🔍 Key Concepts

• Difference between two-stroke and four-stroke diesel cycle • Whether low-speed marine diesels are typically used for direct drive to the propeller shaft • Which options describe a design of the engine cycle vs. accessories or ignition systems

💭 Think About

• Ask yourself: For very large, slow-turning main propulsion engines on ships, which cycle is most commonly used to produce high torque at low RPM? • Consider which answer choices are actually complete engine types, and which are just features or components that could apply to many different engines. • Think about whether diesel engines normally use a spark-based ignition system or a different method of igniting fuel.

✅ Before You Answer

• Identify which options describe a thermodynamic/combustion cycle (the overall engine design). • Confirm whether diesel engines normally use spark plugs or compression ignition. • Eliminate any choices that could apply to both gasoline and diesel engines, rather than being specific to large low-speed marine diesels.