Emission Testing Services

EMISSIONS MEASUREMENT AND EVALUATION OF EMISSION CONTROL OPTIONS FOR FERRYBOATS

Client: Blue and Gold Fleet, Pier 41, San Francisco

Blue and Gold Fleet operates sightseeing vessels and the ferry service to Alcatraz Island, part of the Golden Gate National Recreation Area. The company has won many awards for its environmentally-conscious operations. In rebidding the contract for ferry service to Alcatraz Island, the National Park Service required bidders to submit information on emissions from each vessel that they planned to use in that service, as well as a plan for reducing those emissions over time. To fulfill those requirements, Richard Maddux, Blue & Gold Fleet's environmental program director contracted with EF&EE to assist in the development and implementation of a comprehensive vessel air emissions reduction plan. Richard noted that "due to EF&EEs extensive experience in marine ferry emissions testing, we felt that they were the best qualified to assist in our emissions reduction initiatives.

To determine baseline emissions for the fleet, EF&EE performed emission measurements on the main propulsion and generator engines of the Blue and Gold fleet vessels Bay Monarch, Bay Clipper, Harbor Emperor, and Royal Star. To meet the tight schedule, more than 160 emission tests were carried out on the main propulsion and generator engines between February 16 and 23, 2005.

The emission measurements were performed in accordance with ISO 8178, and with the "Protocol for Measurement of Air Pollutant Emissions from Ferry Boats" previously developed by EF&EE for the San Francisco Bay Water Transit Authority. The pollutants measured were particulate matter (PM), oxides of nitrogen (NOx), carbon monoxide (CO), carbon dioxide (CO2), and total hydrocarbons (HC). As required by the Park Service, emission measurements on the main engines were performed in five separate steady-state modes, corresponding to the four modes of the ISO E3 marine engine test cycle, plus idle. To better assess real-world emissions, measurements were also performed in transient operation, during a simulated roundtrip from San Francisco's Pier 41 to Alcatraz Island. Generator emissions were measured in the five steady-state modes of the ISO D2 test cycle.

Analysis of the results showed that fuel consumption and pollutant emissions could be reduced substantially by two operational changes: reducing vessel cruise speed to about 9.5 knots, and assigning the lowest-emitting vessels to Alcatraz ferry service whenever possible. These two operational measures were calculated to reduce fuel consumption, CO2, and PM emissions from the ferry fleet by 37%, NOx emissions by 40%, and CO and HC emissions by about 20% each. Further emission reduction measures that could potentially have been applied included the use of diesel oxidation catalysts, diesel particulate filters (DPFs), NOx reduction catalysts (NRC), selective catalytic reduction (SCR) systems, and hybrid electric drive systems. EF&EE calculated that a combination of DPFs, SCR, and the operational changes outlined above could reduce PM and NOx emissions from the ferry fleet 89% by 2010.

     
RAVEM system unit and exhaust probe installed aboard M.V. Royal Star