Canadian National Railway (CN) is testing two liquefied natural gas (LNG) fuelled locomotives in service in northern Alberta, Canada.

The locomotives are undergoing tests along the 300-mile stretch between Edmonton and the oil sands region of Fort McMurray.

In order to start the tests, CN has renovated its two existing 3,000hp Electro-Motive Diesel (EMD) SD40-2 diesel locomotives to hybrid engines which will use 90% natural gas, with 10% diesel fuel for ignition.

Fuelling and maintenance for the locomotives will be carried out in Edmonton with Energy Conversions (ECI) supplying the conversion kits and the natural gas fuelling is being provided by Encana.

CN executive vice-president and chief operating officer Keith Creel said that the railway has launched the locomotive test to explore the use of natural gas as a potential alternative to conventional diesel fuel.

"This reflects CN’s continuing drive to look for ways to improve operating efficiency and advance the company’s sustainability agenda," Creel said.

"Natural gas has a lower carbon content compared with diesel fuel, so that locomotives using natural gas – if the railway technology employing this form of energy ultimately proves viable – would produce significantly fewer carbon dioxide emissions."

According to ECI the move is expected to cut carbon dioxide emissions by 30% and nitrogen oxide emissions by 70%.

CN is also collaborating with EMD, Westport Innovations and Gaz Métro Transport Solutions (GMTS) to develop a new natural gas locomotive engine, as well as a specialised tender rail to carry fuel.

"The locomotives are undergoing tests along the 300-mile stretch between Edmonton and the oil sands region of Fort McMurray."

For the test programme, the railway will also provide two 4,300hp SD70M-2 EMD locomotives.

Under the project, EMD will provide technical expertise to combine the natural gas engine, related components and controls in the locomotive, including Westport’s high-pressure direct injection (HPDI) technology and natural gas fuel system technologies.

For the initiative, GMTS will develop natural gas liquefaction requirements and distribution systems, while a new natural gas tender rail will be jointly developed by the project partners.

The partners expect to test the new engines in a laboratory in 2013 and road-test the prototype locomotives in 2014.

Image: CN is refurbishing its two EMD SD40-2 diesel locomotives to hybrid engines to carry out the tests in northern Alberta Photo: courtesy of Brandon Priebe.