Cargo liquefaction in heavy weather: Swedish P&I Club scenario

2013-12-27

It was August and the vessel was loading iron ore in Indonesia, to be discharged in Vancouver. It had been raining heavily for two weeks. The site where the vessel was loading

was a pier on an island. The iron ore mine was further inland on the island and the ore was

transported by barge and loaded onto the vessel. When loading was complete the Master was given a loading certificate from the shipper which indicated that the cargo had a moisture level which was 2% below the TML (Transportable Moisture Limit).

During loading a surveyor had been present for the owners account and had done moisture tests on the cargo using the can method and not in a laboratory. The shipper stated that they had used the onsite laboratory for the moisture test. During the stay in port the vessel’s engineers carried out some maintenance on the main engine turbocharger. The job was completed a couple of hours before departure. The Master received information that there would be heavy weather during the Pacific crossing. He did not think it would be of any real concern for the vessel so he did not change the planned great circle route. This route would take the vessel about 60 miles south of the predicted storm path.

The master had sailed on the Pacific for many years and knew that the vessel should not have a problem sailing this route. The manager did not use any professional weather routing service but relied on the Master’s experience. After a couple of days the storm took a more

southerly path and the vessel started to encounter strong winds at beaufort 8, from a NE direction. The vessel reduced speed to minimize the impact of the waves which had become

very large.

The turbocharger for the main engine suddenly failed. This caused the main engine to stop and the vessel suffered a blackout. The vessel was now pitching and rolling a lot because of the large waves. With great difficulty the engineers managed to dismantle the turbocharger, it was found that a bearing had failed and caused severe damage to the compressor and turbine-rotating parts. It was impossible to do the required repairs because of the vessel’s heavy pitching and rolling. The master could not steer the vessel into the wind because of the blackout. The vessel started to drift.

The vessel started to list to the starboard side. It was obvious that something was wrong as the

vessel didn’t return to an upright position and continued to list more to starboard. The Master suspected that the cargo had shifted or in worst case liquefied. The master decided that the vessel was in real danger and sent out a Mayday. At about the same time the vessel started to ballast the port side to compensate for the starboard list. A big wave hit the vessel on the port side and the vessel disappeared into the sea.

Source from : The Swedish Club

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