In the latest edition of its Safety Digest, the UK MAIB described a collision of a cargo ship with a bunker barge, highlighting the possible consequences from inefficient watchkeeping, as well as poor understanding of a vessel’s stability.
The incident
In daylight and good visibility, a laden general cargo vessel commenced its passage to deliver bulk cargo and containerised goods to a group of islands; the ship did the same round-trip every week. Once clear of the harbour, the master and lookout left the bridge and the chief officer was left alone on watch. Having set course on the autohelm, the chief officer did some paperwork at the chart table and then sat down in the bridge chair. A small bunker barge with a cargo of diesel fuel was on coastal passage ahead of the cargo ship. The vessels were on a steady bearing for about 25 minutes before colliding.
The bunker barge quickly listed over 90º and both the master and crewman onboard were extremely lucky to survive. The master escaped from the flooded wheelhouse through a window, and the crewman was washed overboard, but managed to hold onto the bulwark top edge then climb back onboard when the rush of water subsided. The bunker barge suffered a large indentation below the waterline, where it was struck by the cargo ship’s bulbous bow (see figure). There was also significant flooding of the vessel, the main engine seized and there was some pollution from leaking fuel cargo. The master pumped seawater into an empty ballast tank to correct the post-collision list. This reduced the stability of the barge to a dangerous level, but it was later towed back to the safety of a nearby harbour without further incident.
Lessons learned
- Keeping a good lookout is perhaps the most fundamental watchkeeping requirement on any vessel; it is an essential task enshrined in Rule 5 of the COLREGs. In this case, both ships’ watchkeepers were alone and not keeping a proper lookout so neither was aware of the risk of collision before the accident.
- Onboard the cargo vessel, the chief officer missed opportunities to detect the bunker barge by visual, radar and AIS means; this happened because the repetitive nature of the vessel’s tasking made him complacent and he allowed himself to be distracted by paperwork. On board the bunker barge, the master was on watch and was aware of a larger vessel approaching, but he did not monitor its relative movement, assuming that it would keep clear.
- Lone watchkeeping is acceptable during daylight, in good weather conditions and low traffic levels where the OOW can focus on navigational safety. However, the decision to reduce to a lone watchkeeper needs to be taken with care, and all the associated risks properly assessed.
- Understanding stability is critical for maintaining the safety of your vessel, especially if it is damaged. In this case, the master of the bunker barge pumped water into the vessel without understanding the effect on the damaged stability. This made the stability situation worse, not better, and could have resulted in the loss of the vessel and, potentially, the lives of him and his crewman.
