6 75,5 75,5 75,4 75,4 75,4 75,3 630 76,1 75,9 75,6 75,6 75,8 76,1 76,3 76,5 76,8 76,8 76,8 76,7 76,7 800 83,5 83,2 82,5 81,9 81,6 81,4 81,2 81,0 80,8 80,7 80,9 81,1 81,3 1000 86,2 86,2 86,1 85,8 85,2 84,6 84,4 83,9 83,4 82,9 82,7 82,5 82,4 1250 86,5 86,9 87,3 87,5 87,4 87,3 87,3 87,2 87,1 86,8 86,3 85,8 85,4 1600 89,4 89,8 90,5 91,2 91,6 92,0 92,4 92,6 93,0 93,2 93,2 93,1 93,1 2000 95,1 95,6 96,2 96,9 97,5 98,2 98,4 99,0 99,5 100,0 100,4 100,7 100,9 2500 97,7 98,4 99,2 99,9 100,5 101,1 101,4 101,9 102,5 103,0 103,5 104,0 104,5 3150 95,1 96,4 97,9 99,1 99,8 100,5 101,0 101,6 102,2 102,8 103,3 103,7 104,2 4000 86,8 87,2 88,4 89,6 91,0 92,3 93,5 94,5 95,6 96,7 97,3 97,8 98,3 5000 84,8 85,8 86,9 88,1 89,2 90,2 90,4 91,4 92,3 93,3 94,4 95,4 96,4 6300 82,1 82,8 83,6 84,6 85,6 86,5 87,3 88,2 89,1 90,0 90,9 91,7 92,5 8000 80,9 81,2 81,6 82,1 82,9 83,6 84,3 84,8 85,5 86,2 87,0 87,8 88,5 10000 80,4 80,7 81,1 81,6 82,0 82,4 82,6 83,0 83,3 83,7 84,4 85,0 85,5 A- weighted 103,0 103,7 104,7 105,5 106,2 106,8 107,2 107,8 108,4 109,0 109,4 109,9 110,3
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Table C.3. Sound power level per meter train of aerodynamic noise around the bogie areas (0,5 m above railhead) Speed (km/h) Freq. 200 210 220 230 240 250 260 270 280 290 300 310 320 (Hz) 25 88,1 89,0 89,6 90,2 90,7 91,0 98,7 98,4 98,3 98,5 98,3 98,2 98,0 31,5 88,0 88,8 89,8 90,5 91,4 92,1 91,6 94,5 94,6 94,7 95,1 95,0 95,1 40 89,4 89,7 89,9 90,6 90,7 91,0 88,5 92,1 92,8 93,4 93,9 94,5 95,0 50 88,2 88,7 89,8 90,8 91,8 92,7 90,7 93,2 94,4 95,0 96,0 96,7 97,0 63 89,2 90,4 91,6 92,5 93,5 94,4 95,6 93,1 93,2 93,0 92,3 91,8 90,1 80 90,9 92,2 93,4 94,2 95,3 96,3 94,9 93,4 93,4 93,1 92,7 91,7 89,3 100 92,9 94,0 94,4 95,2 95,8 96,5 97,0 88,8 89,5 90,7 90,1 90,1 90,1 125 93,0 93,8 94,4 95,0 95,5 96,0 90,5 91,2 91,6 92,0 92,5 92,8 93,1 160 92,3 92,7 92,9 93,5 93,7 93,9 91,3 91,7 92,4 92,9 93,5 94,1 94,6 200 90,3 90,5 91,0 91,5 92,0 92,4 93,3 92,5 92,8 93,1 93,2 93,2 93,1 250 88,7 88,9 88,1 87,5 86,9 86,1 93,6 92,2 92,7 92,8 93,3 93,4 93,3 315 79,6 79,6 80,5 81,5 82,2 83,0 95,7 92,2 93,3 94,3 95,6 96,1 96,8 400 77,0 77,7 78,3 79,2 79,8 80,3 93,7 93,0 94,3 95,6 96,7 97,8 98,9 500 74,5 75,1 75,7 76,3 76,9 77,4 94,4 95,0 96,2 97,3 98,4 99,5 100,5 630 71,5 72,1 72,6 73,4 73,9 74,5 96,2 96,6 97,9 99,1 100,0 101,2 