Ore carriers in the Great Lakes en route to modernized steel mills in Ohio. A fishing boat returning to a New England pier. Roughnecks atop a derrick on an oil rig drilling for oil. High-speed commuter ferries discharging passengers at Wall Street in New York City. A Mississippi towboat pushing grain barges from America's heartland to New Orleans for export.
Diesels provide propulsion for almost all commercial vessels.
Restrictions on the use of diesel propulsion would have ripple effects across the entire American economy. Large slow-speed diesels have replaced steam turbines as the engine of choice for large ocean going vessels. Slow-speed diesels run at low engine revolutions allowing for direct drive applications to turn propellers. The higher revolutions from this category of diesels require some form of intermediate transfer of power. Reduction gears or electric propulsion motors constitute the majority of medium and high-speed diesel propulsion applications.