Exam Question

### (a) Objectives of a Satisfactory Propeller Shaft Alignment
A satisfactory propeller shaft alignment is critical for the reliable and efficient operation of the main propulsion system. The primary objectives are:
* **Uniform Bearing Load Distribution**: To ensure that the static and dynamic loads on all main engine, intermediate shaft, and sterntube bearings are distributed evenly and remain within the manufacturer's specified design limits. This prevents overloading of individual bearings, which can lead to wiping of white metal, excessive wear, and premature failure.
* **Minimization of Bending Stresses**: To prevent inducing excessive bending stresses in the crankshaft and the propeller shafting. Misalignment concentrates stress, which can lead to fatigue cracks and catastrophic failure of the crankshaft or shaft sections.