Noise and vibration

Railway transport is the most sustainable transport mode, as it consumes less energy, needs less space and produces less CO2 than any other transport mode. However, noise has long been the main environmental challenge for railway stakeholders. The public and their political representatives urge railway stakeholders to become quieter. But a lot has been achieved, and more activities are on the way.

UIC Network Noise and Vibrations

The UIC Network Noise and Vibrations (NNV) promotes effective management of railway noise and vibration in the context of sustainable development. The group forms a center of excellence; it supports transfer of knowledge, coordinates events/activities, leads research projects and facilitates communication with key stakeholders. It works in close cooperation with other railway organisations, the EU commission and national authorities. The work of the Network is based on the Environmental Strategy of UIC and CER of December 2010.
NNV provides a technical lead on transport noise and vibration policy, in particular:

  • The rail sector response to growing pressure from the EU, national governments, lineside inhabitants, health organisations and NGOs.
  • Evaluation, review and guidance on upcoming new noise and vibration legislative initiatives and mitigation policy ideas and incentives (e.g. noise differentiated track access charges, prohibition of cast iron brake blocks, rail dampers etc.). In addition, it will consider the effects of noise mitigation methods on vibration and vice versa.

UIC Network Noise is concerned with all aspects of railway noise, e.g. rolling noise, stationary noise, and noise from shunting yards.
UIC Network Vibrations is dedicated to study vibrations and ground borne noise issues.
The expert meetings of NNV are held twice in a year.

For further information about The UIC Network Noise and Vibrations:

Projects and activities of UIC NNV

State of the Art Report - Railway Induced Vibration - 2017

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The UIC Sustainable Unit working group on vibration has just published the Vibrations State-of-the-Art Report. In modern daily life, people are exposed to many types of vibration. The vibration is often accepted as obvious and no cause for concern, for example when driving a car or when taking a lift. In some cases, vibration originating from sources outside the house may be felt inside (...)

The UIC Sustainable Unit working group on vibration has just published the Vibrations State-of-the-Art Report.

In modern daily life, people are exposed to many types of vibration. The vibration is often accepted as obvious and no cause for concern, for example when driving a car or when taking a lift. In some cases, vibration originating from sources outside the house may be felt inside dwellings. This applies for example to heavy road traffic, trams and railway lines, both on surface lines and in tunnels. This vibration is typically observed as a gentle trembling of the house, usually of the floor people are standing on. The vibration itself can generate a rumbling sound, caused by the vibrating building radiating sound into the rooms (known as structure-borne sound). Secondary noise, i.e. rattling of loose doors, pottery, etc., can further amplify the audible noise or make it more noticeable.

Whether or not the vibration can be perceived depends on many factors, including distance to the source, speed and type of the traffic, quality of the road or track, type and build-up of the ground, and the construction of the building itself. Modifications performed in the soil (modification of the sewer network, for example) or even in adjacent buildings can give rise to an increase of vibration or ground-borne noise. Contrary to popular belief, vibration caused by passing trains is far too weak to cause even cosmetic damage (when the structural integrity of the building is affected) to buildings. Nevertheless, residents affected by vibration may experience annoyance and could thus voice concern. The degree to which the vibration sensation is masked by audible noise can also play a role, as well as personal sensitivity.

Railway-induced vibration was first noticed and labelled an issue in relation to underground train lines. It is only in recent times that the vibration from surface lines is getting more attention. Vibration is usually accompanied by ground-borne noise. The relative significance of these two phenomena depends mainly on the soil type. In countries with stiff soils, e.g. solid rock, ground-borne noise is generally more important than vibration, and dominant vibration frequencies are higher (i.e. around 50 Hz). In countries with soft soil such as clay or peat, vibration may be more important than ground-borne noise and dominant vibration frequencies are lower (around 5 Hz). This difference in soil type is an important factor affecting the performance and selection of mitigation measures.

For railways, vibration is most often generated by the contact between the train wheel and the railway track. The vibration then travels from the track, through the ground and into the building foundation. Generally, the strength of ground vibration reduces as one moves away from the track. However, the strength of vibration may increase when moving up floors inside the building due to resonances of the building structure.

There are a number of mitigation measures available that can be applied to either the track or the vehicle. Because local factors (terrain, construction of individual buildings, space etc.) have a strong influence, the effectiveness of these measures can differ greatly from case to case. The prediction of vibration levels is thus a complex process and often involves a large degree of uncertainty. In some cases, especially existing situations, the cost of mitigation may be prohibitively expensive. In assessing vibration and designing mitigation, expert judgement is required.

Guidelines for acceptable levels of vibration vary from country to country. The impact on residents depends strongly on individual and local circumstances. Therefore, any values mentioned in this report should be interpreted with great care.
For new situations (railway lines or residential and other property development), it may be required to assess vibration and propose mitigation measures in the environmental impact assessment. For existing situations, most countries do not have a legal obligation for railway companies to assess and mitigate vibration. However, railways take residents’ concerns seriously and, where appropriate, will support an assessment and consider mitigation measures.