102,3 800 68,4 69,0 69,6 70,5 71,0 71,5 98,7 97,6 98,7 99,8 100,7 101,6 102,5 1000 65,7 66,3 66,9 67,5 68,1 68,6 98,2 98,0 98,9 99,7 100,5 101,3 102,0 1250 62,8 63,4 64,2 65,0 65,7 66,4 97,2 97,1 97,6 98,2 99,1 99,5 100,0 1600 60,4 61,2 62,0 63,0 63,7 64,4 94,7 94,9 95,6 96,3 97,0 97,7 98,3 2000 58,6 59,4 60,2 61,0 61,7 62,4 93,2 92,4 92,2 92,1 91,9 91,6 91,3 2500 56,6 57,4 58,2 59,0 59,7 60,4 86,2 86,0 86,7 87,5 88,1 88,7 89,3 3150 54,5 55,3 56,1 57,0 57,7 58,4 84,2 84,1 84,6 85,1 85,8 86,2 86,6 4000 52,4 53,2 54,0 55,0 55,7 56,4 81,2 81,2 81,7 82,2 82,7 83,1 83,5 5000 50,6 51,4 52,2 53,0 53,7 54,4 78,2 78,3 78,8 79,4 79,9 80,3 80,7 6300 48,5 49,3 50,1 51,0 51,7 52,4 75,2 75,4 75,8 76,3 77,0 77,4 77,8 8000 46,4 47,2 48,0 49,0 49,7 50,4 72,2 72,4 72,9 73,4 73,9 74,3 74,7 10000 46,2 45,4 46,7 47,9 49,0 50,0 69,2 70,0 71,0 71,9 72,8 73,6 74,5 A- weighted 86,3 86,7 87,0 87,4 87,8 88,1 105,1 104,8 105,6 106,4 107,2 108,0 108,8
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Table C.4. Sound power level per meter train of pantograph noise* (5 m above railhead) Speed (km/h) Freq. 200 210 220 230 240 250 260 270 280 290 300 310 320 (Hz) 25 81,3 82,9 84,5 86,0 87,3 88,7 89,9 91,2 91,5 91,9 92,5 92,8 93,1 31,5 82,9 84,5 86,2 88,0 89,5 91,1 92,7 87,7 88,2 88,7 89,2 90,0 90,4 40 85,5 87,5 88,2 88,6 89,3 89,6 89,9 85,2 85,8 86,4 87,0 87,6 88,1 50 83,8 84,2 84,6 85,1 85,7 86,3 86,8 83,2 86,2 89,1 91,1 93,6 96,2 63 80,3 80,9 82,3 84,2 85,7 87,4 89,1 95,2 96,3 97,4 98,4 99,3 100,3 80 81,9 83,9 86,1 88,2 89,7 91,6 93,4 96,2 97,3 98,4 99,4 100,4 101,4 100 85,8 88,0 89,6 90,1 90,7 91,3 91,8 97,2 96,8 96,4 96,3 96,0 95,6 125 85,5 86,1 86,6 87,1 87,7 88,3 88,8 89,2 90,0 90,7 91,5 92,3 93,0 160 82,1 82,7 83,3 83,8 84,7 85,3 85,8 88,2 89,4 90,6 91,6 92,7 93,8 200 79,5 80,1 80,6 81,1 81,7 82,3 82,8 89,7 90,9 92,1 93,1 94,2 95,3 250 76,5 77,1 77,5 77,8 78,3 78,6 78,9 91,2 92,7 94,1 95,2 96,5 97,8 315 72,7 73,0 73,4 73,7 74,3 74,6 74,9 94,2 94,5 94,7 95,0 95,7 95,9 400 68,5 68,9 69,2 69,6 70,3 70,6 70,9 90,2 90,6 91,1 91,6 92,0 92,4 500 64,8 65,2 65,5 65,8 66,3 66,6 66,9 87,2 88,8 90,2 91,4 92,8 94,1 630 60,7 61,0 61,4 61,7 62,3 62,6 62,9 90,7 92,4 94,1 95,6 96,7 98,2 800 56,5 56,9 57,2 57,6 58,3 58,6 58,9 95,2 95,6 96,1 96,6 97,0 97,4 1000 52,8 53,2 53,5 53,8 54,3 54,6 54,9 92,2 92,6 93,1 93,6 94,0 