Bulk oil cargoes – shortage and


contamination claims Over recent years there has been a marked increase in


the incidence of claims arising from the carriage of oil cargoes. The claims are often substantial and may allege either shortage or contamination or both. In the past it was believed that measurement inaccuracies and all the problems related to the carriage of oil in bulk were understood. Recent research and advances in technology and analytical techniques have uncovered information which is of considerable significance. The purpose of this article is to provide guidance on how tanker operators can minimise the risk of cargo loss or damage and defend themselves should claims arise.


Oil shortages


In general, oil shortage claims are based upon a discrepancy between the quantity of cargo as stated in the bill of lading and the outturn quantity as calculated in the discharge port. Both these figures are frequently derived from shore-tank calibration data. The most common arguments are that:


● The ship is bound by the figure stated in the bill of lading


● The shore tank calibrations are more accurate than the ship’s tank calibrations


● The oil has become contaminated by water after loading


● Some oil remains onboard the ship.


The carrier’s defence is commonly based upon the accuracy of the ship’s cargo figures and seeks to demonstrate that they were comparable with the bill of lading figure, that there was no significant in transit loss, that any onboard quantity (OBQ) prior to loading has been taken into consideration and that all the cargo has been discharged with none remaining onboard (ROB).


In the following pages each phase of a typical tanker voyage is followed chronologically and likely causes of difficulty are considered.


Before arrival at the load port


The correct preparation of the cargo tanks in readiness for the grade of cargo to be carried is covered in the section dealing with contamination claims. Aside from ensuring the minimum safe quantity of clean ballast for arrival, the cargo officer should prepare a loading plan


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taking into account stability, trim and stress. Where draft restrictions permit, it may be advisable to plan for leaving the loading port with a trim that avoids the need for internal transfers of cargo during the loaded passage. The inert gas system, if fitted, should be fully operational in readiness for the forthcoming cargo operation. The oxygen content of the cargo tanks should be as low as possible before arrival and a record of all tank readings should be maintained.


On arrival at the berth


Once the ship is securely moored it is important to arrange liaison with representatives from the shore loading facility and to ensure continued good communications throughout the loading. All relevant information must be exchanged between ship and shore including details of the ship’s loading plan, maximum loading rates, shutdown procedures, safety regulations and cargo data.


Before loading


After all ballast has been discharged other than any permanent ballast which may be discharged simultaneously with the loading of the cargo, the ship’s cargo valves and pipelines should be correctly set for the reception of cargo and the relevant tank valves opened. Any residual ballast water should be pumped or drained from the pipeline system either overboard in the case of clean ballast or into a suitable slop tank but always in compliance with the local oil pollution regulations. Before loading, it is customary for a joint inspection of the cargo tanks to be made by shore representatives and ship’s officers to confirm that the tanks are properly drained of water and in a suitable condition to load the designated cargo. In general, the completion of such an inspection does not relieve the owner of his responsibility to ensure the correct condition of the cargo tanks. In large tankers and where tanks are inerted, such inspections are difficult and it may be necessary to rely on the ship’s gauging equipment rather than any visual inspection. Preparations for the loading of multigrade cargoes are dealt with under the section covering cargo contamination claims. The measurement of any OBQ should be carefully undertaken preferably jointly with the shore representatives. The depth of any residues should be measured at as many locations as possible and at least at the forward and after ends of the tanks. Tank cleaning hatches should be utilized as appropriate.


During loading


The loading sequence of tanks should be planned in advance with the ship’s stability and stress conditions in mind. It is customary to begin loading at a slow rate but


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