The present report reflects the state of the art, which is mainly based on the experience of the European rail-operating community, publications from academia and consultancy, the results of the collaborative research projects RIVAS and Cargovibes, and the work of standardisation committees, insofar as it has been published.

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State of the art Report - Railway Noise in Europe - 2016

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Railway transport is the most sustainable transport mode, as it consumes less energy, needs less space and produces less CO2 than any other transport mode. However, noise has long been the main environmental challenge for railway stakeholders. The public and their political representatives urge railway stakeholders to become quieter. But a lot has been achieved, and more activities are on the (...)

Railway transport is the most sustainable transport mode, as it consumes less energy, needs less space and produces less CO2 than any other transport mode. However, noise has long been the main environmental challenge for railway stakeholders. The public and their political representatives urge railway stakeholders to become quieter. But a lot has been achieved, and more activities are on the way. This report describes the recent developments and their impact.

This report is an update of a previous version, entitled Railway Noise in Europe, which was published in 2010. During the past few years’ significant developments have taken place with respect to legislation and approach, approval and application of technical solutions, responsibilities of the various parties involved and ways to persuade stakeholders to engage in common enterprises to improve the noise situation. At the same time, there is greater insight into the effects of noise on exposed residents and a growing pressure on railway enterprises and infrastructure managers to reduce noise where feasible. As a consequence, a significant noise reduction has been achieved for millions of European residents. Passenger vehicles with noisy cast iron brake blocks have been phased out in large parts of Europe. The retrofitting of significant parts of the rail freight fleet with composite brake blocks has started. In addition, old noisy wagons are scrapped every year and the new wagons replacing them are much quieter. Many kilometers of noise barriers have been constructed, a large number noise insulated windows installed and measures on the track introduced.

There are a wide variety of stakeholders concerned with the management of railway noise. The rail sector has to deal with regulations and demands from the European Commission, national authorities, regional and city authorities, citizen groups and individuals, and to align these requirements with the railways’ own strategies. This report describes how this is currently done and seeks to inform the associated discussions.

Noise exposure and the cost of noise control must be effectively managed if rail is supposed to increase its market share, and in doing so to reduce the total environmental impact of the whole transport sector.

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UIC Research Project: Managing Noise from Parked Trains - 2014

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Noise from parked trains is an increasing problem. In response to this, UIC have commissioned Müller-BBM to complete a technical review of the issues. The increase in noise issues related to parked trains is largely a product of urbanization and modernization. In passenger transportation old fashioned composites of locomotives carrying passenger coaches are more and more being exchanged with (...)

Noise from parked trains is an increasing problem. In response to this, UIC have commissioned Müller-BBM to complete a technical review of the issues. The increase in noise issues related to parked trains is largely a product of urbanization and modernization. In passenger transportation old fashioned composites of locomotives carrying passenger coaches are more and more being exchanged with modern multiple units that generally come with a far larger number of technical aggregates. In addition more and more yards and sidings are located in urban areas, which inevitably raises the number of people affected by noise from parked rolling stock.
Nowadays, parked railway units have to be short-term ready for operation.

Thus, different aggregates as heating ventilation and air conditioning (HVAC) or compressors are often in operation during the parking of the vehicle and cause noise. Especially the blow-off via the exhaust valve of the air dryer within the air supplying device is very noisy. Fluctuations due to multiple compressors running at slightly different rotational speeds can further tension the problem. The location of some of the aggregates on the roof of the vehicle makes countermeasures such as sound barriers far less effective. Particularly low floor multiple units which are popular with local and regional train services encounter this problem, as most of their aggregates generating noise on the parked train are located on the roof.

The parking areas are often located in urban areas, so that the noise emission of parking vehicles leads to complaints from local residents. These complaints can lead to restrictions on railway operators, who often need to carry out essential preparation work (e.g. cleaning) and maintenance of rolling stock at night.

Managing the noise from parked trains is complicated as different parties are involved like infrastructure managers, operators and fleet owners. The problem has increased for Infrastructure Managers and Rolling Stock Undertakers as some European countries have adopted national legislation to control noise from parked trains at night. The current revision of the TSI Noise includes limit values within the stationary noise section for the operation of the main air compressor (as the main intermittent noise source) and the exhaust valve of the air dryer (as the main impulsive noise source). This addresses two problems of parked rolling stock, it does not, however, cover all aspects of parked trains and it only applies for trains to be ordered in the future.

Due to the complexity of the problem, a comprehensive analysis of the problem is necessary, including typical operating conditions of parked trains and the respective operating conditions of the aggregates.
The presented research project compiles a number of possible strategies to manage the noise from parked trains and intends to give guidance for infrastructure managers and rolling stock operators as well as fleet owners to deal with the problem.

