2011X02 Capsize whilst Loading

Official Report No. 7008.

The vessel was about three quarters of the way through loading. At the same time the vessel was discharging contaminated oil from a double bottom tank. The Master, who was standing on the quay, witnessed the ship take a heavy roll as one of the 20 foot containers was lifted. He was told by the stevedores that the weight of that container was 20.8 tonnes and that the planned stow for it was on the second tier on bay 4 on deck. The Master stopped the loading temporarily for about ten minutes and informed the Chief Officer that he was not happy with the second tier of containers on bay 4. The C/O then altered the stow from second tier on bay 4 to bottom tier on bay 5. When loading resumed there were about twenty containers still to load. Whilst lifting the third to last container, using the ship's own crane, the vessel suddenly heeled over to port towards the quayside. The Master attempted to control the list with the ballast but this did not produce the desired effect, the vessel continued to list further until she capsized. The Master and C/O attempted to free the vessel's moorings but did not succeed.

The subsequent official enquiry found that the proximate cause of the capsize was the attempted lift of a heavy container from the wharf at a time when the ship had little or no residual stability. The suspension of the heavy container from the jib of the crane caused a large and sudden heel to port which took the vessel to an angle beyond which all righting levers were negative (capsizing levers). The vessel was unable to recover and capsize became inevitable. At this stage nothing could be done to remedy the situation, which in a very short time was exacerbated by the shifting of cargo containers across the deck and sea water flooding the engine room through an open trap hatch on the main deck.

The Chief Engineer stated that he believed the cargo containers on deck shifted at the same time as the lurch. By the time he arrived down the Engine Room, some two minutes after the initial heel to port, it was already completely flooded due to the open trap hatch on the main deck. The violent heel was probably temporarily arrested by the wharf fenders. However, at this stage the vessel had no righting levers and complete capsize eventually followed as the capsizing lever took over and the hull was 'levered' out away from the wharf.

The following factors contributed to the unstable condition of the vessel and her subsequent capsize and sinking:

• No regard was paid by the ship's staff to the importance of preparing a curve of righting levers (GZ's) for the vessel in her loaded condition.
• Too much reliance by the ship's staff was placed upon the initial GM as a criterion for the vessel's stability in all conditions of loading and at all angles of heel.
• No allowance was made for free surface effect when calculating the original GM of the vessel. The instructions in the stability booklet clearly state that KG corrected for free surface must be used.
• The casual approach by the ship's staff to the calculation of the original GM. There appeared to have been a disagreement between the C/O and a previous Master as to the value of the KG of the cement in the holds. Both opinions were wrong and an incorrect value had been used. This was a major factor in the miscalculation of the stability.
• No attention was paid to a letter written by the owners, this indicated that a Deck Cargo Licence had been granted for 740 tonnes, being consistent with condition No 7 in the stability book. At the time of the accident the vessel had 1150 tonnes on deck, a 55% excess. The vessel had already breached the limit with the first tier of containers on deck. The letter also stated: "...the total vertical moment of the deck cargo is the critical figure affecting stability. While in certain advantageous loadings, it may be possible to exceed the given moment of 9590 tonne/metres (Condition 7), for general purposes, it is recommended that this should not be done". At the time of the accident the vertical moment on deck was approximately 14538 tonne/metres.

This error, coupled with the incorrect estimation of the KG of the cement, and neglecting the free surface effect, was a major factor in the cause of the accident. The vessel was in a very precarious state with respect to stability and was clearly not seaworthy at the time of the accident. If, by some chance, the accident had not happened when it did, the vessel would have certainly capsized within a very short time of commencing the voyage, perhaps with very serious loss of life to those on board. Fortunately, as it happened, no-one was injured.

Some responsibility for the accident must be attributed to the ship's Managers. It is their responsibility to see that the ship is correctly managed in all respects, this includes all technical and operational matters on ships under their management and the assurance that they are carried out in a safe and competent manner. They must also ensure that staff appointed to ships under their management are given adequate guidance on the operation of those ships and to monitor their performance thereafter.