Machinery breakdown leads to a collision

While proceeding to a berth, a tanker experienced main engine failure and collided with a barge berthed outboard of another vessel moored alongside a breakwater. The fully laden vessel (a tanker) entered the breakwater with a speed of 8.3 knots and was swinging to starboard when the main engine was stopped. The pilot ordered hard to port and dead slow ahead as the vessel continued to swing to starboard, but the main engine failed to respond. The pilot ordered bow thruster full to port, although the master advised it would be ineffective at speeds over 6 knots. The vessel subsequently collided with a moored barge at around 4.5 knots.

• Before berthing, company procedural checks were carried out and all were found satisfactory.
• Weather conditions at the time of the incident were light wind, a calm sea with no swell, and good visibility.
• The bridge was manned by the master, second officer, lookout, helmsman and pilot. ECDIS was used as the primary means of navigation.

• Detailed inspection identified significant hull damage although the vessel was not holed.
• Investigation revealed that engine control system maintenance work conducted 6 days beforehand had not been properly completed nor had it been inspected afterwards.
• A red locking pin (see photos) had not been correctly secured back into position and during manoeuvring had shaken loose due to vibration. This activated the emergency manoeuvring system which overrode both the bridge and engine room control systems.
• The root causes for this incident were found to be a lack of understanding of the risks by the engineering officers carrying out the checks, which were not overseen by a supervising officer – a company procedural requirement which was not followed.