Exam Question

### (a) Piston and Gudgeon Pin Assembly (Medium Speed Trunk Engine)
A trunk piston in a medium-speed engine is a single-piece or composite component that performs multiple functions: it seals the combustion chamber, transmits gas pressure to the connecting rod, and guides the piston's movement within the cylinder liner.
**Key Components and their Positions:**
1. **Piston Crown:** The uppermost section of the piston, directly exposed to the high pressures and temperatures of combustion. In modern medium-speed engines, this is often a separate piece made of high-strength steel, bolted to the piston skirt. It contains the ring grooves.