94,4 1250 48,8 49,2 49,7 50,4 51,2 51,9 52,6 89,2 89,6 90,1 90,5 91,3 91,7 1600 45,9 46,7 47,5 48,2 49,2 49,9 50,6 86,2 86,6 87,1 87,6 88,0 88,4 2000 44,1 44,9 45,7 46,4 47,2 47,9 48,6 83,2 83,5 83,7 84,1 84,4 84,6 2500 42,1 42,9 43,7 44,4 45,2 45,9 46,6 79,2 79,5 79,7 80,2 80,5 80,8 3150 40,0 40,8 41,6 42,4 43,2 43,9 44,6 75,2 75,5 75,7 76,0 76,7 76,9 4000 38,0 38,8 39,5 40,3 41,2 41,9 42,6 71,2 71,5 71,7 72,1 72,4 72,6 5000 36,1 36,9 37,7 38,4 39,2 39,9 40,6 67,2 67,5 67,7 68,2 68,5 68,8 6300 34,0 34,8 35,6 36,4 37,2 37,9 38,6 63,2 63,5 63,7 64,0 64,7 64,9 8000 32,0 32,8 33,5 34,3 35,2 35,9 36,6 59,2 59,5 59,7 60,1 60,4 60,6 10000 31,4 32,7 31,9 33,0 34,1 35,2 36,2 55,2 56,1 57,1 57,9 58,8 59,6 A- weighted 76,5 77,3 78,0 78,6 79,3 79,9 80,5 99,4 100,0 100,6 101,4 102,0 102,7
* A pantograph can also be treated as a point source – in the case 10*log10(165) = 22.2 (dB) should be added to the tabular values.
Note: Cooling fan noise may have some effect on the total noise level. However, the source data for this noise type is currently not available.
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Annex D Default noise source data for high-speed railway systems under 200 km/h
As required by Trafikverket, the default source data for the speed range 30 km/h – 200 km/h are also provided for rolling noise and aerodynamic noise (referring to Annex C), while not for traction noise because representative data for this noise type is not available at this time.
Table D.1-1. Sound power level per meter train of rail/track radiation (0,01 m above railhead) Speed (km/h) Freq. 30 40 50 60 70 80 90 100 110 120 (Hz) 25 54,4 56,8 57,8 58,6 59,2 59,8 60,3 60,8 61,2 61,6 31,5 56,5 59,1 60,8 61,6 62,2 62,8 63,3 63,8 64,2 64,6 40 58,4 60,3 62,4 64,0 64,7 65,3 65,8 66,3 66,6 67,0 50 60,9 61,4 62,9 64,5 66,1 66,9 67,4 67,9 68,3 68,7 63 64,2 63,9 64,4 65,7 66,7 68,3 69,4 70,0 70,4 70,8 80 68,0 69,0 68,7 68,9 69,8 70,8 71,7 72,9 73,7 74,5 100 73,5 73,2 73,8 73,6 73,4 74,1 74,8 75,6 76,3 77,2 125 77,0 74,1 74,2 74,8 74,6 74,5 74,4 75,1 75,6 76,3 160 79,2 77,5 75,3 74,9 75,8 75,9 75,7 75,6 75,5 75,8 200 79,9 81,3 79,7 77,8 77,0 77,5 78,2 78,1 78,0 77,9 250 79,8 83,2 84,1 83,0 81,2 80,2 79,6 80,2 80,8 80,9 315 81,4 85,4 87,9 88,9 88,6 87,0 85,6 84,9 84,5 84,7 400 76,8 81,2 84,3 86,5 87,8 87,9 87,7 86,3 