Exam Question
Explain briefly how the different moving parts of a main engine are subjected to various stresses. Name the stresses and justify by stating how they originate. (16)
Class 4 (4th Engineer)
MEKM
📅 Jul 2025
Reference Answer
### Analysis of Stresses on Main Engine Moving Parts
The principal moving parts of a large, two-stroke marine diesel engine are subjected to a complex combination of cyclic stresses arising from four primary sources:
1. **Gas Pressure:** The high-pressure combustion gases acting on the piston crown.
2. **Inertia Forces:** Forces required to accelerate and decelerate the reciprocating masses (piston, crosshead, piston rod) and rotating masses.
The principal moving parts of a large, two-stroke marine diesel engine are subjected to a complex combination of cyclic stresses arising from four primary sources:
1. **Gas Pressure:** The high-pressure combustion gases acting on the piston crown.
2. **Inertia Forces:** Forces required to accelerate and decelerate the reciprocating masses (piston, crosshead, piston rod) and rotating masses.
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