In the case of WETA's three new vessels, the shipyard Dakota Creek Industries, the design team at AMD Ferries and mtu engine experts from Rolls-Royce worked together very closely from scratch to find the solution that everyone could live with. “Not taking up any more space than absolutely necessary while still meeting all the criteria governing add-on modules and ease of maintenance was initially a headache. But we were a closely knit team and very focused from the start and made fast progress on planning and construction,” explained Jeff Sherman, from mtu marine engine sales at Rolls-Royce in the US.
The Pyxis plies the waters between Vallejo and San Francisco four times a day, carrying each way as many as 445 passengers who prefer to take a ferry rather than contend with traffic jams and overcrowded public transport. The crossing takes about an hour. The ferry's propulsion system comprises twin Series 4000 mtu engines, each with 2,560 kW power output, which can accelerate the vessel to 34 knots while still meeting environmental requirements. That is owing to advances in turbocharging, combustion and fuel injection, which, combined with the new SCR system, facilitate a 75% reduction in NOx emissions compared to IMO II, and a 65% reduction in particulates compared to EPA Tier 3.