85,3 84,3 500 73,4 80,7 84,0 86,5 88,5 89,9 90,9 90,7 90,6 89,7 630 68,2 75,4 80,8 83,6 85,6 87,6 89,0 90,1 90,9 91,1 800 64,2 71,2 76,7 81,6 84,1 86,0 87,5 89,1 90,2 91,3 1000 64,3 70,0 75,4 79,6 84,2 86,9 88,7 90,2 91,4 92,7 1250 62,7 66,2 70,7 75,1 78,3 82,4 85,9 87,7 89,1 90,5 1600 63,6 66,1 68,8 72,3 75,8 79,2 81,4 84,7 87,4 89,6 2000 64,4 66,9 68,9 70,8 73,4 76,5 79,2 81,9 83,5 86,1 2500 58,6 61,4 63,4 64,9 66,3 68,4 70,5 73,0 75,1 77,3 3150 61,3 63,7 65,8 67,4 68,6 69,9 70,9 72,7 74,3 76,2 4000 59,6 62,1 64,0 65,7 67,1 68,3 69,2 70,2 71,0 72,2 5000 61,5 64,1 66,0 67,4 68,9 70,2 71,3 72,2 72,9 73,8 6300 57,9 60,3 62,3 63,9 64,9 66,3 67,4 68,4 69,2 70,0 8000 55,6 58,2 59,9 61,5 63,0 64,0 64,8 65,9 66,8 67,7 10000 56,4 59,0 61,0 62,4 63,7 65,0 66,1 66,8 67,4 68,3 A- weighted 80,3 84,6 87,7 90,1 92,1 93,8 95,3 96,6 97,7 98,8
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Table D.1-2. Sound power level per meter train of rail/track radiation (0,01 m above railhead) Speed (km/h) Freq. 130 140 150 160 170 180 190 (Hz) 25 61,8 62,2 62,5 62,8 63,0 63,3 63,6 31,5 64,9 65,3 65,6 65,9 66,0 66,3 66,5 40 67,4 67,7 68,0 68,3 68,5 68,8 69,1 50 68,9 69,3 69,6 69,9 70,1 70,4 70,7 63 71,1 71,4 71,7 72,0 72,2 72,5 72,7 80 74,9 75,2 75,5 75,8 76,0 76,3 76,5 100 77,9 78,8 79,3 79,6 79,8 80,1 80,4 125 76,8 77,4 78,2 78,9 79,4 80,1 80,4 160 76,3 76,7 77,2 77,7 78,1 78,5 79,2 200 77,8 77,7 78,0 78,4 78,7 79,1 79,5 250 80,8 80,7 80,6 80,6 80,5 80,5 80,8 315 85,1 85,6 85,6 85,5 85,5 85,4 85,3 400 83,9 83,5 83,6 84,1 84,4 84,8 84,7 500 88,9 87,9 87,2 86,9 86,6 86,2 86,6 630 90,9 90,8 90,0 89,2 88,6 87,8 87,4 800 92,0 92,7 92,9 92,7 92,7 92,6 91,9 1000 93,6 94,7 95,5 96,1 96,6 97,1 97,0 1250 91,4 92,4 93,5 94,4 95,0 95,9 96,4 1600 90,9 92,1 93,2 94,1 94,7 95,5 96,4 2000 88,6 90,7 92,4 93,4 94,3 95,3 96,1 2500 78,6 80,5 82,6 84,6 86,3 88,2 89,1 3150 78,0 79,7 81,6 83,2 83,9 85,4 87,2 4000 73,6 74,8 76,4 77,9 79,2 80,6 82,0 5000 74,3 75,1 76,1 77,3 78,2 79,3 80,6 6300 70,6 71,2 71,9 72,6 72,9 73,5 74,5 8000 68,4 69,1 69,7 70,2 70,6 71,1 71,7 10000 68,9 69,8 70,5 71,1 71,6 72,1 72,6 A- weighted 99,7 100,7 101,5 102,2 102,8 103,5 104,0
