Blackout During Manoeuvring in Port
Your 8,000 TEU container ship is manoeuvring in port at 0400, with two tugs made fast and a pilot on board. The main engine is on bridge control. Suddenly the main switchboard trips: both diesel generators stop and the emergency generator starts but does not pick up load. The main engine stops. The vessel is drifting towards a moored barge. The bridge is calling for power. You are the engineer on watch in the engine room with one junior engineer.
1. What are your immediate actions in the engine room?
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Priority: restore power and propulsion as fast as possible, while supporting the bridge.
- Confirm the blackout. Check the main switchboard: are both generators stopped, and is the emergency generator running but its breaker open? Check for the cause: a trip on the main breaker, a generator protection relay operation, or a fault on the busbar.
- Start the emergency generator load. If the emergency generator is running but not supplying load, check its breaker and the emergency switchboard. The emergency generator should supply steering gear, navigation lights, and emergency lighting. Confirm it is on load.
- Start a main generator. Start one diesel generator manually and close its breaker to the main switchboard once voltage and frequency are correct. Do not attempt to close onto a faulted busbar. If the trip was caused by a short circuit, isolate the faulty circuit first.
- Restore essential auxiliaries. Start the lubricating oil pump, cooling water pumps, and fuel oil supply for the main engine. Check that the main engine is ready for restart.
- Communicate. Inform the bridge immediately of progress and expected time to restore power. The master and pilot need to know whether propulsion will be available in time to avoid the barge.
2. The main breaker tripped because of a fault on a bow thruster circuit. How does this affect your recovery plan?
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The fault must be isolated before the main busbar is re-energised.
- Identify and isolate. Confirm which circuit tripped and open the isolator for the bow thruster feeder. Do not reclose the main breaker until the faulty circuit is positively isolated.
- Check for damage. Inspect the bow thruster breaker and feeder for signs of flashover or overheating. If there is visible damage, the circuit must remain isolated and the fault recorded.
- Restore the busbar. With the faulty circuit isolated, start a generator and close the main breaker. Bring on essential auxiliaries in sequence to avoid overloading a single generator.
- Restore propulsion. Once the main engine auxiliaries are running, inform the bridge that propulsion is available. The bow thruster will not be available, which affects manoeuvring; the master and pilot must be told.
- Investigate. After the vessel is safe, investigate the cause of the bow thruster fault. A blackout during manoeuvring is a serious incident and must be reported and investigated under the safety management system.