The North Carolina Department of Transportation (NCDOT) Ferry Division operates 22 ferry vessels on seven routes that serve over 800,000 vehicles and over 1.8 million passengers per year. These vessels range from typically 10 to 50 years of age with typically two large diesel main engines and one diesel auxiliary engine per vessel. Some engines predate U.S. Environmental Protection Agency (EPA) emission standards. Many engines, including those certified to emissions standards based on the date of manufacture, have been in service for many years with accumulated wear and differing service or rebuild history; thus, their in-use emissions may differ from emissions certification values. A limited number of new vessels are entering the fleet to replace older vessels. The Ferry Division periodically seeks grants from federal or state agencies or programs to procure funding for vessel modifications or upgrades. Such applications typically require assessment of the energy and environmental impacts of the proposed project including reduction of air pollutant emissions. The Ferry Division has a long-term goal to move toward green, sustainable technology and operations. A baseline emission inventory is needed to assess for which ferry vessels and routes engine emission-reducing interventions would be the most beneficial. However, there are no empirical data based on representative and actual operations upon which to quantify baseline main and auxiliary engine emission rates for the existing NCDOT ferry fleet.
The objectives of this project are to: (1) establish a methodological framework to measure real-world ferry main and auxiliary engine exhaust concentrations; (2) quantify real-world ferry engine energy use and exhaust emissions; (3) develop a baseline emission inventory for NC ferry vessel engine fleet; and (4) identify and recommend opportunities to reduce emissions. The research will include the following tasks: (1) develop procedures and scheduling for field measurements of vessel engine emissions; (2) instrument preparation and calibration; (3) measurement of real-world engine emissions under actual operations; (4) data quality assurance; (5) develop baseline emission inventory for vessel engine fleet; and (6) assess emission reductions from upgrading or replacing older vessel engines.
This project is highly significant because this will be the first large-scale evaluation and quantification of real-world ferry engine energy use and emissions for the NCDOT ferry fleet. The products of this project will enable the NCDOT Ferry Division to: (1) quantify engine emissions under actual operating conditions for the NCDOT ferry fleet; (2) compare among ferry vessels to identify priorities for interventions to reduce engine energy use and emissions for the highest energy consuming and emitting engines; and (3) quantify the air pollutant emissions reduction potential of upgrading or replacing older vessel engines to demonstrate the benefits of such interventions in applications for federal grants supporting capital acquisition projects, such as for engine or ferry replacement.
This project will set a baseline for possible future work, such as to characterize the emissions benefits of alternative fuels or retrofitted emission control systems. In addition, with the developed ferry engine emission inventory, possible future work can quantify the benefits of reductions in onroad vehicle emissions avoided by ferry vessel service as part of grants for capital acquisition and for strategic planning purposes. Moreover, this work can be used to support public messaging regarding the commitment of the NCDOT Ferry Division to environmental awareness and sustainability, and to raise awareness of various stakeholders regarding the environmental benefits associated with ferry operations.
