Engine Data Logging of TxDOT Galveston Ferry Operations

This paper presents results from a study intended to generate engine operating profiles and exhaust temperature characteristics for the fleet of five ferries operated by the Texas Department of Transportation (TxDOT) between Galveston and Port Bolivar, Texas. Data logging of the TxDOT Galveston ferries was an important first step in assessing NO_x reduction technologies. Based on the data logging, the following conclusions are drawn; While EMD and DDC engine exhaust temperatures monitored during in-use operations were below 260°C for a majority of the time, more than 70 percent of the EMD engine NO_x emissions occurred at exhaust temperatures greater than 260°C during in-use operations. This is based on in-situ emissions data from an EMD engine of a ferry (Greer) in which emissions measurements were performed; the EMD 12-645-E6 propulsion engines operated well below their 1,120 kW rating; Actual in-use engine operating conditions of the EMD 12-645-E6 engines are not well represented by EPA E2 and E3 marine certification test cycles; EPA engine certification data may not be directly applicable for estimating in-use emissions; Emissions testing at two additional test points during EPA certification testing would capture TxDOT ferry actual operating modes.