Question 49 DDE04 - Designated Duty Engineer - 1000-4000 HP

The Correct Answer is B **Explanation for Option B (Correct Answer):** Option B is correct because the presence of a "rather large amount of water" within the cylinders of a diesel engine is a critical warning sign of a severe mechanical failure, most commonly a breach in the cooling system (e.g., a cracked cylinder head, a failed head gasket, or a cooling jacket failure). Water, being incompressible, can lead to immediate and catastrophic engine failure upon starting (known as hydrostatic lock or hydrolock) if enough liquid remains. Even if the bulk of the water has been expelled through the indicator/test valves, the underlying problem (the source of the leak) still exists. Starting the engine would likely cause: 1. Immediate damage (if any water remains). 2. Progressive damage and corrosion to internal components (pistons, rings, liners, bearings) due to water/coolant contamination. 3. Overheating or failure of the cooling system as combustion gases might enter the jacket water space. Therefore, the only safe and appropriate action is to stop all starting attempts and thoroughly investigate and repair the fault before running the engine. **Explanation of Incorrect Options:** * **A) Start the engine, but monitor all fluid levels very closely, especially that of the jacket water.** This is dangerous. Monitoring the fluid levels does nothing to prevent hydrostatic lock or the continuous contamination/damage caused by the leak while the engine is running. The underlying issue is too severe to simply "monitor." * **C) Start the engine, but maintain the jacket water expansion tank level higher than normal.** This approach attempts to mask or compensate for a potential leak but does not address the fundamental structural failure allowing water ingress. It increases the risk of damaging the cooling system or engine components due to increased static pressure or continued leakage. * **D) Start the engine, but run the engine with the cylinder test valves cracked slightly open.** Running an engine with the indicator/test valves open is unsafe, inefficient, and potentially damaging. It allows combustion gases to escape, reducing power and creating excessive noise/heat, while offering no reliable protection against continued water ingress or damage. It is an improper operational procedure.