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Huge leak discovered in fresh water system

What happened?

Daily soundings of fresh water tanks on a vessel revealed that they were emptying fast – 35 tonnes over 24 hours. A thorough check was conducted of all cabins including the hospital and cabins not currently in use, and no leak or open tap was discovered. Engineers checked all possible valves on the system for leakage, and made a double check of all tanks, which when compared with the previous sounding, found that there was no change in reading – the water was gone; it was not an error of measurement.

What went wrong? Investigation and findings

It was noticed in due course that water was flowing continuously from an overboard discharge on the port side. The galley, laundry room and mess room were thoroughly checked once again. A bain-marie (the device used to keep food warm at the serving point in the mess) inlet and discharge valve were left open. Since there was no overflow from the bain-marie, the leak had not been detected at first.

What were the causes of the incident?

The root cause was considered to be inadequate supervision.

What lessons were learnt? And what were the actions?

A poster with location of valves for bain-marie with marked close/open position was displayed in the mess room and the operation of the valves explained to mess crew.

Members may wish to refer to the following incident:

Near-miss: Unexpected water ingress during fault finding of a cracked water pipe


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