Question 398Motor Plants - Assistant Engineer

The correct answer is B) variable speed governor. Direct reversible main propulsion diesel engines would normally be fitted with a variable speed governor. This type of governor is used to maintain a variable engine speed, which is necessary for the engine to provide reversible propulsion. The variable speed governor allows the engine speed to be adjusted as needed to control the speed and direction of the vessel. The other answer choices are not correct because: A) a constant speed governor maintains a fixed engine speed, which would not be suitable for a reversible propulsion engine; C) an isochronous hunting governor is designed to maintain a constant engine speed, again not suitable for a reversible propulsion engine; and D) a nutating disk governor is a less common type of governor that is not typically used for direct reversible main propulsion diesel engines.