High Exhaust Temperature and Turbocharger Surge at Sea
At 02:10 on a 4,800 TEU container ship, the main engine (MAN B&W 6S60MC-C, 14,280 kW) is at 82% MCR on a 26-hour passage to Le Havre. Cylinder 4 exhaust gas temperature has risen from 338 °C to 412 °C in 25 minutes; turbocharger No.1 surges at 76–79% speed whenever load exceeds 70%. Scavenge air pressure is normal, air cooler outlet temperature 42 °C, fuel viscosity at engine inlet 13.8 cSt, and all other cylinders are 335–345 °C. The chief engineer has one spare exhaust valve and no spare turbocharger cartridge on board. Weather is Beaufort 6, and the nearest sheltered anchorage is 9 hours away; Le Havre has no repair berth for 30 hours. The charterer is pressing to maintain schedule, and the company technical superintendent is unreachable until 08:00. The bridge asks whether to reduce speed or stop. Fuel ROB is sufficient for 9 days at full sea speed.
1. What is your initial technical assessment and immediate engine-room actions?
Read the worked answer
Assessment. An isolated cylinder-4 exhaust temperature rise of about 74 °C, with surge only above 70% load and normal scavenge pressure and air-cooler outlet, points first to a cylinder-specific exhaust restriction or leakage-burned exhaust valve or seat, valve gear fault, or injector/fuel-pump problem-rather than general air-cooler or turbocharger fouling. The surge is likely a symptom of uneven exhaust pulses. I would not assume the turbocharger is the root cause.
Immediate actions. Reduce load to 65–68% and confirm surge stops. Compare cylinder 4 exhaust temperature, fuel index, and turbocharger vibration and bearing temperature. Check fuel-pump rack movement and injector leakage/return. If an injector is suspect, change it from spares. Do not open the exhaust valve at sea. Reduce load further if exhaust temperature remains above 400 °C or surge recurs. Increase rounds to every 30 minutes, record all parameters, and inform the bridge so speed changes are coordinated.
2. Do you continue to Le Havre at reduced load, divert to the 9-hour anchorage, or stop?
Read the worked answer
Decision. Continue toward Le Havre at reduced load only while the fault is stable and controllable. The 9-hour anchorage has no repair capability, so diverting gains little unless the engine becomes unsafe; stopping at sea in Beaufort 6 adds drift and weather risk. Le Havre gives spares and technical support, even with a 30-hour repair berth wait.
Set clear abort criteria: exhaust temperature above 430 °C, turbocharger vibration or bearing temperature rising, repeated surge at 60% load, audible valve noise, or crankcase mist. If any occurs, reduce to safe load and divert or anchor. Keep the charterer informed, but schedule pressure must not override machinery limits. Prepare the spare valve, request a technician to meet the ship, and ensure the bridge knows the reduced-speed manoeuvring implications.
3. What notifications and records are required, and how do you manage the schedule pressure?
Read the worked answer
Notify the master immediately, then the company technical superintendent at 08:00, the operations/charterer desk, the port agent, and class if the repair affects class or the ship will arrive with a known defect. Make an SMS risk assessment and issue standing orders covering load limits, monitoring intervals, and abort criteria. Record times, loads, temperatures, surge events, fuel-pump and injector checks, and every decision in the engine logbook and planned-maintenance system. Do not falsify or omit the defect to protect the schedule. If the ship proceeds, send a factual arrival condition report so the terminal and class surveyor can plan. Schedule pressure is managed by giving operations a realistic speed/ETA range and the conditions under which the ship will stop or divert.