The Panamanian flag general cargo vessel Sun Breeze berthed at the West Australian port of Bunbury on 16 August 1999 to load a cargo of sawn timber.
The vessel loaded packs of timber of various sizes, most of which had no weights marked on them. During loading, the master estimated weights of cargo loaded in each of the vessel's two hatches by draught survey. When the hatches were full, the weight of cargo loaded on the hatch tops and deck was limited by the master's requirement to maintain a minimum metacentric height (GM) of 50 cm.
After loading was completed on 21 August, the vessel's GM, after allowing for free surface effects in certain tanks, was calculated to be 47 cm.
After lashing of the deck cargo was completed, Sun Breeze sailed at 1800 the same day for China. The vessel was upright when the harbour master piloted it from the port. After the harbour master disembarked, the engine revolutions were increased to sea speed at 1830.
When the master left the bridge, the 3rd mate changed the steering from manual to autopilot, at which time the ship started turning to starboard on its own accord. He changed back to manual steering, ordering helm to bring the vessel back on course. The vessel then seemed to him to list initially to port before listing to starboard.
The master returned to the bridge, by which time the list was about 15° or 20° to starboard. He stopped the engine and the list increased before settling at about 25°. The vessel lost some packs of timber from no. 1 hatch top over the side at this time. A distress message was sent out at about 1848 before the master anchored the vessel at 1900. The harbour master went out to the ship and non-essential crewmembers were disembarked by a tug.
The master corrected the list by ballasting side tanks. He advised the owner of the ship of the situation and obtained permission from the harbour master to re-enter the port after a surveyor had verified the vessel's stability.
The vessel berthed at Bunbury once more at 1310 on the 22nd August. The cargo was restowed and secured and the amount of deck cargo was reduced, after which the vessel sailed for the discharge port in China, where it arrived safely on 10 September 1999.
These conclusions identify the different factors contributing to the incident and should not be read as apportioning blame or liability to any particular organisation or individual.
Based on all the evidence available, the following factors are considered to have contributed to the incident:
- All fuel, diesel, fresh water and some ballast tanks were slack, reducing the vessel's stability.
- The cargo in the holds and tween decks was not secured to prevent movement in a seaway in accordance with the approved cargo securing manual.
- The ship's stability was based on an inclining experiment that did not meet IMO approved standards. As a result, the position of the lightship centre of gravity is in question.
- The stability information supplied to the ship contained incorrect data on free surface moments.
- Packages of timber were not marked with their weights and the master had to estimate weights in each compartment by draught survey.
- The lashings at hatch no. 1 were incorrectly set up, opening to permit the cargo to be lost overboard after the vessel listed.
- The voyage instructions mentioned lashings for the deck cargo. It made no mention of securing arrangements for cargo in the hatches.
- The master did not have a copy of the charter party, neither was he informed of correct stowage factors or weights of the type of cargo to load. He did not have sufficient information with which to prepare a proper loading plan and exercise proper oversight of loading.
- The owner, master and the vessel's agent did not inform the Australian Maritime Safety Authority that the vessel would be loading timber deck cargo.
- The master did not have a copy of the code of safe practice for the carriage of timber deck cargoes, neither did the ship's approved cargo securing manual include timber deck cargoes.
- The stability calculations did not allow for absorption of water by the deck cargo or for consumption of fuel from low tanks once the vessel was at sea.
In addition, the Inspector considers that the master would have been justified in delaying loading of the cargo until he was given all information necessary to ensure the ship's safety.
|Date:||21 August 1999||Investigation status:||Completed|
|Release date:||07 June 2001||Occurrence category:||Incident|
|Report status:||Final||Highest injury level:||None|
|Type of operation||General cargo|
|Damage to vessel||Minor|
|Departure point||Bunbury, WA|