Emissions rules change the landscape
ENGINES: At the end of 2008 Electro-Motive Diesel announced an order from Canadian National Railway for a further 40 SD70M-2 locomotives to be delivered in early 2010. These will use the 710 series diesel engine, which reached a milestone when the 7 500th engine was completed in late 2008.
The 710 is now one of the most successful engines from EMD, which has invested tens of millions of dollars to meet US and European exhaust emissions standards. The company says that in the past two years it has been granted 37 patents for technologies centred on reducing emissions and improving fuel efficiency.
The 710 engine meets US EPA Tier 2 standards, and in 2006 the 12-710G3B-T2 and 16-710G3B-T2 were the first locomotive engines to receive type approval for the Stage IIIA limit values of European Directive 97/68. Further improvements in fuel efficiency have come from intelligent management of accessory loads.
EMD expects the engines will achieve Stage IIIB compliance and meet NOx emissions limits without the need for urea after-treatment, which would bring the expense of handling a second fluid.
‘The new emissions requirements have really changed the landscape for the EMD 710 engine’, according to Martha Lenz, Product Leader Engine Systems, who believes it is an exciting time for the company. ‘Our two-stroke engine has a number of inherent advantages in terms of managing combustion and emissions. For a given horsepower, less fuel is burned per combustion event, allowing better management of the injection event and of the combustion temperatures. The 710 engine has proven to be a very NOx-friendly engine, in that there is less trade off between NOx reduction and fuel efficiency compared to other engines.’
EMD engines are approved for use with biodiesel blends, and work is underway with operators to evaluate the use of higher concentrations.