Gas Turbines USCG Q#172 (Set 1)

On a gas turbine propulsion vessel, you notice a slow but steady increase in gas turbine vibration and specific fuel consumption as the voyage has progressed. What would be a good maintenance technique to use to correct these increases?

Official USCG Answer & Rule Citation

Correct Answer: Option A — Secure the engine and water wash the compressor off-line.

Increased vibration and specific fuel consumption are classic indicators of compressor fouling. Deposits on the compressor blades disrupt airflow, causing aerodynamic imbalances and reduced efficiency. An off-line water wash restores the original blade profile and surface finish, effectively cleaning the compressor and returning the engine to its design performance parameters.

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All Gas Turbines Sets Practice Set 1