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Railway Noise - Technical Measures Catalogue
July 2013

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There is a growing awareness of the impact of railway noise on public health, which has resulted in pressure from line-side inhabitants, governments and health organizations for increased noise mitigation. As a consequence, noise can be a limiting factor for many railway operations, introducing additional costs for mitigation, demands for limits on availability/capacity and resistance to expansion of the network.

Recent years have seen the development of new, and refinement of existing, strategies and technologies for noise management. Railway companies often face calls to implement these, and demonstrate that progress has been made with the use of new and innovative technology.

By collating best practice and case studies from "real life" tests and adding the theoretical knowledge in this Catalogue, UIC stimulates the implementation of publically available knowledge, demonstrate the progress that has been made and also manage stakeholder expectations.

This Noise Technical Measures Catalogue surveys recent developments for three topics in
separate chapters:

  • Curve Squeal
  • Noise from freight marshalling yards
  • Noise from switches

In addition, one final chapter is dedicated to measures against rolling noise: rail and wheel dampers, K and LL blocks, noise barriers and acoustic grinding.
Curve squeal Curve squeal is a highly annoying sound that is radiated by trains running through sharp curves. Much progress has been made during the past decades in understanding this phenomenon. Mitigation measures aim at avoiding squeal events or at least reducing their duration or strength. Flange lubrication and top-of-rail application of friction modifiers have demonstrated to be very effective (reduction1: 5-20 dB(A)), provided that the dosing devices receive constant and dedicated maintenance. Friction products can be applied from trackbased as well as vehicle-mounted devices and there are many manufacturers and suppliers of such devices.

Special bogie designs, aiming at improved steering performance in curved as well as straight track, also reduce squeal noise and are potential solutions for the future, provided that safety issues can be solved adequately.

Noise from freight marshalling yards
Marshalling yards are areas where freight trains are decoupled and coupled. Because of the large scale of the yard, mitigation by noise barriers is no option. Among the most important noise sources are screeching rail brakes (retarders), peak noise from coupling vehicles and starting diesel engines, and steady noise from locomotive engines and auxiliary systems. Recently, new solutions for noisy rail brakes have been developed, showing promising noise performances (5-15 dB(A)). For stationary noise of several locomotives, technical modifications have been developed. Stationary noise of diesel engines, for example to operate cooling vents, may be avoided by using a way-side electric power supply.

Noise from switches
Switches and crossings are among the most sensitive parts of the railway system, claiming a large part of the maintenance budget. Switches and crossings also produce noise: impact noises from joints (if present) and screeching noise similar to curve squeal. In a traditional switch, a wheel encounters several gaps, causing a train to produce a rattling sound. Jointless switches are state-of-the-art nowadays (2-4 dB(A)) on lines where trains run at operational speeds. Squeal noise and flange rubbing noise in switches may receive the same treatment as squeal noise in curves (5-20 dB(A)).

Rolling noise
Rolling noise is the most common type of railway noise and there are many technical
measures that reduce it. High levels of rolling noise arise from irregularities on the wheel
tread and rail head, called roughness. Roughness of the rails can be controlled by
maintenance grinding and can be further reduced by acoustic grinding. Acoustic grinding
requires that the rails are ground or polished as soon as a certain reference noise level is
exceeded (1-3 dB(A)). The potential of acoustic grinding will increase if all train wheels are smooth as well. A large improvement in this field is expected from the homologation of LL braking blocks, which make retrofitting of freight vehicles a cost-effective option (8-10 dB(A)).

By application of rail dampers (0-3 dB(A)) and wheel dampers (0-2 dB(A)) a further noise reduction can be achieved. Rail dampers are applied in several countries. The noise reduction depends largely on the characteristics of the track system without rail dampers.

Promising developments for urban areas are low-close barriers, typically placed at only 1.70 m from the track with a height of 0.70-0.85 m. In certain cases low-close barriers are acoustically equivalent to much higher conventional barriers, their advantage being that they do not block the view. However, in view of safety issues with barriers placed that close to the traffic, to date only few countries have decided about homologation.

The real cost of railway noise mitigation - A risk assessment - 2013

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National noise legislation requires rail infrastructure managers throughout Europe to take noise mitigation measures. Practically, the choice is between vehicles related measures (for example brake shoe retrofitting), track related measures (for example rail dampers), measures in the propagation path (for example noise barriers) and measures at the receiver (for example double glazing). The (...)

National noise legislation requires rail infrastructure managers throughout Europe to take noise mitigation measures. Practically, the choice is between vehicles related measures (for example brake shoe retrofitting), track related measures (for example rail dampers), measures in the propagation path (for example noise barriers) and measures at the receiver (for example double glazing). The costs of the different measures are a crucial parameter when making this choice.

