18. Railways and railway operation

Contents - Previous - Next


1. Scope

2. Environmental impacts and protective measures

2.1 Overview
2.2 Fixed track installations, track layouts
2.3 Exhaust gas emissions
2.4 Utility materials and residues

2.4.1 Lubricants
2.4.2 Rehabilitation of oil-contaminated ground
2.4.3 Solvents
2.4.4 Wood preservatives
2.4.5 Scrap

2.5 Wastewater
2.6 Transfer systems
2.7 Weed control
2.8 Faecal matter
2.9 Hazardous goods transport
2.10 Noise abatement
2.11 Organisational measures

3. Notes on the analysis and evaluation of environmental impacts

4. Interaction with other sectors

5. Summary assessment of environmental relevance

6. References


1. Scope

The sector of railways and railway operation encompasses the construction of railway lines and systems as well as actual railway operation.

The railway sector is strongly characterised by its economic environment; its aim is to provide transport services by rail, making use of relevant resources. Its efficiency depends on the resources used, the manner in which they are employed and the infrastructure of fixed-location facilities.

Various kinds of tractive power are used, mainly diesel locomotives. The types of waggons and loading facilities and the operations management depend on the volumes of passengers and goods carried. For the transport of hazardous materials, special requirements must be met in order to avoid the risk of environmental damage.

To a greater extent than other sectors, such as agriculture or the foodstuffs industry, railways largely use standard technologies, so that the potential environmental effects and the means of avoiding them are largely similar.

Railways generally have their own comprehensive infrastructures, normally encompassing all rolling stock and track. They undertake tasks which are also performed by commercial operators, such as engine maintenance works.

Railways are generally state-run, although other companies are often responsible for monitoring observance of government regulations.


2. Environmental impacts and protective measures

Railway construction and operation have unavoidable effects on the environment, such as incursions into the landscape or emissions of exhaust gases and noise.

Other effects such as emissions of pollutants in workshop areas and in the event of accidents depend largely on the equipment and the care with which work is carried out.

2.1 Overview

Environmental impacts in the case of railways and railway operation are derived from

- the planning and implementation of the infrastructure, especially of the track,
- the characteristic features of the rolling stock used (traction method, age and condition, technical standards, safety equipment)
- the operational condition of the track and fixed-location installations (condition of the track, signal systems, stations, marshalling yards, workshops)
- the operations management, including the qualifications of the personnel and the maintenance measures. In this context, awareness of environmental problems on the part of management and workforce is crucially important
- the nature, handling and risk potential of the goods being transported
- the volume of passengers and freight and the resulting degree of utilisation.

2.2 Fixed track installations, track layouts

· Effects on the soil

Due to the space which they occupy, railway tracks may cause valuable areas of land to be taken up (loss of agricultural land or biotope, lines laid through rainforest etc.); lines intersect residential areas and may initiate economic activities which lead to the destruction of natural resources as a background effect or consequence (establishment of charcoal-fired blast furnaces along a line, construction/utilisation of a line for transport of tropical timber etc.).

When railway lines or systems are constructed, earth is displaced. Embankments need to be built, for example, and the earth required for this is derived from elsewhere. The spoil from tunnel construction needs to be disposed of in an environmentally acceptable way, if it cannot be used for embankment construction nearby. The same applies to the construction of lines in cuttings. When the soil is exposed, there is a risk of erosion. In the area of railway installations (such as stations), surface construction causes the ground to become sealed and compacted.

· Surface water

Both on embankments and - more particularly - in cuttings, which often have considerable water discharge areas above them, care must be taken to ensure effective methods of lateral water drainage. Water courses, rerouted if necessary, must be large enough to lead the surface water away effectively. Recultivation and replanting are needed to combat erosion due to rainwater and landslip.

Even if railways, unlike other transport systems, do not seal the surface so that rainwater is still able to soak away, it must be assumed that errors in layout and design will cause water pooling and consequent damage. Streams and other water collection points may be polluted unless they are screened against the ingress of surface water.

