\r\nNS is replacing its entire Chicago shunting locomotive fleet with GP33ECOs through a $US 30m public-private partnership, which is being supported by the Federal government with a $US 19m grant from the Congestion Mitigation and Air Quality Improvement Program (CMAQ).\r\nNS designed and built the locomotives at its Juniata Locomotive Shops in Altoona, Pennsylvania, using components supplied by Electro-Motive Diesel. The power unit is a 2.24MW-output, EPA Tier 3-certified, 12-cylinder EMD 710 engine. NS plans to put 18 of the locomotives to work at its five major Chicago freight yards by the end this year. Three of the locomotives are configured as "mother-slug" units, with traction-motor-only slugs added for extra power.\r\nThe units are expected to reduce particulate matter emissions by 6.88 tonnes per year and cut nitrous oxide emissions by 178 tonnes annually, while using less fuel than older locomotives. Based on GP50s built in the 1980s, the GP33ECO features an "Admiral Cab," which has been designed by NS to meet the latest Federal Railroad Administration (FRA) crashworthiness standards, together with EMD's EM2000 microprocessor-based engine control system and idle-reduction technology.\r\nEarlier this year, NS introduced 10 ECO locomotives at its Atlanta yard, and next year plans to add three more units at its Macon and Rome yards in Georgia with additional CMAQ grants.