Planned Maintenance Overdue on Critical Pump
The vessel is on a 14-day voyage across the Atlantic. The planned maintenance system (PMS) shows that the main sea water cooling pump is overdue for overhaul by 500 running hours. The pump is critical for cooling the main engine. The last overhaul was 2 years ago. The pump is showing signs of reduced performance: slightly lower pressure and unusual noise. The next port is 10 days away. The engine room is short-staffed due to illness, and the crew is busy with routine watchkeeping. The OIM must decide whether to defer maintenance or perform it underway.
1. What factors should the OIM consider in deciding whether to defer maintenance or perform it underway?
Read the worked answer
Factors:
- Criticality: Pump failure could lead to main engine overheating and loss of propulsion.
- Condition: Noise and reduced pressure indicate potential wear; risk of sudden failure.
- Resources: Short-staffed, but overhaul may require 4-6 hours with two engineers.
- Risk of underway maintenance: Stopping the pump requires switching to standby pump; if standby is available and reliable, maintenance can be done. But if standby pump is also due for maintenance, risk increases.
- Regulatory: SMS may require critical equipment maintenance to be done within specified intervals; deferral requires risk assessment and approval.
- Weather: Rough seas may make maintenance difficult.
- Spares: Availability of spare parts on board.
Decision: If standby pump is in good condition, perform maintenance underway with risk assessment. If not, defer with monitoring and prepare for emergency.
2. Outline a plan for performing the overhaul underway, including safety measures and contingencies.
Read the worked answer
Plan:
- Risk assessment: Identify hazards (e.g., flooding, electrical, mechanical). Ensure standby pump is operational and tested.
- Isolation: Stop pump, isolate electrically and mechanically (valves, lockout/tagout).
- Drain and disassemble: Follow manufacturer's procedure. Use proper PPE.
- Inspect components: Check impeller, wear rings, bearings, seals. Replace worn parts.
- Reassemble and test: Run pump and check for leaks, vibration, and performance.
- Contingency: If problems arise, have standby pump ready to start. If overhaul cannot be completed, reassemble and defer with monitoring.
- Communication: Inform bridge and crew; schedule during low load periods.
- Documentation: Record maintenance in PMS.