2.3 Exhaust gas emissions

The incidence of exhaust gas depends in the first instance on the type of traction involved.

Electric locomotives do not of themselves produce any exhaust gases. The effects of power generation are not dealt with here; refer to the appropriate environmental brief.

Steam locomotives will not be considered here either, being now very rare.

The essential pollutants in exhaust gas from diesel engines are:

- carbon monoxide (CO)
- hydrocarbons (HC)
- nitrogen oxide (NO
- sulphur dioxide (SO
- particle emissions (soot).

The extent of the emissions from diesel engines depends essentially on these factors:

- the load and speed of the engine
- the load depends in turn on the weight of the train (the train burden) and the speed of travel, which in most cases is determined by the track
- combustion processes (direct, precombustion chamber)
- operating process (two-stroke, four-stroke)
- standard of maintenance
- quality of fuel

As regards the degree of utilisation, trains may be under-utilised or they may be loaded to the limit of their capacity.

The causes of under-utilisation are:

- too few passengers on passenger trains,
- goods trains travelling with too little freight. Because the number of waggons in this case is also low, the weight which is being transported to no purpose remains limited to the relevant proportion of the locomotive’s weight.
- slow travelling speeds because of the condition of the track. The travel resistance which the locomotive is required to overcome drops at lower speeds.

The causes of locomotives being loaded to the limit of their capacity are:

- coupling loads are exceeded
- long gradients
- shortage of locomotives.

2.4 Utility materials and residues

2.4.1 Lubricants

The main lubricants used are as follows:

Lubricant   Area of use
Engine oil in combustion engines
Viscous oils in gear boxes
link drive systems
axle bearings
Hydraulic oil in track machinery
axle drives
hydraulic gears

Oil consumption in engines contributes to exhaust gas emissions, but is less than 0.5 % of fuel consumption.

Another factor which likewise cannot be avoided is the emission of lubricating oil from locomotives with link or chain drives, which can lead to contamination of soil, groundwater, and surface water.

These types of drives are obsolete and should no longer be used when new equipment is procured.

When procuring any kind of oil, care should be taken to ensure that they are free of PCB (polychlorine biphenyl) components. These produce highly poisonous dioxins on combustion.

Another major environmental problem is the disposal of waste oil.

The aim of establishing a regulated system for dealing with used oil is to transfer recyclable used oil to a processing point, laying down appropriate conditions (such as pollutant content, products to be recovered separately, bans on mixing) and thereby minimising the proportion of waste oil which cannot be processed and therefore requires costly disposal. On the one hand this ensures the most environment-friendly possible method of disposal, and on the other it helps keep costs down. Waste oils of different types and containing different pollutants should, as far as possible, be collected and led away for processing or disposal separately.

Basically there are three groups of waste oils:

Waste oil group 1: Waste oils whose composition and place of origin are such that they are suitable for recycling
Waste oil group 2: Waste oils which can be used for energy production
Waste oil group 3: Waste oils which require disposal as refuse.

2.4.2 Rehabilitation of oil-contaminated ground

There are well established processes for the rehabilitation of ground which has been contaminated by oil and certain kinds of chemicals; specific kinds of bacteria are applied to the contaminated ground, which feed on the oils and chemicals in the soil. Clay soils can be cleaned to a depth of one metre and sandy soils to a depth of two metres by applying the bacteria to the surface, with additional nutrients if need be. Cleaning is more difficult at greater depths, where it is necessary to introduce atmospheric oxygen.

High ambient temperatures are ideal for biological cleaning. The bacteria are active at temperatures of 10°C and above.

The extent of the damage must be established by test bores and monitored throughout the cleaning process.

Alternatively, the soil can be removed and incinerated after the pollutant content has been assessed, using special incineration systems. It may be possible to use the residue in road construction.

2.4.3 Solvents

Solvents mostly involve halogenated hydrocarbons.

Used solvents must be stored separately according to the main component of the initial product. These substances must not be used for normal cleaning purposes; as far as possible substitutes should be used for that purpose.

