SWISS Federal Railways (SBB) prides itself on efficiency, reliability and the fact that per head of population it is one of the world's most heavily used railways.

The Swiss are also particularly proud of their rail system's sustainability. Preserving the environment is now considered so important that it is at the heart of SBB's company strategy which includes a pledge to reduce greenhouse gas emissions by 30% from 1990 levels by 2020. The entirely electrified network already sources around 75% of its energy from SBB's own hydro-electric power stations, and the railway says that it is constantly looking at new technologies to reduce noise and vibrations from its trains.

SBB is certainly not alone in subscribing to a green agenda. All members of the Community of European Railways (CER) and European Infrastructure Managers signed up to the 30% reduction pledge in 2009 with various efforts to source energy from renewable sources underway. For example, German Rail (DB) is purchasing 19.8% of its electricity from renewable sources, well above its 15-16% target, while Finland's VR has switched its energy source entirely to hydro-electric power, halving its CO2 output. In Belgium, infrastructure manager Infrabel has fitted the roof of the Schoten Rail Tunnel near Antwerp with 17,820 solar panels. Covering a total length of 3.4km, it is now generating 3300MW of electricity annually.

Mr Alex Veitch, the International Union of Railways' (UIC) head of sustainable development, says these examples coupled with evidence the association has compiled in a series of reports clearly demonstrates that railways are buying into the clean and green transport debate.

In Europe while traffic levels have remained relatively static in the past 20 years, CO2 emissions have been reduced by 32% overall, including 20% in the passenger sector, and 38% from freight. European railways are now sourcing on average 30% of their electricity from renewable sources. In China, railway transport has increased dramatically over the last decade, which is matched by an improvement in efficiency.

Veitch is also encouraged by the rhetoric from developing rail markets. In Morocco rail projects are depicted as part of the country's sustainable transport future, while the Rio de Janeiro - São Paulo high-speed line project in Brazil is played up as a green transport solution.

"The sustainability efforts that we have identified are currently very European orientated, with most of the emphasis on improving energy efficiency, reducing air pollution and noise emissions, but we are trying to widen this knowledge to members further afield, to understand what they might be doing already, and where they might be able to do more," Veitch says. "There is evidence that railways in Korea and Japan are just as good if not better at promoting sustainability than their European counterparts."

Veitch says that the widespread push for electrification in Europe in particular has contributed massively to rail's green image. In 2009 53% of lines were electrified compared with 30% in 1990 with 80% of traffic now using electric trains. SNCB in Belgium uses electric traction on 95% of its passenger services and 83% of SNCB logistics services. Coupled with diesel locomotive renewal, this has enabled the railway to reduce exhaust emissions by 75-90% over the past 20 years.

17,820 solar panels on roof of Schöten rail tunnel in Antwerp.Improving the efficiency of operations by reducing energy consumption is another area that railways are embracing mainly because it comes with the added attraction of reducing costs. Railways used 13% less energy in 2009 than they did in 1990 per passenger-km, and 19% less per tonne of freight. For example, Turkish State Railways (TCDD), Slovenian Railways (SZ), Spanish passenger operator Renfe, JR East, and Netherlands Railways (NS), among others, have all invested in technology to reduce rolling stock energy consumption and retrained drivers to drive in a more efficient manner. French National Railways (SNCF) has also enacted a 19-step plan to reduce its 800m annual energy bill by 5-10%.

Veitch says that these initiatives are certainly a step in the right direction and are producing positive results, but there is still a long way to go. He says that railways are doing well at reducing emissions and noise, but can do more to adopt sustainable technologies and working practices throughout all elements of their operation.

"We need to promote the adoption of efficient rolling stock, and energy efficient operations at stations and in operations," Veitch says. "We need to push this a little further than the obvious. The statistics show that there is already a strong belief in this concept across the world, but we need to identify further incentives to push railways to improve."

