Coast Guard Exams
Question 89Motor Plants - 1st Asst/Chief70% to pass

You are onboard a vessel with a slow-speed crosshead type engine. The fuel just received has a significantly lower sulfur content than the previous bunkers. Which of the following would be a concern due to the reduced sulfur content?

AI Explanation
The correct answer is B) Base number of the cylinder oil. The reduced sulfur content in the fuel can lead to a decrease in the base number (BN) of the cylinder oil. Cylinder oils are formulated with detergent and dispersant additives, including alkaline compounds, to neutralize the acidic byproducts of combustion. With lower sulfur fuel, there is less acid formation, requiring a lower BN cylinder oil to prevent excessive alkali buildup in the engine. The other options are not directly affected by the change in fuel sulfur content.