Every effort should be made to ensure that solvents are recovered by the supplier. If this proves impossible, they should not be disposed of other than as special waste.

2.4.4 Wood preservatives

If impregnated wood is used at all, e.g. for sleepers, any residues must be disposed of in special incineration plants, which may for example be connected to power stations. Impregnation agents with minimal environmental impact are to be preferred (take special care with wood preservatives containing PCPs).

2.4.5 Scrap

Before recycling scrap, care must be taken to ensure that any environmentally harmful substances have been eliminated in the proper manner, such as

- waste oil
- coolant residues in lathe turnings.

During the scrapping process, hazardous substances such as heavy metals must be removed and disposed of in the least environmentally harmful way.

2.5 Wastewater

The wastewater from plants using acidic cleaning agents (e.g. for stainless steel waggons) or alkaline cleaning agents must be neutralised.

Cleaning plants for rolling stock produce wastewater contaminated with oil and grease, and engine oil changes result in waste oil. The wastewater can be adequately cleaned at source by simple oil separators. Chemical processing, which also removes emulsions from the wastewater, is complex and expensive.

Small quantities of waste oil should be incinerated using a system suitable for small volumes. The composition of the waste oil must be known, since there is a possibility of dioxin formation.

Where oil separators are installed, it is advisable to use pipe cleaning equipment to keep the outflows of the cleaning troughs clear, since they are prone to blockage.

The following safety precautions may be necessary for important groundwater areas:

- diversion (relaying) of wastewater pipes out of the more confined protected zone,
- drainage of wastewater within the protected area through impermeable pipes,
- impermeable drainage pipes and fortified trench beds instead of unfortified side ditches.

2.6 Transfer systems

Railways operate a series of discharge systems for petroleum products which constitute a hazard to water, such as fuel, waste oil and fuel oil. Transfer takes place, for example, from railway tank waggons to road tankers or fixed-position tank farms, and during the fuelling of diesel locomotives. The systems are to be planned and operated in such a way that the oils cannot overflow or escape, i.e. so that no bodies of water can be contaminated. In the first instance, as many transfer points as possible are to be combined to form a few centrally located and intensively used facilities. Systems such as these are to be avoided in water conservation areas or headwater regions. Protection of transfer facilities essentially involves paving the surfaces and drainage with separation. Limit monitors are of course necessary.

Full-hose dry couplings offer far greater protection against losses during transfer. If couplings such as these are used, only a small area at the edge of the track needs to be paved.

2.7 Weed control

The trackbed needs to be kept free of weeds for a number of reasons (e.g. to prevent derailment). Depending on the vegetation of the terrain through which the track runs, chemical weed eradication may be possible, though alternative methods such as manual weeding are to be recommended.

2.8 Faecal matter

Lines which carry passenger traffic are subject to contamination with faecal matter. The faeces leave the coach through a downpipe and land on the track.

Epidemiological research has revealed that:

- The UV fraction in sunlight kills micro-organisms within a period of 2-3 hours,
- No bacteria will reach the groundwater.

At high speeds, it is possible that the pressure wave created by two trains meeting in a tunnel will cause a blowback. New coach designs allow for the faeces to be deposited in containers. In any event, orderly disposal is to be ensured.

2.9 Hazardous goods transport

A basic principle in conveying hazardous goods must be that every substance is handled in accordance with specific rules. Areas affected by this rule are:

- packing
- load securing
- transportation
- packing together with other substances
- action in emergencies.

Rule-books must be adopted covering all substances liable to be transported.

It is also recommended that international uniform hazardous goods codes be used, classified according to the UN numbering system which describes methods of handling many different substances.

The most hazardous types of goods fall into the following categories:

- inflammable liquid substances (fuels)
- toxic substances
- corrosive substances
- explosive substances.

The substances are to be designated precisely in the waybill. Instructions on handling, action in emergencies etc. for the individual hazardous substances should be available in every station and in every locomotive.