The common rail position is that rail freight retrofitting is the most cost efficient measure. This position was underlined in the UIC Noise Action Plan, adopted in 1998. This notion was based on the results obtained in the research project STAIRRS, where the costs of different mitigation options were compared. The results of STAIRRS have been quoted many times since they were first published. Almost 15 years have
passed since. Therefore, the current study was launched with the objective to review and update the information on which the STAIRRS results were based. Particularly the current study addresses the fact that cost data should be based on life cycle cost assessment rather than merely investment costs in order to have a fair comparison between options.

In the frame of the current study, an attempt was made to collect practical data on cost elements such as maintenance costs and life span of certain measures. For rail freight retrofitting, such an assessment has been made in full detail, and the intention was to compare this data with similar data for the other options. In addition, information was collected on the amount of noise migration required in the different member states, based on current legislation. It was found, that very little detailed information is available from the infrastructure managers. Usually, once the noise mitigation measure has been installed, the costs for its maintenance are hardly ever earmarked and therefore are difficult to assess. Moreover, the life span of many measures is not exhausted yet, so that renewal costs data are not reliably available either.

Based on the best estimates available, and using current cost assessment methods, an overall assessment was made comparing the Net Present Value and Equivalent Annual Costs for a range of noise mitigation options. The assessment leads to the firm conclusion that rail freight retrofitting is the preferred option, thus confirming the conclusions from the previous STAIRRS project. The updated graph is presented below. In comparison to the original STAIRRS graph, the number of vehicles to be retrofitted
was adapted to the current best estimate (350 000 wagons instead of 710 000 wagons). The cost indicators were changed to Net Present Value instead of the indicator “Present Cost” PCx, which is not as well defined.

See the document
Real noise reduction of freight wagon retrofitting - Supporting communication on noise reduction - Synthesis report - 2013

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Freight trains are the main contributors to noise from mixed railway lines. The railway sector, represented by UIC, proposes the retrofitting of the existing European freight fleet, by replacing cast iron brake blocks with composite (organic or sinter metal) brake blocks. Over the past years, various scenarios have been proposed to support the sector financially to achieve this goal. Whether (...)

Freight trains are the main contributors to noise from mixed railway lines. The railway sector, represented by UIC, proposes the retrofitting of the existing European freight fleet, by replacing cast iron brake blocks with composite (organic or sinter metal) brake blocks. Over the past years, various scenarios have been proposed to support the sector financially to achieve this goal. Whether or not this program should be supported by public means depends on the benefit of the operation. The benefit can be expressed as the reduction of noise levels to be achieved by retrofitting.
In the past decade, many field tests have been carried out, focusing on the feasibility of retrofitting and the economical and safety implications of it. Occasionally, such tests have been combined with noise measurements intended to assess the achieved reduction of noise levels.

The study reported here has collected more than 120 reports on such experiments. In only 39 of these, noise data were reported. These data have been analyzed, interpreted and converted. It turns out, that absolute pass by noise levels show large spread, mainly because of different track conditions. This is illustrated in the graph from section 4.1

On the basis of these absolute levels, no simple single figure could be derived with respect to the achievable reduction. Therefore, the noise data have been converted to a situation where the track conditions have been normalized to the roughness graph according to the CEN ISO 3095. This normalization to the roughness curve is used only as a point of comparison. The normalized roughness spectrum does not represent an actual real situation; it is merely a compromise between various good
quality tracks in Europe. It turns out that, after this conversion, the results are very consistent and similar, with very few exceptions.

From this analysis we conclude, that, for a track roughness normalized to the CEN ISO 3095 limit, the following reductions are achieved compared to a similar wagon equipped with cast iron brake blocks:

  • K-blocks [3]: - 8 to 10 dB(A)
  • LL Jurid 777 block: - 7 to 8 dB(A)
  • LL Cosid 952/LL Cosid 952-1 block: - 8 to 9 dB(A)
  • LL Becorit IB116 block: - 10 to 12 dB(A)

It is emphasized here that a reduction of 7 to 10 dB(A) implies that 5 to 10 times as many trains can be operated with the same long term average noise level, i.e. within the same legal limit.

In practical situations, if the real track roughness exceeds the CEN ISO 3095 values, the reduction would be less than the values shown above. For other tracks however, with lower roughness levels than the CEN ISO 3095 curve, the reduction would be similar to or even larger than the value indicated above. This would apply for instance to the “especially monitored track” (besonders überwachtes Gleis) in Germany.
For a relatively good quality track, the reduction values could be typically 3 dB(A) less than indicated above. In exceptional cases with bad track quality the reduction could be negligible.

See the document
Rail Dampers, Acoustic Rail Grinding, Low Height Noise Barriers - 2012

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There are many noise mitigation options open to railways. Some of them - such as noise barriers - have a known effect and are used widely, others such rail dampers, acoustic rail grinding or low height noise barriers are still controversial for various reasons. Since each railway has limited opportunities to extensively test these controversial measures, the Network Noise of UIC decided to (...)

