Near-Zero Emitting Diesel-Electric Locomotive Using A High-Speed Diesel Engine

A diesel-electric locomotive includes a diesel emissions reduction unit, including an inlet configured to receive an exhaust stream of a high-speed diesel engine; means for trapping at least a portion of diesel particulate matter contained in the exhaust stream; an aqueous NH3 dosing system including a dosing controller in communication with an electronic locomotive controller and a nitrogen oxide ("NOx") concentration sensor and an ammonia ("NH3") concentration sensor, at least one oxidation catalyst panel arranged to isolate the NOx concentration sensor from NH3 in the exhaust stream; mixing elements located between the dosing system and the NOx and NH3 concentration sensors to mix metered aqueous NH3 in the exhaust stream; a selective catalyst reactor bed located between the mixing elements and the NOx and NH3 concentration sensors; and an exhaust heating system in communication with at least one of the dosing and electronic locomotive controllers.