The weak points in handling hazardous substances on railways occur in the following areas:

- Unsuitable packaging
(e.g. flat pallets with film instead of grid box pallets as specified for the materials concerned)
- Incorrect or absent load securing
- Marshalling, reloading
- Most accidents occur with very small consignments which do not fulfil the requirements outlined above. Accidents involving tank waggons etc. are rare
- Untrained personnel, missing documents.

Standard equipment for rescue services includes envelope containers, pumping equipment and tank waggons. The fire services often perform these tasks, on the railways as well.

Every railway company should employ a hazardous goods officer to whom the regional hazardous goods managers are subordinate. Appropriate training and advanced training must be provided in this area.

2.10 Noise abatement

Railways generate varying levels of noise, including noise from actual rail traffic (rail traffic noise) and from the infrastructures involved in railway operation, such as marshalling yards, transfer stations for combined load traffic or workshops. Noise emissions depend on the intensity of operation and the location of the railway engineering facilities being used. Noise immissions provoke physical and psychological reactions in people, and to that extent railway noise is considered to be less of a burden than road traffic noise.

Because of their extensive track and ancillary systems, marshalling yards cover the largest area of any train formation facilities. The wide range of operational procedures involved in train shunting and train formation and the operations which the ancillary systems involve produce noise emissions of differing levels and frequency of occurrence. The active and passive noise abatement measures which can be applied when constructing new marshalling facilities or converting existing ones generally fall into the following individual areas:

- general structural layout of a marshalling yard system,
- distance from other buildings,
- rolling stock,
- organisation of operations and
- marshalling equipment.

The most effective way of improving the noise situation of marshalling yards is through automation.

2.11 Organisational measures

From what has been said in sections 2.4 to 2.9, it is clear that the environmental impacts of railway operation are attributable in large measure to human actions.

The measures needed in this context are, in particular:

- Adequate and comprehensive education and training of personnel. Cooperation with other transport operators such as harbour companies, airlines and road hauliers is recommended.
- Improving the training and manpower of the operating organisation.
- The creation of a technical and administrative infrastructure (disposal and supervision of disposal, monitoring of technical and personnel standards etc.). Deployment of personnel with responsibility for problem areas such as hazardous goods etc.
- The use of detergents which are "environment-friendly" or which can be satisfactorily disposed of under the local circumstances.

Environmental damage can only be successfully avoided by creating an adequately equipped organisation responsible for the administration, maintenance, operation and supervision of environmentally hazardous undertakings, and by strengthening and motivating it to deal with the tasks in hand.


3. Notes on the analysis and evaluation of environmental impacts

Emissions from railway vehicles and systems in operation, resulting from the design and build quality, can be determined from manufacturers’ specifications or from measurement results.

Railway administrations have made numerous attempts to determine the extent of noise from rail traffic and to test the effectiveness of noise abatement measures. Thanks to these experiments, appropriate measures can be taken in future to prevent excessive noise.

Hazardous goods regulations should be established for the domestic and international forwarding of hazardous goods, determining which hazardous goods may be conveyed, how they are to be packed and marked, how the vehicles are to be constructed and equipped and when and how they are to be inspected, how the vehicles are to be identified and matters to be taken into account upon loading and unloading as regards loading methods and stowing, as well as the transport itself.

Environmentally correct methods of treating wastewater and solid wastes are well known and must be implemented.

However, since environmental pollution occurs in railway operation due to ignorance of the consequences, negligence or deliberate action (to economise on disposal), the supervisory authorities must be enabled (and provided with the necessary equipment and measuring devices):

- to identify and analyse environmental impacts
- to evaluate them with a view to avoidance
- to ensure adequate monitoring and
- to implement suitable administrative measures (orders and prohibitions, fines, criminal prosecution, organisation of disposal resources etc.) in an effective manner.


4. Interaction with other sectors

Goods are frequently transferred between railways and ships. See the environmental brief Shipping regarding the construction and operation of harbour and port installations.

Some parts of the road transport and inland waterway systems have similar problems to railways, particularly in the area of vehicle and ship maintenance. In this regard, see the environmental briefs Wastewater Disposal, Solid Waste Disposal and Disposal of Hazardous Waste.

