🔍 Key Concepts

• Engine governors and their purpose on internal combustion engines • Safety margin between rated speed and maximum allowable overspeed • Typical percentage limits used in marine engineering safety standards for overspeed protection

💭 Think About

• Think about why an engine needs a governor and what could happen if the engine speed goes too far above its rated speed. • Consider what would be a reasonable safety margin: big enough to allow normal fluctuations, but small enough to prevent dangerous overspeed. • Compare each percentage with what you know about overspeed risks—at what point would mechanical stress and failure risk become unacceptably high?

✅ Before You Answer

• Identify what rated speed means (normal maximum continuous operating speed, not emergency or short‑term speed). • Ask yourself which percentage would likely be used in regulations as a conservative safety limit, not just what an engine might survive. • Eliminate any option that seems too high to be considered a safe, regulated overspeed limit for continuous-duty marine engines.