16-cylinder diesel meets toughest US regulations

“This means we have climbed to the king’s class of emissions regulations with our engines for yachts and commercial vessels. I am pleased that we can now offer our customers these clean and powerful propulsion packages,” said Denise Kurtulus, head of marine business at Rolls-Royce’s Power Systems division.

The U.S. EPA Tier 4 regulations are considered the most stringent emissions standard for marine applications, requiring the propulsion system to have very low particulate and nitrogen oxide emissions throughout its lifecycle. Rolls-Royce is working on EPA Tier 4 approval for additional cylinder variants of the MTU Series 4000 propulsion system and is gradually bringing them to market. Since 2018, Rolls-Royce has already been offering the engine Series 4000 propulsion systems with the international IMO III certificate, which also enables operation in special emission control areas (North American coast, Caribbean, North Sea and Baltic Sea).

Rolls-Royce has successfully tested the MTU propulsion system, which includes the engines and SCR exhaust aftertreatment, during test bench runs and around 10,000 hours of operation in ferries and tugs operated in the U.S. by the San Francisco Water Emergency Transportation Authority (WETA) and Foss Maritime. “Thanks to the great cooperation with our customers, we were able to collect the necessary data to reach this milestone. All voyages to date with the total of 10 MTU propulsion systems have been satisfactory. Customers can rely on our engines,” explains Christof von Bank, who is responsible for marine sales in the U.S. at Rolls-Royce.

WETA is already operating three high-speed ferries in San Francisco Bay with the new MTU propulsion systems, testing their emissions performance among other things. The 34-knot aluminium catamaran Pyxis, which entered service in 2019, was the first passenger ferry in the United States to field test the EPA Tier 4-compliant MTU engines.

By Jake Frith