200647 Collision with vessel at anchor

While approaching the customary waiting anchorage off a very busy port by night, it was observed that the planned anchoring position was already congested. Accordingly, the master selected an alternative position further to the east.

The approach to the new anchorage involved crossing a busy east-west traffic lane on a northerly heading with a strong easterly tidal stream flowing. Slowing down on her final approach while also giving way to stand-on through traffic, the vessel came under the steadily increasing influence of the current. It was intended to anchor seaward of two anchored vessels by bringing up the head by aiming for the stern of the vessel upstream. At this time, the bridge team comprised the master, third officer and the helmsman.

During the subsequent investigation it emerged that on this approach course, the helmsman experienced the strong cross-set, but failed to report it to the master. The master placed undue reliance on the Arpa, with the third officer intermittently calling out CPA distances of the two ships on the master's prompting.

With the distance less than a cable to the nearest ship, the master realised that the turn to port was too slow and that his vessel was rapidly setting on to the vessel downstream. The anchor party was asked if the bow would clear the downstream vessel, but with the rapidly closing distance, the party briefly retreated due to the imminent impact. As a final collision avoidance measure, the master ordered hard starboard rudder in an attempt to pass downstream of both vessels, then rudder midships and engines full astern, and finally with the ships nearly parallel, engine was again put ahead. Despite these actions, a glancing contact was made with the bow of the other vessel.

Following the incident, the ship maneuvered clear and anchored. Later that day, after class inspection, the vessel was allowed to proceed to another port for permanent repairs.

Root cause/contributory factors

1. The vessel was not manoeuvred in accordance with good seamanship; anchors and astern engine power not used effectively;
2. Effects of the tidal stream not taken into account;
3. Bridge team composition deficient in number and experience (third officer);
4. Over-reliance placed on Arpa without appreciating its limitations in close quarter situations;
5. Error chain allowed to develop, master's error of judgment not spotted or corrected by third officer;
6. Hasty final alteration to passage plan;
7. Overlooking VTIS assistance;
8. Although there was no firm evidence of fatigue being a factor, the previous day's hectic cargo discharge operation could have had some affect on the master and chief officer, and extra security watches may have dulled the reflexes of the deck crew.

Other valuable lessons

• Approaching and departing from crowded anchorages are tricky manoeuvres and must be planned with great care and must have clearly defined 'abort points'.
• More training on such manoeuvres must be given to deck officers and ratings both on shore-based simulators and on board, when conditions permit.
• Anchors must always be cleared and manned well before approaching anchorages.
• Approach to anchoring position must be made stemming the current.
• Simplified method of determining wheel-over positions must be included in on-board familiarisation training and in vessel manoeuvring characteristics data posted on the bridge.
• Company procedures/checklists may degenerate into paper tools without proper understanding and implementation.
• Junior officers and ratings must be trained in 'error chain breaking' techniques and be encouraged to contribute actively to bridge team operations.