There are many noise mitigation options open to railways. Some of them - such as noise barriers - have a known effect and are used widely, others such rail dampers, acoustic rail grinding or low height noise barriers are still controversial for various reasons.

Since each railway has limited opportunities to extensively test these controversial measures, the Network Noise of UIC decided to collect results and measurement conditions of these three noise abatement measures. This report first de-scribes some elementals of noise control as well as quantities that are important for understanding the arguments made. It then describes the three noise mitigation methods in more detail, explains why they are controversial and finally lists and comments on the experience made to date.

The experience in other countries was obtained by asking members of the UIC Network Noise as well as representatives from other European countries. The request for information was sent in mid 2011. In addition this report was sent to Network Noise members in mid 2012 for comments and for additional results not available in 2011.A limited number of results where obtained from other sources.

The main conclusions of the report are:

Rail dampers:

  • There is a large variability in the results ranging from small increases in noise to a maximum noise reduction of usually not more than 3 dB.
  • The effects of dampers are influenced by many parameters such as construction (rail pad stiffness) or traffic. However for many of the results these parameters were not measured. Therefore it is difficult to compare the results or to use the results from one situation in order to predict the effects in another one.
  • Network wide cost-benefit analyses have not been undertaken to date. The ongoing Swiss project is the first to attempt this.
  • The STARDAMP project and the ongoing Swiss trials are the first systematic approaches to the problem measuring all relevant parameters. The results of these projects still outstanding and will be included in further editions of this report.

Rail grinding:
Only two countries – Germany and The Netherlands – have implemented acoustic rail grinding procedures.

  • In Germany the procedure allows a legal noise reduction of 3 dB, while in The Netherlands specific noise reduction aims are defined.
  • Lacking are network wide cost benefit analyses. It is suggested that these are undertaken, best in a cooperative approach by the railways.

Low height noise barriers:

There is not much information available on low height noise barriers to date and the trials are mostly not precise enough to undertake a final conclusion on the issue. The basic arguments are still the same:

  • From an acoustical point of view low height barriers are comparable r to normal barriers and they have the advantage of fitting into the landscape.
  • On the other hand, there is not yet enough ex-perience to satisfactorily address maintenance and security questions. Some countries (e.g. Norway) do not report problems, others (e.g. Switzerland) are not pursuing the issue because of these concerns.
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On the END Consultation - Noise limits and trigger values - 2012

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The European Directive on the Assessment and Management of Environmental Noise has been in force since 2002. It requests Member States to produce strategic noise maps of the major transport infrastructure and of agglomerations. The maps shall be made public and serve to assess the number of citizens in each Member States that are exposed to potentially harmful noise from roads, railways, (...)

The European Directive on the Assessment and Management of Environmental Noise has been in force since 2002. It requests Member States to produce strategic noise maps of the major transport infrastructure and of agglomerations. The maps shall be made public and serve to assess the number of citizens in each Member States that are exposed to potentially harmful noise from roads, railways, airports and and industrial activities.

In addition, Member States shall set up Action Plans to reduce noise where it
is excessive and protect areas where the noise quality is good. The public shall be consulted with respect to these Action Plans. The European Commission has reviewed the implementation of the Directive in 2010 and has proposed some improvements. In 2012, a public consultation was launched on the contents of this proposal. The railway sector responds to this consultation, among others, through the current report.

It is in the interest of the railway sector in Europe to create a level playing field with all other transport modes. To that effect, the railways strive for an internalization of external cost. Moreover, the railways wish to maintain and reinforce their image of environmental friendliness and guarantee the capacity, quality and availability of the European rail infrastructure.

With respect to these interests, the following issues are emphasized:

  • The Directive ignores the impact of some of the transport modes, such as inland waterways,and for other stressors than noise (e.g. air quality or CO2), there is no distinct assessment of the impact of different transport modes.
  • The noise annoyance correction factor, which indicates railway noise to be less annoying than road traffic or air traffic noise at equal noise exposure, is completely ignored. This leads to a situation where the railways’ contribution to the annoyance and health effects in Europe is largely overestimated.

Furthermore, the railway sector feels that the overall results produced by the noise mapping should enhance tighter type approval limits for road vehicles, as these are the dominant noise source by far. This policy element is essential to the success of the Directive but is currently not merging.

Finally, the harmonized noise limits as proposed by some Member States represent a serious threat to the
operation of railways, if they were to be based on the extremely low night time limits proposed by he World Health Organisation.

See the document
UIC Project, Exploring bearable noise limits and emission ceilings for the railways: Part 1 - National and European legislation and analysis of different noise limit systems - 2011

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The question ‘What are bearable limits for environmental railway noise?’ is discussed regularly in different forums at both National and European levels. To inform this debate, UIC has commissioned dB Vision to perform a systematic evaluation of all aspects affecting what is ‘bearable’. This allows UIC to propose, for the first time, a well balanced noise limit considering the interests of (...)

