Cargo Hold Bilge Alarm During Loading
You are the second engineer on a bulk carrier loading grain in an estuary berth. During loading, the cargo hold bilge alarm for No.4 hold activates. The hold is partially loaded. The bilge alarm is a float switch in the bilge well, connected to an alarm on the bridge and in the engine room. The weather is calm. The vessel is at a berth with a tidal range of 4 metres. The chief engineer is ashore. The master asks you to investigate.
1. What are the possible causes of the bilge alarm, and how do you investigate?
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Possible causes:
- Genuine water ingress through a hull defect, a leaking hatch cover, or a sea water pipe passing through the hold.
- Cargo sweat or condensation from the cargo or from the hold atmosphere.
- A faulty float switch or wiring, giving a false alarm.
- Water from the deck entering through a hatch cover or a damaged coaming.
- Ballast water leaking from an adjacent double bottom tank into the hold.
Investigation:
- Do not enter the hold without following enclosed space procedures. The hold is partially loaded and the atmosphere may be unsafe.
- Check the bilge well by sounding or by pumping the bilge well to a holding tank and measuring the quantity. If water is present, note its appearance and smell.
- Check adjacent ballast tanks for level changes that could indicate a leak.
- Inspect the hatch cover from the deck for damage or poor sealing.
- Test the float switch by lifting it manually to confirm the alarm circuit works.
Report findings to the master and chief engineer. If genuine ingress is confirmed, loading should stop and the source must be found before it continues.
2. You find the bilge well contains about 200 litres of fresh water. What is your assessment and what do you recommend?
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Fresh water in a grain hold is a serious concern.
- Source. Fresh water is unlikely to be sea water. It may be condensation, water from the deck, or water from the cargo itself. Check the hatch cover seals and the hold atmosphere. Check whether the hold was properly ventilated.
- Cargo risk. Grain is hygroscopic and can swell, heat, or spoil if wetted. Even a small amount of water can damage the cargo and create a claim. The affected grain must be assessed.
- Stability and structural risk. Water in the hold adds weight and free surface. With a partial load, the effect on stability must be assessed. The master must be informed so that stability calculations can be updated.
- Recommendation. Stop loading in No.4 hold. Pump out the bilge well and monitor the rate of accumulation. If water continues to accumulate, the source must be found before loading resumes. Notify the shipper, the charterer, and the classification society as appropriate. Record everything with times and quantities.
- Do not conceal. Any water ingress must be reported. Concealment could invalidate insurance and endanger the vessel.