The industry's leanest, greenest eco-locomotives

As the world continues to explore new ways of limiting carbon emissions in the transport sector and beyond, a new wave of eco-friendly locomotives is emerging to maximise the environmental benefits of rail transport.


norfolk southern

Norfolk Southern goes eco friendly

Unveiled late last year, US railroad Norfolk Southern's new fleet of environmentally friendly locomotives are the result of a $30m public-private partnership to replace the entire Chicago yard locomotive fleet, supported by a $19m in grant funding through the US Congestion Mitigation and Air Quality Improvement Program.

"These locomotives will be rolling billboards in Chicago for years to come, [and are] of one of the finest examples of collaboration between public and private partners to think and act big on diesel emission reduction technology," said Norfolk Southern vice president for mechanical Don Graab.

The 3,000 horsepower engines, which are also present at the company's Atlanta yard, will be used at Norfolk Southern's five Chicago rail yards and will use less fuel compared to older, more traditional locomotives.

Norfolk Southern claims that the eco-friendly technology will prevent the release of 7.58 tons of particulate matter, 196 tons of nitrogen oxides pollutants annually, and reduce particulate matter emissions by 76%. The engines also meet the US Environmental Protection Agency's tier 3 emissions standards for locomotives.

Rolls-Royce: hybrid power

Rolls-Royce has successfully manufactured engines for a host of industries, and now the company has turned its attention to rail. Its hybrid power system is a combined diesel-electric system that also incorporates batteries, using regenerative braking to store energy that would otherwise be wasted.

The hybrid rail technology works by using the kinetic energy initially generated by the diesel engine and recovering this for storage in a battery, which can be used later in the journey.

Under the company's MTU division, the system has been trialled in Germany on a Siemens train and demonstrated 25% more fuel efficiency than a current model. It could also reduce the noise associated with train travel on lines that are not electrified and play a part in the future of Britain's railways.

"People may be familiar with the idea of hybrid power when they see buses and cars on their local streets," said Dr Ingo Wintruff, head of the MTU's rail business, in May 2015. "But the concept could be transformational for non or partly-electrified railways in Britain."

Hydrogen rail technology

Hydrail - an umbrella term for hydrogen rail - is represented by the annual International Hydrail Conference, and has its origins in research at the Jet Propulsion Laboratory and Argonne National Laboratory in the 1970s and 1980s.

Hydrogen fuel, which is most commonly used in fuel cells which provide electric current, was first used in Canada in 2002, in the Fuel Cell Propulsion Institute's Mine Locomotive. This was followed by the Japan's Railway Technical Research Institute's testing of a hydrogen-fuelled railway train undercarriage.

In the UK, the University of Birmingham ran a hydrogen powered locomotive in 2012, using a hydrogen fuel cell to power electric motors and charge its car batteries. The locomotive included an advanced 'metal hydride' storage cylinder that was capable of holding 5,000 litres of hydrogen at low pressure.

Dr Stuart Hillmansen, from the university's School of Electronic, Electrical and Computer Engineering, said at the time: "Our hydrogen powered locomotive is a clean and efficient example of how hydrogen power could work for future trains on non-electrified routes. We hope that our efforts will encourage the rail industry to take a closer look at this exciting technology."

Alstom hybrid

Alstom's plug-in hybrid

Alstom's shunting locomotive uses a hybrid drive that produces up to 50% less CO2, and promises a 70% reduction in pollutant emissions. Depending on its use, the locomotive can spend between 50% and 75% of its service time in battery mode.

On top of this, Alstom's plug-in hybrid has been selected by Audi to be used at its Ingolstadt factory. This locomotive can operate for up to two hours at a time in electric mode, and is then plugged in for re-charging.

Head of the Audi plant railway in Ingolstadt Johann Schmid said the plug-in locomotive will "set new standards in shunting and rail transport".

The emission-free train

Its headline grabbing name aptly describes this impending invention from Alstom.

"This new generation of trains with fuel cell technology is the first in the world for passenger transportation," said Alstom Transport president Henri Poupart-Lafarge in 2014, adding: "In times of increasing costs for energy and higher level of pollution, the development of a completely emission-free train is key."

But, how will they work? As Poupart-Lafarge highlights, it is the use of fuel cell technology that is all important. Trains will be equipped with a fuel cell drive that converts energy from a fuel into electricity through a chemical reaction. Such an arrangement, says Alstom, will consume less energy compared with a conventional diesel unit.

A letter of intent has been signed with several German states and the German Federal Ministry of Transportation will also lend its support to the project. Alstom is now developing two prototype vehicles at its Salzgitter site in Germany and hopes to begin trials in 2018.

TEM

LNG locomotives

The use of liquefied natural gas (LNG) is growing rapidly in the maritime industry and is also beginning to gain traction as an alternative rail propulsion system.

Last year Russian Railways commissioned the Russian Institute of Research, Design and Technological Studies to test gas-reciprocating traction technology, while in 2013 trials began on what has been described as the world's first LNG-generated locomotive, the TEM19.

As of last February, this locomotive had completed more than 300 hours of testing. It features a detachable tank at the front of the engine that houses fuel and a propulsion unit with motor-generator, powered by LNG. The TEM19 was delivered to Russian Railways in November.

Meanwhile, a report released by the US Energy Information Administration in April 2015 revealed that LNG could lower railroad fuel bills, although it noted that "switching from diesel fuel to LNG would require a new delivery infrastructure for locomotive fuel".

Experiments have already taken place in Canada and GE has developed the MicroLNG, which the company claims can liquefy natural gas at any point along a gas distribution network.