The railway sector, being primarily devoted to the transport of passengers and goods, also ties in with the environmental briefs Spatial and Regional Planning and Transport and Traffic Planning.


5. Summary assessment of environmental relevance

Railway lines intersect landscapes and regions, but thoughtful planning and execution will alleviate these partitioning effects. Electric trains do not of themselves cause any air pollution, while diesel trains cause slight pollution. Rail traffic noise is less than road noise and is felt to be less unpleasant. Railway lines should be routed out of the way of settled areas. In densely populated areas and where trains travel at high speeds, noise abatement measures may prove necessary.

International standards should be used as the basis for regulations on the construction and safety of railway vehicles and handling facilities; this will lead to the use of railway equipment generally enabling safe and environment-friendly transportation on the basis of an appropriately planned and executed network infrastructure. In certain cases it may however be necessary to impose construction measures which go beyond these rules, or deviate from them, in order to take account of particular local conditions.

A further requirement is that the personnel and the controlling and supervising authorities and operating organisations should be fully aware of the potential environmental effects, risks and preventive measures; they should have appropriate training and receive institutional support in carrying out their tasks.

To this end, the training courses, the resources for performing monitoring and supervision tasks and financing must be made available in good time.

An environmentally acceptable railway system can only be created with

- safe, state-of-the-art transport equipment (rolling stock, handling facilities),
- equally safe operation by trained personnel,
- and institutionally strong operating organisations to maintain the rolling stock and systems, to control traffic operations and to inspect and monitor the effects on the environment, with close harmony between these three areas.


6. References

Altölverordnung of 27.10.1987.

Buchwald/Engelhardt (1980): Handbuch für Planung, Gestaltung und Schutz der Umwelt, Munich

Bundesbahn-Zentralamt Munich: Report of October 01 1985 Az 36.3602 Flmma 1; Schadstoffemissionen der Dieselmotoren in Brennkrafttriebfahrzeugen der DB.

Bundesbahn-Zentralamt Minden: Richtlinie zur Altölentsorgung nach der Altölverordnung, Verfügung V.5407 Mauag 2.3 of June 01 1989.

DIN-Sicherheitsdatenblätter nach der Gefahrstoffverordnung (Ordinance on Hazardous Substances).

Deutsche Bundesbahn: Bautechnische Gewässerschutzmaßnahmen an Umfüllstellen (DS 800/6/III).

Deutsche Bundesbahn: Bestimmungen über sicherheitstechnische Maßnahmen nach Freiwerden gefährlicher Güter (DS 423/II).

Deutsche Bundesbahn: Anlagen für den Betriebsmaschinendienst (DS 800/7).

Deutsche Bundesbahn: Entwerfen von Bahnanlagen (DS 800).

Deutsche Bundesbahn: Richtlinien für bauliche Schallschutzanlagen an Eisenbahnstrecken (DS 810, Teil 1 und 2).

Deutscher Eisenbahn-Gütertarif: Teil I Abteilung; Anlage zur Verordnung über die innerstaatliche und grenzüberschreitende Beförderung gefährlicher Güter mit Eisenbahnen (Gefahrgutverordnung Eisenbahn - GGVE) of 22 July 1985.

Gesetz über die Vermeidung und Entsorgung von Abfällen (Abfallgesetz) of August 27 1986.

Inter-American Development Bank: Environmental Checklist for Transportation Projects, no place, no date.

Overseas Development Administration (ODA): Manual of Environmental Appraisal, pp. 60 - 62;no place, no date.

Verordnung über die Entsorgung gebrauchter halogenierter Lösemittel, of 23.10.1989, BGBL (Federal Law Gazette) 1989, page 1918.

Verordnung über die innerstaatliche und grenzüberschreitende Beförderung gefährlicher Güter mit Eisenbahnen (Gefahrgutverordnung Eisenbahn - GGVE) of 22 July 1985. BGBL (Federal Law Gazette) 1985, Teil I, p. 1560.

Contents - Previous - Next