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Table D.2-1. Sound power level per meter train of wheel radiation (0,5 m above railhead) Speed (km/h) Freq. 30 40 50 60 70 80 90 100 110 120 (Hz) 25 29,4 31,8 32,8 33,6 34,2 34,8 35,3 35,8 36,2 36,6 31,5 29,5 32,1 33,8 34,6 35,2 35,8 36,3 36,8 37,2 37,6 40 31,9 33,8 35,9 37,5 38,2 38,8 39,3 39,8 40,1 40,5 50 35,9 36,4 37,9 39,5 41,1 41,9 42,4 42,9 43,3 43,7 63 40,8 40,5 41,0 42,3 43,3 44,9 46,0 46,6 47,0 47,4 80 46,1 47,1 46,8 47,0 47,9 48,9 49,8 51,0 51,8 52,6 100 53,5 53,2 53,8 53,6 53,4 54,1 54,8 55,6 56,3 57,2 125 58,6 55,7 55,8 56,4 56,2 56,1 56,0 56,7 57,2 57,9 160 62,4 60,7 58,5 58,1 59,0 59,1 58,9 58,8 58,7 59,0 200 64,8 66,2 64,6 62,7 61,9 62,4 63,1 63,0 62,9 62,8 250 67,6 71,0 71,9 70,8 69,0 68,0 67,4 68,0 68,6 68,7 315 77,4 81,4 83,9 84,9 84,6 83,0 81,6 80,9 80,5 80,7 400 70,4 74,8 77,9 80,1 81,4 81,5 81,3 79,9 78,9 77,9 500 61,5 68,8 72,1 74,6 76,6 78,0 79,0 78,8 78,7 77,8 630 57,2 64,4 69,8 72,6 74,6 76,6 78,0 79,1 79,9 80,1 800 56,6 63,6 69,1 74,0 76,5 78,4 79,9 81,5 82,6 83,7 1000 53,6 59,3 64,7 68,9 73,5 76,2 78,0 79,5 80,7 82,0 1250 52,3 55,8 60,3 64,7 67,9 72,0 75,5 77,3 78,7 80,1 1600 55,9 58,4 61,1 64,6 68,1 71,5 73,7 77,0 79,7 81,9 2000 62,7 65,2 67,2 69,1 71,7 74,8 77,5 80,2 81,8 84,4 2500 66,4 69,2 71,2 72,7 74,1 76,2 78,3 80,8 82,9 85,1 3150 67,6 70,0 72,1 73,7 74,9 76,2 77,2 79,0 80,6 82,5 4000 63,1 65,6 67,5 69,2 70,6 71,8 72,7 73,7 74,5 75,7 5000 64,5 67,1 69,0 70,4 71,9 73,2 74,3 75,2 75,9 76,8 6300 64,6 67,0 69,0 70,6 71,6 73,0 74,1 75,1 75,9 76,7 8000 64,3 66,9 68,6 70,2 71,7 72,7 73,5 74,6 75,5 76,4 10000 63,8 66,4 68,4 69,8 71,1 72,4 73,5 74,2 74,8 75,7 A- weighted 76,7 80,1 82,6 84,5 85,8 87,2 88,5 90,1 91,5 93,1
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Table D.2-2. Sound power level per meter train of wheel radiation (0,5 m above railhead) Speed (km/h) Freq. 130 140 150 160 170 180 190 (Hz) 25 36,8 37,2 37,5 37,8 38,0 38,3 38,6 31,5 37,9 38,3 38,6 38,9 39,0 39,3 39,5 40 40,9 41,2 41,5 41,8 42,0 42,3 42,6 50 43,9 44,3 44,6 44,9 45,1 45,4 45,7 63 47,7 48,0 48,3 48,6 48,8 49,1 49,3 80 53,0 53,3 53,6 53,9 54,1 54,4 54,6 100 57,9 58,8 59,3 59,6 59,8 60,1 60,4 125 58,4 59,0 59,8 60,5 61,0 61,7 62,0 160 59,5 59,9 60,4 60,9 61,3 61,7 62,4 200 62,7 62,6 62,9 63,3 63,6 64,0 64,4 250 68,6 68,5 68,4 68,4 68,3 68,3 68,6 315 81,1 81,6 81,6 81,5 81,5 81,4 81,3 400 77,5 77,1 77,2 77,7 78,0 78,4 78,3 500 77,0 76,0 75,3 75,0 74,7 74,3 74,7 630 79,9 79,8 79,0 78,2 