Exam Question

### (a) Method of Hydraulic Jacking to Check Bearing Loads
**1. Principle and Objective**
The primary objective of checking bearing loads via hydraulic jacking is to verify the correct alignment of the main propulsion shaft line. It ensures that each bearing supports its designed static load, preventing overloading or underloading which can lead to bearing failure, shaft fatigue, excessive vibration, and potential damage to the stern tube or gearbox.
The method involves applying a measured vertical lifting force directly beneath the shaft near a bearing and simultaneously measuring the vertical displacement of the shaft. The relationship between the applied force and the lift reveals the load carried by the bearing.