In Georgia, Norfolk completed 41 total switcher locomotive conversions by replacing the old unregulated or TIER 0 locomotives with a combination of 25 Mother Eco Switcher Locomotives meeting TIER 3 and 16 slugs.  The Mother Eco Locomotives and Slugs are easily recognizable by the green wave. The slug provides electric tractive effort using power from a TIER 3 diesel engine on the Mother Eco Locomotive.  The 41 conversions are reducing NOx emissions by 329 tons per year (65% reduction) and PM emissions by 16 tons per year (85% reduction).

NS is actively working with EMD on deployment of TIER 4 technology including diesel particulate filters (DPF) and selective catalytic reduction (SCR) technologies.  A TIER 4 technology can reduce particulate matter (PM) emissions by up to 90% and nitrogen oxide (NOx) emissions by up to 80%.

NS has significantly improved fuel economy over its 2015 baseline.  NS uses LEADER (Locomotive Engineer Assist Display Event Recorder) to improve fuel efficiency.  The program optimizes the trains operations via controlling speed and dynamic braking.  The program has reduced fuel consumption from 1.28 gal/ton-mile to 1.17 gal/ton-mile resulting in $80 million dollars in cost savings, which is an 8.6% reduction. NS continues to seek improvements in fuel efficiency.  NS is actively working to implement distributive power for its line haul operations, which involves placing locomotive engines in the front, end and middle of a train.  This distributive power approach offers the potential for a 10% reduction if fuel consumption and 3% reduction in emissions.