77,6 76,8 76,4 800 84,4 85,1 85,3 85,1 85,1 85,0 84,3 1000 82,9 84,0 84,8 85,4 85,9 86,4 86,3 1250 81,0 82,0 83,1 84,0 84,6 85,5 86,0 1600 83,2 84,4 85,5 86,4 87,0 87,8 88,7 2000 86,9 89,0 90,7 91,7 92,6 93,6 94,4 2500 86,4 88,3 90,4 92,4 94,1 96,0 96,9 3150 84,3 86,0 87,9 89,5 90,2 91,7 93,5 4000 77,1 78,3 79,9 81,4 82,7 84,1 85,5 5000 77,3 78,1 79,1 80,3 81,2 82,3 83,6 6300 77,3 77,9 78,6 79,3 79,6 80,2 81,2 8000 77,1 77,8 78,4 78,9 79,3 79,8 80,4 10000 76,3 77,2 77,9 78,5 79,0 79,5 80,0 A- weighted 94,5 96,0 97,5 98,8 99,8 101,1 102,1
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Table D.3-1. Sound power level per meter train of aerodynamic noise around the bogie areas (0,5 m above railhead) Speed (km/h) Freq. 30 40 50 60 70 80 90 100 110 120 (Hz) 25 59,3 60,3 63,6 69,2 73,7 76,3 78,8 80,9 81,1 80,7 31,5 56,1 59,7 67,0 71,3 74,5 77,2 77,1 76,5 77,4 78,8 40 54,7 63,5 68,3 72,1 73,2 72,4 73,9 75,6 77,6 79,5 50 57,2 64,5 69,2 69,1 69,7 71,8 74,3 76,7 78,5 79,9 63 59,3 65,4 64,8 67,0 69,9 72,9 75,1 76,8 79,0 81,1 80 60,2 60,5 63,8 67,7 70,8 73,1 76,0 78,6 79,6 80,5 100 57,2 59,9 64,8 68,1 71,5 74,8 76,1 77,2 78,7 80,5 125 55,0 60,9 65,0 69,3 72,1 73,4 75,4 77,5 79,8 81,9 160 55,7 61,1 66,8 68,9 71,1 73,8 76,7 79,3 81,9 84,1 200 56,2 62,9 65,4 68,6 72,2 75,4 78,7 81,5 83,3 84,7 250 57,3 61,5 65,6 70,0 74,1 77,6 79,9 81,5 82,8 84,0 315 35,6 44,6 52,0 58,0 62,5 66,3 69,3 71,7 73,4 75,1 400 36,7 46,3 53,9 58,8 62,7 65,9 67,8 69,7 71,4 73,1 500 38,4 48,1 54,1 58,6 61,5 63,9 66,0 68,1 68,4 68,0 630 40,0 48,3 53,7 57,0 59,6 62,3 62,2 61,5 62,4 64,1 800 40,7 47,8 51,6 55,1 56,0 55,2 56,9 59,0 60,3 61,7 1000 40,5 45,8 50,1 49,9 50,6 53,1 54,8 56,4 57,6 58,8 1250 39,1 44,3 43,8 46,1 48,6 50,6 52,1 53,5 54,7 56,0 1600 37,0 37,1 40,9 43,6 45,6 47,4 48,8 50,4 51,5 52,9 2000 31,9 35,1 38,4 40,7 42,7 44,6 46,0 47,6 48,8 50,0 2500 28,1 32,5 35,4 37,9 39,8 41,8 43,3 44,7 46,1 47,6 3150 25,8 29,5 32,5 35,1 37,0 38,8 40,6 42,4 44,0 45,8 4000 22,7 26,5 29,6 31,9 34,2 36,5 38,5 40,5 42,1 43,6 5000 19,9 23,8 26,6 29,6 32,2 34,7 36,7 38,5 40,1 41,6 6300 17,0 20,7 24,4 27,7 30,3 32,6 34,6 36,4 38,0 39,6 8000 13,9 18,4 22,5 25,6 28,2 30,5 32,5 34,4 36,0 37,6 10000 12,8 18,3 22,1 24,9 26,9 30,3 31,4 34,2 34,6 36,9 A- weighted 53,0 58,5 62,6 66,2 69,6 72,6 75,0 76,9 78,5 79,9