Green suppliers

With demand for sustainability increasing, the world's rolling stock manufacturers and equipment suppliers are playing into this environmental consciousness to the extent that some are even marketing themselves on their own contributions to a greener society. By developing products which not only provide cost savings but are green, suppliers are standing out in a competitive marketplace.

Of course getting railways to support a sustainability project which provides an immediate cost-benefit is much easier than investing simply to be green. Veitch says that this is now the greatest challenge the UIC faces in encouraging sustainability. He points to the continuing saga of replacing creosote sleepers, and investing in new low-noise brake pad technologies which require substantial investments as areas where railways are not performing as well.

"It is very easy to make the case for environmental or sustainability measures that save money. Energy efficiency is perhaps the best example of this. However some environmental measures require a cost, and it can be more difficult for railways," Veitch says. "Brussels can help in Europe by adopting policies and incentives to promote environmental measures. There might be other innovative steps that we can take like encouraging railways to source more of their power from renewables, and to spend the money they are saving through energy efficiency measures to develop these sources for their own use."

Legislation already providing these benefits includes regulations on emissions from rail vehicles which is prompting suppliers to develop innovations designed specifically to comply with these standards. The European Union's stage IIIB emission and the United States' Environmental Protection Agency (EPA) Tier 4 standards are the latest to be adopted and both have similar requirements. Under the rules, all engines greater than 130kW manufactured on and after January 1 2011 have to reduce the levels of particulate matter (PM) and nitrogen oxides (NOx) produced, and regulate emissions of hydrocarbons and carbon monoxide.

Tier 4 standards are a particularly pressing issue in the United States where diesel traction remains dominant. Railways here are also experimenting with bio-fuels as a means of reducing emissions which is an area that has received only limited attention in Europe. Veitch says that Amtrak participated in a particularly successful study on its Heartland Flyer service. The bio-diesel blend B20, which is 20% pure bio-fuel and 80% diesel, was used and produced no more wear on the locomotive than traditional fuels while operating below the US EPA limits for this GE P32-8 locomotive.

Rio+20

The Rio+ 20 conference held earlier this year was expected to produce groundbreaking legislation that would have reinforced this push for sustainability and shape the future of transport policy for countries in the United Nations (UN).

Unfortunately Veitch says that the language of the document eventually adopted at the conference was very generic with no specific commitments outlined. He says that this was particularly disappointing but that the UIC remains committed to engaging in similar events in the future.

"A lot of work went into it and while it is frustrating, it is important not to be too cynical," he says. "We must stay engaged with it so when the opportunity comes we can make the case for rail. If we don't do it, and do not make our presence felt at these events it is very hard to get back in because we will lose the connections. Other people will be there because it is so competitive between the different modes of transport."

One concrete commitment that did emerge from the conference which could have a far-reaching effect on future rail projects in developing countries was the pledge by the world's eight largest development banks to provide $US 175bn towards sustainable transport projects over the next 10 years.

On announcing the plans in Rio, representatives from the World Bank and Asian Development Bank said that the transport sector is the fastest growing source of greenhouse gas emissions due to past emphasis on road projects in urban planning. By improving public transport, they said hundreds of thousands of lives might be saved, the quality of air improved, and congestion eased.

The pledge is a shift from the banks' traditional support for road and is expected to result in city governments and the private sector leveraging 10-20 times more money towards rail, bus and cycle lane projects. Mr Marc Juhel, sector manager for transport at the World Bank, is expected to announce further details of the commitment in Venice this month.

For Veitch such a substantial outlay on sustainable transport projects is a very encouraging sign for the future and indicates just how far the world has come. "Without Rio this wouldn't have happened," he says. And while there remains a lot more to be done, he believes that people are finally buying into the idea of sustainability which will only benefit the environment, the public and rail technology.

"Ten years ago there were only 25 people meeting to discuss this issue," Veitch says. "They were a lone voice in a massive organisation. Ten years on there is huge support and the fact that it is being discussed in the mainstream at places like the UN is very encouraging for the future."