The question ‘What are bearable limits for environmental railway noise?’ is discussed regularly in different forums at both National and European levels. To inform this debate, UIC has commissioned dB Vision to perform a systematic evaluation of all aspects affecting what is ‘bearable’. This allows UIC to propose, for the first time, a well balanced noise limit considering the interests of lineside residents and also what is feasible for the railways.

The findings are presented in a two-part report titled ‘Bearable noise limits and emission ceilings for the railways’. Please click below to download the reports.

This study clearly demonstrates that:

  • Railway noise reception limits should not be set lower than 55 dB Lnight
  • Below 55 dB Lnight it is more cost-effective to mitigate road traffic noise
  • Reductions below 50 dB Lnight incur large costs with diminishing returns
  • Achieving the WHO night noise guideline of 40 dB Lnight would result in high costs and a massive impact on transport and the spatial environment.
See the document
UIC Project, Exploring bearable noise limits and emission ceilings for the railways: Part 2 - Cost and benefit study for different noise limits - 2011

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The question ‘What are bearable limits for environmental railway noise?’ is discussed regularly in different forums at both National and European levels. To inform this debate, UIC has commissioned dB Vision to perform a systematic evaluation of all aspects affecting what is ‘bearable’. This allows UIC to propose, for the first time, a well balanced noise limit considering the interests of (...)

The question ‘What are bearable limits for environmental railway noise?’ is discussed regularly in different forums at both National and European levels. To inform this debate, UIC has commissioned dB Vision to perform a systematic evaluation of all aspects affecting what is ‘bearable’. This allows UIC to propose, for the first time, a well balanced noise limit considering the interests of lineside residents and also what is feasible for the railways.

The findings are presented in a two-part report titled ‘Bearable noise limits and emission ceilings for the railways’. Please click below to download the reports.

This study clearly demonstrates that:

  • Railway noise reception limits should not be set lower than 55 dB Lnight
  • Below 55 dB Lnight it is more cost-effective to mitigate road traffic noise
  • Reductions below 50 dB Lnight incur large costs with diminishing returns
  • Achieving the WHO night noise guideline of 40 dB Lnight would result in high costs and a massive impact on transport and the spatial environment.
See the document

Noise Annoyance Correction Factor, 2010
When the intensity of noise and duration of the exposition to noise increase, the effects on human beings increase as well. Residents will be more annoyed, the closer they live to a railway line or a motorway. And also: the passage of a single train per hour will be less annoying than a train every five minutes. These conclusions are usually presented as so-called dose-response relationships. Such relations were derived from field studies in the nineteen seventies. Usually they relate self-reported annoyance (assessed on the basis of score in a questionnaire) to long term average noise level.
In the early eighties it was found, in several of these field studies, that at equal long term average exposure, railway noise caused fewer people being annoyed than road traffic noise. This result was the basis for a differentiation in legal noise limits between road and rail traffic; the difference usually amounts to 5 dB. Some 6 member states introduced this differentiation, either in limits or in the prediction method. In Germany, the limits are identical for road and rail noise, but the prediction method introduces the 5 dB correction factor. This correction factor has been given the name “railway bonus”, a somewhat unlucky choice, since many people think that this correction factor is merely reflecting the environmental benefit of rail transport relative to road transport. As the above introduction illustrates, there are other, more fundamental reasons for this factor.

Over time, the justification of the noise annoyance correction factor was frequently questioned. Certainly at times, when the public discussion on railway noise increased, for example when high speed lines were planned, or currently in situations with rapid growth of freight transport. UIC has commissioned a study from DHV in The Netherlands, reviewing the available references on this topic, both recent and historical. The study concludes, on the basis of numerous international references, that most field studies confirm that the correction factor is still justified, even when traffic circumstances have changed. This applies to the classical relations, where long term average noise levels are currently expressed as Lden (day-evening-night level, with penalties for evening and night included), and “annoyance” is the self reported result of a score list, currently standardized by the ICBEN . Moreover, these two parameters invariably show rather good correlation.

Poor correlation is found, when other parameters are chosen. For example, there is a tendency to apply maximum noise levels instead of energy equivalent levels as the dose parameter. Particularly for night time noise, a wide range of parameters can be found, registering e.g. sleep disturbances. When comparing sleep near a railway line to sleep near a road, the window setting often disturbs the picture: most people near a busy road sleep with windows closed.

More study is needed to find ways to company the regular dose parameters such as Lden to the other, more incidental parameters. For the time being, there are no fundamental indications that the railway noise annoyance correction factor should be omitted.

