Question 70Motor Plants - 1st Asst/Chief

The correct answer is D) reduced during periods of low load operation. The rate of cylinder lubricating oil metered to each cylinder of a large, low-speed, main propulsion diesel engine is typically reduced during periods of low load operation. This is because the engine requires less lubrication when operating at lower loads, as there is less wear and tear on the engine components. Reducing the cylinder lubricating oil during low load operation helps to optimize the engine's efficiency and minimize unnecessary oil consumption. The other options are incorrect because: A) the lubricating oil rate is not adjusted hourly at constant RPM, B) the rate is not lower at sea compared to maneuvering, and C) the rate is not the same regardless of operating conditions.