Which of the following is NOT a listed ship engine type?

• A. Diesel
• B. Gas turbine
• C. Steam turbine
• D. Nuclear

Answer: (D)

Ship propulsion relies on a few main engine types. Diesel engines are common for their efficiency and long-range reliability on many merchant ships and naval vessels. Gas turbines provide high shaft power with a favorable power-to-weight ratio, making them ideal for fast ships and modern warships. Steam turbines have historically powered large vessels and are still used in some big ships where abundant steam is available and high shaft power is needed. Nuclear propulsion, while used on certain naval vessels, is a specialized system that isn’t part of the standard, general list of ship engine types. It’s focused on reactors driving steam turbines and is not considered a routine ship engine type in the same way the others are, which is why it’s not listed here.