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Table D.3-2. Sound power level per meter train of aerodynamic noise around the bogie areas (0,5 m above railhead) Speed (km/h) Freq. 130 140 150 160 170 180 190 (Hz) 25 80,1 81,4 82,5 83,5 84,6 85,8 87,0 31,5 80,0 81,6 83,1 84,6 85,7 86,5 87,3 40 81,3 82,5 83,6 84,5 85,9 87,2 88,3 50 81,2 83,1 84,6 86,2 86,7 87,1 87,9 63 83,1 83,5 84,3 84,8 85,7 87,0 88,1 80 81,2 82,8 84,2 85,6 87,1 88,5 89,7 100 82,2 84,1 85,7 87,2 88,9 90,4 91,5 125 83,9 85,9 87,5 89,3 90,6 91,4 92,3 160 86,3 87,3 88,4 89,4 90,2 91,0 91,7 200 85,9 86,9 87,8 88,6 89,0 89,3 90,0 250 85,0 85,4 86,2 86,5 86,9 87,5 88,1 315 76,2 77,6 79,1 80,3 80,7 80,2 80,0 400 74,7 74,1 73,8 73,2 73,9 75,0 76,1 500 67,2 68,6 70,0 71,2 72,1 72,8 73,9 630 65,6 66,5 67,8 68,6 69,3 70,0 70,8 800 62,7 63,6 64,6 65,4 66,2 66,9 67,8 1000 59,8 60,7 61,8 62,6 63,3 64,1 65,1 1250 57,0 57,9 59,1 59,9 60,6 61,3 62,1 1600 53,9 54,8 55,8 56,6 57,5 58,6 59,5 2000 51,0 52,2 53,5 54,5 55,5 56,5 57,7 2500 49,0 50,2 51,7 52,8 53,8 54,7 55,7 3150 47,1 48,4 49,6 50,7 51,7 52,7 53,6 4000 45,0 46,2 47,5 48,5 49,5 50,5 51,6 5000 43,0 44,2 45,5 46,6 47,6 48,6 49,7 6300 41,0 42,2 43,6 44,7 45,7 46,7 47,6 8000 39,0 40,2 41,5 42,5 43,5 44,5 45,6 10000 36,9 38,9 40,7 42,4 42,0 43,5 44,9 A- weighted 81,2 82,0 83,0 83,8 84,5 85,0 85,7
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Table D.4-1. Sound power level per meter train of pantograph noise* (5 m above railhead) Speed (km/h) Freq. 30 40 50 60 70 80 90 100 110 120 (Hz) 25 32,5 36,3 40,0 49,1 60,2 64,1 67,8 71,0 73,1 72,4 31,5 29,2 34,1 46,9 56,5 61,1 65,2 66,7 65,9 65,7 67,5 40 27,0 42,0 51,9 57,5 60,6 59,5 60,3 62,7 64,9 67,8 50 31,1 46,1 52,9 54,3 53,9 56,9 59,9 63,3 66,4 69,3 63 38,4 47,1 47,8 49,5 53,2 57,5 61,4 64,8 68,2 71,5 80 39,4 41,5 44,6 49,7 54,8 59,1 63,5 67,5 70,2 71,2 100 36,3 38,8 45,2 51,2 56,5 61,6 64,5 65,8 66,5 67,7 125 31,5 39,4 46,7 53,3 58,5 59,9 61,0 62,4 64,1 67,6 160 31,6 41,1 49,4 53,2 54,5 56,3 59,6 63,8 68,0 71,6 200 33,1 43,6 47,7 49,6 52,6 58,0 63,3 67,7 71,5 72,7 250 35,2 41,9 44,3 49,5 56,1 61,9 66,0 67,4 68,5 69,7 315 35,0 38,4 45,5 53,7 59,7 61,5 62,9 64,3 65,4 66,5 400 31,6 39,9 49,6 54,6 56,5 58,3 59,7 61,4 62,5 63,7 500 31,4 43,8 49,3 51,6 53,5 55,6 57,0 58,4 59,4 60,2 630 35,6 43,4 46,2 48,4 50,7 52,5 53,6 54,6 55,3 56,2 800 36,6 40,2 