Oilers/Plant Tenders (HHC) Civil Service Practice Exam

What is the mechanism used to rotate the crankshaft of a marine engine for repairs called?

1. Generator

2. Jacking engine

3. Starting motor

4. Lubricator pump

The correct answer is: Jacking engine

The mechanism used to rotate the crankshaft of a marine engine for repairs is called a jacking engine. This specialized device is employed to manually or mechanically turn the crankshaft, allowing technicians and engineers to perform maintenance, inspections, or repairs on the engine components without needing to start the engine itself. It is particularly useful in situations where an engine is taken offline for service, as it provides the necessary torque to move heavy components smoothly. Jacking engines typically consist of a motor or a gearbox that controls the rotation speed and direction of the crankshaft. Their application is critical in ensuring that engines can be effectively maintained, enhancing reliability and safety during operations. In contrast, the other options serve different purposes: a generator produces electrical power; a starting motor is designed to initiate the engine's operation; and a lubricator pump circulates oil to minimize friction and wear between moving parts. Each of these components plays a distinct role within the nautical engine system, but none are specifically designed to rotate the crankshaft for maintenance like a jacking engine does.