事故の教訓:燃料油による貨物の汚染

<要旨>新造バルカーのホールド2か所に貨物を積荷中、500トンの燃料油(HFO)を両舷の2番燃料タンクに補給したところ、作業終了直後に左舷側タンクの燃料が減少していることが遠隔測定システムにより発覚しました。結果的に、約2,200トンの貨物を積んだ第3ホールドに約60トンの燃料油が漏れており、多大な損害が発生しました。この事故から得られる教訓としては、建造後初の航海の際は船の構造上の重大な欠陥が発見されることが多いため、航海前に、ホールドに隣接している燃料およびバラストタンクのふたがきちんと密閉されていることを確認しなければならない、ということです。また仮にこの確認を怠り、ふたの密閉性が確保されていなかった場合は、不堪航(Unseaworthy)と判断される可能性もあります。

This vessel was loading a bulk cargo in two of the vessel's lower holds. During the loading operation, the vessel bunkered 500 MT of HFO into no.'s 2 port and starboard fuel oil side tanks. Shortly after the completion of bunkering operations, the Chief Engineer (C/E) noticed the level of no.2 port fuel oil tank was decreasing from observation of the remote gauging system. Upon investigation, the C/E found a large quantity of fuel oil in no.3 cargo hold ladder trunk and immediate measures were taken to transfer fuel from no.2 port to other bunker tanks. It was calculated that about 60 MT of fuel had leaked into no.3 cargo hold containing about 2,200 MT of cargo. Further investigation revealed that the oil was leaking from an inadequately secured tank access cover. Approximately 200 MT of cargo was contaminated, which was segregated, packed in bags and discharged.

The vessel was a new building and it was the first time that no.2 port fuel oil tank had been filled since departing the shipyard. It was apparent that one of the tank access lids had not been properly closed at the time of delivery as a large number of securing nuts were found to be slack after the incident. Although the damaged cargo was sold to a local salvage buyer at a depreciated value, a very large amount of time and expense was consumed in handling and storing the damaged cargo as well as in thoroughly cleaning the contaminated cargo holds.

• The first voyage of a vessel after delivery from the builders is critical and very often the time when shipyard deficiencies are discovered, sometimes with serious consequences
• Prior to taking delivery from builders, the water/oil tight integrity of tanks must be tested and confirmed by Owners representatives
• The failure to ensure that bunker and ballast tank access lids in way of the cargo hold boundaries are tight before commencement of the voyage may render the vessel unseaworthy. In the event of a claim, the Owners ability to rely on customary Hague Visby Rule rights and immunities will be prejudiced.