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Responsibility for ensuring that cargo tanks are suitably prepared to carry the nominated cargo rests with the master. He is responsible for putting standard procedures in place to prepare the tanks and to complete the necessary documentation of preparations and inspections.

3.5.1 Tank inspection
Before loading, tanks should be inspected by a ship's officer, shore terminal representative and (probably), by independent petroleum inspector (who may represent the buyer and/or seller of the oil). The following levels of inspection may be completed:

  • On inerted ships - the remote gauges (normally in the CCR), are checked to see that they indicate all cargo tanks are empty.

  • On inerted ships - the tape and bob, or portable probe is used to verify the innage of all tank bottom contents and its measurements are used to determine the quantity of same if any measurable product is found.

  • On non-inerted product ships - tank hatches or ullage ports may be opened and the tank bottoms are sighted to verify that the tank is 'dry' (no liquid can be seen), below the hatch or ullage port.

  • On non-inerted product ships - the tanks may be ventilated and entered to verify that they are completely free of liquid, scale, sediment and/or clingage and that the coatings are in good condition. Tank entry for inspection at the loading terminal requires implementation of the full tank entry procedure as described in Section 2.15 of this handbook. After in-tank inspection, ensure that all openings are suitably closed (as indicated in section 2.17).

  • If pipelines have been drained, the fact that they are empty should be demonstrated to the inspectors.
  • 3.5.2 Inspection certificate or on board quantity (OBQ) certificate
    When the tank inspection has been completed, the members of the inspection party should sign an 'inspection certificate' indicating the date, port, name of the ship and which tanks have been inspected. The certificate should indicate that the tanks have been found 'suitable for the loading of cargo' and indicate the name and grade of the cargo to be loaded. It was previously customary to request independent inspectors signature on a 'dry certificate'. Since cargo tanks are seldom completely dry, independent inspectors correctly refuse to sign such documents. If the master insists that the 'dry certificate' form be used, he will probably not obtain the independent inspector's signature. It is better to obtain what is actually needed, certification that the tanks are suitable for loading the nominated cargo, than to have no independent certification at all.
    If pipelines have been demonstrated to be empty, that fact should also appear on the certificate.
    Request that shore terminal and independent inspectors print their full names and the names of the organisations they represent below their signatures. The inspecting ship's officer or chief officer should also sign the certificate.
    After tank inspection is complete, make a logbook entry indicating the time of completion, names of the inspectors and the fact that tanks were found suitable for loading. If the independent inspector refuses to issue or sign a 'suitably clean' certificate, then one should be prepared and signed the chief officer and the master.

    3.5.3 Measuring and sampling on-board cargo
    Before loading, all material in cargo and slop tanks must be measured and sampled. On board quantity (OBQ), of cargo and slop tank contents must be ullaged, water cut and sampled, with the samples properly labelled and sealed by the independent petroleum inspector.
    The quantity of material in the ship's pipelines must be declared by the chief officer. The independent inspector will not certify the pipelines amounts, but may indicate on his report that the loading lines are 'said to contain' an amount of cargo indicated by the chief officer. An OBQ certificate should be prepared and signed by the inspector.
    The master should note any protest he has concerning the independent inspector's or shore terminal representative's recording of the OBQ quantities/qualities.
    The quantity of sediment in cargo tanks is often the cause for some contention. Any mis-measurement of sediment can be minimised by ensuring that the ship has available suitable measurement equipment (a pointed bob) and accurate total depth measurements for each and every tank ullage point. The pointed bob can then be trusted to accurately reflect the depth of sediment provided it is seen to strike bottom at the indicated total depth of the applicable ullage point. For accurate sediment measurement, the tank should be sounded at four or more points.

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