The railway noise bonus - Discussion paper on the noise annoyance correction factor - 2010

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See the document
Environmental Noise Directive Development of Action Plans for Railways - 2008

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Following the European Environmental Noise Directive (END directive n°2002/49/EC), noise mapping have to be done for large agglomerations and important infrastructures, every five years. The year after, the noise maps have to be followed by action plans. The first round was July 2007 for noise maps and July 2008 for actions plans. For railways, it concerned : infrastructures with more that (...)

Following the European Environmental Noise Directive (END directive n°2002/49/EC), noise mapping have to be done for large agglomerations and important infrastructures, every five years. The year after, the noise maps have to be followed by action plans.

The first round was July 2007 for noise maps and July 2008 for actions plans. For railways, it concerned :

  • infrastructures with more that 60 000 trains by year
  • railway lines circulating inside the agglomerations with more than 250 000 persons.

The following rounds will concerned infrastructures with more than 30 000 trains by year and agglomerations with more than 100 000 persons.

Even if the national authorities are responsible for the establishment of the maps, it is important for railways to be involved in the procedure.

UIC has published two documents to inform railways on this issue.

In December 2009 UIC had the UIC END workshop: "The EU Directive 2002/49 (END) Challenges of the European railways - options and obligations" in Copenhagen.

See the document

SILENCE project, 2008
The Silence project focused on the development of noise reduction solutions for rail and road, more particularly for urban situations, applying a global approach, with work packages dealing with noise sources to be evaluated, and work packages on global modelling, noise annoyance and noise mapping.

The general approach of the project was to identify and establish a ranking of the main noise sources, and to develop solutions of reduction for them. In a second step, the impact of these solutions on the total noise level could be evaluated using a global model. For this objective, the VAMPPASS tool, created during the project, delivered usual information like sound pressure level, spectrum and signature, but also sound samples of the pass-by, necessary for annoyance tests.

Prototypes of silent trains and silent tracks have been tested with the tool and some promising solutions have been found and presented all along the day, like actions on the diesel powerpack (encapsulation…), modification of the cooling system, use of wheel dampers for the train, and track dampers for the track. These solutions have been tested by retrofitting existing trains, but some of these solutions could be more efficient being planned since the creation phase of new vehicles.
As examples, the following noise reduction can be expected on the total noise level:

  • 5 dB(A) by reducing the rolling noise with wheel and rail dampers,
  • 8 dB(A) for a DMU at 80 kph, combining the different solutions tested.

The case of depots has also been studied.

Noise Reduction in European Railway Infrastructure - 2007

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According to the UIC/CER report ‘Noise reduction in European infrastructure’ (2007), every year, between €150 and €200 million is spent in Europe on building noise barriers and installing insulated windows, more or less meeting with acceptance from residents. Transferring a part of these founds to the retrofitting of freight wagons would provide the same reduction in noise and would save (...)

According to the UIC/CER report ‘Noise reduction in European infrastructure’ (2007), every year, between €150 and €200 million is spent in Europe on building noise barriers and installing insulated windows, more or less meeting with acceptance from residents. Transferring a part of these founds to the retrofitting of freight wagons would provide the same reduction in noise and would save money.

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Curve squeal noise, 2005
Curve squeal is an intense tonal noise that may occur on curves or on switches. The high noise level causes annoyance for people living in the vicinity of a squealing railway track as well as for passengers waiting in stations with curves. The character of the noise is very intense with high frequencies (up to 10,000 Hz) and high amplitudes that can be up to 100 dB(A) in 10 m distance.

To answer to this problem, the UIC Combating Curve Squeal project was designed to find measures against the annoying high-pitched noise created during pass-bys of trains in certain curves. A first phase, completed in 2003, was aimed at analyzing existing knowledge and developing models while the second phase, described in the report below, intended to increase confidence in selected mitigation measures.
A selection of friction modifiers and water were tested on two different rigs and under field conditions in Switzerland, France and the UK.
In conclusion, no optimal solutions could be found that would work under all circumstances. For each curve the trade-off between performance, dosage and costs must therefore be evaluated separately.

Status and options for the reduction of noise emission from the existing European rail freight wagon fleet, 2004
This report investigates the status and options for retrofitting of the existing European rail freight fleet based on a study commissioned by the European Commission and jointly funded together with the railways (UIC and CER), the wagon owners (UIP and UIRR) and the manufacturers (UNIFE). AEA Technology has been commissioned as consultant including the specific task of performing an independent third party assessment of the existing activities and results of the rail sector in the field of noise.

Status and Options for the Reduction of Noise Emission from the Existing European Rail Freight Wagon Fleet - 2004

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STAIRRS project, 2003
The STAIRRS proposal was submitted in response to the EU´s 5th Framework Programme "Sustainable Mobility and Intermodality: Competitive and Sustainable Growth", where the need was identified for a study to assess the relative effectiveness, benefits and costs of a number of railway noise mitigation options applied to vehicles or track.

