During your watch, you notice the main engine turbocharger is "surging" — a repetitive banging/pulsing noise accompanied by fluctuating exhaust temperatures. What is the most likely cause and your immediate response?

A. Surging is typically caused by a mismatch between the airflow the turbocharger is producing and what the engine is demanding — common causes include a fouled turbine/compressor, blocked air filters, fouled scavenge spaces, or a rapid reduction in engine load; the immediate response is to reduce load/speed to bring the engine back into a stable operating range, then investigate the root cause (inspect filters, air cooler, turbine/compressor cleanliness) before returning to higher load

B. Surging only ever indicates a fuel pump fault and the fuel pumps should be changed immediately

C. The correct response is to increase load further to "push through" the surge

D. Surging is a normal characteristic of all turbochargers at any load and requires no action

A. Only that the pump has been switched off

B. That the engine logbook has been updated first

C. Nothing extra — thermal oil drains are routine and can be opened immediately

D. That the system has cooled and depressurised, and you are positioned clear of the drain point's discharge path

A. Treat the gap as a hazard in its own right: apply a suitable cooling/depressurising period and full PPE before proceeding, and raise the procedure gap with the Chief Engineer

B. Delegate the task to a junior rating without further briefing, since the procedure covers it

C. Skip the task until a class surveyor is on board

D. Follow the procedure exactly as written — if it doesn't mention cooling or PPE, they're not required