CN is testing locomotives in northern Alberta fuelled primarily by natural gas instead of diesel.
CN says it's exploring the use of natural gas as an alternative to diesel to lower fuel costs and reduce carbon dioxide emissions.
"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," said Keith Creel, executive vice-president and chief operating officer, in a press release Thursday.
The company retrofitted diesel engines in two 3,000-horsepower locomotives to hybrid engines burning 90 per cent natural gas, with 10 per cent diesel fuel for ignition.
The engines are expected to reduce carbon dioxide emissions by 30 per cent and nitrogen oxide emissions by 70 per cent over a locomotive's life cycle, CN said.
The natural gas locomotives are being tested on the 300-mile run north from Edmonton to Fort McMurray.