The outcome of the project was to provide a cost benefit software tool to assess various noise mitigation strategies, to provide measurement methodologies to enable characterization of railway vehicles and railway track separately and to develop a consensus between legislators, railway operators, railway infrastructure managers and the railway supply industry on the means of balancing the environmental needs of the Community with the noise mitigation options available and the costs of their implementation.

The conclusions of the project was as following:

  • The most efficient noise mitigation step to take is to ensure that freight trains have smooth wheels. By itself however it does not achieve sufficient noise reduction to achieve targets being placed on the railways and must be supplemented by further measures taken on wheels and tracks.
  • A combination of smooth wheels, rail absorbers and optimised wheels is more effective than the use of noise barriers, even when 4 m high, at a lower cost.

A series of workshops were held within the project with the following conclusions:

  • Pressure from the implementation of noise creation legislation for railways is essential step for reducing noise levels. It was recognized, however, that some change to the EU funding policies would be needed so that where it was shown to be cost effective, financial support should be given to noise mitigation at source instead of it being used to construct of line side noise barriers.
  • Application of operational constraints, even locally, in order to reduce noise is not consistent with the commercial requirements of railway operation particularly whilst attempting to fulfill the objective of transferring traffic from road to rail and needing to maintain competitive with respect to road transport.

Noise creation limits for railways, 2002
This report sets out current knowledge of the phenomenon of railway noise and the potential of technical measures to mitigate it. The report also contains proposals for future achievable and affordable noise creation limits which are based on this knowledge.

The conclusions of the report is as following:

  • The developing EU policy framework for environmental noise will require noise creation limits for rail vehicles. It is essential that the limit values adopted are technically feasible and affordable.
  • Measuring noise created by moving trains is problematic; empirical observations (for the same type of train at the same time) often show considerable variability. Any discussion about noise creation values must acknowledge this variability.
  • Several countries have introduced noise creation limits. They have limited effect in the absence of a Europe-wide initiative.
  • There is considerable empirical knowledge of the noise performance of existing trains; the results of collaborative railway research endeavour over many years have identified a number of technical measures shich will reduce noise creation.
  • Application of these measures to existing vehicles is much more expensive than incorporation in new designs.
  • The paper proposes limit values for noise creation by conventional vehicles, by high speed trains and by stationary trains. These are technically feasible and will be affordable when incorporated in the specification of new designs.
  • The paper also proposes limit values for noise creation by freight vehicles, which are retrofitted. Although technically feasible retrofitting with the existing technology is not cost neutral to date. To find financing solutions is an essential prerequisite if an early reduction in the noise created by the existing freight vehicles is to be achieved.
Noise Creation Limits for Railways - Background information from UIC Subcommission Noise and Vibration - 2002

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Noise Creation Limits for Railways - Main Report - 2002

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Railway Noise Research - Summary of Activities since 1990 - 1998

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This report describes the noise research carried out by ERRI and a number of European railways until 1998. It evaluates the options available to aim for a target of a 20 dB(A) noise reduction for freight vehicles compared with current levels in 1998. The paper concentrates on work that has, in the main, been funded by the UIC but also identifies certain national initiatives. The summary (...)

This report describes the noise research carried out by ERRI and a number of European railways until 1998. It evaluates the options available to aim for a target of a 20 dB(A) noise reduction for freight vehicles compared with current levels in 1998. The paper concentrates on work that has, in the main, been funded by the UIC but also identifies certain national initiatives.

The summary indicates that a great deal of work has been carried out and a high level of knowledge has been accumulated to find effective solutions to reduce railway noise in its creation and reception.

There are still areas of research where work can be identified to further reduce railway noise but these need to be prioritized to meet strategic aims. However it is evident that social and legislative pressures will continue to determine that railways will need to concentrate further efforts on noise reduction techniques.

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UIC focus noise

UIC Focus Noise - February 2009

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Unfortunately, two errors slipped in focus no. 3 : Page 1, in the interview of Mr Kunst, the statement “The Dutch system for the reduction of track access charges for silent freight wagons is currently being implemented in Austria." is not correct and should be replaced by : “Within OeBB there is no such system in preparation at the moment. In fact, representatives of OeBB are just (...)

Unfortunately, two errors slipped in focus no. 3 :

Page 1, in the interview of Mr Kunst, the statement “The Dutch system for the reduction of track access charges for silent freight wagons is currently being implemented in Austria." is not correct and should be replaced by :
“Within OeBB there is no such system in preparation at the moment. In fact, representatives of OeBB are just participating in international expert discussions / panels to get a view and impression about the market, legal and technical developments in this area, in the same manner as most of the other infrastructure managers”.

Page 2, the statement "... At this moment, the following K blocks are temporarily permitted for use in international freight wagons: CoFren C810, Jurid 816M and Becorit 929-1SG. ..." is not correct, as the the K-blocks CoFren C810 and Jurid 816 M are fully approved (the system K is fully homologated since 2003).

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