Cargo Loss Prevention - What An Inspector Should do during Pre-Loading Surveys & Cargo Planning

Dear Petrol Inspector,

With regard to recent cargo shortages, I feel we should be enlightened more on how to take careful measures to ensure cargo losses are prevented as much as possible. We know what they say about "...prevention - being better than cure"

Claims for alleged shortages, after completion of discharge, are based on the difference between the bill of lading figures and the out-turn quantities. Even if both terminals (or STS vessels) carry out their measurements diligently, each will round off temperature and ullage readings in its favour, so differences must be expected, and extreme diligence is required by responsible personnel. In general the bill of lading quantity may be overstated and the out-turn quantity may be understated.

In the absence of other comparisons, the ship is the only common factor and, therefore, the measurements taken on board are critical. It is absolutely essential to the ship’s interests to ensure that all cargo inspections are carried out carefully and comprehensively. The cargo inspector must be accompanied at all times by the Chief Officer and his ullage measurements actively verified. 

Inspectors are as prone to error as any one else. Where more than one method of measurement is available use them for comparison and to confirm the accuracy of measurements made. This means that the vessel should have well calibrated UTI tapes and the relative accuracy of readings, if more than one tape is available, should be known.

The following steps in my experience can be taken to prevent incidents of petroleum cargo losses in future during Pre-Loading Surveys and then during Cargo planning.

Pre-Loading Surveys

1. In clean product trade, cargo tanks should normally be clean and dry for loading, unless loading without cleaning tanks has been agreed with the Operations Unit. BE AWARE THAT EVEN WHEN THE VESSEL IS ON A TIME CHARTER, THE OWNER REMAINS RESPONSIBLE FOR PRESENTING CLEAN TANKS FOR LOADING. HENCE TANK CLEANING INSTRUCTIONS FROM CHARTERERS SHOULD ALWAYS BE CONFIRMED WITH THE OWNERS.
2. Ensure that tanks have been gas-freed, mopped dry after water wash, and re-inerted (if vessel has inert gas or if that is part of the pre-loading instructions);
3. If any cargo tanks are not dry, determine the on board quantity (OBQ) of the previous cargo;
4. Prior to the OBQ survey all cargo line valves should be opened up to drain them and then closed.
5. Ensure that the vessel does not have any list and trim is allowed for during calculations.
6. Each tank should be dipped at the aft most dipping point, and the OBQ determined.

Cargo Planning

1. Obtain full details of the nominated cargo with reference to quantity, quality, carriage and discharge. If this is not available in the voyage orders, then ask for full details before the cargo is loaded.
2. Check and confirm that the vessel can load, carry and discharge the nominated cargo quantity safely, especially with regard to draft, trim and stability
3. To avoid large vapour losses, do not vent the cargo unnecessarily and ensure that the PV valves are in good condition and operate at designed pressures. These good practices should be followed, immaterial of the duration of the voyage.

You can comment on other preventive measures that you are aware of in your own experience.

Next time we shall dwell on "During Loading" and "After Loading"

Till then - 

...keep inspecting properly & professionally!