43,3 45,6 47,3 48,5 49,4 50,5 51,2 52,2 1000 33,6 37,5 40,3 42,2 43,3 44,7 45,5 46,8 47,4 48,2 1250 30,5 34,5 36,7 38,3 39,5 40,9 41,8 42,8 43,4 44,4 1600 27,6 30,4 32,4 34,2 35,3 36,5 37,4 38,5 39,2 40,2 2000 24,1 26,6 28,7 30,2 31,3 32,7 33,5 34,8 35,4 36,2 2500 20,2 22,9 24,7 26,3 27,5 28,9 29,8 30,8 31,6 33,1 3150 16,0 18,7 20,7 22,1 23,6 24,8 26,1 28,0 29,5 31,0 4000 12,1 14,6 16,7 18,2 19,7 22,0 24,0 26,0 27,6 29,1 5000 8,2 10,9 12,7 15,1 17,7 20,2 22,2 24,0 25,6 27,1 6300 4,0 6,7 9,9 13,0 15,8 18,1 20,1 22,0 23,5 25,1 8000 0,1 3,9 8,0 11,1 13,7 16,0 18,0 19,9 21,5 23,1 10000 -2,1 3,4 7,3 10,0 12,0 15,5 16,6 19,3 19,8 22,1 A- weighted 41,4 47,5 52,0 55,6 58,6 61,0 63,2 65,1 66,8 68,2
* A pantograph can also be treated as a point source – in the case 10*log10(165) = 22.2 (dB) should be added to the tabular values.
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Table D.4-2. Sound power level per meter train of pantograph noise* (5 m above railhead) Speed (km/h) Freq. 130 140 150 160 170 180 190 (Hz) 25 71,6 71,9 73,4 74,9 76,1 77,9 79,7 31,5 69,4 71,2 73,5 75,6 77,6 79,5 81,2 40 70,4 72,8 75,1 77,2 79,3 81,5 83,5 50 71,9 74,6 77,2 79,7 82,1 82,6 83,0 63 74,6 76,4 76,9 77,9 78,3 78,9 79,7 80 71,9 72,6 73,5 74,3 75,3 77,7 79,7 100 68,7 70,7 73,4 76,1 78,6 81,3 83,8 125 70,9 74,2 77,4 79,9 82,8 84,1 84,7 160 75,3 77,6 78,5 79,3 80,0 80,7 81,5 200 73,7 74,6 75,5 76,3 77,0 77,7 78,4 250 70,7 71,6 72,4 73,6 74,4 75,1 75,7 315 67,9 68,8 69,6 70,5 71,3 71,7 72,2 400 64,7 65,4 66,0 66,6 67,0 67,4 68,1 500 60,9 61,4 62,2 62,7 63,2 63,6 64,0 630 56,9 57,4 57,9 58,9 59,3 59,7 60,2 800 52,9 53,4 54,0 54,6 55,0 55,4 56,1 1000 48,9 49,4 50,2 50,7 51,2 51,6 52,0 1250 45,0 45,5 46,1 47,0 47,5 47,9 48,3 1600 40,9 41,4 42,0 42,6 43,1 44,0 45,0 2000 36,9 37,7 39,0 40,1 41,1 42,0 43,0 2500 34,5 35,7 36,9 38,3 39,3 40,2 41,2 3150 32,7 33,9 35,1 36,2 37,2 38,2 39,1 4000 30,5 31,7 33,0 34,1 35,1 36,0 37,1 5000 28,5 29,7 31,0 32,1 33,2 34,1 35,0 6300 26,5 27,7 28,9 30,2 31,2 32,2 33,1 8000 24,5 25,7 27,0 28,1 29,1 30,0 31,1 10000 24,2 24,1 25,9 27,6 27,2 28,6 30,0 A- weighted 69,6 70,8 71,9 73,0 74,0 74,9 75,7
* A pantograph can also be treated as a point source – in the case 10*log10(165) = 22.2 (dB) should be added to the tabular values.
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