Question 168General Subjects - 1st Asst/Chief

The correct answer is D) Gas turbine. Gas turbine propulsion systems for ships typically operate at high speeds, requiring a geared-drive system with a double reduction gear to match the lower operating speeds of the propeller. This allows the gas turbine to operate at its optimal high-speed range while reducing the speed to a suitable level for the propeller. In contrast, slow speed diesel, medium speed diesel, and high speed diesel engines do not typically require a double reduction gear, as their operating speeds are already better suited for direct coupling to the propeller.