"The re-powered locomotive will demonstrate how well the clean combustion of the QSK95 engine and Cummins SCR exhaust after-treatment work together as an integrated system to achieve the ultra-low Tier 4 emissions levels, easily accommodating the space claim of the larger medium-speed engine they replace, and requiring no additional cooling capacity," said Randy Nelson, marketing director - Cummins Rail Business.
The SCR exhaust aftertreatment removes oxides of nitrogen (NOx) emissions, leaving the engine combustion to remove Particulate Matter (PM). This approach avoids the need for added complexity on the engine, and enables the combustion formula to be fully optimized for fuel efficiency.
The SCR after-treatment system used with the QSK95 engine has been specifically designed for locomotive re-powers by Cummins Emission Solutions to occupy a space claim very similar to that of the exhaust silencers. SCR is a well-proven technology, with over 600,000 systems utilized by Cummins engines since introduced in 2005.